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Space-elevator-in-the-making wins $900,000 NASA prize
GEORGE BERNARD/NHPA
UPFRONT
Northern forests are cool CHAMPIONS of carbon offsetting may have been barking up the wrong tree. It is generally assumed that the tropics are the best place to plant forests in order to sequester carbon and cool the planet, but a study of the effects of tree planting is casting doubt on this idea. To maximise climate benefits we should be planting trees at higher latitudes, the study suggests. Alvaro Montenegro at the University of Victoria in British Columbia, Canada, and colleagues used high-resolution satellite data to work out where new forests would bring the biggest benefit. They estimated the net climate impact of planting trees on 5-kilometre-square plots of cropland in locations where forests can be expected to thrive. Their calculations took into
account both the cooling effect of the trees soaking up CO2 and the heating effect which would result from the trees reflecting less sunlight than the crops they replaced. To their surprise, Montenegro’s team found that on balance, planting forests in northern Russia, central Canada and Europe would cool the climate more effectively than planting them in India, Brazil and most of China (Global and Planetary Change, DOI: 10.1016/j. gloplacha.2009.08.005). Govindasamy Bala at the Indian Institute of Science in Bangalore reckons existing tropical carbonoffsetting schemes may still have the edge, however. Montenegro’s study may have overestimated the amount of carbon forests in Siberia and Canada can store, he warns.
–Better than tropical trees–
NASA’s rope trick TODAY a cable dangling beneath a helicopter, tomorrow a climb to the stars. The far-out idea of space elevators has been brought a step closer by a robot whose climbing prowess has bagged its makers a previously unclaimed NASA prize. To build a space elevator, one end of a cable thousands of kilometres long would be anchored on or near the equator, while the far end is deployed in space. Robots climbing the cable should provide a cheap route into space, the scheme’s advocates say, but huge technological hurdles remain. One of the most pressing of these is finding a way to supply power to the robot. So in 2005 NASA inaugurated the Power
“One of the most pressing technological hurdles is finding a way to supply power to the robot” Beaming Challenge, an annual competition in which robotic climbers, powered wirelessly from the ground, attempt to ascend a cable. Prize money 6 | NewScientist | 14 November 2009
totalling $2 million has been on offer for successful challengers. Now a robotic climber built by a team called LaserMotive, based in Seattle, Washington has won $900,000 for a 900-metre climb up a cable suspended from a helicopter hovering above Edwards Air Force Base in Mojave, California. The climber took its power from on-board photovoltaic cells that absorb energy from a groundbased infrared laser. On 4 November, LaserMotive’s robot completed the climb in 4 minutes, an average climb rate of about 3.7 metres per second. The following day it did slightly better, climbing at 3.9 metres per second. Two other climbers stalled during their attempts and were unable to continue. NASA is holding the remaining prize money in reserve for climbs faster than 5 metres per second. Though a space elevator is only a distant prospect, NASA is interested in wireless power transmission for other applications, such as beaming power to lunar rovers travelling in shadowed craters where no solar energy is available.
At last, it works GENE therapy is coming in from the cold. Two boys treated three years ago with a gene therapy for X-linked ALD, the brain disease featured in the film Lorenzo’s oil, fared so well that doctors have treated a third and are now looking for adult volunteers. “They have normal, family lives,” says Nathalie Cartier of the Descartes University in Paris, France, a member of the team that pioneered the ALD gene therapy. ALD is caused by a faulty gene
that prompts the myelin sheath coating nerves in the brain to wear away, causing impaired speech, movement and eventually death. Cartier and her colleagues took blood stem cells from two 7-yearold boys with ALD, infected the cells with a virus carrying a correct copy of the defective gene, then re-injected the stem cells. The boys’ symptoms stabilised within 14 months and have not worsened since (Science, DOI: 10.1126/science.1171242). Early gene therapy trials were stopped after triggering cancer.
Fly-by may solve speed anomaly WHAT’S causing spacecraft to mysteriously accelerate? The Rosetta comet-chaser’s fly-by of Earth on 13 November may provide the answer. The anomaly emerged in 1990, when NASA’s Galileo spacecraft whizzed by Earth to get a boost from our planet’s gravity and gained 4 millimetres per second more than expected. Other probes experienced the same effect, leading some to suggest that Einstein’s theory of gravity needs modifying to explain it.
All eyes are now on Rosetta, which is set to swing by Earth again this week. If it gains an extra 1.1 millimetres per second relative to Earth, it would vindicate a formula that reproduces the anomalies seen so far. The formula, published in 2008 by ex-NASA scientist John Anderson and his team, hints that Earth’s rotation may be distorting space-time more than expected and thus influencing nearby spacecraft, though no one can explain how.
