July 19, 2013
NASA Attempts ‘Hail Mary’ To Recover Kepler Space Telescope
Lee Rannals for redOrbit.com - Your Universe Online
NASA is launching a last-ditch "Hail Mary" attempt to try and bring its Kepler mission back to life.
The US space agency said that over the next week, the Kepler team will attempt tests to explore recovery of the spacecraft's reaction wheels, which failed back in May. Kepler needs its reaction wheels to help stabilize it as it searches for exoplanets around distant stars.
The team will be continuing its efforts to conduct tests on reaction wheel 2 on Monday or Thursday next week. NASA said results of the wheel performance tests will be announced later this month and an update will follow.
Kepler had reaction wheel two fail in July 2012 and wheel four a couple of months ago. The spacecraft requires three reaction wheels to control precision pointing and to resume data collections for its search. Kepler's photo-detector registers more than 100,000 stars at a time, and it must remain extremely steady so that the stars do not wander across the optics.
"The team is grateful for the outpouring of well wishes and support," said Roger Hunter, Project Manager of the Kepler mission.
"There are two possible ways to salvage the spacecraft that I"m aware of," Hubbard said. "One is that they could try turning back on the reaction wheel that they shut off a year ago. It was putting metal on metal, and the friction was interfering with its operation, so you could see if the lubricant that is in there, having sat quietly, has redistributed itself, and maybe it will work."
He mentioned that the other plan would be to use thrusters and the solar pressure exerted on the solar panels to try and act as a third reaction wheel and provide additional pointing stability.
"I haven't investigated it, but my impression is that it would require sending a lot more operational commands to the spacecraft," the professor added.
Although the spacecraft has been defunct since May, it has collected so much data that scientists could be announcing new discoveries from the mission for years to come. Kepler was able to complete its primary three-and-a-half-year mission. So far, scientists using Kepler have found hundreds of Earth-sized planet candidates orbiting the habitable zone around stars, and more than 2,300 planet candidates have been identified.
Astronomers published a study back in June that used Kepler data. This team said they found that many of the stars and planets discovered are larger than thought, and a quarter of them are 35 percent bigger.