Whenever I see an article like this and something at nasa has broken, it seems like they always are soliciting a new project. It makes me wonder, why not just build the exact same thing again (with the broken parts fixed, of course)?
This strikes me as an excellent thing to do - if they can find a project that can fund the ongoing costs of Kepler, then it makes sense to reuse it.
Kepler looks off the plane of the Galaxy at stars that are typically several kiloparsecs away. In other words, we are never going to visit these worlds. Now that Kepler has revealed that planets are common, it will be much more interesting to find nearby planets that we have a better chance of characterizing, seding probes to, or even visiting one day.
This is what TESS will do: http://en.wikipedia.org/wiki/Transiting_Exoplanet_Survey_Sat...
Kepler, for example, has already used up its budget to build, launch, and operate the telescope for several years. Even if free replacement hardware was available there may not be enough money to launch it. Also, the way most spacecraft are built is as one off prototypes, so building another copy, even if all the spare parts were available, is a very non-trivial endeavor. Even if it didn't take as long as building the original it would still be fairly expensive just to go through all of the necessary testing and integration steps.
The end result of all of this is that it rarely makes sense to spend the time and money to refly a spacecraft and instead it usually makes more sense to simply forge ahead and seek funding for a follow-on mission of a new design.
Here's a few case studies. The inaugural launch of the Ariane 5 rocket failed, which resulted in the loss of 4 "Cluster" spacecraft which were designed to study Earth's magnetosphere (a loss of about $370 million in hardware). However, ESA decided to fund replacements and they built 4 new satellites, making use of flight spares and extra hardware to save on costs, and then launched the new satellites on 2 separate Soyuz-Fregat flights. However, it still cost almost as much money to launch Cluster II as for the originals, so this was a rather heroic effort on ESA's part.
In 1999 the Wide Field Infrared Explorer (WIRE) spacecraft was launched, shortly after launch there was a malfunction that caused a loss of the main science instrument on the orbital telescope. The mission was not replaced. However, the loss of WIRE caused other IR survey mission proposals to receive greater interest, which led to the funding of the "Next Generation Sky Survey" Medium-class Explorer mission. This infrared full-sky survey mission was launched in 2009 (as WISE, the Wide-field Infrared Survey Explorer) and achieved all of the science goals of the original WIRE mission.
In 1993 all contact was lost with the Mars Observer spacecraft right at the moment of planned orbital insertion. This loss led to a re-evaluation of the unmanned Mars exploration program at NASA and eventually led to around 10 new missions to Mars over the following 2 decades, most of them successful.
However, I do wonder why they build 1 Kepler space telescope and not 2, or 3, and then store the already built ones until they are wanted.
Additionally, you can incorporate lessons learned (from an engineering perspective, not science) into the next instrument. Some things work well and are preserved, and others don't.
Here's a link to some tech awards relevant to future exoplanet instruments: http://exep.jpl.nasa.gov/technology/
On the flipside, I guess the arguments for componentization apply. If off-the-shelf components are improving all the time, integrating them into a full spacecraft should be getting cheaper and easier over time.
What I really wonder about is, given how troublesome and relatively lightweight gyros are, why didn't they have more spares?
If you're going to have to launch a new spacecraft anyway, why not take some of those lessons into account when you build the next one?
Can a robot fix the thing?
and however "powerful" the shuttle was, it couldn't get to something 3 light-minutes away (which was kepler's distance, the last time i looked)
http://en.wikipedia.org/wiki/Armageddon_(1998_film)
"American Components, Russian Components, all the same, all made in Taiwan!"
But yeah, the space shuttles were LEO only. IIRC the highest they ever went was up to Hubble, and I think that was pretty close to the most they could manage.
Though now that I think about it, I am pretty sure they generally jettisoned the external fuel tanks with a little fuel left over, maybe they could delay the jettison to get into slightly higher orbits than usual.
[1]http://en.wikipedia.org/wiki/Kepler_(spacecraft)#Spacecraft_...
Also, it was never economical to fix Hubble with the Shuttle. It was just fortuitous that the Shuttle program was desperate for things to do and ended up subsidizing the launch costs for the Hubble servicing missions. In terms of the ultimate bottom line the US spent nearly $8 billion to fix a $2.5 billion telescope. Granted, I think that even that expenditure was worthwhile but from a strict cost accounting it would have made more sense to simply build and launch additional telescopes.