Spaceflight

After four years of bold talk about focusing its return-to-the-Moon programme on a permanent international outpost at the Moon's southern polar Shackleton crater, NASA now suggests its plans may stop at less ambitions Apollo-style sorties.

In an extraordinary admission, the space agency's acting administrator Christopher Scolese told a House of Representatives appropriations subcommittee on 29 April that it is still working on what "return to the Moon" meant. He described the options as an outpost, which he called "expensive", or extended sortie missions such as Apollo.

In 2005 NASA developed an architecture for outpost missions and has since spent billions of dollars developing its Ares I crew launch vehicle, Orion crew exploration vehicle and completed early work for its Altair lunar lander and Ares V cargo launch vehicle to enable an outpost.

The concept of seven-month missions for four crew with international involvement followed US president George Bush's 2004 vision for space exploration that envisaged a 2020 return to the Moon.

President Barack Obama wants a review of the space agency's "core mission" and this will take place once his administrator candidate is appointed, replacing Scolese. Scolese told the subcommittee he does not know who the candidate is.

Scolese was giving testimony to the US House of Representatives' commerce, justice, science, and related agencies appropriations subcommittee. The space agency's budget is incorporated into its annual appropriation bill. The fiscal year 2009 bill was passed in March. Scolese, previously associate administrator, has been acting administrator since the 20 January resignation of Bush's NASA appointee Michael Griffin.