With Fuel Exhausted, NASA Retires Kepler Telescope (space.com)

ewhac writes: NASA today announced that it is retiring the Kepler telescope after nearly ten years of service -- double its initial mission life. In that time, Kepler discovered over 2,600 exoplanets, most of which are between the size of Earth and Neptune, sparking an entirely new field of astronomical research, and revealing for the first time just how common exo-planetary systems are. With its fuel supply exhausted, Kepler is no longer able to maneuver or reorient itself to make observations. NASA has elected to decommission the spacecraft and leave it in its current, safe orbit away from Earth.

Comments

Fill 'er up?

[Squeeonline]

Why not refuel? Would the cost of a refueling mission be greater than a whole new telescope?

Re:Fill 'er up?

[Calydor]

There might not even be an accessible fuel valve.

Re:Fill 'er up?

[Anonymous Coward]

Kepler orbits the sun, not the earth, in an earth trailing orbit. So, yes, the cost of refueling it would be a bit high. One might say the cost would be astronomical.

Re:Fill 'er up?

[DarkOx]

Even if you could build some sort of fuel tanker craft to go a fuel up the telescope, that was cheaper than a new scope and lest costly to launch you still have to consider the risks..

You are talking about doing something by remote control our automation over vast distances; with limited ability to make any corrective actions once the match is struck so to speak. It requires an extremely high degree of precision as well. The slightest anomaly or error and you miss by mile trying to do something where millimeters count.

Our Areo-space engineers have done a lot of amazing things - frankly things that many thought would never be possibly. They are super smart folks who deserve a great deal of respect. Still something like this would have a pretty good probability of failure. Much more so because it was not planned at the outset and has not been done before so they have no experience with it. You have to add the chance of failure times the cost of the effort at least. Really its worse than that because we are talking about a single event not a case of of we are going to do this 1000 times and odds are 1% of the time it won't work so we more or less can expect to have to scrap 10 units..

Re:if only

[bruce_the_loon]

For Hubble, maybe. But Kepler is currently 187 million kilometers behind Earth on a heliocentric orbit and drifting back at 31km/s. Nothing we had, have or will have for a long time can reach there to do a refueling job. It was designed as a sacrificial instrument from the start.

Salud!

[HeckRuler]

Farewell and thank you for a job well done. It's important to remember to count all the victories and remind ourselves at how good it can be. Who would have thought that astronomy would be a hot field? But with better eyes and better thoughts we can peer deeper into the inky blank and make better sense of what we're seeing. Human advancement is possible. The stars are ever closer. Thank you Kepler.

Re:Salud!

[sheramil]

Farewell and thank you for a job well done.

Did the last person to use it leave it pointed at the Earth or something? It's still going to be pointed at something. Have it take pictures of that.

Not much of a choice

[CptJeanLuc]

With "its fuel supply exhausted", NASA has "elected to [...] leave it in its current, safe orbit". If you have only one option, seems to me there is not much electing to be done ...

Re: Not much of a choice

[hackertourist]

No, they can't do either.
  - spiral into the sun needs alot of delta-V Kepler doesn't have
  - use light reflection to sail it requires an active system to keep the attitude stable, Kepler doesn't have that either.

Re: if only

[ShanghaiBill]

A DSV-1 with suitable payload could get there.

At great cost with money that should go for the next generation of spacecraft.

Look, Kepler served its purpose. It confirmed over a thousand exo-planets, and thousands more unconfirmed. It is not particularly useful to find a few hundred or even a thousand more. Kepler has been in space for 10 years, and was built with tech even older than that. It is time to move on.

We need a NEW spacecraft that can detect smaller planets, planets further from their star, and even exo-moons. We need to be able to look for spectroscopic signs of O2 in star-crossing exo-planets, which may mean life. Spending $500M on a refueling mission will accomplish none of this.

Re: if only

[Gavagai80]

Nobody has any theory for how to make an interstellar probe return. Any solar sail that can manage to keep accelerating long enough to get up to an appreciable fraction of the speed of light will have no prayer at stopping, because solar sails only work within star systems and it'll be going so fast it'll pass through the star system in far, far less time than it spent accelerating in ours. You need an equal amount of time in the same energy conditions to decelerate as you had to accelerate.

Re: if only

[Jjeff1]

We have a replacement, it's called TESS https://tess.mit.edu/ It's not quite the same as Kepler, but has a similar mission. Good news is TESS's imaging sensors cover a LOT more area than Kepler.

Re:Planned obsolescence

[Calydor]

How would you plan to refuel something that is ~150 million kilometers, roughly 100 million miles, away from your planet?

Re:Planned obsolescence

[sexconker]

It doesn't need that much precision, really.

Get on a similar orbit. Slow down until it's 100 miles away. Match speed.
Tap the gas to adjust gradually. When you're getting close, initiate some capture or docking maneuver. You can do either extremely slowly. For a capture, you can extend the arm and wait for mission control to confirm. Then you can open the arm and wait for confirmation. Then you can lower the arm and wait for confirmation. Then you can close the arm and wait for confirmation. Then you can retract the arm and wait for confirmation. Then you can attempt refueling connection and wait for confirmation. Then you can open the valve on the receiver and wait for confirmation. Then you can open the valve on the giver and wait for confirmation. Then you can reverse the process.

At each step you can pause and wait. And each step gets you to a separate step where you've got more control. You don't need to hit a hole in one from Earth to Keppler. You drive out, use your wedge on the hazards, then pull out your putter once you're on the green.

Re: if only

[UnknowingFool]

The whole problem with your premise is that it requires omnipotence and premonition. In hindsight you can claim something wasn't efficient when it exceeded the original goals but back when these things were launched no one had any knowledge of the future in how long things would last.

NASA never claimed one iota of what say they claimed. Instead NASA was given clear mission parameters and a budget which they had to meet. In the specific case of the rovers they didn't know the severity of dust storms or how badly it would degrade battery charging. The worst case scenario had to be used to design the system.

Opportunity has possibly suffered the worst case scenario that NASA planned more than 16 years ago: an intense dust storm has possibly drained the batteries to the point where the rover is likely dead for good. It just took 16 years for it to happen.