STS 109 mission included five EVAs to install new equipment including the Advanced Camera for Surveys

The Space Shuttle Columbia returned to Earth on 12 March following the successful completion of the ambitious Hubble Space Telescope (HST) servicing mission.

Preparations are under way for two more Shuttle missions - both to the International Space Station (ISS) - on 4 April and in early May by orbiters Atlantis and Endeavour.

The STS 109 mission included five EVAs to install new equipment in the HST. During the first, a lighter and more powerful solar array was fixed to the Hubble on 4 March. The second EVA on 5 March included the installation of the second solar panel and the replacement of one of Hubble's gyroscopes. The third EVA, a day later, was to replace the HST's power control unit, during which - for the first time since it was launched in April 1990 - Hubble was turned off.

The fourth EVA, on 7 March, was to attach a new instrument, the Advanced Camera for Surveys, replacing the Faint Object Camera. The final spacewalk, on 8 March, completed the repair of the HST's Near Infra-red Camera and Multi-Object Spectrometer with the addition of a new neon gas cryo-cooler.

Meanwhile, the Aerospace Safety Advisory Panel says that NASA is too focused on the short-term needs of the Space Shuttle system and long term safety planning is suffering, putting the entire system at risk. The panel, which comprises independent experts that oversee NASA and other government agencies, says that "unless appropriate steps to reduce future risk and increase reliability are taken expeditiously" NASA may be forced to ground the shuttle until time-consuming improvements can be made. With continued budget constraints, risks will inevitably increase, the panel says.

Sean O'Keefe, NASA's new administrator, says the agency's accounts are in such a bad state that accounting company PricewaterhouseCoopers is unable to complete an audit. As a result, O'Keefe says that he will not know until the summer how much more it will cost to complete the ISS.

Source: Flight International