Space plane to rescue NASA
Jeff Hecht
NASA reshuffled its human space transport programmes on Wednesday, in the hope of solving its most pressing problem - replacing its ageing space shuttle fleet.
The agency had planned to develop a full replacement, but that has now been pushed into the distant future. Spacecraft development will now not begin before 2009. Instead a smaller vehicle called the orbital space plane will be an interim replacement to ferry astronauts to the International Space Station and fill the role of escape capsule.
But its first flight to the ISS is not expected before 2010, leaving a four-year gap from the end in 2006 of the present Russian agreement to supply Soyuz capsules as escape vehicles. Soyuz capsules also are the only alternative to the shuttle for delivering crew members to the station.
Filling that gap is likely to involve extending the life of the space shuttle yet further, and this forms the third part of NASA's new plan. To facilitate the plan, US President George W Bush has asked Congress to shift money within NASA's 2003 budget, though not to increase the total.
Leaking hose
NASA's Integrated Space Transportation Plan will need to succeed in finding shuttle replacements where earlier NASA efforts failed. And each incident like the leaking oxygen hose that delayed this week's planned Endeavour launch is another reminder that the clock is running down fast.
The orbital space plane is needed to fill a crucial hole: a way to return the ISS crew to the ground in case of emergency. Shortly after taking office, the Bush Administration chopped the ISS budget, dropping plans for a crew return vehicle holding up to seven astronauts. That left the ISS crew dependent on the Russian Soyuz modules, which have to be replaced every six months.
The new plan calls for developing a new small winged vehicle launched on new rockets developed by the Pentagon's Evolved Expendable Launch Vehicle programme.
Return capsule
NASA documents envision delivering the first space plane to the ISS in 2010, where it would remain as a return capsule. Two years later, NASA wants the space plane to transfer its first crew to the ISS. If successful, the space plane could become the primary vehicle carrying crews to the ISS between 2015 and 2020.
Focusing near-term development on the space plane leaves the program to find a long-term shuttle replacement concentrating on technology until 2009, when development of a new spacecraft would begin.
Finally, the plan calls for more spending on extending the shuttle lifetime and enhancing its safety and reliability. The goal is to keep the shuttle flying for at least another decade, and hold open the option of using it through at least 2020, nearly 40 years after the first shuttle flight.
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