Dawn Finishes Mars Phase

February 27, 2009
This image was taken near the point of closest approach to Mars on Feb. 17, 2009, during Dawn's gravity assist flyby. Image credit: NASA/JPL/MPS/DLR/IDA, and the Dawn Flight Team

(PhysOrg.com) -- With Mars disappearing in its metaphorical rearview mirror, NASA's Dawn spacecraft's next stop is the asteroid belt and the giant asteroid Vesta. Dawn got as close as 549 kilometers (341 miles) to the Red Planet during its Tuesday, Feb. 17, flyby.

Dawn's navigators placed the spacecraft on a close approach trajectory with Mars so the planet's gravitational influence would provide a kick to the spacecraft's velocity. If Dawn had to perform these orbital adjustments on its own, with no Mars gravitational deflection, the spacecraft would have had to fire up its engines and change velocity by more than 9,330 kilometers per hour (5,800 miles per hour).

The achieved goal of the flyby was to obtain this orbital pick-me-up, making possible its voyage to asteroid Vesta and, later, the dwarf planet Ceres. But Dawn's science teams used this massive target of opportunity to also perform calibrations of some of the scientific instruments. Calibration images were taken by Dawn's framing camera, and the Gamma Ray and Neutron Detector also observed Mars for calibration. These data will be compared to similar observations taken by spacecraft orbiting Mars.

Further observations were planned during the flyby, but fault detection software canceled the data collection and put the spacecraft into safe mode, a limited-activity precautionary status. The cause was determined to be an inappropriate software response to an expected temporary loss of valid data from the spacecraft's star tracker in the vicinity of Mars, and engineers were able to restore the spacecraft to normal operations within 48 hours.

While the spacecraft will never be back in the vicinity of Mars again, the Dawn team is using the event to fine-tune its software.

The spacecraft has already traveled about 1.8 million kilometers (1.1 million miles) beyond Mars. It has 30 months and 1.8 billion kilometers (1.1 billion miles) to go before its rendezvous with Vesta in 2011.

Dawn's 4.8-billion-kilometer (3-billion-mile) odyssey includes orbiting Vesta and the dwarf planet Ceres in 2015. These two giants of the asteroid belt have been witness to much of our solar system's history. By using Dawn's instruments to study both objects for several months, scientists can more accurately compare and contrast the two. Dawn's science instrument suite will measure geology, elemental and mineral composition, shape, surface topography, geomorphology and tectonic history, and will also seek water-bearing minerals. In addition, the Dawn spacecraft's orbital characteristics around Vesta and Ceres will be used to measure the celestial bodies' masses and gravity fields.

Provided by NASA

Explore further: Photonics dawning as the communications light for evolving NASA missions

Related Stories

NASA Spacecraft Falling For Mars

February 13, 2009

(PhysOrg.com) -- Launched in September of 2007, and propelled by any one of a trio of hyper-efficient ion engines, NASA's Dawn spacecraft passed the orbit of Mars last summer. At that time, the asteroid belt (where Dawn's ...

Dawn Glides Into New Year

November 21, 2008

(PhysOrg.com) -- NASA's Dawn spacecraft shut down its ion propulsion system today as scheduled. The spacecraft is now gliding toward a Mars flyby in February of next year.

Mars longevity champion launched 15 years ago

April 6, 2016

The NASA spacecraft that was launched 15 years ago this week carried the name 2001 Mars Odyssey and the hopes for reviving a stymied program of exploring the Red Planet.

Dawn spacecraft begins approach to dwarf planet Ceres

December 30, 2014

(Phys.org)—NASA's Dawn spacecraft has entered an approach phase in which it will continue to close in on Ceres, a Texas-sized dwarf planet never before visited by a spacecraft. Dawn launched in 2007 and is scheduled to ...

The revolutionary ion engine that took spacecraft to Ceres

March 9, 2015

The NASA spacecraft Dawn has spent more than seven years travelling across the Solar System to intercept the asteroid Vesta and the dwarf planet Ceres. Now in orbit around Ceres, the probe has returned the first images and ...

Recommended for you

Hubble catches a transformation in the Virgo constellation

December 9, 2016

The constellation of Virgo (The Virgin) is especially rich in galaxies, due in part to the presence of a massive and gravitationally-bound collection of over 1300 galaxies called the Virgo Cluster. One particular member of ...

Scientists sweep stodgy stature from Saturn's C ring

December 9, 2016

As a cosmic dust magnet, Saturn's C ring gives away its youth. Once thought formed in an older, primordial era, the ring may be but a mere babe – less than 100 million years old, according to Cornell-led astronomers in ...

Khatyrka meteorite found to have third quasicrystal

December 9, 2016

(Phys.org)—A small team of researchers from the U.S. and Italy has found evidence of a naturally formed quasicrystal in a sample obtained from the Khatyrka meteorite. In their paper published in the journal Scientific Reports, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.