- Email: [email protected]
Future European launcher plans
~
Acta Astronautica Vol.51, No. 1-9, pp. 537-548, 2002
Pergamon
www.elsevier.com/locate/actaastro
P I h S0094-5765(02)00087-5
© 2002 Publishedby ElsevierScienceLtd Printedin GreatBritain 0094-5765•02 $- see frontmatter
FUTURE EUROPEAN LAUNCHER PLANS Marco Caporicci, Luisa lnnocenti E u r o p e a n Space A g e n c y , Paris, France
Abstract The paper reports about the conclusions of a strategic reflection conducted within ESA in the field of reusable transportation strategy and it describes in particular the current lines of action for the development of future reusable launcher technologies. On-going relevant programmes are discussed and the plans for future complementary activities are given. Special emphasis is given to in-flight demonstration through the development of test beds and experimental vehicles. Possible benefits deriving from international co-operation in this field are discussed. © 2002 Published by Elsevier Science Ltd.
Introduction In recent times the space transportation scenario
has undergone a substantial evolution due to: the uncertainty of the space activities and the associated markets (commercial versus governmental missions, Low Earth Orbit missions versus Geostationary orbit missions, etc.) the evolution of the budgets available to the various space agencies, the attempts to create increasing cooperation at international level, In Spring 2001 the ESA Director General decided to start an internal working group on this matter in co-operation with representatives of those Member States (Belgium, France, Germany, Italy, The Netherlands and Spain) having a major involvement in this sector. The aim of the activity was to achieve an overall European vision for reusable space transportation systems, integrating relevant ESA and national efforts and allowing Europe to make real progress towards the objectives, which it aims at fulfilling by 2007.
Mandate of the group was to propose an integrated approach for European reusable transportation systems and schemes for international co-operation allowing faster progress, with special reference to the European participation into the International Space Station Crew Return Vehicle (CRV). This date of 2007 is seen as an important milestone because: it is the current USA reference date for a decision for the Space Shuttle replacement by a more modem and efficient reusable system; by this date the CRV is expected to begin its operational phase at the ISS; it is the date of completion of the European investments associated to the current expendable launcher developments (Ariane 5 Plus and Vega). The working group mandate was translated in a series of questions for further analysis: what are the European objectives in the field of reusable space transportation systems with particular reference to the 2007 milestone? bow can a CRV development fit part of these objectives and advance the European technology level? which additional activities should be initiated at European level to ensure a timely development of the technologies required for future reusable transportation systems? which additional international co-operations might be beneficial to advance such technology development process? The answers given by the working group to these questions, together with the extensive preparation work perforrned internally in ESA, represent the basis for a new reusable launcher technology development programme, currently proposed by ESA, which aims at satisfying the
538
52nd IAF Congress
identified
European
objectives activities
the proposed programme and will be described in the following
objectives.
The
European
paragraphs.
the availability
Already
scenario
in
1998 NASA
associated A substantial
reduction
of the access to space
cost is pursued at world-wide
expendable
first
concepts,
new
CRVKTV
(Crew Transfer
conventional
of technologies
reusability
of
enabling
the transportation
system. approach
short-term
is strongly
competition
driven
second one has more ambitious
by the
and
the
role
of
a
Vehicle).
demonstration.
This
development
work
led
-
the expendable sufficient
-
of the Space partial vehicle
could
not
achieve
operational
low to be interesting
costs
for commercial
-
only if government incentives are used (the weak market limits the commercial possibility of private funding); a new crew transfer vehicle has uses across
for commercial
multiple
development
exists
architectures.
independent industrial studies In parallel conducted in co-operation by U.S., European and Japanese companies for
the
transportation may not be
mitigation
help enable low cost space
access; potential
case
In fact, the interest of reusability
systems do no have
to meet the safety goals
for human space transportation; a robust technology risk will
around
-
the
Shuttle, which reusability, but
launch
reliability
programme
of
and
to
of these U.S. studies were
the Space Shuttle should be replaced 2010;
of the reusable space transportation
and the associated technology
sufficiently activities.
designs,
-
The USA has been active since the 60’s in the
which
the risk
technologies
that:
targets and aims
at substantial cost reductions, capable influencing the volume of the space markets.
development implemented
RLV
The main conclusions
and it aims at achieving
limited, although important, cost reductions for at least the next decade of operations. The
conception
re-evaluated
these critical
launch vehicles;
the development low-cost
with
started the Space Transportation Architecture studies, which looked at Shuttle derived
level.
Two parallel avenues are followed: the improvement of
The
expendable
steady level. This strongly limits the possibility for private investments for new systems. International
-
of more performing
launchers and as a consequence the number of commercial GTO launches is essentially at a
concluded
development
that of
a business a
reusable
system could not be created on the
stated in absolute and its advantages have to be established taking into account the accessible
basis of the commercial market only and that, even including the totality of the governmental missions orbital infrastructure related to
market, vehicle
technology
the
defined
mission,
capabilities and the development cost and duration. In
1996 the U.S. National
the
required
technology
servicing
and military development
applications,
the initial
cost should be borne by
governments.
Space Policy
gave
On these bases, the USA providing safe and reliable
has identified that operation of space
NASA the responsibility to initiate partnerships with industry to jointly develop reusable launch vehicle technologies. based on the assumption
systems is the responsibility of the government and has initiated the Space Launch Initiative
that the satellite market would support the commercial development of a new (Reusable
of the technologies
Launch century.
Vehicle)
In the meantime
RLV
around
the commercial
the
failure
turn
of
of the
telecommunication satellite constellations has led to a much more limited commercial market in LEO than expected a few years ago. The mass of the geostationary satellites is increasing due to
(SLI).
The programme
transportation
aims at the development
required
system replacing
for a new reusable the Space Shuttle
around 2012. NASA has greater responsibility than in the previous programme and participation in the identification of the technical, programmatic and business risks associated with the RLV development. The programme focus is shifted toward increased safety and reliability, with the following objectives:
539
52nd IAF Congress -
-
crew loss risk of I in 10000 missions, cost of 1000 S per pound to LEO.
expertise
development
automation and life support systems) allowing it to secure an important role in future co-operative
decision
(in
technologies,
for the new system
around 2007.
safety
systems, re-entry propulsion systems. GNC.
on-orbit
missions. Therefore
European strategy and obiectives During effort
the year 2000 Europe performed for the definition
of a European
a broad Strategy
for Space. In this frame, the ESA Council approved in June 2000 a Resolution defining the European
Strategy
for: 1.
maintaining,
2.
completing,
for Launchers, as a priority,
veness of Ariane 5
which
-
called
-
of European manufactured small medium launchers, complementary the technologies
necessary
longer-term
developing, demonstrating
competition,
study
and
space
targeting
in-flight
transportation
commercial
systems,
evaluate
devoted
-
to
technology
programmes have for the ground
improvement
of the Ariane
already been put in infrastructure, the 5 performance
the
future
low
at this
developments cost
commercial
transportation systems should not preclude options for future manned transportation); to position Europe for a choice in due time for an autonomous development of a commercial
transportation
participation
to
system an
or
the
international
exploration initiative, depending evolution of the market scenarios While place
and
sufficiently
system may be decided
the
possible
the European Spaceport in Kourou.
reusable
designs
moment,
and on the
ground and in flight; ensuring the quality and efficiency of operations and services for the customer at
such technologies and their maturation through a
transportation
for by
experimenting such technologies
to
are critical
risks of the successive developments (while no development of a new manned space
new launch systems that may be required for
systems;
detailed to be able to correctly
and to
Ariane 5...; preparing
for reusable transportation to validate demonstrate
up
and co-ordinated which
manned transportation
by the addition
objectives
manner the technologies,
system
in the medium term, the range
of launch services offered
European
coherent on-ground demonstration approach;
the competiti-
. .;
the identified
to 2007 are: to advance in an efficient
upon the and space
agency programmes.
and
the development of complementary launchers (Vega), the development of future technologies
Key reusable sDace transportation technoloeies and in-flieht demonstration
still require an adequate frame. A considerable Such activities
of work
was performed
in past European
programmes
European capabilities for access to space for commercial and strategic reasons.
