Featured Research

from universities, journals, and other organizations

Mars Science Laboratory computer issue resolved

Date:
February 13, 2012
Source:
NASA/Jet Propulsion Laboratory
Summary:
Engineers have found the root cause of a computer reset that occurred two months ago on NASA's Mars Science Laboratory and have determined how to correct it.

This artist concept features NASA's Mars Science Laboratory Curiosity rover, a mobile robot for investigating Mars' past or present ability to sustain microbial life.
Credit: NASA/JPL-Caltech

Engineers have found the root cause of a computer reset that occurred two months ago on NASA's Mars Science Laboratory and have determined how to correct it.

The fix involves changing how certain unused data-holding locations, called registers, are configured in the memory management of the type of computer chip used on the spacecraft. Billions of runs on a test computer with the modified register configuration yielded no repeat of the reset behavior. The mission team made this software change on the spacecraft's computer last week and confirmed this week that the update is successful.

The reset occurred Nov. 29, 2011, three days after launch, during use of the craft's star scanner. The cause has been identified as a previously unknown design idiosyncrasy in the memory management unit of the Mars Science Laboratory computer processor. In rare sets of circumstances unique to how this mission uses the processor, cache access errors could occur, resulting in instructions not being executed properly. This is what happened on the spacecraft on Nov. 29.

"Good detective work on understanding why the reset occurred has yielded a way to prevent it from occurring again," said Mars Science Laboratory Deputy Project Manager Richard Cook of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The successful resolution of this problem was the outcome of productive teamwork by engineers at the computer manufacturer and JPL."

The Mars-bound spacecraft performed a brief alignment activity using its star scanner and sun sensor on Jan. 26. During the alignment observations, the star scanner detected Mars.

"Our target is in view," said JPL's Steve Collins, attitude control subsystem engineer for Mars Science Laboratory's cruise from Earth to Mars.

The spacecraft began normal use of its star tracker and true celestial navigation this week after its software update.

The Mars Science Laboratory mission will use its car-size rover, Curiosity, to investigate whether the selected region on Mars inside Gale Crater has offered environmental conditions favorable for supporting microbial life and favorable for preserving clues about whether life existed. Curiosity will land on Mars on Aug. 6, 2012, Universal Time and Eastern Daylight Time (evening of Aug. 5, Pacific Daylight Time).

The spacecraft's cruise-stage solar array is producing 704 watts. The telecommunications rates are 1 kilobit per second for uplink and 800 bits per second for downlink. The spacecraft is spinning at 1.97 rotations per minute.

As of 9 a.m. PST (noon EST, or 1700 Universal Time) on Friday, Feb. 10, the spacecraft will have traveled 127 million miles (205 million kilometers) of its 352-million-mile (567-million-kilometer) flight to Mars. It will be moving at about 17,800 miles per hour (28,600 kilometers per hour) relative to Earth and at about 63,700 mph (102,500 kilometers per hour) relative to the sun.

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Science Laboratory mission for the NASA Science Mission Directorate, Washington.

More information about Curiosity is online at: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ .


Story Source:

The above story is based on materials provided by NASA/Jet Propulsion Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Jet Propulsion Laboratory. "Mars Science Laboratory computer issue resolved." ScienceDaily. ScienceDaily, 13 February 2012. <www.sciencedaily.com/releases/2012/02/120209111111.htm>.
NASA/Jet Propulsion Laboratory. (2012, February 13). Mars Science Laboratory computer issue resolved. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2012/02/120209111111.htm
NASA/Jet Propulsion Laboratory. "Mars Science Laboratory computer issue resolved." ScienceDaily. www.sciencedaily.com/releases/2012/02/120209111111.htm (accessed September 2, 2014).

Share This




More Space & Time News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: NASA Captures Solar Flare

Raw: NASA Captures Solar Flare

AP (Sep. 1, 2014) NASA reported the sun emitted a mid-level solar flare, on August 24th. NASA's Solar Dynamics Observatory captured the images of the flare, which erupted on the left side of the sun. (Sept. 1) Video provided by AP
Powered by NewsLook.com
Space Shuttle Discovery's Legacy, 30 Years Later

Space Shuttle Discovery's Legacy, 30 Years Later

Newsy (Aug. 30, 2014) The space shuttle Discovery launched for the very first time 30 years ago. Here's a look back at its legacy. Video provided by Newsy
Powered by NewsLook.com
Experiment Tests Whether Universe Is Actually A Hologram

Experiment Tests Whether Universe Is Actually A Hologram

Newsy (Aug. 27, 2014) Researchers at Fermilab are using a device called "The Holometer" to test whether our universe is actually a 2-D hologram that just seems 3-D. Video provided by Newsy
Powered by NewsLook.com
SpaceX’s Falcon 9 Rocket Explodes After Liftoff

SpaceX’s Falcon 9 Rocket Explodes After Liftoff

Newsy (Aug. 23, 2014) The private spaceflight company says it is preparing a thorough investigation into Friday's mishap. Video provided by Newsy
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