Introduction
Introduction
NASA's human spaceflight program is stuck in low orbit, held back by budget constraints, political bickering, competing visions and daunting technical challenges. A White House-commissioned panel has warned that the program is on an “unsustainable trajectory” because of funding limitations, and plans to build a new generation of rockets, return to the Moon and eventually go to Mars are under intense scrutiny. Meanwhile, the impending termination of the Space Shuttle could leave a seven-year gap during which the United States could have to rely on Russia to ferry astronauts to space. The future of NASA's human spaceflight program — including whether to build a lunar settlement — rests heavily on whether the Obama administration presses for more space funding. Meanwhile, private companies are working to ...