The agency's Constellation project aims to replace the retiring space shuttle with Ares I, which will fly the Orion crew capsule to near-Earth orbit, and Ares V to carry a rocket and lunar lander. But to do this, NASA needs tens of billions of extra dollars over the next decade (New Scientist, 25 April, p 6).
Ares I has also been beset by technical problems and its advocates now find themselves struggling to defend it against rival spacecraft. What were fringe alternatives a few months ago are now being seriously considered.
Representatives argued for their concepts (see graphic) last week in Washington DC at the first public meeting of an expert committee tasked by the White House to recommend future spacecraft and mission options for NASA (New Scientist, 16 May, p 7).
An emissary from a group of rebel NASA engineers promoted a family of rockets called Jupiter. Executives from several aerospace companies pushed for various commercially built rockets. Even the NASA space shuttle manager, John Shannon, suggested an alternative, the Heavy Launch Vehicle, in which space shuttle rockets boost a light Apollo-like capsule to orbit.
All the rockets have enough muscle to take a crew capsule to the International Space Station, which is in low-Earth orbit, but only a few can handle more distant missions. The most powerful are the largest of the Jupiter group and the Heavy Launch Vehicle, each of which could provide the lift needed for moon missions. The Jupiter rocket could even bring Mars within reach, its backers claim.
NASA's current plan involves developing both Ares I and its more powerful companion, Ares V. The two rockets would rendezvous in low-Earth orbit, transferring a crew capsule from Ares I to a rocket and a lunar lander carried by Ares V. These then combine and fly to the moon, leaving the Ares rockets behind.
However, many now doubt that Congress will be willing to fund more than one new rocket, so if the agency continues with Ares I, it may be the only rocket it gets. The committee will report at the end of August.
