Smoke-smelled shuttle/station spacesuit scuttles spacewalks

William Atkins
Wednesday, 14 November 2007 19:36

Science - Space

A pressure-chamber test at the NASA Johnson Space Center on Friday, November 9, 2007, in which an astronaut smelled smoke inside his spacesuit, continues to prevent any further spacewalks until the problem is resolved.          

So far, no evidence of any source of the smell has been found by NASA engineers investigating the problem. Also, all the spacesuit hardware has been found in good working order, without any evidence of being damaged from combustion or contamination.

The smoke was smelled during a ground test inside the simulated U.S. Quest airlock in which astronauts are introduced to the spacesuits, which are called extravehicular mobility units (EMUs), prior to going up into space. With the pure oxygen atmosphere inside the space suits, any abnormal smells cause great concerns for the safety of the astronaut inside. The EMUs provide complete life-support for the astronaut, whether on the ground or in space.

As a result of the smell, all future spacewalks have been banned until the matter is resolved.

Since Friday, the day the problem occurred, engineers at the Johnson Space Center have run numerous tests on the smelly spacesuit, including gas sample and gas filter analyses on the carbon dioxide-scrubbing canister--a prime suspect of the smell.

In addition, a mishap investigation board has been formed by NASA. The board will continue to make recommendations on the EMUs until the problem is resolved satisfactorily.

In the best case resolution, the spacewalks will be able to proceed on Novermber 20 and 24. In the worst case resolution, the EMUs will need replacement of certain faulty parts, which could delay the construction of the space station by months. However, a workaround could be possibly implemented—by using the Russian spacesuits instead of the U.S. EMUs.

The next spacewalk at the International Space Station is scheduled for November 20, 2007, with a second one coming on November 24. Both are critical and must be performed before the STS-122 mission can lift off, now scheduled for December 6, 2007.

On these two spacewalks, ISS crewmembers Whitson and Tani will connect power, coolant, and data lines to the new Harmony module in preparation for the European Space Agency’s Columbus laboratory being connected to it when it is delivered by the space shuttle Atlantis on the STS-122 mission.

If the STS-122 mission is delayed because of the situation with the space suits, future missions may need to be delayed, too. In all, resolving this problem is paramount in keeping NASA on schedule with its completion of the space station in 2010, in time to retire the space shuttle fleet.

A go-ahead for the spacewalks could be given as early as Thursday, November 15, 2007.

For additional information on the NASA spacesuit, or EMU, go to the NASA website “The Space Shuttle Extravehicular Mobility Unit (EMU)”.

For information about the EMU from the manufacturer, Hamilton Sundstrand, go to “Extravehicular Mobility Unit (EMU)”.