In what could be termed as a rare event, NASA’s Mars Atmosphere and VolatileEvolutioN (MAVEN) spacecraft that orbits planet Mars avoided a head-on collision with the red planet’s moon Phobos. It managed to escape the collision after it was forced to perform a previously unplanned manoeuvre this week.
The MAVEN spacecraft has been studying Mars’ upper atmosphere, ionosphere and interactions with the sun and solar wind for more than two years.
The velocity of the spacecraft MAVEN was boosted by 0.4 metres per second after it carried out a rocket motor burn. Though the correction was small, it was enough for the MAVEN to avoid the crater-filled moon by about 2.5 minutes.
The MAVEN spacecraft has performed the collision avoidance for the first time at Mars to steer clear of Phobos. The orbits of both MAVEN and Phobos are at such difference of time that it is ensured they will not collide.
MAVEN has an elliptical orbit around Mars. It 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 (JPL) in 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, they had a high probability of colliding if no action were taken.
“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 manoeuvre flawlessly,” said MAVEN Principal Investigator Bruce Jakosky of the University of Colorado in Boulder.
(With inputs from PTI)