Featured Research

from universities, journals, and other organizations

Global Surveyor's Orbit Raised While Solar Panel Is Analyzed

Date:
October 15, 1997
Source:
National Aeronautics And Space Administration
Summary:
The lowest point of Mars Global Surveyor's aerobraking orbit has been raised temporarily, and aerobraking has been suspended while the flight team analyzes data to understand why one of the spacecraft's two solar panels, which had not fully deployed, exhibited unexpected motion during a recent dip through the upper Martian atmosphere.

The lowest point of Mars Global Surveyor's aerobraking orbit has been raised temporarily, and aerobraking has been suspended while the flight team analyzes data to understand why one of the spacecraft's two solar panels, which had not fully deployed, exhibited unexpected motion during a recent dip through the upper Martian atmosphere.

The spacecraft's current 35-hour orbit around Mars, which was taking it down to 75 miles (121 kilometers) above the Martian surface during each of its closest passes over the planet, has been raised to 105 miles (170 kilometers). The orbit was raised Oct. 12 by the operations team at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA, and Lockheed Martin Astronautics, Denver, CO, by performing a brief, 5.15-mile-per-hour (2.3-meter-per-second) propulsive burn at the farthest point of the spacecraft's orbit around Mars. The panel's performance has had no effect on spacecraft power.

"We're taking a hiatus from aerobraking for the next few weeks while we study data to try to model and understand the apparent deflection of the solar panel that never fully deployed and latched in place after launch," said Glenn E. Cunningham, Mars Global Surveyor project manager at JPL. "This delay in the aerobraking process will probably change the spacecraft's final mapping orbit from the originally planned 2 p.m. local Mars time passage over the planet's equator to another time, and we are studying several other orbits that will give us nearly the same quality of science results."

Preliminary data from the panel indicate that it has moved past what would have been its fully deployed and latched position, Cunningham said. In addition, the panel has shown some movement, rather than maintaining its rigid position during aerobraking. These changes occurred during the spacecraft's fifteenth close approach to Mars, on Oct. 6, when the density of the Martianatmosphere doubled unexpectedly.

During the next few weeks, the Mars Global Surveyor flight team will leave the spacecraft's orbit in the current, 35-hour revolution around Mars, which will not take the spacecraft through the upper atmosphere of Mars, while they analyze data and simulate conditions in the Martian atmosphere to understand the behavior of the solar panel. This hiatus also means the spacecraft's solar panels will not be reconfigured for each close pass over Mars, but will remain in the normal cruise position.

"We can't yet explain what has happened," Cunningham said. "We saw the unlatched panel move past the latched-up position, and it remains past that point now. By raising the spacecraft's orbit above the upper atmosphere, the panel should not shift further because it will not be exposed to the aerodynamic forces of the Martian atmosphere."

Several other mapping orbits are available to Mars Global Surveyor to carry out its science objectives. The flight team will explore alternatives in the next few weeks to accomplish the lowest orbit possible and achieve a "sun-synchronous" orbit that will allow Global Surveyor to fly over the Martian equator at the same local solar time each orbit. These sun-synchronous orbits are designed so that the spacecraft's instruments always see Mars at the same lighting angle on every pass over the surface.

"As we step back from aggressive aerobraking temporarily, we will have the opportunity to study the situation until we fully understand it. We will take advantage of this opportunity to return some spectacular data from the camera and laser altimeter," Cunningham said. "The thermal emission spectrometer and magnetometer/electron reflectometer also will continue to collect data while we remain in this holding pattern."

The Mars Global Surveyor atmospheric advisory group reported that the Martian atmosphere has more than doubled in thickness in the last week. Global Surveyor is designed to withstand more than a 50 percent increase in atmospheric density, but began showing movement in the solar panel last week, during the fifteenth close approach on Oct. 6.

Additional information about the Mars Global Surveyor mission is available on the World Wide Web by accessing JPL's Mars news site at URL:

http://www.jpl.nasa.gov/marsnews

or the Global Surveyor project home page at URL:

http://mars.jpl.nasa.gov

Mars Global Surveyor is part of a sustained program of Mars exploration, known as the Mars Surveyor Program. The mission is managed by JPL for NASA's Office of Space Science, Washington, DC. JPL's industrial partner is Lockheed Martin Astronautics, Denver, CO, which developed and operates the spacecraft. JPL is a division of the California Institute of Technology, Pasadena, CA.


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. "Global Surveyor's Orbit Raised While Solar Panel Is Analyzed." ScienceDaily. ScienceDaily, 15 October 1997. <www.sciencedaily.com/releases/1997/10/971015055533.htm>.
National Aeronautics And Space Administration. (1997, October 15). Global Surveyor's Orbit Raised While Solar Panel Is Analyzed. ScienceDaily. Retrieved August 2, 2014 from www.sciencedaily.com/releases/1997/10/971015055533.htm
National Aeronautics And Space Administration. "Global Surveyor's Orbit Raised While Solar Panel Is Analyzed." ScienceDaily. www.sciencedaily.com/releases/1997/10/971015055533.htm (accessed August 2, 2014).

Share This




More Space & Time News

Saturday, August 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Study Says The Moon Was Deformed Early In Its History

New Study Says The Moon Was Deformed Early In Its History

Newsy (July 31, 2014) Scientists say when the moon was young, it was deformed by the Earth's gravitational pull, which gave it a lemon-like shape. Video provided by Newsy
Powered by NewsLook.com
Supply Ship Takes Off for International Space Station

Supply Ship Takes Off for International Space Station

AFP (July 30, 2014) The European Space Agency's fifth Automated Transfer Vehicle (ATV-5) is takes off to the International Space Station on an Ariane 5 rocket from French Guiana. Duration: 00:34 Video provided by AFP
Powered by NewsLook.com
Raw: Rocket Launches Into Space With Cargo Ship

Raw: Rocket Launches Into Space With Cargo Ship

AP (July 30, 2014) Arianespace launched a rocket Tuesday from French Guiana carrying a robotic cargo ship to deliver provisions to the International Space Station. (July 30) Video provided by AP
Powered by NewsLook.com
In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) Video provided by AP
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