ESA level. ESA reusability with
investigated launch the FLS (Future
important
preservation
amount
of the
Another
shall allow
driver for the development
of
the transportation technology comes from the human space flight and space exploration
at national
and
vehicle
Launch Systems) and WLC (Winged Launcher Configuration) studies in the 80’s, the FESTIP programme
in the 90’s
and recently
with
the
activities. With the decision to participate to the development of the International Space Station, Europe renounced to the development of an
preparation of the FLTP. In parallel several technology demonstration activities were conducted, which allowed European industry to gain full understanding of
autonomous
the reusable transportation
infrastructure
for
human
space
flight. Moreover due to the cost and complication linked to the manned missions. it is
issues.
likely that in the evolved political human exploration enterprises will pursued in international co-operation. field Europe aims at developing
The Hermes programme
scenario only be In this strategic
system technological
in the second half of the
80’s and the successive MSTP and capsule work (CTV, ARD) performed in the early 90’s, allowed IO develop the European competence in
52nd IAF Congress
540 the field of manned transportation advanced considerably atmospheric
re-entry.
In parallel.
system
-
systems and
the technologies
reusable
and technology
reusable space transportation national HOTOL
work
management
in
in Germany, and French
Europe
competence transportation
has acquired a good field of in the
level of reusable
systems; it has also developed
technologies
that
in
specific
areas
unrelated
or
fragmented,
variable
requirements
hardware
demonstration
flight
demonstration
and
responding
without
activities.
reliable
-
various mission phases; redundant avionics
-
subsystems; software validation
-
advanced
to
performing
in
organized activities
the
set for
of
It is considered
flight
-
for
that in-flight
demonstration
initial
logic has been identified,
demonstration
activities
-
high
the
re-entry
re-entry
should
performance,
-
experimental realistic
vehicles allowing flight
to verify
in a
environment
step; concept demonstrator fully finally a representative of the selected system and its
-
may
development
technological
reusable
LOXiLHz
and
re-entry transonic/subsonic aerodynamics for typical space transportation vehicle shapes, through and
physical catalysis,
-
landing,
phenomena,
several technologies, including their operations and reusability features represent the successive
a
to an
main rocket propulsion; and aerothermodynamics
improved
-
(i.e. automatic
aerothermodynamic
be required
before
the
full
is undertaken.
include:
CFD
-
field
costs;
etc.);
be
LOX/Hydrocarbon -
vehicles or on-board of
technological
-
mission for
specific through in flying
development
in order to achieve
identified
of
and
a well
reliable evaluation of the risks associated operational vehicle development. areas
complexity:
may be developed for the of the issues related to a specific
for
provided by a set of system studies providing guidance to the technological investigations and implementing in the vehicle design the results
The
is
test beds verification
activities
from the demonstrations,
experimentation
launchers with limited
need
2002-2007
launchers
these
life
need for several of the above For this purpose a progressive in-
technologies may be conducted passenger experiments, consisting
Express,
vehicles, leading to demonstration on-ground The overall and in-flight experimentation. requirements
and
operational
the
technology
reusable
and
In particular
identified period
interface
which includes vehicles of growing
in Europe has been limited
group
architectures
support systems.
IRDT.
working
for the
and verification;
man-machine
hardware on existing The
and health
and robust GNC algorithms
an absolute technologies.
sufficient
to the re-entry of few capsules as ARD, MIRKA,
and both
key place
European industry at a leadership level worldwide. But in many cases such developments were
using
systems;
-
research activities. Today
hot structures
reliable vehicle health monitoring
for
was performed
programmes as Saenger in the United Kingdom
and repairable
thermal protection systems, ceramic and metallic materials;
linked to
experimental modelling
phenomena shock
the
(turbulence,
wave
/
need
to
be
experimented.
International
co-
operation
is considered
as a useful
tool
for
associated
reducing
the
investments
and
for
transition,
accelerating
boundary
On-poine
low-mass cr>,ogenic tanks, both and composite. with integral
reusable insulation; large size, highly loaded, low-mass maintainable composite structures;
required
the developments.
layer
interaction); flight mechanics; reusable metallic
experimentation
with
methods
of
The first three types of in-flight
are expected to be part of the technology development phase until 2007. In particular reusability operations and atmospheric re-entry
and
relevant
European
twoerammes
At
this time relevant European programmes, the Future Launchers Technology include Programme (FLTP), the European participation to the ISS Crew Return Vehicle. the on-going definition
studies
for
low-cost
541
52nd IAF Congress aerothermodynamic
experimentation
and several national programmes Germany,
PRORA
This
(EXPERT)
(i.e. ASTRA
in
in Italy, the Pre-X studies in
France, etc.) The FLTP
activities,
specifically
conceived
for
the development of the European competence for reusable launch vehicles. have been put on hold and are being reviewed: to achieve a better synergy between the ESA activities
the and activities,
technology
-
national aim of
the
represents the
an opportunity for an transportation reusable
of
demonstrations and an extension of the overall system know-how and avionics competence. The expanded set of European activities, including system requirements avionics
definition,
architectures,
reusability
operations,
etc. will
to update the fundamental
future reusable transportation
of the programme,
and
taking
into
account
the weakening
of the commercial
space
transportation
market
requirements to
define
and
agreed
provide
contribute
of the European
flight
for
systems and it will
opportunities
for
full
re-entry
demonstrations. The increased European participation
and
to the
competence
the
for manned flight; well
and
aerothermo-
dynamics, trajectory analyses, hot structures, vehicle health management systems, on-orbit and integration spacecraft operations, refurbishment and vehicle verification, development
hypothesis
mechanical
re-entry
inscribing them in a single European logic; objectives
-
relevant with
also
increase
recognised
seen in a development
perspective
should be leading to
future manned reusable transportation systems (i.e. CTV), which could be the subject of an
management rules at European level. The IS!? CRV vehicle is conceived as a reusable
extended strategic co-operation.
transportation system, in the form of a lifting body, whose mission is under demonstration A
through several atmospheric drop tests and the X-38 V201 orbital re-entry flight. The choice of the applied technologies has been voluntary directed toward those, which will be also used on future Crew Transfer Launch Vehicles.
Vehicles
The present European
thermal
protections,
participation
Although
several
determined
to the CRV
Most
hot
making
structures, and
Group considered in the area of usefully
manned
interface,
technologies
will
advancement
of the European
crew
that the re-entry
contribute
times
of
the
technologies,
of
components
In fact, the use of well elements having
lead to cost reductions,
proposed to increase its participation development in order to maintain
advanced technology
permanent ISS crew to seven astronauts as required for an appropriate exploitation of the ISS facilities.
that
improvements
current
launch vehicles
be capable
developments
elements
or of
costs may often
which
are considered
the performance introduction of
gain more
elements.
