NASA optimistic over shuttle problem
NASA has expressed confidence that a cooling system problem aboard space shuttle Columbia would not prematurely end the spacecraft’s mission to overhaul the Hubble Space Telescope.
Shuttle managers continued to study the problem today and planned to meet in the afternoon to discuss whether a coolant loop, which helps dissipate heat from the vehicle, would be able to operate within acceptable limits for the rest of the 11-day mission.
‘‘We’re very optimistic we have a plan that will conclude we will be able to press on with the full mission duration,’’ said shuttle manager Ron Dittemore. ‘‘I don’t think there should be any cause for us to be in any concern of the state of the spacecraft.’’
A low flow rate in one of the shuttle’s two coolant loops for payload-bay radiators was detected shortly after Columbia arrived in orbit following its launch around dawn Friday.
The loop appeared to be blocked by debris. While low, the flow rate is slightly above flight rule minimums.
Dittemore said initial reports of the problem painted a ‘‘gloomy’’ picture, but the situation had improved.
If Columbia’s crew of seven astronauts is given the go-ahead to proceed, they will catch up to the telescope on Sunday. Early today astronauts carried on with their work, which included checking out the shuttle’s robotic arm and their spacewalking suits and tools.
During five spacewalks next week, two pairs of astronauts will equip Hubble with more rigid and energy-efficient solar wings, a new power-control unit, a more reliable steering mechanism, a refrigeration system to restore function to an infrared camera that ran out of coolant, and a new camera that’s 10 times more efficient than the craft’s most powerful camera.
The amount of work being done during the spacewalks is making this the most complicated Hubble servicing mission yet.
The changing of the power control unit could be the most nerve-racking task during the repair mission.
To replace the unit, Hubble will need to be completely powered down - the first time this has happened in orbit.
Columbia recently underwent a two-and-a-half year overhaul. It is NASA’s first shuttle orbiter, having made its initial flight in April 1981.
