NASA orbiter steers clear of Mars moon Phobos

March 2, 2017
This artist's sketch shows MAVEN above Mars.Credits: NASA

NASA's MAVEN spacecraft performed a previously unscheduled maneuver this week to avoid a collision in the near future with Mars' moon Phobos.

The Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft has been orbiting Mars for just over two years, studying the Red Planet's , ionosphere and interactions with the sun and . On Tuesday, Feb. 28, the spacecraft carried out a rocket motor burn that boosted its velocity by 0.4 meters per second (less than 1 mile per hour). Although a small correction, it was enough that—projected to one week later when the collision would otherwise have occurred—MAVEN would miss the lumpy, crater-filled moon by about 2.5 minutes.

This is the first collision avoidance maneuver that the MAVEN spacecraft has performed at Mars to steer clear of Phobos. The orbits of both MAVEN and Phobos are known well enough that this timing difference ensures that they will not collide.

MAVEN, with an around Mars, has an orbit that crosses those of other spacecraft and the moon Phobos many times over the course of a year. When the orbits cross, the objects have the possibility of colliding if they arrive at that intersection at the same time. These scenarios are known well in advance and are carefully monitored by NASA's Jet Propulsion Laboratory in Pasadena, California, which sounded the alert regarding the possibility of a collision.

With one week's advance notice, it looked like MAVEN and Phobos had a good chance of hitting each other on Monday, March 6, arriving at their orbit crossing point within about 7 seconds of each other. Given Phobos' size (modeled for simplicity as a 30-kilometer sphere, a bit larger than the actual moon in order to be conservative), they had a high probability of colliding if no action were taken.

Said MAVEN Principal Investigator Bruce Jakosky of the University of Colorado in Boulder, "Kudos to the JPL navigation and tracking teams for watching out for possible collisions every day of the year, and to the MAVEN spacecraft team for carrying out the maneuver flawlessly."

Explore further: MAVEN observes Mars moon Phobos in the mid- and far-ultraviolet

Related Stories

Video: MAVEN set to slide into orbit around Mars

September 17, 2014

A NASA mission to Mars led by the University of Colorado Boulder is set to slide into orbit around the red planet this week after a 10-month, 442-million mile chase through the inner solar system. 

MAVEN on track to carry out its science mission

February 4, 2014

The MAVEN spacecraft and all of its science instruments have completed their initial checkout, and all of them are working as expected. This means that MAVEN is on track to carry out its full science mission as originally ...

MAVEN studies passing comet and its effects

October 21, 2014

NASA's newest orbiter at Mars, MAVEN, took precautions to avoid harm from a dust-spewing comet that flew near Mars today and is studying the flyby's effects on the Red Planet's atmosphere.

Recommended for you

Orbital mayhem around a red dwarf

December 18, 2017

In the collective imagination, planets of a solar system all circle in the equatorial plane of their star. The star also spins, and its spin axis is aligned with the spin axes of the planetary orbits, giving the impression ...

Mars and Earth may not have been early neighbors

December 18, 2017

A study published in the journal Earth and Planetary Science Letters posits that Mars formed in what today is the Asteroid Belt, roughly one and a half times as far from the sun as its current position, before migrating to ...

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.