While
will
proven
than the
market conditions, commercial demand,
to the CRV the nominal
and subsystems
low production
more interesting obtained through
US has
service today are manufacturing
have been already used or are improvements of those developed for previous launcher versions.
for
imposed by the ISS budget. ESA
in
materials,
the
to the
of
little has been achieved
launchers
use
has been
for the reduction
cost is the introduction
technologies,
to
adaptations of the final products according specific requirements of future vehicles.
in the past
that a key element
competence
reusable transportation systems, although the heating level and the limited number of reuses will require further developments and
Due to the limitations Administration to the
innovative until now.
in the field of re-
mechanisms
(man-machine
The ESA Working CRV developments
Reusable
of the launch vehicle
consists mainly in contributions entry aerothermodynamics, technologies seats).
and
new European reusable launcher technologv DroPramme. PEARL
and
derivatives
might,
of
the
under favourable
be supported by the in no case the private sector
of undertaking necessary
for
those long term a
revolution
in
launch vehicle technology. The high
cost of access to space leads to the
evident fact that only high added value applications or missions having a strategic value for the governments are today based in space.
542
52nd IAF Congress
The space activities
remain therefore
limited and
this does not allow the creation of a mass market. Without a mass market, it is not possible for the private sector to invest in new launcher developments and the entire cost of the space activities falls back to the governments.
activities
(including
launch
related developments) substantial investments around 2005.
vehicle
and
do not allow in new activities
After that date the completion
IS fc unt
of a number of or
the
going major developments is expected to mak available sufficient budgets for progressing fastt in the demonstration activities.
bottleneck in access to space represented by the development of drastically innovative technologies. This corresponds to a precise political decision by the governments, which
On this basis a programme phasing on tw periods covering respectively 2002-2004 an 2005-2007 appears adequate for satisfying tb
The
first
step
is therefore
to
overcome
must be capable of providing continuous to the technology development effort
support without
counting on a fast return of their investments.
European objectives. In the first
way it will be possible to achieve in the long term those drastic reductions of access to space cost, which are needed to make of the space activities a mass market. Only in this
The proposed Reusable
;
new programme
(Programme Launchers)
for
has been name
European
Advance
and it has the followin
objectives: to perform the necessary system work an technology demonstration activities in systematic and coherent manner; -
Notwithstanding the above-mentioned contributions deriving from the participation to the CRV development and the associated co-
available
the ESA programme.
PEARL
Since this will remain for many years to come a pre-development non-competitive sector, it is expected that substantial benefits may be. drawn from the establishment of international cooperations.
phase the investments
ESA level should be complemented by nation: activities performed in strict co-ordination wit
to collect programme,
the heritage of thereby making
the FLT use of tr
operation activities, there is a need for Europe to increase the effort dedicated to such technology
associated available funding; technolog drive complementary to developments at national level so as 1 achieve a synergetic development an
developments.
demonstration
The ESA working
group concurred
for Europe to start a well-organised
on the need technology
-
The first phase of the programme should include studies for identification an system
-
development effort of adequate size, including system studies, technology demonstration on-
preliminary
setting
up
of
uncoordinated
national
transportation identification requirements; -
initiatives and the discussions over management issues have led to dispersion of the available budgets on a wide range of subjects and little results achieved. Dispersed sufficient
national developments cannot by themselves to advance
design of several reusable spat
transportation concepts, taking into accou both commercial payload as well as manne
ground and the development of experimental vehicles, as required to prove reusability and to cover all the vehicle flight phases. The
logic.
mission needs, allowing tt of the associated technolog
technology developments in the areas c aerothermodynamics, reusable propulsion cryogenic tanks, lightweight structures, hc structures and thermal protections, dedicate to the advancement of the competence fc generic problems common to several syster
be the
-
vehicle reusability;
in time for the
-
development flight test investigation;
and beds
On the other hand the current engagements of the ESA Member States in space infrastructure
-
definition experimental
preparation of tw and vehicles for the demonstratio
European competence 2007 target date.
as required
configurations,
which are operation of low-co for basic phenomer
S2nd IAF Congress
operations and of the reusability atmospheric re-entry of a winged vehicle. The second phase of the programme is expected: to continue the systems studies in order to achieve a detailed definition level and a correct estimation of the associated development and operation costs; to continue the technology demonstration activities on-ground; to develop and operate in-flight the two experimental vehicles.
543
experimental vehicle and reusable first stage propulsion; large thrust and high performance LOX/LH> propulsion technologies; exploitation of low-cost launch opportunities for technology demonstration; use of existing test facilities for propulsion, aerothermodynamics and hot structures; joint developments and use of foreign offthe-shelf components for experimental vehicles.
PEARL National activities should be directed toward supporting the implementation of the above technical activities. The programme activities should be organised and phased so as to achieve maximum benefit from the parallel X-38 and CRV developments and cross fertilisation of the technology development process.
phase 1 activities
The technology development and demonstration activities will require inputs and harmonization through the execution of system activities. But before any design work is started, it is necessary to update the estimates of the user needs, to forecast the commercial
launch market
trends and the future manned mission needs, and to finalise the vehicle design requirements.
The ESA working group considered that international co-operation should be part of the European strategy: to reduce the cost of the demonstration activities in the technology development process in the short term; to evaluate the interest of possible joint developments of both experimental vehicles as well as future operational systems in the longer term. Co-operation with the United States, Russia and Japan are being evaluated, each having its own characteristic and field of application. Such co-operations should take place, as far as possible, without exchange of funds between the two parties and should not target redistribution of the current production activities. For the longer term joint developments could be envisaged, provided that an opening of the respective space markets is achieved. European industry should not become dependent upon foreign technologies and therefore should master the technologies developed through the co-operation activities. Europe could benefit of available experience in selected fields as: liquid oxygen / hydrocarbon propulsion (using both kerosene and methane) for
On this basis, the objectives of the system work for the period 2002 - 2004 will be: To identify preferred launcher concepts for commercial missions as well as for manned space transportation. In particular, phase A design work will be conducted; To guide the technology work, to monitor its coherence and to include its results, with the aim reach by the end of the second PEARL phase (2002-2007) that the critical technologies have reached a degree of maturation sufficient to minimise the uncertainties of the programme development cost and schedule; To provide measurable objectives to be met by on-ground technology developments and in-flight experimentation; To provide system design data on which inflight experimentation should be based (e.g. shape, GNC..); To develop the system designs to sufficient detail that the advantages of the identified concepts with respect to cost, flexibility. safety are quantified accurately (e.g. recurrent launch costs shall be forecast with 5% accuracy).
52nd IAF Congress
544
For The plans for in-flight
experimentation
must be
elaborated with careful consideration of which kind of operational reusable vehicles Europe may need to develop, what are the specific technological needs for those vehicles, and which of those technologies demand in-flight
the
development
automatic
and verification
landing capabilities
required
of
the
for future
reusable
stages, the development of the PHOENIX test bed (Fig. 4) has been undertaken within the ASTRA German national programme. Such winged vehicle has a low ratio between lift and drag as expected for a typical
reusable stage
verification.
shape designed for atmospheric re-entry and hypersonic flight. It is proposed to include such
Moreover the in-flight experimentation logic (Fig.2) must take into account the previous flight
project PEARL
experience,
gained mainly
of capsules (ARD,
through
MIRKA,
as a contribution by Germany in-flight demonstration activities.
the re-entry
EXPRESS,
IRDT,
While the two test beds above are dedicated
etc.), as well as the experience expected to be gained through other programmes, as the X-38
the demonstration
V20 I demonstration
reproduce the behaviour of representative configurations in relevant the environments.
