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Operational trends in Russian navigation satellite systems
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Space Policy 199713(1) 5-7 © 1997ElsevierScienceLtd. Allrightsreserved Printed in GreatBritain 0265-9646/97/$17.00
ELSEVIER
Viewpoint Operational trends in Russian navigation satellite systems Geoffrey E. Perry While the Russian space programme is generally agreed to be in a parlous state because of financial constraints, there is evidence that Russian navigation satellite systems are less affected by this than would be expected. It is demonstrated that certain satellites have longer lives than believed in the West and can be retired, then reactivated as the need arises. A judicious policy of in-orbit storage, reactivation of retired satellites and on-orbit maintenance is ensuring that the Russian systems do not fall victim to the decline in launch rates. © 1997 Elsevier Science Ltd.
Geoffrey E. Perry, MBE is the founder of the Kettering Group. He can be reached at 4 Silverton Close, Bude, Cornwall, EX23 8TG UK.
1Tarasenko, Maxim V., Current status of the Russian space programme. Space Policy, 12, 1 (1996) 19-28. 2Wood, C.D., private communication.
SPACE POLICY
February
1997
Tarasenko wrote, 'Infrequent replacements cause aging of constellations, with a growing number of spacecraft operating beyond their warranty period. While earlier spacecraft tended to be replaced as soon as their warranty expired, these days customers are forced to use them for as long as they continue to perform'. 1 A review of the Russian navigation constellations, the low Earth-orbit systems and the counterpart of America's GPS Navstar, the global navigation satellite system, GLONASS, supports this claim and prompts further speculation. The operational Parus (sail) military constellation consists of a Cosmos satellite having an 83 ° inclination to the equator, in a near-circular orbit at 1000km with an orbital period close to 105min, in each of six planes spaced at 30 ° intervals around the equator. Table 1 gives the Cosmos numbers of satellites launched annually since the commencement of an era of d#tente at the end of the 1980s. The decline in launch-rate is clearly evident. However, the table does not tell the complete story. Decoding, by Chris Wood of the Kettering Group, of a telemetry transmission on 149.91MHz from 1123 to 1125 U TC
on 10 July 1996 revealed that the six active satellites at that time were Cosmos 2327, 2184, 2218, 2173, 2142 and 2279. 2 It is immediately obvious that three of these satellites, Cosmos 2184, 2173 and 2142 had been followed by subsequent launches into planes 2, 4 and 5. Monitoring of transmissions on 1 January 1996 had shown that the active satellites at that time were Cosmos 2266, 2310, 2218, 2173, 2233 and 2279. Cosmos 2266 was replaced as the active satellite in plane 1 by the newly-launched Cosmos 2327 at the end of January. Cosmos 2233 was deactivated and replaced in plane 5 by Cosmos 2142 and, after little more than one year's service, Cosmos 2310 was deactivated and replaced in plane 2 by Cosmos 2184. These operations were not without precedent. In 1995 Cosmos 2173 had been reactivated as the operational satellite in plane 4, taking over from Cosmos 2239 which had replaced it in April 1 9 9 3 . Similar changes in operational status had been noted as far back as July 1986 and May 1987 when Cosmos 1634 was reactivated in plane 6 for short periods when Cosmos 1759 was turned off. Even earlier, Cosmos 1535 in plane 3 and Cosmos 1464 in plane 5, with temporary identity numbers 8 and 9,
5
Viewpoint Table 1. Military navigation satellites in the Cosmos series Year
Plane 1
Plane 2
Plane 3
Plane 4
Plane 5
Plane 6
1990 1991 1992 1993 1994
-[2135] 2195 2266
2074 -2184
2061 2154 2218 --
2100 2173 -2239
2142 --
2180
1995
[2321]
2310
--
--
2327
--
--
--
1996
2233 2279
2334
'on replacement, a satellite retained the potential for reacturation'
3Soviet
Space
(1989),
488-492.
6
Programs:
1981-87,
Pt.
