The Kepler Spacecraft operates into a “safe mode” according to NASA, as engineers are trying to resume control of the Earth-size planet-hunting tool:
Controllers found Tuesday that Kepler had gone into a “safe mode” and one of the reaction wheels needed to orient the spacecraft would not spin, Associate NASA Administrator John Grunsfeld told reporters. NASA engineers are trying to figure out whether they can get the balky part back into service or whether they can resume control by another method, Grunsfeld said. ”We’re not ready to call the mission over,” he said. But at roughly 40 million miles from Earth, “Kepler is not in a place where I can go up and rescue it.” The Kepler mission has identified 132 planets beyond our solar system since its launch in 2009, leading scientists to believe that most stars in our galaxy have planets circling them. It has gone into a “safe mode” with its solar panels facing back at the sun, giving controllers intermittent communication with the craft as it spins.
The Kepler Telescope faces problems with one of its reaction wheels, which help it to keep its precision steering:
“Kepler was my North, my South, my East and West, my working week, no weekend rest, my noon, my midnight, my talks, my song; I thought Kepler would last forever: I was wrong.” So laments planet hunter Geoff Marcy, with a due nod to W. H. Auden, upon hearing the news that NASA’s Kepler space telescope is probably close to ending its search for extrasolar planets. But the pioneering telescope has been hobbled by a damaged reaction wheel, NASA announced at a press conference. These wheels help Kepler keep its orientation in space, and precision steering is crucial to the mission. The telescope has been watching some 150,000 stars near the constellation Cygnus for changes in brightness caused by a planet crossing, or transiting, its face as seen from Earth. To do this, it needs to keep the same specific pixels of its light detector trained on given stars for months at a time. Kepler started out with four reaction wheels – one to control its motion around each axis and one spare. One wheel stopped turning in July last year, leaving the telescope with no backup. In January, a second wheel began misbehaving, so mission managers gave Kepler a small break from planet hunting, in the hopes that a spot of R&R would fix the problem.
NASA’s planet-hunting Kepler telescope is broken, potentially jeopardizing the search for other worlds where life could exist outside our solar system. If engineers can’t find a fix, the failure could mean an end to the $600 million mission’s search, although the space agency wasn’t ready to call it quits Wednesday. The telescope has discovered scores of planets but only two so far are the best candidates for habitable planets. ‘‘I wouldn’t call Kepler down-and-out just yet,’’ said NASA sciences chief John Grunsfeld. NASA said the spacecraft lost the second of four wheels that control its orientation in space. With only two working wheels left, it can’t point at stars with the same precision. In orbit around the sun, 40 million miles from Earth, Kepler is too far away to send astronauts on a repair mission like the way Grunsfeld and others fixed a mirror on the Hubble Space Telescope. Over the next several weeks, engineers on the ground will try to restart Kepler’s faulty wheel or find a workaround. The telescope could be used for other purposes even if it can no longer track down planets.
More importantly, the Kepler Spacecraft mission is the first of its kind focused on finding Earth-size planets:
A faulty steering apparatus may bring an early end to NASA’s Kepler space telescope, a $600 million tool in the space agency’s quest for life elsewhere in the universe. Kepler is the first NASA mission capable of finding Earth-size planets in or near the habitable zone, the range of distance from a star where the surface temperature of an orbiting planet might be suitable for liquid water. Launched in 2009, it has discovered thousands of such planets, including a pair just 1,200 light years away. Called Kepler-62-e and Kepler-62-f, the news of their discovery came about one month ago. But yesterday, Kepler’s mission ran into trouble. Kepler is powered by four solar panels, and the spacecraft must execute a 90-degree roll every 3 months to reposition the solar panels to face the sun while keeping its eye precisely aimed. Kepler launched with four wheels to control that motion — and one of them failed last year. The space telescope was placed in “thruster-controlled safe mode” yesterday, said NASA spokesman J.D. Harrington. “Unfortunately, Kepler isn’t in a place where I can go up and rescue it,” John Grunsfeld, associate administrator, science mission directorate at NASA said during a hastily arranged press conference Wednesday afternoon.
Finally, NASA engineers have to work hard for solving the problem, as they didn’t declare the Kepler Spacecraft dead yet…