To
achieve
affordable
flight.
a
complete,
demonstration
progressive
programme,
based on the successive execution passenger experiments on-board
and
complex
vehicles, on the development of dedicated flight
named EXPERT
of two
on low-cost
and it will
configuration
of
experiment
is to analyse transition,
catalysis and
real
shock
layer interactions
flight instrumentation
and
flight
including
techniques:
reproduction
free stream will
of flight
covering
of all the vehicle flight
of
and flight
systems (including
l
.
a winged HERCULES,
novel
of two
re-entry
a winged operations called SOCRATES,
The
actual
launch
will
regimes experimental
vehicle
called
and reusability
vehicle,
cost
depend
of
a future
reusable
to a large extent
on the
practicality of the turnaround operations. It is therefore necessary to acquire a hands-on inflight experience on reusability before committing to a new launcher development. The
main
purpose
experimentation technologies turnaround
This test bed will be used for the verification means for free stream tracking), and integration into the TPS measurement techniques, as
and
data
be studied in detail, in
order to improve physical modelling extrapolation methodologies.
the air-data
.
launcher
Emphasis shall be put on the quality
data; ground
flight
wave
using state-of-the-art
The aim is to improve the design tools by actually performing wind-tunnel, flight and CFD activities.
to
vehicle
development scenarios, demonstration of the vehicle reusability the associated refurbishment operations,
carry out 3 flights
launchers. The goal of the in-flight gas effects
are required
.
have led to the selection vehicles, that is:
oxidation, boundary
vehicles
phenomena,
(Fig.3).
This vehicle will have a ballistic a blunt cone/flare
experimental
to
more
Evaluations taking into account the needs for inflight experimentation for: . maturation of the various critical technologies relevant to the more likely
Studies are on-going for the definition of a low cost test bed dedicated to the investigation of the aerothermodynamic
of specific technologies,
activities
of in-flight of existing
test beds and finally on the development experimental vehicles are proposed.
basic relevant
to the
of
diagnostic
for the design of the flight
well as for qualifying extrapolation methods through scaled model testing in European ground based facilities.
of
the
is to apply
repeated cycles in
reusability
flight
to selected
critical
flight and ground order to verify their
practical adequacy for low-cost operation. .
The main technical flight
reusability
areas on which
experimentation
will
the infocus
are the following: . . .
Thermal protection and hot structures: damages, NDI, repair, replacement, ageing Structural tanks : damages in operation, leakage and permeability, NDI, repair, Health monitoring: exploration of diagnostic
52nd IAF Congress
545
Fig. I - European strategy in the launch sector
Phoenix
-
EXPERT w-entry experiments
Reusable 2nd Winged
re-entry
X-38 V131 Transonx drop rests and parafo~l landmg
A
Reusable
Cryogenic
Vehxle
Propulsion
/
X-38V201 B re-entry demonstrawan
CRV V20lR Manned re-en,r) Hwrablc
2003
2006
Fig. 2 - Possible European in-flight
;010
demonstration
manned re-en,ry _._/ 2015
logic
Fig. 3 _- Possible shape under study for the low-cost aerothermodynamic
test bed EXPERT
52nd IAF Congress
546 and limitations
.
after flight Propulsion
:
.
propellant sloshing effect on piloting GNC: guidance during ascent, abort cases.
been developed and tested on ground in the frame of the parallel technology activities. Such
Landing with initial dispersions. Maintenance cycle
work, already
. .
fuel
prior, during and
Of course an additional purpose of in-flight experimentation will be to offer the opportunity to test in flight hardware elements, which have
possibilities
management,
Operations: how to launcN vehicle with a small team
The SOCRATES
vehicle
residual
produce to
land
the
thermodynamics,
(possibly
by
a liquid
(Fig.5).
oxigen
conceived
/
propulsion
system,
from the adaptation
of existing
hardware.
derived It shall
25 to 30 flight missions
under various loading and speed conditions, a maximum Mach number of 7. In-flight
experimentation
areas
reusable propulsion,
must also prove
Management with national One
of the
setting
up
major
difficulties
European
will aero-
cryogenic
programmes
encountered
technology
systems
aspects.
with This concerned that
the management
programmes and in order synergy with the national
and with the guidance algorithm
integrated
should yield the
accuracy until the touchdown of demonstration will also
benefit future crew transfer vehicles.
of the national
activities, which generally relies on budgets independent from ESA, as well as the European
low speed landing. The lift to drag ratio of the chosen shape combined with its manoeuvrability,
For the implementation
of the above-mentioned to achieve good programmes, an
will be management approach necessary, making use of all competence available at European level in the frame of an ESA programmatic
set up. This should be based
on the ESA rules and procedures For this demonstration a smaller vehicle, called HERCULES (Fig.
in
development
for reusable transportation
has been linked to the management
activities.
preliminary experimental
of
and svnergy Drogrammes
the defined reusable launcher shape constitutes an appropriate aerodynamic compromise for flight from the beginning of the re-entry until the
expected trajectory point. This type
the
to
hydrocarbon
methane)
be capable of performing
in
tanks, lightweight structures, hot structures and thermal protections, health management systems.
answer the above questions, has been preliminary designed as a vehicle of about IO tons of mass at take-off, with a length of II meters and a wing span of 5.5 meters. It will be propelled
in the first phase of PEARL,
developments
experimental 6) has been
defined. For cost reasons this vehicle should be compatible with
the geometric dimensions imposed by the small launcher (e.g. Vega) selected to inject it into a stable orbit. So a vehicle about 4.5 meters long and having a wing span limited to 2.5 meters results, which should have a landing mass of about 1200- 1300 kg.
make use of the expertise ESA and national technical programmatic
co-ordination.
This
facilitate
would
national same
activities technical
the
and it should
and capabilities of centres, under ESA
co-ordination
currently centres
managed under
with by
the
national
procedures.
Conclusions Its mass is limited by the choice of the vehicle wing span, taper ratio, and low speed lift so as to keep reasonable
landing
speeds, of the order of
From past work Europe has gained a good understanding of the issues associated with the
100 m/s.
development of reusable transportation systems. In some fields Europe has also gained a role of
The SOCRATES and HERCULES experimental vehicles will be defined in detail during the first
leadership at world-wide
phase of PEARL and their development will be initiated. Nevertheless the required development time and financial resources will lead to in-flight experimentation of the two vehicles in the second phase of the PEARL programme.
Nevertheless such achievements are by far not sufficient to master space transportation vehicle reusability in an economic manner.
level.
52nd IAF Congress
Fig. 4 - The PHOENIX test bed for automatic landing demonstration, under development in the national German programme ASTRA.
Fig. 5 - The SOCRATES reusability and operation experimental vehicle
Fig. 6 - The HERCULES winged un-propelled re-entry vehicle.
547
52nd IAF Congress
548
Europe needs to prepare now a new generation of cheaper transportation
more performing space and vehicles and needs to keep in
contact with the technology development on-going at world-wide level. It is now the time
for
Europe
to agree on a
common strategy reusable for transportation for the current decade initiate a demonstration
technology programme
process
space and to
development of adequate size.
and
Such a programme should achieve maximum use of the European resources and it should rely on international cooperation to increase the attainable results. This paper has described PEARL as currently proposed and has identified the technical activities, which are being included in it as a basis for further discussion.
