Planet-Hunting Kepler Spacecraft Suffers Major Failure, NASA Says

[Buster's Uncle]

Planet-Hunting Kepler Spacecraft Suffers Major Failure, NASA Says
By Mike Wall | SPACE.com – 5 hrs ago...

An artist's interpretation of the Kepler observatory in space.


This chart depicts the frequencies of planets based on findings from NASA's Kepler space observatory. The results show that one in six stars has an Earth-sized planet in a tight orbit.

 
This story was updated at 5:20 p.m. EDT.

The planet-hunting days of NASA's prolific Kepler space telescope, which has discovered more than 2,700 potential alien worlds to date, may be over.

The second of Kepler's four reaction wheels — devices that allow the observatory to maintain its position in space — has failed, NASA officials announced Wednesday (May 15).

If one or both of those failed wheels cannot be brought back, the telescope likely cannot lock onto target stars precisely enough to detect orbiting planets, scientists have said. [Gallery: A World of Kepler Planets]


Staring at stars

The $600 million Kepler spacecraft spots exoplanets by flagging the tiny brightness dips caused when they pass in front of their host stars from the instrument's perspective. The mission's main goal is to determine how common Earth-like alien planets are throughout the Milky Way galaxy.

Kepler needs three functioning reaction wheels to stay locked onto its more than 150,000 target stars. The observatory had four wheels when it launched in March 2009 — three for immediate use, and one spare.

One wheel (known as number two) failed in July 2012, giving Kepler no margin for error. And now wheel number four has apparently given up the ghost as well, after showing signs of elevated friction for the past five months or so.

"This is something that we've been expecting for a while, unfortunately," NASA science chief John Grunsfeld told reporters today.

Grunsfeld is a former astronaut who flew on five space shuttle missions, including three that serviced or upgraded NASA's Hubble Space Telescope in Earth orbit. But in-space repair is not an option for Kepler, which circles the sun rather than Earth and is currently about 40 million miles (64 million kilometers) from our planet.


A new mission?

The Kepler team is not taking the wheel failures lying down. Engineers will try to recover number two and number four, perhaps by turning the wheels to power through any deterioration in their mechanisms, team members have said.

"I wouldn't call Kepler down and out just yet," Grunsfeld said.

If this and other measures don't work, however, Kepler will probably get a new mission, likely one that emphasizes scanning the heavens over its previous "point and stare" operations.

The team is already thinking about what a new scanning mode might be able to accomplish. Researchers are also trying to figure out ways to conserve fuel, so Kepler can keep operating for as long as possible if it needs to start using its thrusters to help point at targets.


Kepler's legacy

Whatever the future holds for Kepler, the mission will go down in history as an incredible success, researchers say.

While just 132 of Kepler's 2,700-odd planet candidates have been confirmed by follow-up observations to date, mission scientists estimate that more than 90 percent will end up being the real deal.

Further, the telescope's discoveries have allowed researchers to take an unprecedented, systematic look at worlds beyond our solar system — learning, for instance, that small, rocky planets are much more common throughout the Milky Way galaxy than gas giants like Saturn or Jupiter, at least in close-in orbits.

"Kepler has opened up the next set of questions in exoplanets," said Paul Hertz, astrophysics director at NASA Headquarters in Washington, D.C.

"Before we flew Kepler, we didn't know that Earth-sized planets in habitable zones were common throughout our galaxy," Hertz added. "We didn't know that virtually every star in the sky had planets around them. Now we know that."

Kepler also outlasted its prime mission life of 3.5 years; it has been working on an extended mission that takes it through at least fiscal year 2016.

While the observatory may not spot any more exoplanets from here on out, that doesn't mean the flood of Kepler discoveries will slow down anytime soon.

"We've really only sort of looked at half the dataset so far. We just haven't had the time and the processing hours to go through it all," Kepler deputy project manager Charlie Sobeck, of NASA's Ames Research Center in Moffett Field, Calif., told SPACE.com late last month.

Once Kepler stops finding planets, he added, "the scientific output of the mission would continue for at least another year or two before you would see a dropoff."

http://news.yahoo.com/planet-hunting-kepler-spacecraft-suffers-major-failure-nasa-203147459.html

They're talking about attitude gyros, yes?

[Buster's Uncle]

NASA craft's planet-hunting days may be numbered
By ALICIA CHANG | Associated Press – 2 hrs 42 mins ago...

This artist rendition provided by NASA shows the Kepler space telescope. The spacecraft lost the second of four wheels that control the telescope’s orientation in space, NASA said Wednesday, May 15, 2013. If engineers can’t find a fix, the failure means the telescope won’t be able to look for planets outside our solar system anymore. (AP Photo/NASA)

 
LOS ANGELES (AP) — 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.

Kepler was launched in 2009 in search of Earth-like planets. So far, it has confirmed 132 planets and spotted more than 2,700 potential ones. Its mission was supposed to be over by now, but last year, NASA agreed to keep Kepler running through 2016 at a cost of about $20 million a year.

Just last month, Kepler scientists announced the discovery of a distant duo that seems like ideal places for some sort of life to flourish. The other planets found by Kepler haven't fit all the criteria that would make them right for life of any kind — from microbes to man.

