Tim Furniss/LONDON
Russia has requested that US space agency NASA fly two more Shuttle Mir Missions (SMMs) to provide logistics support to extend the life of the Mir space station for at least three further manned missions up to at least mid-1999.
The request lends support to evidence that the International Space Station (ISS) is confronted by longer delays than announced because of software integration problems.
The proposed flights will provide supplies to the Mir. No further missions are planned by NASA astronauts aboard the station once Andrew Thomas returns next month aboard the STS91 on the ninth and last of the current SMMs, to be launched on 2 June.
Moscow further fuelled the speculation late last month by announcing that the already delayed launch of the Russian Control Module planned for August is now unlikely to take place before October because of hold-ups further down the production chain. Although no official announcement has been made, the first ISS Shuttle flight, planned for September carrying the first US Node, would also be pushed back.
The Russian Service Module launch has been further delayed from December until possibly March 1999 and the first manned ISS mission is likely to be pushed back to mid-summer. It may be decided that there is not much point in launching the first ISS components so early if follow-on flights will be delayed.
The software problems, affecting particularly the US Laboratory Module - which may also be delayed further into 1999 - have gone largely unreported, while NASA has accused Russia of causing delays, mainly because of budgetary problems.
NASA is under financial pressure also, with the latest cost estimate for the ISS rising to $24 billion from the $17 billion estimated, and a completion date more likely to be 2006, three years late, according to an independent review panel appointed by NASA.
The delays leave gaps in the Space Shuttle schedule. The further occupations of the Mir and flights of the SMMs will enable the Russian Space Agency and NASA to remain fully employed in manned space activities, and to keep the Mir going until possibly 2000.
With practically all its Shuttle missions from 1999 onwards allocated to the ISS, there could be drastic reductions in Shuttle activity this year and in early 1999. NASA has already suggested a reflight of the current STS 90/Neurolab medical research mission, to fill a gap in the manifest this summer.
NASA has also argued, however, that keeping the Mir going for longer will only use up Soyuz and Progress launches previously destined to support the early ISS missions. Progress vehicles will be required to assist in the de-orbiting of the Mir station which was originally planned for late 1999.
Source: Flight International