2
reactivated to provide additional coverage following the failure of Cosmos 1448 in plane 1 at the end of 1984. 3 Such instances demolished Western beliefs that Parus satellites had relatively short service lives before failing. It was clear that, on replacement, a satellite was 'retired' and retained the potential for reactivation if necessary. Cosmos 2135, shown in parentheses in the table, did not immediately replace Cosmos 2026 in plane 1. It did not become operational until March 1992, thirteen months after launch. This was a demonstration of on-orbit storage, somewhat akin to the Stacked-Oscar-On-Scout, SOOS, programme of the analogous American navigation system, Transit, in which pairs of satellites, from a batch which had remained in store due to earlier satellites far exceeding their design life, were placed in orbit to be available when and if required. However, the uncertainty provoked by the impending dissolution of the USSR may have been a contributory factor in this instance. Although there have been no further examples of on-orbit storage within the Parus system, the reactivation of a satellite and deactivation of its newer replacement may be seen as a policy of squeezing as much value as possible from an older satellite whilst, at the same time, conserving a more recent satellite until its use is absolutely essential to maintain the constellation. The 5 September 1996 launch of Cosmos 2334 into plane 1 was surprising since Cosmos 2327, only launched on 16 January, was still operating normally. In fact, considering Cosmos 2321, which failed to achieve the desired orbit when the second burn of the upper
stage of the Cosmos-3M booster failed, the last three launches have been into plane 1. A further surprise was the transmission f r e q u e n c ~ 150.03MHz, hitherto exclusively used by satellites in plane 5. Cosmos 2327 was deactivated one week later and Cosmos 2142 continued to share the 150.03 MHz frequency with the newest satellite. On 25 February 1995, signals on the Tsikada civil system's frequency of 150.00MHz persisted for some time after the predicted setting of the only satellite to be named Tsikada at launch and which, at that time, had not been brought into operation. The only other operational civil system satellite in the vicinity at the time was Cosmos 2230 in plane 11, from which signals had not been logged since 8 February, but that was not due to rise for another 12 minutes. Predictions for Cosmos 2181, which had been replaced by Cosmos 2230, were generated to test the hypothesis that the signals were emanating from a satellite in plane 11 which had been reactivated to replace Cosmos 2230. These did not fit the observations but predictions for Nadezhda 1, its predecessor, did. Telemetry confirmed that Nadezhda 1 was shown as the operational satellite in plane 11. Although Nadezhda I had been retired for more than three years it helped to fill the gap until the launch of Cosmos 2315 in the following July. (See Table 2.) Another example of extracting maximum value from an aging satellite was provided by Nadezhda 3, the oldest operational civil satellite, in plane 12 of the Tsikada system during the second half of August. For more than one week, when its transmitter was ~off', the Tsikada system was reduced to only three, instead of four,
SPACE POLICY February 1997
Viewpoint Table 2. Civil navigation satellites Year
4GLONASS status over the period from October 1982, through March 1993. Note 6.
SPACE P O L I C Y F e b r u a r y
1997
Plane 11 1
Plane 12
Plane 13
Plane 14 --
1989
Nadezhda
--
--
1990
--
--
--
Nadezhda
1991
--
Nadezhda
2123
--
1992
2181
--
--
--
1993
2230
--
--
--
1994
--
--
--
Nadezhda
1995
2315
--
Tsikada
--
active satellites. Fears that Nadezhda 3 had failed completely were allayed early on 28 August when it was observed to be transmitting 'time only' information on two consecutive passes. Full data transmission had been resumed by 1925 UTC that evening, suggesting that it had merely been temporarily deactivated for maintenance. GLONASS satellites frequently undergo such brief periods of maintenance. In addition to periods of maintenance, the GLONASS programme has provided an example of deactivation of an operational satellite when replaced after exceeding its design life. Cosmos 1987, which had been launched in January 1989, was replaced after exceeding its threeyear design life by more than one year, although still fully operational. A Russian document used the phrase 'driven into spare as of 14 Mar 93'. 4 GLONASS satellites, launched three at a time, on Proton boosters populate three planes separated at 120°-intervals around the Equator. The eight operational satellites in each plane are spaced at 45 °-intervals around the plane. Although plane 2, the third of the planes to be filled, had the six satellites from the first two launches into that plane still operational when the time came to complete the constellation in
3
2
4
December 1995, nevertheless, in order to utilise the full capability of the Proton booster, three satellites, Cosmos 2323, 2324 and 2325, were launched into the vacant slot 9. Cosmos 2325 remained at that location, Cosmos 2323 moved 180° around the plane to slot 13, whilst Cosmos 2324 has continued to drift slowly round the orbit at a rate of 0.083 ° per day relative to the fixed slots. At this rate it would take rtearly twelve years to return to the location of slot 9. It can be expected that, on the failure of one of the other satellites in plane 2, Cosmos 2324 would be quickly moved to that satellite's location to restore full operational capability, demonstrating an advantage of on-orbit storage. When failures occur in planes 1 and 3 it will be interesting to observe if triple launches to those planes furnish more examples of on-orbit storage or if single payload launches using a different booster are employed. In summary, it has been shown that both Russian navigation satellite constellations are coping with the decline in launch rates imposed by financial constraints by reviving 'retired' assets to extract their full value, on-orbit maintenance of existing assets, and on-orbit storage to maximise booster availability.
