REAL LIFE NEWS: MARS ORBIT GETTING CROWDED
by Hazed
Two of the spaceships orbiting Mars had a near miss a few months ago, prompting NASA to tighten up its traffic control measures.
The Mars Reconnaissance Orbiter and the MAVEN, both NASA ships, came within two kilometres of each other in early January. There are now five live orbiters around Mars (those two plus NASA’s Mars Odyssey, India’s Mars Orbiter Mission and the ESA’s Mars Express) plus one that is no longer operating but is still in orbit, NASA’S Mars Global Surveyor. Many of their orbits intersect – click the source link below to see an image showing how their orbits criss-cross each other.
NASA’s new monitoring regime follows all orbiters non-stop, checking for potential collisions, and where it looks like two crafts are going to get close they send out automated messages to the teams running the missions, so they can prepare for collision-avoidance manoeuvres. This monitoring is not as easy as it sounds, because as NASA says, “The amount of uncertainty in the predicted location of a Mars orbiter a few days ahead is more than a mile (more than two kilometers).”
“Calculating projections for weeks ahead multiplies the uncertainty to dozens of miles, or kilometers. In most cases when a collision cannot be ruled out from projections two weeks ahead, improved precision in the forecasting as the date gets closer will rule out a collision with no need for avoidance action.”
It’s a problem that can only get worse over the coming years, as more countries join the space race and send orbiters to Mars.
Source: http://www.theregister.co.uk/2015/05/05/mars_needs_traffic_cop_to_stop_probe_prangs_says_nasa/