International Space Station is home to six U.S., Russian, European, Japanese and Canadian astronauts at any one time. Photo Credit/NASA photo
NASA has raised the prospect that the U. S.led, 15-nation International Space Station partnership may have to de-staff the orbiting science laboratory in mid-November, if Russia’s investigation and recovery from the Aug. 24 loss of the Progress 44 re-supply mission is long running.
The unpiloted Progress capsule, filled with nearly three tons of supplies for the station, crashed into the remote Altai region of Siberia last week, after a failure of the Soyuz-U rocket’s third stage 320 seconds into flight. The Soyuz-U third stage is similar to the third stage of the Soyuz-FG rocket used to launch three person U. S., European, Japanese and Canadian crews to the orbital outpost.
The crew launches are scheduled four times a year.
A Russian commission, which is expected to have NASA technical representation, has been formed to establish the root cause of the failure. Airborne search teams are looking for wreckage in the mountainous crash zone.
“We’re going to do what’s the safest for the crew and for the space station, which is a very big investment of our governments,” Mike Suffredini, NASA’s international space station program manager, told a news briefing on Monday. “Our job is, as stewards of the government, to protect that investment, and that’s exactly what we’re going to do.”
He placed the decision point on station staffing at mid-November, the point at which the last three of the station’s current six U. S., Russian and Japanese crew members are scheduled to descend to Earth.
“There is a greater risk of losing ISS if it were unmanned than if it were manned,” said Suffredini. “The risk increase is not insignificant.”
Personnel in U. S.and Russian control centers would take over.
Before they depart the station, the last astronauts would install internal backup power and cooling lines and configure the docking systems for the arrival of unpiloted Progress freighters. External experiments could continue to operate as well as some automated internal science experiments, Suffredini said.
The space station has been continuously staffed since the first U. S.and Russian crew floated aboard on Nov. 2, 2000.
Early in the program, the station supported three astronauts and cosmonauts. Following the 2003 loss of shuttle Columbia, the station staff dropped to two U.S.and Russian astronauts, as the partnership struggled to keep them supplied with food, water and spare parts. The station’s crew grew to six astronauts after shuttle missions resumed in the 2005-06 and NASA equipped the orbital outpost with the hardware to recycle air and water.
NASA’s final shuttle flight, a mega re-supply mission using Atlantis in July, left the outpost stocked for six person operations well into 2012.
However, the current dilemma over station staffing is driven by issues related to the Soyuz, not food, air and other equipment.
Each spacecraft remains docked to the station after it delivers new crew members to serve as a life boat.
Each of the Russian capsules is certified for 200 days of flight, a restriction based on the degradation of the propulsion system. There are also restrictions on when a Soyuz can make a parachute descent into remote Kazakhstan. There must be enough daylight on the Kazakh plains for helicopter borne search and rescue crews to find the spacecraft and assist the astronauts quickly.
Wintry weather also restrict recovery of the Soyuz crews.
In order to keep the station staffed with six people for as long as possible, station managers announced Monday that current station crew members Ron Garan, of NASA, and Russians Andrey Borisenko and Alexander Samokutyaev will postpone their scheduled Sept. 8 descent to Earth, after 156 days by at least a week. The launch of three replacements on Sept. 21 has been postponed as well.
The final current three crew members, American Mike Fossum, Russian Sergei Volkov and Japan’s Satoshi Furukawa, are scheduled to descend to Earth on Nov. 16, or after 162 days.
Sunlight and wintry conditions in Kazakhstan at that time of year afford little leeway for an extension.
And NASA and Russian officials would like at least two unmanned test flights of an upgraded Soyuz booster before launching a new crew to the station.