Headlines > News > No Fourth Spacewalk Needed

No Fourth Spacewalk Needed

Published by Klaus Schmidt on Thu Apr 15, 2010 8:54 am via: NASA
Share
More share options
Tools
Tags

(NASA) – Space shuttle Discovery’s seven-member STS-131 crew will begin its day by unloading the last transfer items in the Leonardo Multi-Purpose Logistics Module and then closing the hatches between it and the Harmony node in preparation for its return to the shuttle’s payload bay.

Overnight International Space Station and Space Shuttle mission managers agreed there is no need for a fourth spacewalk to replace the nitrogen tank assembly that has a jammed valve. Station ground teams have determined the station can operate for an extended period of time in the current configuration. The team is continuing to troubleshoot the stuck valve and is looking at options for future replacement of the nitrogen tank assembly should that be necessary.

STS-131 Commander Alan Poindexter and Mission Specialist Naoko Yamazaki work with lithium hydroxide (LiOH) canisters on space shuttle Discovery's middeck while docked with the International Space Station. Image credit: NASA

STS-131 Commander Alan Poindexter and Mission Specialist Naoko Yamazaki work with lithium hydroxide (LiOH) canisters on space shuttle Discovery's middeck while docked with the International Space Station. Image credit: NASA

The stuck valve is in a nitrogen tank assembly needed to pressurize a new ammonia tank installed on the station during this mission’s three spacewalks. It keeps ammonia circulating through radiators that dissipate the heat generated by the station’s electronic systems.

Ground teams were concerned a high beta angle would cause the ammonia in the new tank assembly to expand and exceed the capacity of the radiators without the nitrogen to keep the system circulating. The beta angle – the angle between the sun and the plane of the orbit – is increasing, creating higher temperatures.

At 8:41 a.m. EDT, Mission Specialists Naoko Yamazaki and Stephanie Wilson will use the station’s robotic arm to move Leonardo back into the shuttle’s cargo bay.

This is the seventh time Leonardo has carried supplies and equipment to the station. The next time it returns with the STS-133 crew in September it will remain berthed to the station.

No comments
Start the ball rolling by posting a comment on this article!
Leave a reply
You must be logged in to post a comment.
© 2014 The International Space Fellowship, developed by Gabitasoft Interactive. All Rights Reserved.  Privacy Policy | Terms of Use