Acta Astronautica Vol.51, No. 1-9, pp. 537-548, 2002
Pergamon
www.elsevier.com/locate/actaastro
P I h S0094-5765(02)00087-5
© 2002 Publishedby ElsevierScienceLtd Printedin GreatBritain 0094-5765•02 $- see frontmatter
FUTURE EUROPEAN LAUNCHER PLANS Marco Caporicci, Luisa lnnocenti E u r o p e a n Space A g e n c y , Paris, France
Abstract The paper reports about the conclusions of a strategic reflection conducted within ESA in the field of reusable transportation strategy and it describes in particular the current lines of action for the development of future reusable launcher technologies. On-going relevant programmes are discussed and the plans for future complementary activities are given. Special emphasis is given to in-flight demonstration through the development of test beds and experimental vehicles. Possible benefits deriving from international co-operation in this field are discussed. © 2002 Published by Elsevier Science Ltd.
Introduction In recent times the space transportation scenario
has undergone a substantial evolution due to: the uncertainty of the space activities and the associated markets (commercial versus governmental missions, Low Earth Orbit missions versus Geostationary orbit missions, etc.) the evolution of the budgets available to the various space agencies, the attempts to create increasing cooperation at international level, In Spring 2001 the ESA Director General decided to start an internal working group on this matter in co-operation with representatives of those Member States (Belgium, France, Germany, Italy, The Netherlands and Spain) having a major involvement in this sector. The aim of the activity was to achieve an overall European vision for reusable space transportation systems, integrating relevant ESA and national efforts and allowing Europe to make real progress towards the objectives, which it aims at fulfilling by 2007.
Mandate of the group was to propose an integrated approach for European reusable transportation systems and schemes for international co-operation allowing faster progress, with special reference to the European participation into the International Space Station Crew Return Vehicle (CRV). This date of 2007 is seen as an important milestone because: it is the current USA reference date for a decision for the Space Shuttle replacement by a more modem and efficient reusable system; by this date the CRV is expected to begin its operational phase at the ISS; it is the date of completion of the European investments associated to the current expendable launcher developments (Ariane 5 Plus and Vega). The working group mandate was translated in a series of questions for further analysis: what are the European objectives in the field of reusable space transportation systems with particular reference to the 2007 milestone? bow can a CRV development fit part of these objectives and advance the European technology level? which additional activities should be initiated at European level to ensure a timely development of the technologies required for future reusable transportation systems? which additional international co-operations might be beneficial to advance such technology development process? The answers given by the working group to these questions, together with the extensive preparation work perforrned internally in ESA, represent the basis for a new reusable launcher technology development programme, currently proposed by ESA, which aims at satisfying the
538
52nd IAF Congress
identified
European
objectives activities
the proposed programme and will be described in the following
objectives.
The
European
paragraphs.
the availability
Already
scenario
in
1998 NASA
associated A substantial
reduction
of the access to space
cost is pursued at world-wide
expendable
first
concepts,
new
CRVKTV
(Crew Transfer
conventional
of technologies
reusability
of
enabling
the transportation
system. approach
short-term
is strongly
competition
driven
second one has more ambitious
by the
and
the
role
of
a
Vehicle).
demonstration.
This
development
work
led
-
the expendable sufficient
-
of the Space partial vehicle
could
not
achieve
operational
low to be interesting
costs
for commercial
-
only if government incentives are used (the weak market limits the commercial possibility of private funding); a new crew transfer vehicle has uses across
for commercial
multiple
development
exists
architectures.
independent industrial studies In parallel conducted in co-operation by U.S., European and Japanese companies for
the
transportation may not be
mitigation
help enable low cost space
access; potential
case
In fact, the interest of reusability
systems do no have
to meet the safety goals
for human space transportation; a robust technology risk will
around
-
the
Shuttle, which reusability, but
launch
reliability
programme
of
and
to
of these U.S. studies were
the Space Shuttle should be replaced 2010;
of the reusable space transportation
and the associated technology
sufficiently activities.
designs,
-
The USA has been active since the 60’s in the
which
the risk
technologies
that:
targets and aims
at substantial cost reductions, capable influencing the volume of the space markets.
development implemented
RLV
The main conclusions
and it aims at achieving
limited, although important, cost reductions for at least the next decade of operations. The
conception
re-evaluated
these critical
launch vehicles;
the development low-cost
with
started the Space Transportation Architecture studies, which looked at Shuttle derived
level.
Two parallel avenues are followed: the improvement of
The
expendable
steady level. This strongly limits the possibility for private investments for new systems. International
-
of more performing
launchers and as a consequence the number of commercial GTO launches is essentially at a
concluded
development
that of
a business a
reusable
system could not be created on the
stated in absolute and its advantages have to be established taking into account the accessible
basis of the commercial market only and that, even including the totality of the governmental missions orbital infrastructure related to
market, vehicle
technology
the
defined
mission,
capabilities and the development cost and duration. In
1996 the U.S. National
the
required
technology
servicing
and military development
applications,
the initial
cost should be borne by
governments.
Space Policy
gave
On these bases, the USA providing safe and reliable
has identified that operation of space
NASA the responsibility to initiate partnerships with industry to jointly develop reusable launch vehicle technologies. based on the assumption
systems is the responsibility of the government and has initiated the Space Launch Initiative
that the satellite market would support the commercial development of a new (Reusable
of the technologies
Launch century.
Vehicle)
In the meantime
RLV
around
the commercial
the
failure
turn
of
of the
telecommunication satellite constellations has led to a much more limited commercial market in LEO than expected a few years ago. The mass of the geostationary satellites is increasing due to
(SLI).
The programme
transportation
aims at the development
required
system replacing
for a new reusable the Space Shuttle
around 2012. NASA has greater responsibility than in the previous programme and participation in the identification of the technical, programmatic and business risks associated with the RLV development. The programme focus is shifted toward increased safety and reliability, with the following objectives:
539
52nd IAF Congress -
-
crew loss risk of I in 10000 missions, cost of 1000 S per pound to LEO.
expertise
development
automation and life support systems) allowing it to secure an important role in future co-operative
decision
(in
technologies,
for the new system
around 2007.
safety
systems, re-entry propulsion systems. GNC.
on-orbit
missions. Therefore
European strategy and obiectives During effort
the year 2000 Europe performed for the definition
of a European
a broad Strategy
for Space. In this frame, the ESA Council approved in June 2000 a Resolution defining the European
Strategy
for: 1.
maintaining,
2.
completing,
for Launchers, as a priority,
veness of Ariane 5
which
-
called
-
of European manufactured small medium launchers, complementary the technologies
necessary
longer-term
developing, demonstrating
competition,
study
and
space
targeting
in-flight
transportation
commercial
systems,
evaluate
devoted
-
to
technology
programmes have for the ground
improvement
of the Ariane
already been put in infrastructure, the 5 performance
the
future
low
at this
developments cost
commercial
transportation systems should not preclude options for future manned transportation); to position Europe for a choice in due time for an autonomous development of a commercial
transportation
participation
to
system an
or
the
international
exploration initiative, depending evolution of the market scenarios While place
and
sufficiently
system may be decided
the
possible
the European Spaceport in Kourou.
reusable
designs
moment,
and on the
ground and in flight; ensuring the quality and efficiency of operations and services for the customer at
such technologies and their maturation through a
transportation
for by
experimenting such technologies
to
are critical
risks of the successive developments (while no development of a new manned space
new launch systems that may be required for
systems;
detailed to be able to correctly
and to
Ariane 5...; preparing
for reusable transportation to validate demonstrate
up
and co-ordinated which
manned transportation
by the addition
objectives
manner the technologies,
system
in the medium term, the range
of launch services offered
European
coherent on-ground demonstration approach;
the competiti-
. .;
the identified
to 2007 are: to advance in an efficient
upon the and space
agency programmes.
and
the development of complementary launchers (Vega), the development of future technologies
Key reusable sDace transportation technoloeies and in-flieht demonstration
still require an adequate frame. A considerable Such activities
of work
was performed
in past European
programmes
European capabilities for access to space for commercial and strategic reasons.
