London, Aug 8(ANI): The NASA has said that an attempt to fix the International Space Station (ISS)'s faulty cooling system, which involved the longest ever spacewalk from the station, has failed.
The two American astronauts, Doug Wheelock and Tracy Caldwell Dyson, spent over eight hours outside the space station, but were unable to unbolt and remove a pump that failed on July 31.
It was the longest spacewalk in the ISS' history and the sixth longest ever.
"It was a tough one as spacewalks go," The Telegraph quoted an announcer from NASA's mission control in Houston, Texas, as saying.
Experts had warned ahead of the spacewalk that the operation was challenging because the astronauts would be handling ammonia lines at full operating pressure, which makes them stiff.
The pair had slept in an airlock beforehand to allow their bodies to adjust to different pressure conditions.
A second spacewalk is planned for Wednesday when the astronauts will once again attempt to repair the system.
The ISS crew has been forced to reduce power after the fault, but NASA officials insist that the three Americans and three Russians aboard are not in danger.
Without thermal controls, temperatures on the ISS's Sun-facing side can soar to 121C (250F), plunging to minus 157C (-250F) on the dark side, NASA said.
According to reports, the station is now operating on a single string, and has no safeguard in case of further cooling system failures. (ANI)