7
Space Policy 199713(1) 5-7 © 1997ElsevierScienceLtd. Allrightsreserved Printed in GreatBritain 0265-9646/97/$17.00
ELSEVIER
Viewpoint Operational trends in Russian navigation satellite systems Geoffrey E. Perry While the Russian space programme is generally agreed to be in a parlous state because of financial constraints, there is evidence that Russian navigation satellite systems are less affected by this than would be expected. It is demonstrated that certain satellites have longer lives than believed in the West and can be retired, then reactivated as the need arises. A judicious policy of in-orbit storage, reactivation of retired satellites and on-orbit maintenance is ensuring that the Russian systems do not fall victim to the decline in launch rates. © 1997 Elsevier Science Ltd.
Geoffrey E. Perry, MBE is the founder of the Kettering Group. He can be reached at 4 Silverton Close, Bude, Cornwall, EX23 8TG UK.
1Tarasenko, Maxim V., Current status of the Russian space programme. Space Policy, 12, 1 (1996) 19-28. 2Wood, C.D., private communication.
SPACE POLICY
February
1997
Tarasenko wrote, 'Infrequent replacements cause aging of constellations, with a growing number of spacecraft operating beyond their warranty period. While earlier spacecraft tended to be replaced as soon as their warranty expired, these days customers are forced to use them for as long as they continue to perform'. 1 A review of the Russian navigation constellations, the low Earth-orbit systems and the counterpart of America's GPS Navstar, the global navigation satellite system, GLONASS, supports this claim and prompts further speculation. The operational Parus (sail) military constellation consists of a Cosmos satellite having an 83 ° inclination to the equator, in a near-circular orbit at 1000km with an orbital period close to 105min, in each of six planes spaced at 30 ° intervals around the equator. Table 1 gives the Cosmos numbers of satellites launched annually since the commencement of an era of d#tente at the end of the 1980s. The decline in launch-rate is clearly evident. However, the table does not tell the complete story. Decoding, by Chris Wood of the Kettering Group, of a telemetry transmission on 149.91MHz from 1123 to 1125 U TC
on 10 July 1996 revealed that the six active satellites at that time were Cosmos 2327, 2184, 2218, 2173, 2142 and 2279. 2 It is immediately obvious that three of these satellites, Cosmos 2184, 2173 and 2142 had been followed by subsequent launches into planes 2, 4 and 5. Monitoring of transmissions on 1 January 1996 had shown that the active satellites at that time were Cosmos 2266, 2310, 2218, 2173, 2233 and 2279. Cosmos 2266 was replaced as the active satellite in plane 1 by the newly-launched Cosmos 2327 at the end of January. Cosmos 2233 was deactivated and replaced in plane 5 by Cosmos 2142 and, after little more than one year's service, Cosmos 2310 was deactivated and replaced in plane 2 by Cosmos 2184. These operations were not without precedent. In 1995 Cosmos 2173 had been reactivated as the operational satellite in plane 4, taking over from Cosmos 2239 which had replaced it in April 1 9 9 3 . Similar changes in operational status had been noted as far back as July 1986 and May 1987 when Cosmos 1634 was reactivated in plane 6 for short periods when Cosmos 1759 was turned off. Even earlier, Cosmos 1535 in plane 3 and Cosmos 1464 in plane 5, with temporary identity numbers 8 and 9,
5
Viewpoint Table 1. Military navigation satellites in the Cosmos series Year
Plane 1
Plane 2
Plane 3
Plane 4
Plane 5
Plane 6
1990 1991 1992 1993 1994
-[2135] 2195 2266
2074 -2184
2061 2154 2218 --
2100 2173 -2239
2142 --
2180
1995
[2321]
2310
--
--
2327
--
--
--
1996
2233 2279
2334
'on replacement, a satellite retained the potential for reacturation'
3Soviet
Space
(1989),
488-492.
6
Programs:
1981-87,
Pt.