ESA level. ESA reusability with
investigated launch the FLS (Future
important
preservation
amount
of the
Another
shall allow
driver for the development
of
the transportation technology comes from the human space flight and space exploration
at national
and
vehicle
Launch Systems) and WLC (Winged Launcher Configuration) studies in the 80’s, the FESTIP programme
in the 90’s
and recently
with
the
activities. With the decision to participate to the development of the International Space Station, Europe renounced to the development of an
preparation of the FLTP. In parallel several technology demonstration activities were conducted, which allowed European industry to gain full understanding of
autonomous
the reusable transportation
infrastructure
for
human
space
flight. Moreover due to the cost and complication linked to the manned missions. it is
issues.
likely that in the evolved political human exploration enterprises will pursued in international co-operation. field Europe aims at developing
The Hermes programme
scenario only be In this strategic
system technological
in the second half of the
80’s and the successive MSTP and capsule work (CTV, ARD) performed in the early 90’s, allowed IO develop the European competence in
52nd IAF Congress
540 the field of manned transportation advanced considerably atmospheric
re-entry.
In parallel.
system
-
systems and
the technologies
reusable
and technology
reusable space transportation national HOTOL
work
management
in
in Germany, and French
Europe
competence transportation
has acquired a good field of in the
level of reusable
systems; it has also developed
technologies
that
in
specific
areas
unrelated
or
fragmented,
variable
requirements
hardware
demonstration
flight
demonstration
and
responding
without
activities.
reliable
-
various mission phases; redundant avionics
-
subsystems; software validation
-
advanced
to
performing
in
organized activities
the
set for
of
It is considered
flight
-
for
that in-flight
demonstration
initial
logic has been identified,
demonstration
activities
-
high
the
re-entry
re-entry
should
performance,
-
experimental realistic
vehicles allowing flight
to verify
in a
environment
step; concept demonstrator fully finally a representative of the selected system and its
-
may
development
technological
reusable
LOXiLHz
and
re-entry transonic/subsonic aerodynamics for typical space transportation vehicle shapes, through and
physical catalysis,
-
landing,
phenomena,
several technologies, including their operations and reusability features represent the successive
a
to an
main rocket propulsion; and aerothermodynamics
improved
-
(i.e. automatic
aerothermodynamic
be required
before
the
full
is undertaken.
include:
CFD
-
field
costs;
etc.);
be
LOX/Hydrocarbon -
vehicles or on-board of
technological
-
mission for
specific through in flying
development
in order to achieve
identified
of
and
a well
reliable evaluation of the risks associated operational vehicle development. areas
complexity:
may be developed for the of the issues related to a specific
for
provided by a set of system studies providing guidance to the technological investigations and implementing in the vehicle design the results
The
is
test beds verification
activities
from the demonstrations,
experimentation
launchers with limited
need
2002-2007
launchers
these
life
need for several of the above For this purpose a progressive in-
technologies may be conducted passenger experiments, consisting
Express,
vehicles, leading to demonstration on-ground The overall and in-flight experimentation. requirements
and
operational
the
technology
reusable
and
In particular
identified period
interface
which includes vehicles of growing
in Europe has been limited
group
architectures
support systems.
IRDT.
working
for the
and verification;
man-machine
hardware on existing The
and health
and robust GNC algorithms
an absolute technologies.
sufficient
to the re-entry of few capsules as ARD, MIRKA,
and both
key place
European industry at a leadership level worldwide. But in many cases such developments were
using
systems;
-
research activities. Today
hot structures
reliable vehicle health monitoring
for
was performed
programmes as Saenger in the United Kingdom
and repairable
thermal protection systems, ceramic and metallic materials;
linked to
experimental modelling
phenomena shock
the
(turbulence,
wave
/
need
to
be
experimented.
International
co-
operation
is considered
as a useful
tool
for
associated
reducing
the
investments
and
for
transition,
accelerating
boundary
On-poine
low-mass cr>,ogenic tanks, both and composite. with integral
reusable insulation; large size, highly loaded, low-mass maintainable composite structures;
required
the developments.
layer
interaction); flight mechanics; reusable metallic
experimentation
with
methods
of
The first three types of in-flight
are expected to be part of the technology development phase until 2007. In particular reusability operations and atmospheric re-entry
and
relevant
European
twoerammes
At
this time relevant European programmes, the Future Launchers Technology include Programme (FLTP), the European participation to the ISS Crew Return Vehicle. the on-going definition
studies
for
low-cost
541
52nd IAF Congress aerothermodynamic
experimentation
and several national programmes Germany,
PRORA
This
(EXPERT)
(i.e. ASTRA
in
in Italy, the Pre-X studies in
France, etc.) The FLTP
activities,
specifically
conceived
for
the development of the European competence for reusable launch vehicles. have been put on hold and are being reviewed: to achieve a better synergy between the ESA activities
the and activities,
technology
-
national aim of
the
represents the
an opportunity for an transportation reusable
of
demonstrations and an extension of the overall system know-how and avionics competence. The expanded set of European activities, including system requirements avionics
definition,
architectures,
reusability
operations,
etc. will
to update the fundamental
future reusable transportation
of the programme,
and
taking
into
account
the weakening
of the commercial
space
transportation
market
requirements to
define
and
agreed
provide
contribute
of the European
flight
for
systems and it will
opportunities
for
full
re-entry
demonstrations. The increased European participation
and
to the
competence
the
for manned flight; well
and
aerothermo-
dynamics, trajectory analyses, hot structures, vehicle health management systems, on-orbit and integration spacecraft operations, refurbishment and vehicle verification, development
hypothesis
mechanical
re-entry
inscribing them in a single European logic; objectives
-
relevant with
also
increase
recognised
seen in a development
perspective
should be leading to
future manned reusable transportation systems (i.e. CTV), which could be the subject of an
management rules at European level. The IS!? CRV vehicle is conceived as a reusable
extended strategic co-operation.
transportation system, in the form of a lifting body, whose mission is under demonstration A
through several atmospheric drop tests and the X-38 V201 orbital re-entry flight. The choice of the applied technologies has been voluntary directed toward those, which will be also used on future Crew Transfer Launch Vehicles.
Vehicles
The present European
thermal
protections,
participation
Although
several
determined
to the CRV
Most
hot
making
structures, and
Group considered in the area of usefully
manned
interface,
technologies
will
advancement
of the European
crew
that the re-entry
contribute
times
of
the
technologies,
of
components
In fact, the use of well elements having
lead to cost reductions,
proposed to increase its participation development in order to maintain
advanced technology
permanent ISS crew to seven astronauts as required for an appropriate exploitation of the ISS facilities.
that
improvements
current
launch vehicles
be capable
developments
elements
or of
costs may often
which
are considered
the performance introduction of
gain more
elements.
