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Mars Reconnaissance Craft begins adjusting orbit MISSION STATUS REPORT Posted: March 31, 2006 NASA's Mars Reconnaissance Orbiter yesterday began a crucial six-month campaign to gradually shrink its orbit into the best geometry for the mission's science work. Three weeks after successfully entering orbit around Mars, the spacecraft is in a phase called "aerobraking." This process uses friction with the tenuous upper atmosphere to transform a very elongated 35-hour orbit to the nearly circular two-hour orbit needed for the mission's science observations.
On Thursday, Mars Reconnaissance Orbiter fired its intermediate thrusters for 58 seconds at the far point of the orbit. That maneuver lowered its altitude to 333 kilometers (207 miles) when the spacecraft next passed the near point of its orbit, at 6:46 a.m. Pacific time today (9:46 a.m. Eastern Time). "We're not low enough to touch Mars' atmosphere yet, but we'll get to that point next week," said Dr. Daniel Kubitschek of NASA's Jet Propulsion Laboratory, Pasadena, Calif., deputy leader for the aerobraking phase of the mission. The phase includes about 550 dips into the atmosphere, each carefully planned for the desired amount of braking. At first, the dips will be more than 30 hours apart. By August, there will be four per day. "We have to be sure we don't dive too deep, because that could overheat parts of the orbiter," Kubitschek said. "The biggest challenge is the variability of the atmosphere." Readings from accelerometers during the passes through the atmosphere are one way the spacecraft can provide information about upward swelling of the atmosphere due to heating. The Mars Climate Sounder instrument also has the capability to monitor changes in temperature that would affect the atmosphere's thickness. "We demonstrated that we're ready to support aerobraking, should we be needed," JPL's Dr. Daniel McCleese, principal investigator for the Mars Climate Sounder, said of new test observations. observations.
Using aerobraking to get the spacecraft's orbit to the desired shape, instead of doing the whole job with thruster firings, reduces how much fuel a spacecraft needs to carry when launched from Earth. "It allows you to fly more science payload to Mars instead of more fuel," Kubitschek said. Once in its science orbit, Mars Reconnaissance Orbiter will return more data about the planet than all previous Mars missions combined. The data will help researchers decipher the processes of change on the planet. It will also aid future missions to the surface of Mars by examining potential landing sites and providing a high-data-rate communications relay. JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. |
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Full coverage of the Expedition 13 crew's launch aboard a Russian Soyuz spacecraft to begin a six-month mission aboard the International Space Station.
External cameras on the International Space Station captured this incredible footage of the March 29 solar eclipse. The station flew through the eclipse over the Middle East as the moon passed in front of the sun and cast its shadow on the Earth.
A total solar eclipse occurred March 29. This video from Side, Turkey shows the period of totality when the moon slid between the Earth and Sun. The eclipse revealed the Sun's glowing outer halo of million-degree gas, called the solar corona.
In early March, NASA cancelled its Dawn mission built to orbit two of the solar system's largest asteroids using ion engine propulsion. Technical problems and cost overruns were blamed. But in this news conference from March 27, agency officials announce NASA's decision to reverse the cancellation and restart the mission.
Lockheed Martin holds this news conference in Houston on March 24 to announced that it is partnering with the State of Texas to locate the Crew Exploration Vehicle (CEV) program office in Houston, as well as systems engineering, software development and qualification testing, if the corporation wins the NASA contract to build the next generation spacecraft for NASA.
As the Expedition 12 mission aboard the International Space Station winds down, officials managing the flight from Mission Control in Houston hold this retrospective briefing to talk about the highs and lows, the science, the spacewalks and everything in between.
