Today, news broke that the National Reconnaissance Office, which handles satellite-based surveillance, had agreed to transfer two space-capable telescope mirror systems to NASA. At a press call held today, NASA administrators said that while most of the remaining structure for a space-based telescope would still have to be built, the gift could jump-start a planned infrared survey telescope called WFIRST. That is, if Congress allocates money to take advantage of the gift. But at best, the hardware won't be in orbit until the start of the next decade.
The NRO apparently decided that some of the hardware it designed and built for use in spy satellites (but did not place in orbit) would be superfluous for its current needs. Back in January of 2011, the agency got in touch with NASA and offered to transfer the hardware (along with the design and test data from its construction). Since then, NASA has been paying about $100,000 a year to store the two telescopes in Rochester, New York while it decides if and how it can use them.
The primary mirrors of the system are 2.4 meters, the same size as the mirror in Hubble. Paul Hertz, the director of NASA's Astrophysics Division, described the mirrors as being a different shape, "more like a bowl than a shallow disk." They're also much lighter, having benefitted from decades of technology advances. The difference in shape makes these suitable for survey missions, as opposed to high-resolution images. Compared to the Hubble, they would give you "about [a] 100 times bigger area that you can image well."
After NASA's internal analysis, a good match was found between these capabilities and an existing project, the Wide Field Infrared Survey Telescope, or WFIRST. WFIRST is planned to achieve three different goals. Its general survey of the infrared sky should identify objects of interest that could then be examined by the James Webb Space Telescope, which would have a much higher resolving power. The second goal would be to track the distribution of early galaxies and supernovae, which would let us get a better grip on the properties of dark energy accelerating the expansion of the Universe.
The final focus of WFIRST is to provide an independent measure of the frequency and properties of exoplanets. As exoplanets travel between the Earth and distant galaxies, they can act as small gravitational lenses, distorting space in a way that causes a temporary brightening of the background galaxy. Since the degree of change in the incoming light depends on gravitational effects, it provides some information about the mass of the planet doing the lensing.
WFIRST is already in the planning stages, but documents from last year's interim report indicate that the team behind it was considering a 1.3m primary mirror. This means the NRO hardware would provide a significant boost. According to the people on the press call, designing the optical system for a space-based telescope is also the most complex and expensive portion of the development process, and the NRO hardware could save hundreds of millions of dollars.
That said, NASA would still have its work cut out for it. The optical system would need power, communications hardware, pointing systems, insulation, a camera, and many other pieces before it could provide usable data. Then it would need a launch vehicle, which, based on the size of the optical system, would need to be at least an Atlas-class launcher. Of course, the space launch market is changing rapidly—a future version of SpaceX's Falcon was raised as a possible option—so this seems to be the least of NASA's worries. As someone on the call put it, there's an office that will take the specifications and "find us an appropriate ride."
Developing all the additional hardware, however, won't come cheap, and even if money were to become plentiful, NASA doesn't think WFIRST could be put in space before 2020. Under "plausible" budgets, 2024 is more likely. But NASA administrators would have to specifically ask for it, and Congress would have to allocate the money. All that NASA will say for now is that the appropriate committee staff members have been briefed.
In the meantime, the agency has to work within some limits imposed by the telescopes' history. It won't be able, for example, to release any pictures until after the mirrors are covered by all that additional hardware. USA Today's Dan Vergano was given an image of the telescope that was used at a recent meeting of the National Research Council. The level of redaction indicates that there will be some significant limits on any NASA design teams. (UPDATE: a reader has indicated this was an image used as a joke as part of a presentation.)
There are a couple of things that really need to be emphasized: NASA did not get a complete system and still has a lot of work to do. It could save them money, but those savings will mostly go toward taking a project in development and making it more likely to fly in an era when NASA is strapped for funds. And despite the similarities in mirror sizes, this is not a replacement for when Hubble inevitably starts to fail, since the hardware is quite different. But that's not a bad thing, given that it will answer questions we can't currently address.
As for the fact that NASA was given two pieces of hardware? Michael Moore of the Astrophysics group said, "We don't anticipate ever being rich enough to use both of them, but it sure is fun to think about, isn't it?"