While
will
proven
than the
market conditions, commercial demand,
to the CRV the nominal
and subsystems
low production
more interesting obtained through
US has
service today are manufacturing
have been already used or are improvements of those developed for previous launcher versions.
for
imposed by the ISS budget. ESA
in
materials,
the
to the
of
little has been achieved
launchers
use
has been
for the reduction
cost is the introduction
technologies,
to
adaptations of the final products according specific requirements of future vehicles.
in the past
that a key element
competence
reusable transportation systems, although the heating level and the limited number of reuses will require further developments and
Due to the limitations Administration to the
innovative until now.
in the field of re-
mechanisms
(man-machine
The ESA Working CRV developments
Reusable
of the launch vehicle
consists mainly in contributions entry aerothermodynamics, technologies seats).
and
new European reusable launcher technologv DroPramme. PEARL
and
derivatives
might,
of
the
under favourable
be supported by the in no case the private sector
of undertaking necessary
for
those long term a
revolution
in
launch vehicle technology. The high
cost of access to space leads to the
evident fact that only high added value applications or missions having a strategic value for the governments are today based in space.
542
52nd IAF Congress
The space activities
remain therefore
limited and
this does not allow the creation of a mass market. Without a mass market, it is not possible for the private sector to invest in new launcher developments and the entire cost of the space activities falls back to the governments.
activities
(including
launch
related developments) substantial investments around 2005.
vehicle
and
do not allow in new activities
After that date the completion
IS fc unt
of a number of or
the
going major developments is expected to mak available sufficient budgets for progressing fastt in the demonstration activities.
bottleneck in access to space represented by the development of drastically innovative technologies. This corresponds to a precise political decision by the governments, which
On this basis a programme phasing on tw periods covering respectively 2002-2004 an 2005-2007 appears adequate for satisfying tb
The
first
step
is therefore
to
overcome
must be capable of providing continuous to the technology development effort
support without
counting on a fast return of their investments.
European objectives. In the first
way it will be possible to achieve in the long term those drastic reductions of access to space cost, which are needed to make of the space activities a mass market. Only in this
The proposed Reusable
;
new programme
(Programme Launchers)
for
has been name
European
Advance
and it has the followin
objectives: to perform the necessary system work an technology demonstration activities in systematic and coherent manner; -
Notwithstanding the above-mentioned contributions deriving from the participation to the CRV development and the associated co-
available
the ESA programme.
PEARL
Since this will remain for many years to come a pre-development non-competitive sector, it is expected that substantial benefits may be. drawn from the establishment of international cooperations.
phase the investments
ESA level should be complemented by nation: activities performed in strict co-ordination wit
to collect programme,
the heritage of thereby making
the FLT use of tr
operation activities, there is a need for Europe to increase the effort dedicated to such technology
associated available funding; technolog drive complementary to developments at national level so as 1 achieve a synergetic development an
developments.
demonstration
The ESA working
group concurred
for Europe to start a well-organised
on the need technology
-
The first phase of the programme should include studies for identification an system
-
development effort of adequate size, including system studies, technology demonstration on-
preliminary
setting
up
of
uncoordinated
national
transportation identification requirements; -
initiatives and the discussions over management issues have led to dispersion of the available budgets on a wide range of subjects and little results achieved. Dispersed sufficient
national developments cannot by themselves to advance
design of several reusable spat
transportation concepts, taking into accou both commercial payload as well as manne
ground and the development of experimental vehicles, as required to prove reusability and to cover all the vehicle flight phases. The
logic.
mission needs, allowing tt of the associated technolog
technology developments in the areas c aerothermodynamics, reusable propulsion cryogenic tanks, lightweight structures, hc structures and thermal protections, dedicate to the advancement of the competence fc generic problems common to several syster
be the
-
vehicle reusability;
in time for the
-
development flight test investigation;
and beds
On the other hand the current engagements of the ESA Member States in space infrastructure
-
definition experimental
preparation of tw and vehicles for the demonstratio
European competence 2007 target date.
as required
configurations,
which are operation of low-co for basic phenomer
S2nd IAF Congress
operations and of the reusability atmospheric re-entry of a winged vehicle. The second phase of the programme is expected: to continue the systems studies in order to achieve a detailed definition level and a correct estimation of the associated development and operation costs; to continue the technology demonstration activities on-ground; to develop and operate in-flight the two experimental vehicles.
543
experimental vehicle and reusable first stage propulsion; large thrust and high performance LOX/LH> propulsion technologies; exploitation of low-cost launch opportunities for technology demonstration; use of existing test facilities for propulsion, aerothermodynamics and hot structures; joint developments and use of foreign offthe-shelf components for experimental vehicles.
PEARL National activities should be directed toward supporting the implementation of the above technical activities. The programme activities should be organised and phased so as to achieve maximum benefit from the parallel X-38 and CRV developments and cross fertilisation of the technology development process.
phase 1 activities
The technology development and demonstration activities will require inputs and harmonization through the execution of system activities. But before any design work is started, it is necessary to update the estimates of the user needs, to forecast the commercial
launch market
trends and the future manned mission needs, and to finalise the vehicle design requirements.
The ESA working group considered that international co-operation should be part of the European strategy: to reduce the cost of the demonstration activities in the technology development process in the short term; to evaluate the interest of possible joint developments of both experimental vehicles as well as future operational systems in the longer term. Co-operation with the United States, Russia and Japan are being evaluated, each having its own characteristic and field of application. Such co-operations should take place, as far as possible, without exchange of funds between the two parties and should not target redistribution of the current production activities. For the longer term joint developments could be envisaged, provided that an opening of the respective space markets is achieved. European industry should not become dependent upon foreign technologies and therefore should master the technologies developed through the co-operation activities. Europe could benefit of available experience in selected fields as: liquid oxygen / hydrocarbon propulsion (using both kerosene and methane) for
On this basis, the objectives of the system work for the period 2002 - 2004 will be: To identify preferred launcher concepts for commercial missions as well as for manned space transportation. In particular, phase A design work will be conducted; To guide the technology work, to monitor its coherence and to include its results, with the aim reach by the end of the second PEARL phase (2002-2007) that the critical technologies have reached a degree of maturation sufficient to minimise the uncertainties of the programme development cost and schedule; To provide measurable objectives to be met by on-ground technology developments and in-flight experimentation; To provide system design data on which inflight experimentation should be based (e.g. shape, GNC..); To develop the system designs to sufficient detail that the advantages of the identified concepts with respect to cost, flexibility. safety are quantified accurately (e.g. recurrent launch costs shall be forecast with 5% accuracy).
52nd IAF Congress
544
For The plans for in-flight
experimentation
must be
elaborated with careful consideration of which kind of operational reusable vehicles Europe may need to develop, what are the specific technological needs for those vehicles, and which of those technologies demand in-flight
the
development
automatic
and verification
landing capabilities
required
of
the
for future
reusable
stages, the development of the PHOENIX test bed (Fig. 4) has been undertaken within the ASTRA German national programme. Such winged vehicle has a low ratio between lift and drag as expected for a typical
reusable stage
verification.
shape designed for atmospheric re-entry and hypersonic flight. It is proposed to include such
Moreover the in-flight experimentation logic (Fig.2) must take into account the previous flight
project PEARL
experience,
gained mainly
of capsules (ARD,
through
MIRKA,
as a contribution by Germany in-flight demonstration activities.
the re-entry
EXPRESS,
IRDT,
While the two test beds above are dedicated
etc.), as well as the experience expected to be gained through other programmes, as the X-38
the demonstration
V20 I demonstration
reproduce the behaviour of representative configurations in relevant the environments.
