NASA's Mercury Spacecraft Gets a Life 'Boost'

Engineers have figured out a way to buy some time for NASA’s Mercury-orbiting MESSENGER spacecraft, which was due to end its four-year mission with a suicidal plunge into the innermost planet in March.

Launched in 2004, MESSENGER — an acronym for Mercury Surface, Space Environment, Geochemistry and Ranging — is about out of hydrazine fuel for its steering thrusters. The spacecraft became the first to put itself into orbit around Mercury in March 2011.

It’s already flying quite low. Engineers estimate its altitude will be just 15 miles above the surface on Jan 21. But on that day, despite its empty gas tan, MESSENGER will attempt a reboost. Engineers instead devised a maneuver using leftover helium from the system that keeps the propulsion system pressurized.

“To my knowledge this is the first time that helium pressurant has been intentionally used as a cold-gas propellant through hydrazine thrusters,” MESSENGER lead propulsion engineer Stewart Bushman, with Johns Hopkins University Applied Research Laboratory, said in a statement.

With its low mass, helium “doesn’t get you much bang for your buck,” he added.

But the boost should buy scientists about another month of time to learn about variations in Mercury’s internal magnetic field and study water ice inside craters in the planet’s northern latitudes.

From Discovery News