NASA has told the US Senate it could decide in the second quarter of 2008 to continue using its orbiter Atlantis after its planned retirement date. Such a decision would raise new budget questions. The agency's administrator Michael Griffin also told the Senate that he wants to fly the Space Shuttle’s two previously unconfirmed contingency missions, extending the remaining Shuttle flights to 13 and raising costs.
The final Atlantis mission has been scheduled for August 2008, leaving a two orbiter fleet of Endeavour and Discovery to operate until 2010. So maintaining a third orbiter until the end of the decade and flying the contingency missions would add operational costs.
The two contingency missions are for International Space Station research equipment and spares. NASA sources have told Flight that Atlantis' proposed retention is for robust manifest planning and “skill retention” within the agency.
Beyond the cost implications of three orbiters beyond 2008, budget requests have previously shown NASA wanted the Shuttle to end by September 2010 – the end of FY2010 – so it can develop its Orion crew exploration vehicle and Ares I crew launch vehicle rocket for a maiden flight between third quarter 2013 and second quarter 2015.
Rising Shuttle costs would add to existing financial pressures caused by neither of NASA’s budgets for FY2007 or FY2008 being approved; the agency is operating at 2006 funding levels.
While the FY2008 budget may be approved before its scheduled end, on 30 September 2008, Griffin warned the the US Senate's science subcommittee's 15 November post-Shuttle space transport plan hearing: “The [Orion maiden flight] dates we have discussed will become worse if we have a full year [without the requested budget].”
As well as Griffin, testimony was given by NASA associate administrator for space operations William Gerstenmaier, and associate administrator for exploration systems Richard Gilbrech.
Gilbrech told the Senate that the agency would need an extra $350 million in FY2009 and $400 million in FY2010 to start manned Orion flights in 2014. To advance that to 2013 would need $1 billion more in both years.