Featured Research

from universities, journals, and other organizations

Wide-Field Infrared Explorer Runs Out Of Hydrogen, Ending Spacecraft's Scientific Mission

Date:
March 9, 1999
Source:
National Aeronautics And Space Administration
Summary:
Ground controllers are slowly gaining control of NASA's Wide-Field Infrared Explorer (WIRE), but the entire supply of frozen hydrogen needed to cool its primary scientific instrument has been released into space, ending the scientific mission of the spacecraft. Spacecraft controllers believe the primary telescope cover was released about three days earlier than planned. As a result sunlight began to fall on the instrument's cryostat, a container of frozen hydrogen designed to cool the instrument.

Ground controllers are slowly gaining control of NASA's Wide-Field Infrared Explorer (WIRE), but the entire supply of frozen hydrogen needed to cool its primary scientific instrument has been released into space, ending the scientific mission of the spacecraft.

"We are very disappointed at the loss of WIRE's science program," said Dr. Ed Weiler, NASA's Associate Administrator for Space Science at NASA Headquarters, Washington, DC. "We are establishing a formal anomaly investigation board to find out what happened, which will help us to plan future missions. I'm confident that many of the scientific goals can be accomplished by upcoming missions such as the Space Infrared Telescope Facility, so it will be science delayed rather than science lost."

Spacecraft controllers believe the primary telescope cover was released about three days earlier than planned. As a result sunlight began to fall on the instrument's cryostat, a container of frozen hydrogen designed to cool the instrument. The hydrogen then warmed up and vented into space at a much higher rate than it was designed to do, causing the spacecraft to spin. Controllers do not know what specifically caused the cover to be released.

WIRE's primary instrument is a 30-centimeter aperture (12.5-inch) Cassegrain telescope enclosed inside a solid hydrogen cryostat. The cryostat was designed to cool the telescope's inner workings to minus-430 degrees F -- cold enough so that the telescope's own heat emissions would not mask the infrared light that it is trying to detect in space.

By early Saturday, the spacecraft's rate of spin had stabilized at about 60 revolutions per minute, giving controllers hope they could start the painstaking process of regaining control of the 563-pound spacecraft. On Saturday, ground controllers developed and uploaded a new computer program to WIRE that began imparting small, countering forces using the satellite's onboard magnetic attitude control system to gently slow the spacecraft's spin.

Controllers have been successfully using this approach to slowly regain control of the spacecraft and reduce the spin rate approximately 3 degrees per second per orbit. WIRE is now rotating about 250 degrees per second. The objective is to reduce the spin rate sufficiently that the onboard system will take over and provide full attitude control. Controllers are hopeful this will be accomplished by the end of this week.

"The spacecraft was never designed to be controlled in this manner," said Jim Watzin, Small Explorer Project Manager, "so it's slow, tedious work. I'm confident by week's end we will have WIRE in a stable configuration, available for any analysis deemed appropriate."

WIRE was launched March 4 at 9:57 p.m. EST from Vandenberg Air Force Base, CA. When the spacecraft made its second pass over one of the WIRE tracking stations, ground controllers determined that WIRE was spinning instead of maintaining a stable position in orbit, and temperatures for the cryostat and the instrument were warmer than expected.

After the anomaly investigation board completes its work with WIRE, engineers plan to use the spacecraft as an engineering testbed to evaluate advanced attitude control systems, communications, and data handling and operations.


Story Source:

The above story is based on materials provided by National Aeronautics And Space Administration. Note: Materials may be edited for content and length.


Cite This Page:

National Aeronautics And Space Administration. "Wide-Field Infrared Explorer Runs Out Of Hydrogen, Ending Spacecraft's Scientific Mission." ScienceDaily. ScienceDaily, 9 March 1999. <www.sciencedaily.com/releases/1999/03/990309063441.htm>.
National Aeronautics And Space Administration. (1999, March 9). Wide-Field Infrared Explorer Runs Out Of Hydrogen, Ending Spacecraft's Scientific Mission. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/1999/03/990309063441.htm
National Aeronautics And Space Administration. "Wide-Field Infrared Explorer Runs Out Of Hydrogen, Ending Spacecraft's Scientific Mission." ScienceDaily. www.sciencedaily.com/releases/1999/03/990309063441.htm (accessed October 23, 2014).

Share This



More Space & Time News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Russian Cosmonauts Kick Off Final Spacewalk of 2014

Russian Cosmonauts Kick Off Final Spacewalk of 2014

Reuters - US Online Video (Oct. 22, 2014) — Russian cosmonauts Maxim Suraev and Alexander Samokutyaev step outside the International Space Station to perform work on the exterior of the station's Russian module. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
Comet Siding Spring Grazes Mars' Atmosphere

Comet Siding Spring Grazes Mars' Atmosphere

Newsy (Oct. 19, 2014) — A comet from the farthest reaches of the solar system passed extremely close to Mars this weekend, giving astronomers a rare opportunity to study it. Video provided by Newsy
Powered by NewsLook.com
Latin America Launches Communications Satellite

Latin America Launches Communications Satellite

AFP (Oct. 17, 2014) — Argentina launches a home-built satellite, a first for Latin America. It will ride a French-made Ariane 5 rocket into orbit, and will provide cell phone, digital TV, Internet and data services to the lower half of South America. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
This Week @ NASA, October 17, 2014

This Week @ NASA, October 17, 2014

NASA (Oct. 17, 2014) — Power spacewalk, MAVEN’s “First Light”, Hubble finds extremely distant galaxy and more... Video provided by NASA
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:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

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