Featured Research

from universities, journals, and other organizations

Spacewalking Astronauts Replace Hubble's Faulty Gyroscopes

Date:
December 23, 1999
Source:
NASA's Johnson Space Center
Summary:
Discovery astronauts completed the two highest priority tasks of their Hubble Space Telescope servicing Wednesday with a space walk that was the second longest in history. Astronauts Steve Smith and John Grunsfeld installed six new gyroscopes and six Voltage/Temperature Improvement Kits in the telescope during their 8 hour, 15 minute spacewalk.

Discovery astronauts completed the two highest priority tasks of their Hubble Space Telescope servicing Wednesday with a space walk that was the second longest in history. Astronauts Steve Smith and John Grunsfeld installed six new gyroscopes and six Voltage/Temperature Improvement Kits in the telescope during their 8 hour, 15 minute spacewalk.

Working deliberately, Smith and Grunsfeld replaced three Rate Sensor Units, each containing two gyroscopes. Four of Hubble’s gyroscopes had failed, making the telescope unable to point itself precisely enough to do science since Nov. 13. At least three operable gyroscopes are needed to point the telescope with the accuracy required to track its astronomical targets.

The spacewalkers also installed Voltage/Temperature Improvement Kits on wiring from Hubble’s solar arrays to each of its six batteries. The kits are designed to improve control of the charging of the space telescope’s 10-year-old batteries.

With Hubble latched upright in the payload bay, Smith and Grunsfeld completed all major tasks scheduled for the first of three spacewalks on three consecutive days. A few minor objectives, including applying lubricant to the door of one of the telescope’s bays and taking close-up photos of the Voltage/Temperature Improvement Kits, were left undone. Flight and telescope controllers decided to cancel the photography job and schedule the 10-minute lubrication job for Thursday’s space walk. The duration of the spacewalk was second only to the 8 hour, 29 minute space walk from Endeavour on STS-49 in May 1992.

A few minor problems helped account for the length of the space walk. One of the old gyroscope-containing Rate Sensor Units was a tight fit in the box designed to protect it on its return to Earth, though eventually it was placed inside and the lid closed. Another involved opening valves and removing caps on the Near Infrared Camera and Multi-Object Spectrometer, in preparation for restoring it to operation during the next Hubble Servicing mission. That task too eventually was completed.

All in all flight and telescope controllers were delighted with the accomplishments of the day.

Major tasks on Thursday's space walk by Michael Foale and Claude Nicollier include replacement of Hubble’s outmoded DF-224 computer with a more modern unit 20 times faster and with six times the memory. They also will replace one of Hubble’s three fine guidance sensors, used to precisely point the telescope and gather scientific data. The astronauts also may perform “get-ahead tasks,” some first scheduled for a fourth space walk. That space walk was cancelled because of delays in Discovery’s launch. Discovery remains in excellent condition, in an orbit with a high point of 380 statute miles and a low point of 369 miles. The next status report will be issued at 11 a.m. or as events warrant.


Story Source:

The above story is based on materials provided by NASA's Johnson Space Center. Note: Materials may be edited for content and length.


Cite This Page:

NASA's Johnson Space Center. "Spacewalking Astronauts Replace Hubble's Faulty Gyroscopes." ScienceDaily. ScienceDaily, 23 December 1999. <www.sciencedaily.com/releases/1999/12/991223012033.htm>.
NASA's Johnson Space Center. (1999, December 23). Spacewalking Astronauts Replace Hubble's Faulty Gyroscopes. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/1999/12/991223012033.htm
NASA's Johnson Space Center. "Spacewalking Astronauts Replace Hubble's Faulty Gyroscopes." ScienceDaily. www.sciencedaily.com/releases/1999/12/991223012033.htm (accessed September 20, 2014).

Share This



More Space & Time News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

MIT BioSuit A New Take On Traditional Spacesuits

MIT BioSuit A New Take On Traditional Spacesuits

Newsy (Sep. 19, 2014) The MIT BioSuit could be an alternative to big, bulky traditional spacesuits, but the concept needs some work. Video provided by Newsy
Powered by NewsLook.com
Boeing, SpaceX to Send Astronauts to Space Station

Boeing, SpaceX to Send Astronauts to Space Station

AFP (Sep. 17, 2014) NASA selected Boeing and SpaceX on Tuesday to build America's next spacecraft to carry astronauts to the International Space Station (ISS) by 2017, opening the way to a new chapter in human spaceflight. Duration: 01:13 Video provided by AFP
Powered by NewsLook.com
East Coast Treated To Rare Meteor Sighting

East Coast Treated To Rare Meteor Sighting

Newsy (Sep. 16, 2014) Numerous residents along the East Coast reported seeing a bright meteor flash through the sky Sunday night. Video provided by Newsy
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins