Weather Woes, Sensor Glitches Follow Discovery to ISS

The space shuttle Discovery's blastoff to the International Space Station was delayed twice the week of Aug. 24 due to stormy weather and a faulty liquid hydrogen valve sensor. The launch finally took place Aug. 29, but bad weather and sensor woes have followed the crew to the ISS.

During the first of three scheduled space walks, on Sept. 1, Astronaut Nicole Stott reported to Mission Control that her spacesuit showed a high reading of her carbon dioxide levels. When Stott said she felt fine despite the reading, NASA responded that the high reading was apparently the result of a "weird sensor" and not to worry.

Earlier during the spacewalk, in which Stott and fellow astronaut Danny Olivas removed an outside ammonia tank to be packed back to Earth, Olivas reported fraying on the index finger of his right glove. NASA said the fraying was minor and gave a go for the rest of the spacewalk.

To add to the day's minor annoyances, Mission Control informed the spacewalkers that they would lose communications for about 30 minutes due to the temporary loss of one of the Tracking and Data Relay Satellites. NASA blamed a thunderstorm at a satellite relay station in Guam.

Despite the glitches, Stott and Olivas completed all of their objectives during the 6-hour spacewalk. They successfully freed the 1,300-pound ammonia tank so one of the ISS' robotic arms could grasp it and place it in Discovery's cargo hold. A new, fully loaded tank will be installed during the second scheduled spacewalk, on Sept. 3.

The Discovery's payload includes the MSRR-1 (Materials Science Research Rack-1), the MELFI (Minus Eighty-Degree Laboratory Freezer for ISS) and the FIR (Fluids Integration Rack).

MSRR-1 will be used for basic materials research related to metals, alloys, polymers, semiconductors, ceramics, crystals and glasses in the microgravity environment. MELFI will be used for long-term storage of experiment samples that are to be returned to Earth for detailed analysis. The FIR is a fluid physics research facility designed to host investigations in areas such as colloids, gels, bubbles, wetting and capillary action, and phase changes, including boiling and cooling.

Discovery's cargo bay also includes the COLBERT (Combined Operational Load-Bearing External Resistance Treadmill), an exercise device named after comedian Stephen Colbert. Equipment and science racks for the orbiting laboratory are riding inside the Leonardo cargo module, which is secured tightly inside Discovery's payload bay. The module will be lifted out of Discovery and locked onto the station so the crew can transfer the gear efficiently.

The crews aboard Discovery and the ISS will continue to transfer items between the spacecrafts, install experiment racks and prepare for the Sept. 3 spacewalk, in addition to conducting media interviews.