NASA has beefed up a process of traffic monitoring, communication and maneuver planning to ensure that Mars orbiters do not approach each other too closely. Last year’s addition of two new spacecraft orbiting Mars brought the census of active Mars orbiters to five, the most ever… The newly enhanced collision-avoidance process also tracks the approximate location of NASA’s Mars Global Surveyor, a 1997 orbiter that is no longer working.
[MAVEN] flies an elongated orbit, sometimes farther from Mars than NASA’s other orbiters and sometimes closer to Mars, so it crosses altitudes occupied by those orbiters. For safety, NASA also monitors positions of ESA’s and India’s orbiters, which both fly elongated orbits.
“Previously, collision avoidance was coordinated between the Odyssey and MRO navigation teams,” said Robert Shotwell, Mars Program chief engineer at NASA’s Jet Propulsion Laboratory, Pasadena, California. “There was less of a possibility of an issue. MAVEN’s highly elliptical orbit, crossing the altitudes of other orbits, changes the probability that someone will need to do a collision-avoidance maneuver. We track all the orbiters much more closely now. There’s still a low probability of needing a maneuver, but it’s something we need to manage.” [More at link]