While ground telescopes can hunt for planets outside our solar system, Kepler is much more advanced and is the first space mission dedicated to that goal.

For the past four years, Kepler has focused its telescope on a faraway patch of the Milky Way hosting more than 150,000 stars, recording slight dips in brightness — a sign of a planet passing in front of the star.

Now "we can't point where we need to point. We can't gather data," deputy project manager Charles Sobeck told The Associated Press.

Scientists said there's a backlog of data that they still need to analyze even if Kepler stopped looking for planets.

"I think the most interesting, exciting discoveries are coming in the next two years. The mission is not over," said chief scientist William Borucki at the NASA Ames Research Center in Northern California, which manages the mission.

Scientists who have no role in the Kepler mission mourned the news. They said the latest loss means the spacecraft may not be able to determine how many Earth-size planets are in the "Goldilocks zone" where it's not too hot or too cold for water to exist in liquid form on the surface. And while they praised the data collected by Kepler so far, they said several more years of observations are needed to nail down that number.

"This is one of the saddest days in my life. A crippled Kepler may be able to do other things, but it cannot do the one thing it was designed to do," Alan Boss of the Carnegie Institution of Washington, who is not part of the Kepler team, said in an email.

In 2017, NASA plans to launch TESS — Transiting Exoplanet Survey Satellite — designed to search for planets around nearby stars.

http://news.yahoo.com/nasa-crafts-planet-hunting-days-may-numbered-011743849.html

[Unorthodox]

Sure would be nice to have a shuttle program to potentially fix things...

[Geo]

Was thinking the same thing.

[Buster's Uncle]

Can NASA's Planet-Hunting Kepler Mission Be Saved?
SPACE.comBy Mike Wall | SPACE.com – 1 hr 50 mins ago..

 
There's a chance that NASA's Kepler space telescope can recover from the malfunction that has halted its wildly successful search for alien planets, mission team members say.

The second of Kepler's four reaction wheels — devices that allow the observatory to maintain its position in space — has failed, depriving Kepler of the ability to lock precisely onto its 150,000-plus target stars, NASA officials announced Wednesday (May 15).

But mission engineers are not conceding that Kepler's planet-hunting days have come to an end, vowing to try their best to recover the failed reaction wheels over the coming weeks.

"I wouldn't call Kepler down and out just yet," NASA science chief John Grunsfeld told reporters Wednesday.


Balky reaction wheels

The Kepler spacecraft spots exoplanets by detecting the tiny brightness dips caused when they pass in front of their parent stars from the instrument's perspective.

The observatory needs three working reaction wheels to do such precision work. When Kepler launched in March 2009, it had four — three for immediate use and one spare.

One of the wheels, known as number two, failed in July 2012, giving Kepler no margin for error. And the loss this week of another one (called number four) puts an end to the spacecraft's exoplanet hunt, unless a fix can be found.

Engineers have begun considering strategies for bringing the wheels back into service. They'll likely try a light touch at times and a brute-force approach at others, officials said.

"Like with any stuck wheel that you might be familiar with on the ground, we can try jiggling it," said Kepler deputy project manager Charlie Sobeck, of NASA's Ames Research Center in Moffett Field, Calif. "We can try commanding it back and forth in both directions. We can try forcing it through whatever the resistance is that's holding it up."

It's also possible that wheel number two will spring back to life if turned on again now, rested and restored after its long break, Sobeck and others say.

"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," Scott Hubbard of Stanford University said in a statement. (Hubbard served as director of NASA Ames during much of Kepler's development and helped guide the mission.)

It will take a few weeks to put together a recovery plan, Sobeck said. It's unknown if any potential fixes will do the trick, but Kepler team members are keeping their fingers crossed.

"There is a reasonable possibility that we will be able to mitigate that problem," said mission principal investigator Bill Borucki, also of NASA Ames. "So I don't think I'd be a pessimist here."

There's no chance of sending astronauts out to service Kepler, as was done five times with NASA's Hubble Space Telescope over the years. Kepler orbits the sun rather than the Earth, and it's currently about 40 million miles (64 million kilometers) from our planet.


Another mission?

Kepler has already outlasted its prime mission life of 3.5 years. And even if both reaction wheels are beyond help, Kepler's science work may not come to an end.

It's possible Kepler could still gather valuable data by switching to a scanning mode, as opposed to the "point and stare" operations that defined its first four years in space. If neither failed reaction wheel is recovered, NASA will carry out studies addressing possible new missions for Kepler.

It's too soon to speculate what such missions might look like, officials said.

"We need to know more about the performance of the spacecraft before we can assess what kind of science we'll be able to do with that performance," Sobeck said.


More discoveries to come

Kepler has spotted more than 2,700 potential exoplanets to date. Just 132 of them have been confirmed by follow-up observations so far, but mission scientists expect that more than 90 percent will end up being the real deal.

And the flood of Kepler finds won't slow for a while even if the instrument can no longer lock onto its target stars. The mission team has only had time to go through about half of Kepler's enormous dataset, which team members say is certain to contain many more gems — including, possibly, the first-ever "alien Earth."

"We have excellent data for an additional two years," Borucki said. "So I think the most interesting, exciting discoveries are coming in the next two years. The mission is not over."

http://news.yahoo.com/nasas-planet-hunting-kepler-mission-saved-170026829.html