UPFRONT
Northern forests are cool CHAMPIONS of carbon offsetting may have been barking up the wrong tree. It is generally assumed that the tropics are the best place to plant forests in order to sequester carbon and cool the planet, but a study of the effects of tree planting is casting doubt on this idea. To maximise climate benefits we should be planting trees at higher latitudes, the study suggests. Alvaro Montenegro at the University of Victoria in British Columbia, Canada, and colleagues used high-resolution satellite data to work out where new forests would bring the biggest benefit. They estimated the net climate impact of planting trees on 5-kilometre-square plots of cropland in locations where forests can be expected to thrive. Their calculations took into
account both the cooling effect of the trees soaking up CO2 and the heating effect which would result from the trees reflecting less sunlight than the crops they replaced. To their surprise, Montenegro’s team found that on balance, planting forests in northern Russia, central Canada and Europe would cool the climate more effectively than planting them in India, Brazil and most of China (Global and Planetary Change, DOI: 10.1016/j. gloplacha.2009.08.005). Govindasamy Bala at the Indian Institute of Science in Bangalore reckons existing tropical carbonoffsetting schemes may still have the edge, however. Montenegro’s study may have overestimated the amount of carbon forests in Siberia and Canada can store, he warns.
–Better than tropical trees–
NASA’s rope trick TODAY a cable dangling beneath a helicopter, tomorrow a climb to the stars. The far-out idea of space elevators has been brought a step closer by a robot whose climbing prowess has bagged its makers a previously unclaimed NASA prize. To build a space elevator, one end of a cable thousands of kilometres long would be anchored on or near the equator, while the far end is deployed in space. Robots climbing the cable should provide a cheap route into space, the scheme’s advocates say, but huge technological hurdles remain. One of the most pressing of these is finding a way to supply power to the robot. So in 2005 NASA inaugurated the Power
“One of the most pressing technological hurdles is finding a way to supply power to the robot” Beaming Challenge, an annual competition in which robotic climbers, powered wirelessly from the ground, attempt to ascend a cable. Prize money 6 | NewScientist | 14 November 2009
totalling $2 million has been on offer for successful challengers. Now a robotic climber built by a team called LaserMotive, based in Seattle, Washington has won $900,000 for a 900-metre climb up a cable suspended from a helicopter hovering above Edwards Air Force Base in Mojave, California. The climber took its power from on-board photovoltaic cells that absorb energy from a groundbased infrared laser. On 4 November, LaserMotive’s robot completed the climb in 4 minutes, an average climb rate of about 3.7 metres per second. The following day it did slightly better, climbing at 3.9 metres per second. Two other climbers stalled during their attempts and were unable to continue. NASA is holding the remaining prize money in reserve for climbs faster than 5 metres per second. Though a space elevator is only a distant prospect, NASA is interested in wireless power transmission for other applications, such as beaming power to lunar rovers travelling in shadowed craters where no solar energy is available.
At last, it works GENE therapy is coming in from the cold. Two boys treated three years ago with a gene therapy for X-linked ALD, the brain disease featured in the film Lorenzo’s oil, fared so well that doctors have treated a third and are now looking for adult volunteers. “They have normal, family lives,” says Nathalie Cartier of the Descartes University in Paris, France, a member of the team that pioneered the ALD gene therapy. ALD is caused by a faulty gene
that prompts the myelin sheath coating nerves in the brain to wear away, causing impaired speech, movement and eventually death. Cartier and her colleagues took blood stem cells from two 7-yearold boys with ALD, infected the cells with a virus carrying a correct copy of the defective gene, then re-injected the stem cells. The boys’ symptoms stabilised within 14 months and have not worsened since (Science, DOI: 10.1126/science.1171242). Early gene therapy trials were stopped after triggering cancer.
Fly-by may solve speed anomaly WHAT’S causing spacecraft to mysteriously accelerate? The Rosetta comet-chaser’s fly-by of Earth on 13 November may provide the answer. The anomaly emerged in 1990, when NASA’s Galileo spacecraft whizzed by Earth to get a boost from our planet’s gravity and gained 4 millimetres per second more than expected. Other probes experienced the same effect, leading some to suggest that Einstein’s theory of gravity needs modifying to explain it.
All eyes are now on Rosetta, which is set to swing by Earth again this week. If it gains an extra 1.1 millimetres per second relative to Earth, it would vindicate a formula that reproduces the anomalies seen so far. The formula, published in 2008 by ex-NASA scientist John Anderson and his team, hints that Earth’s rotation may be distorting space-time more than expected and thus influencing nearby spacecraft, though no one can explain how.