Image

NASA’s planet-hunting space telescope suffers critical failure

July 9, 2013
NASA says two of the Kepler space telescope’s four gyroscopic reaction wheels have failed, making it inoperable for its mission — imaging planets in other solar systems. The reaction wheels let Kepler precisely hold position, which is critical for the long exposures the satellite’s optics need to gather clear images from outside our solar system.

NASA says two of the Kepler space telescope’s four gyroscopic reaction wheels have failed, making it inoperable for its mission — imaging planets in other solar systems. The reaction wheels let Kepler precisely hold position, which is critical for the long exposures the satellite’s optics need to gather clear images from outside our solar system.

Before it failed, Kepler would detect planets by monitoring how the light from some distant stars varied over time as planets revolved about them.

One reaction wheel failed last year, but it was a redundant assembly, and the satellite could function using three wheels. But then a second wheel failed in May, a problem not entirely unexpected, according to NASA administrator John Grunsfeld. “We have some history with wheels by this manufacturer, that they have a limited lifetime,” he explains.

After the second failure, NASA engineers started using onboard thrusters to keep Kepler in the right position and orientated so the solar panels faced the Sun. When they then tried to give control back to the reaction wheels and halt the spinning telescope, three wheels responded properly. But the fourth remained at full torque, a clear sign the wheel has an internal failure. Engineers switched back to thruster control, confident there will be enough fuel to last several months. And if NASA puts the spacecraft in “rest” mode, it could remain on station for several years while engineers decide what to do with it.

Fortunately, Kepler has completed its planned 3.5‑year mission since being launched in March of 2009. It has already found 2,165 eclipsing binary stars, 2,740 possible planets, and 132 definite planets. Many of these newly found planets appear to be Earth-sized and within their star’s habitable zone, where water could exist in liquid form. Plus, there is still a year-and-a-half-worth of data still in the pipeline that scientists have yet to examine. So Kepler will likely be responsible for future planetary discoveries despite being out of action.

Resources: NASA, More on NASA’s Kepler

Sponsored Recommendations

The entire spectrum of drive technology

June 5, 2024
Read exciting stories about all aspects of maxon drive technology in our magazine.

MONITORING RELAYS — TYPES AND APPLICATIONS

May 15, 2024
Production equipment is expensive and needs to be protected against input abnormalities such as voltage, current, frequency, and phase to stay online and in operation for the ...

Solenoid Valve Mechanics: Understanding Force Balance Equations

May 13, 2024
When evaluating a solenoid valve for a particular application, it is important to ensure that the valve can both remain in state and transition between its de-energized and fully...

Solenoid Valve Basics: What They Are, What They Do, and How They Work

May 13, 2024
A solenoid valve is an electromechanical device used to control the flow of a liquid or gas. It is comprised of two features: a solenoid and a valve. The solenoid is an electric...

Voice your opinion!

To join the conversation, and become an exclusive member of Machine Design, create an account today!