Ames: Kepler Nearing the End as Fuel Runs Low

[bystander]

Kepler Nearing the End as Fuel Runs Low
NASA | Ames Research Center | Kepler | 2018 Mar 14

Trailing Earth’s orbit at 94 million miles away, the Kepler space telescope has survived many potential knock-outs during its nine years in flight, from mechanical failures to being blasted by cosmic rays. At this rate, the hardy spacecraft may reach its finish line in a manner we will consider a wonderful success. With nary a gas station to be found in deep space, the spacecraft is going to run out of fuel. We expect to reach that moment within several months.

In 2013, Kepler’s primary mission ended when a second reaction wheel broke, rendering it unable to hold its gaze steady at the original field of view. The spacecraft was given a new lease on life by using the pressure of sunlight to maintain its pointing, like a kayak steering into the current. Reborn as “K2,” this extended mission requires the spacecraft to shift its field of view to new portions of the sky roughly every three months in what we refer to as a “campaign.” Initially, the Kepler team estimated that the K2 mission could conduct 10 campaigns with the remaining fuel. It turns out we were overly conservative. The mission has already completed 16 campaigns, and this month entered its 17th.

Our current estimates are that Kepler’s tank will run dry within several months -- but we’ve been surprised by its performance before! So, while we anticipate flight operations ending soon, we are prepared to continue as long as the fuel allows.

The Kepler team is planning to collect as much science data as possible in its remaining time and beam it back to Earth before the loss of the fuel-powered thrusters means that we can’t aim the spacecraft for data transfer. We even have plans to take some final calibration data with the last bit of fuel, if the opportunity presents itself. ...

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TO BUILD A FIRE by Jack London
(First published in The Century Magazine, v.76, August, 1908, 525-534)

<<There was the fire, snapping and crackling and promising life with every dancing flame. He started to untie his moccasins. They were coated with ice; the thick German socks were like sheaths of iron halfway to the knees; and the moccasin strings were like rods of steel all twisted and knotted as by some conflagration. For a moment he tugged with his numb fingers, then, realizing the folly of it, he drew his sheath-knife.

But before he could cut the strings, it happened. It was his own fault or, rather, his mistake. He should not have built the fire under the spruce tree. He should have built it in the open. But it had been easier to pull the twigs from the brush and drop them directly on the fire. Now the tree under which he had done this carried a weight of snow on its boughs. No wind had blown for weeks, and each bough was fully freighted. Each time he had pulled a twig he had communicated a slight agitation to the tree -- an imperceptible agitation, so far as he was concerned, but an agitation sufficient to bring about the disaster. High up in the tree one bough capsized its load of snow. This fell on the boughs beneath, capsizing them. This process continued, spreading out and involving the whole tree. It grew like an avalanche, and it descended without warning upon the man and the fire, and the fire was blotted out! Where it had burned was a mantle of fresh and disordered snow.>>

[BDanielMayfield]

Kepler has been one of the best missions ever executed. It managed to find thousands of exoplanets. However, due to reaction wheel failures and the noisiness of stars it fell somewhat short of its goal to find earthlike planets in earthlike orbits around sunlike stars.

Are there any plans in the works for additional (hopefully, improved) transiting exoplanet detection missions?

Bruce

[Chris Peterson]

Kepler has been one of the best missions ever executed. It managed to find thousands of exoplanets. However, due to reaction wheel failures and the noisiness of stars it fell somewhat short of its goal to find earthlike planets in earthlike orbits around sunlike stars.

Are there any plans in the works for additional (hopefully, improved) transiting exoplanet detection missions?

The TESS mission launches sometime between now and June, and should detect 1000-2000 exoplanets around nearby stars. WFIRST is still on the books, although the Toddler-in-Chief is trying to kill the funding for that mission. There are numerous ground-based instruments in use, or coming into use. So yes, lots of instrumentation remains.

(I was just out at Ames earlier this week, and ran into an old friend who's on the Kepler team. He says they're operating on the assumption that the fuel will run out in hours, not days or weeks.)

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Click to play embedded YouTube video.