To
achieve
affordable
flight.
a
complete,
demonstration
progressive
programme,
based on the successive execution passenger experiments on-board
and
complex
vehicles, on the development of dedicated flight
named EXPERT
of two
on low-cost
and it will
configuration
of
experiment
is to analyse transition,
catalysis and
real
shock
layer interactions
flight instrumentation
and
flight
including
techniques:
reproduction
free stream will
of flight
covering
of all the vehicle flight
of
and flight
systems (including
l
.
a winged HERCULES,
novel
of two
re-entry
a winged operations called SOCRATES,
The
actual
launch
will
regimes experimental
vehicle
called
and reusability
vehicle,
cost
depend
of
a future
reusable
to a large extent
on the
practicality of the turnaround operations. It is therefore necessary to acquire a hands-on inflight experience on reusability before committing to a new launcher development. The
main
purpose
experimentation technologies turnaround
This test bed will be used for the verification means for free stream tracking), and integration into the TPS measurement techniques, as
and
data
be studied in detail, in
order to improve physical modelling extrapolation methodologies.
the air-data
.
launcher
Emphasis shall be put on the quality
data; ground
flight
wave
using state-of-the-art
The aim is to improve the design tools by actually performing wind-tunnel, flight and CFD activities.
to
vehicle
development scenarios, demonstration of the vehicle reusability the associated refurbishment operations,
carry out 3 flights
launchers. The goal of the in-flight gas effects
are required
.
have led to the selection vehicles, that is:
oxidation, boundary
vehicles
phenomena,
(Fig.3).
This vehicle will have a ballistic a blunt cone/flare
experimental
to
more
Evaluations taking into account the needs for inflight experimentation for: . maturation of the various critical technologies relevant to the more likely
Studies are on-going for the definition of a low cost test bed dedicated to the investigation of the aerothermodynamic
of specific technologies,
activities
of in-flight of existing
test beds and finally on the development experimental vehicles are proposed.
basic relevant
to the
of
diagnostic
for the design of the flight
well as for qualifying extrapolation methods through scaled model testing in European ground based facilities.
of
the
is to apply
repeated cycles in
reusability
flight
to selected
critical
flight and ground order to verify their
practical adequacy for low-cost operation. .
The main technical flight
reusability
areas on which
experimentation
will
the infocus
are the following: . . .
Thermal protection and hot structures: damages, NDI, repair, replacement, ageing Structural tanks : damages in operation, leakage and permeability, NDI, repair, Health monitoring: exploration of diagnostic
52nd IAF Congress
545
Fig. I - European strategy in the launch sector
Phoenix
-
EXPERT w-entry experiments
Reusable 2nd Winged
re-entry
X-38 V131 Transonx drop rests and parafo~l landmg
A
Reusable
Cryogenic
Vehxle
Propulsion
/
X-38V201 B re-entry demonstrawan
CRV V20lR Manned re-en,r) Hwrablc
2003
2006
Fig. 2 - Possible European in-flight
;010
demonstration
manned re-en,ry _._/ 2015
logic
Fig. 3 _- Possible shape under study for the low-cost aerothermodynamic
test bed EXPERT
52nd IAF Congress
546 and limitations
.
after flight Propulsion
:
.
propellant sloshing effect on piloting GNC: guidance during ascent, abort cases.
been developed and tested on ground in the frame of the parallel technology activities. Such
Landing with initial dispersions. Maintenance cycle
work, already
. .
fuel
prior, during and
Of course an additional purpose of in-flight experimentation will be to offer the opportunity to test in flight hardware elements, which have
possibilities
management,
Operations: how to launcN vehicle with a small team
The SOCRATES
vehicle
residual
produce to
land
the
thermodynamics,
(possibly
by
a liquid
(Fig.5).
oxigen
conceived
/
propulsion
system,
from the adaptation
of existing
hardware.
derived It shall
25 to 30 flight missions
under various loading and speed conditions, a maximum Mach number of 7. In-flight
experimentation
areas
reusable propulsion,
must also prove
Management with national One
of the
setting
up
major
difficulties
European
will aero-
cryogenic
programmes
encountered
technology
systems
aspects.
with This concerned that
the management
programmes and in order synergy with the national
and with the guidance algorithm
integrated
should yield the
accuracy until the touchdown of demonstration will also
benefit future crew transfer vehicles.
of the national
activities, which generally relies on budgets independent from ESA, as well as the European
low speed landing. The lift to drag ratio of the chosen shape combined with its manoeuvrability,
For the implementation
of the above-mentioned to achieve good programmes, an
will be management approach necessary, making use of all competence available at European level in the frame of an ESA programmatic
set up. This should be based
on the ESA rules and procedures For this demonstration a smaller vehicle, called HERCULES (Fig.
in
development
for reusable transportation
has been linked to the management
activities.
preliminary experimental
of
and svnergy Drogrammes
the defined reusable launcher shape constitutes an appropriate aerodynamic compromise for flight from the beginning of the re-entry until the
expected trajectory point. This type
the
to
hydrocarbon
methane)
be capable of performing
in
tanks, lightweight structures, hot structures and thermal protections, health management systems.
answer the above questions, has been preliminary designed as a vehicle of about IO tons of mass at take-off, with a length of II meters and a wing span of 5.5 meters. It will be propelled
in the first phase of PEARL,
developments
experimental 6) has been
defined. For cost reasons this vehicle should be compatible with
the geometric dimensions imposed by the small launcher (e.g. Vega) selected to inject it into a stable orbit. So a vehicle about 4.5 meters long and having a wing span limited to 2.5 meters results, which should have a landing mass of about 1200- 1300 kg.
make use of the expertise ESA and national technical programmatic
co-ordination.
This
facilitate
would
national same
activities technical
the
and it should
and capabilities of centres, under ESA
co-ordination
currently centres
managed under
with by
the
national
procedures.
Conclusions Its mass is limited by the choice of the vehicle wing span, taper ratio, and low speed lift so as to keep reasonable
landing
speeds, of the order of
From past work Europe has gained a good understanding of the issues associated with the
100 m/s.
development of reusable transportation systems. In some fields Europe has also gained a role of
The SOCRATES and HERCULES experimental vehicles will be defined in detail during the first
leadership at world-wide
phase of PEARL and their development will be initiated. Nevertheless the required development time and financial resources will lead to in-flight experimentation of the two vehicles in the second phase of the PEARL programme.
Nevertheless such achievements are by far not sufficient to master space transportation vehicle reusability in an economic manner.
level.
52nd IAF Congress
Fig. 4 - The PHOENIX test bed for automatic landing demonstration, under development in the national German programme ASTRA.
Fig. 5 - The SOCRATES reusability and operation experimental vehicle
Fig. 6 - The HERCULES winged un-propelled re-entry vehicle.
547
52nd IAF Congress
548
Europe needs to prepare now a new generation of cheaper transportation
more performing space and vehicles and needs to keep in
contact with the technology development on-going at world-wide level. It is now the time
for
Europe
to agree on a
common strategy reusable for transportation for the current decade initiate a demonstration
technology programme
process
space and to
development of adequate size.
and
Such a programme should achieve maximum use of the European resources and it should rely on international cooperation to increase the attainable results. This paper has described PEARL as currently proposed and has identified the technical activities, which are being included in it as a basis for further discussion.