Tim Furniss/LONDON
A major component change to the Space Shuttle system will be introduced on 2 June when the Discovery STS91 is launched on the ninth Shuttle Mir Mission (SMM).
The Shuttle stack will incorporate the first lightweight external tank (ET) which holds the 543,300 litres of liquid oxygen and 1,460,150 litres of liquid hydrogen that feed the orbiter's main engines. The aluminium-lithium alloy tank is 3,175kg lighter than that of the original ET. This weight saving can be translated into additional payload capability - particularly significant for flights to 51° inclination orbits required for International Space Station (ISS) operations.
The SMM9 crew includes former Salyut cosmonaut Valeri Ryumin, now a senior space director. His brief is to assess the safety of the station and its suitability to continue operations into 2000, which may be attempted if the ISS programme is delayed significantly.
An unsung payload flying on the STS91 may provide scientists with the final evidence to support the Big Bang theory of the creation of the Universe. The alpha magnetic spectrometer (AMS) will search for low-energy charged particles, which will indicate the existence of anti matter and dark matter in the Universe.
Source: Flight International