2
reactivated to provide additional coverage following the failure of Cosmos 1448 in plane 1 at the end of 1984. 3 Such instances demolished Western beliefs that Parus satellites had relatively short service lives before failing. It was clear that, on replacement, a satellite was 'retired' and retained the potential for reactivation if necessary. Cosmos 2135, shown in parentheses in the table, did not immediately replace Cosmos 2026 in plane 1. It did not become operational until March 1992, thirteen months after launch. This was a demonstration of on-orbit storage, somewhat akin to the Stacked-Oscar-On-Scout, SOOS, programme of the analogous American navigation system, Transit, in which pairs of satellites, from a batch which had remained in store due to earlier satellites far exceeding their design life, were placed in orbit to be available when and if required. However, the uncertainty provoked by the impending dissolution of the USSR may have been a contributory factor in this instance. Although there have been no further examples of on-orbit storage within the Parus system, the reactivation of a satellite and deactivation of its newer replacement may be seen as a policy of squeezing as much value as possible from an older satellite whilst, at the same time, conserving a more recent satellite until its use is absolutely essential to maintain the constellation. The 5 September 1996 launch of Cosmos 2334 into plane 1 was surprising since Cosmos 2327, only launched on 16 January, was still operating normally. In fact, considering Cosmos 2321, which failed to achieve the desired orbit when the second burn of the upper
stage of the Cosmos-3M booster failed, the last three launches have been into plane 1. A further surprise was the transmission f r e q u e n c ~ 150.03MHz, hitherto exclusively used by satellites in plane 5. Cosmos 2327 was deactivated one week later and Cosmos 2142 continued to share the 150.03 MHz frequency with the newest satellite. On 25 February 1995, signals on the Tsikada civil system's frequency of 150.00MHz persisted for some time after the predicted setting of the only satellite to be named Tsikada at launch and which, at that time, had not been brought into operation. The only other operational civil system satellite in the vicinity at the time was Cosmos 2230 in plane 11, from which signals had not been logged since 8 February, but that was not due to rise for another 12 minutes. Predictions for Cosmos 2181, which had been replaced by Cosmos 2230, were generated to test the hypothesis that the signals were emanating from a satellite in plane 11 which had been reactivated to replace Cosmos 2230. These did not fit the observations but predictions for Nadezhda 1, its predecessor, did. Telemetry confirmed that Nadezhda 1 was shown as the operational satellite in plane 11. Although Nadezhda I had been retired for more than three years it helped to fill the gap until the launch of Cosmos 2315 in the following July. (See Table 2.) Another example of extracting maximum value from an aging satellite was provided by Nadezhda 3, the oldest operational civil satellite, in plane 12 of the Tsikada system during the second half of August. For more than one week, when its transmitter was ~off', the Tsikada system was reduced to only three, instead of four,
SPACE POLICY February 1997
Viewpoint Table 2. Civil navigation satellites Year
4GLONASS status over the period from October 1982, through March 1993. Note 6.
SPACE P O L I C Y F e b r u a r y
1997
Plane 11 1
Plane 12
Plane 13
Plane 14 --
1989
Nadezhda
--
--
1990
--
--
--
Nadezhda
1991
--
Nadezhda
2123
--
1992
2181
--
--
--
1993
2230
--
--
--
1994
--
--
--
Nadezhda
1995
2315
--
Tsikada
--
active satellites. Fears that Nadezhda 3 had failed completely were allayed early on 28 August when it was observed to be transmitting 'time only' information on two consecutive passes. Full data transmission had been resumed by 1925 UTC that evening, suggesting that it had merely been temporarily deactivated for maintenance. GLONASS satellites frequently undergo such brief periods of maintenance. In addition to periods of maintenance, the GLONASS programme has provided an example of deactivation of an operational satellite when replaced after exceeding its design life. Cosmos 1987, which had been launched in January 1989, was replaced after exceeding its threeyear design life by more than one year, although still fully operational. A Russian document used the phrase 'driven into spare as of 14 Mar 93'. 4 GLONASS satellites, launched three at a time, on Proton boosters populate three planes separated at 120°-intervals around the Equator. The eight operational satellites in each plane are spaced at 45 °-intervals around the plane. Although plane 2, the third of the planes to be filled, had the six satellites from the first two launches into that plane still operational when the time came to complete the constellation in
3
2
4
December 1995, nevertheless, in order to utilise the full capability of the Proton booster, three satellites, Cosmos 2323, 2324 and 2325, were launched into the vacant slot 9. Cosmos 2325 remained at that location, Cosmos 2323 moved 180° around the plane to slot 13, whilst Cosmos 2324 has continued to drift slowly round the orbit at a rate of 0.083 ° per day relative to the fixed slots. At this rate it would take rtearly twelve years to return to the location of slot 9. It can be expected that, on the failure of one of the other satellites in plane 2, Cosmos 2324 would be quickly moved to that satellite's location to restore full operational capability, demonstrating an advantage of on-orbit storage. When failures occur in planes 1 and 3 it will be interesting to observe if triple launches to those planes furnish more examples of on-orbit storage or if single payload launches using a different booster are employed. In summary, it has been shown that both Russian navigation satellite constellations are coping with the decline in launch rates imposed by financial constraints by reviving 'retired' assets to extract their full value, on-orbit maintenance of existing assets, and on-orbit storage to maximise booster availability.
7