Space Shuttle's capacity for ISS missions is inadequate to carry station modules and current OBSS system

NASA is studying a mini-boom sensor system for Space Shuttle thermal protection system inspections because of payload limitations on International Space Station (ISS) assembly missions.

The current orbiter boom sensor system (OBSS) is 30m (100ft) long, consisting of the 15m, 411kg (905lb) Shuttle remote manipulator system (RMS) and the attached inspection boom assembly (IBA), which is also 15m in length and has a mass of 222kg.

Both systems are built by Canadian company MDA, which is to be contracted to help with the mini-OBSS work.

NASA designated MDA as the sole supplier in its 27 July solicitation for upgrades to the RMS and IBA and the development and manufacture of the mini-boom.

"NASA is working on a mini-boom concept that would replace the OBSS on flights where the payload doesn't allow the OBSS to fly," says the US space agency.

Space Shuttles Atlantis and Endeavour have payload capacities of 16,400kg for missions to the ISS. The 2007 missions, Atlantis/STS 120, Discovery/STS 122 and the February 2008 flight Endeavour/STS 124, will be used to transport the very heavy ISS modules, Node-2, the European Space Agency's Columbus laboratory and the Japan Aerospace Exploration Agency's Kibo laboratory, respectively.

The modules' masses would each probably stop the orbiter from carrying the OBSS.

Source: Flight International