NASA has officially noted that they intend to fly 18 more International Space Station (ISS) assembly missions – and one Hubble Space Telescope servicing mission (HSM) – before retiring the Space Shuttle in 2010.
Comments made by NASA Assistant Associate Administrator Mark Uhran note that the ISS construction ambitions have been downscaled.
NASA, who are aiming for three Shuttle missions next year, believe it is possible to fulfil the 19 mission manifest before 2010 – with the expected debut of the Crew Exploration Vehicle (CEV) coming two years later.
The US space agency hopes test flight STS-121 – dubbed RTF 3 (Return to Flight 3) – will finally prove all safety measures are now effective, with a solution to the foam liberation issue believed to have been solved. The major concern was over a piece of foam that shed from the PAL Ramp area of the External Tank (ET) on STS-114. As previously reported, all PAL Ramps will be removed before the launch of Discovery next May.
NASA will have to then launch at least four missions in 2007, 08, 09 and 2010 to reach the 19 flights on the remaining manifest. However, there have been casualties in the process of aligning the Shuttle’s final role for NASA – ISS assembly requirements.
According to Uhran, speaking to USA Today, the Centrifuge Lab – which was to test animals and the affect different levels of gravity have on them – is now highly unlikely to make the final ISS configuration.
The Earth Observatory “Cupola” module will also be scrapped from the manifest, if NASA falls short of the 19 flight manifest before 2010.
And previous noted by NASA as being removed from the manifest, Node 3, was also mentioned by Uhran as too “low priority” to make the trip into Low Earth Orbit. Uhran believes that – by 2008 at the earliest – the ISS will be able to sustain six people without Node 3.
However, while all international contract elements of the ISS will make the trip on the Shuttle, there was no mention of any outstanding work being completed by the SDLV (Shuttle Derived Launch Vehicle) – which is not expect to be in service until around 2015.
Adding to the woes of finalising the construction of the ISS is ESA’s (European Space Agency) nagging problems with their ATV ship. ATV-1 “Jules Verne” was set to help out with assembly missions of the ISS next year, although unofficially ESA has now ruled out the debut of the ship until at least mid 2007 due to problems with laser guidance, final testing of the ATV-ISS docking systems and outstanding hardware system integration and testing.
The highlight of the remaining flights of the Shuttle will be the Hubble Servicing Mission.
While no date has been fixed for the mission which will replace batteries and ensure an extended life of the much-loved telescope past 2010, the mission will be the only flight on the manifest that won’t have the ‘safe haven’ option of the ISS – adding risk should the Shuttle (expected to be Endeavour) sustain serious damage on assent.
NASA is believed to have planned an STS-300 style rescue mission to be in place for this mission – with one of Endeavour’s sister ships being on the adjacent pad should a serious problem arise.
The three Orbiters at the Kennedy Space Center have no outstanding issues in their respective processing status.
Discovery is in the midst of launch processing after her mission earlier in the year, Atlantis – recently de-stacked due to the postponement of STS-121 – has little by the way of processing work until preparations begin for her launch next year – and Endeavour is continuing power up processing after coming out of a near-two year Orbiter Major Modification (OMM) period.
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