The Hubble Space Telescope stands with the Shuttle as one of the most iconic space craft of the past 2 decades. It has been an amazing boon to science giving us images into the far reaches of space, revealing much about the universe that we would not have known without it. For all it has given us however it is starting to show its age after being in space for a continuous 22 years and the last decade has been dedicated to building a successor. Currently the craft lined up to replace it is the James Webb Space Telescope and whilst its a worthy replacement it’s nothing like the Hubble, for better and for worse.
You see Hubble really is a fully fledged observatory in space being able to capture several different wavelengths of light. This is why we’re able to get those gorgeous pictures out of it as the light it sees is pretty close to what our eyes can see. It’s not exact though as the various filters used to create the images are more aligned to detecting distinct spectral emissions so we end up with images made in what’s called the Hubble Palette. The JWST on the other hand is a pure infrared telescope which is great for studying distant and faint objects but is incapable of producing anything like the Hubble does. To really replace Hubble we’d need a telescope, or maybe even a couple specialized ones working in tandem, that covered a similar array of spectra.
Turns out the National Reconnaissance Office had a couple of these spare.
It might come as a bit of a surprise that the US Department of Defense (of which the NRO is a child agency) has a space program that rivals that of NASA in terms of scale and budget, but it has been that way for some time now. Of course their objectives are decidedly different with NASA being focused on science and exploration and the DoD more interested in the intelligence gathering prospects. It seems that as part of their spy satellite programs they have produced 2 telescopes with Hubble like capabilities that they no longer require (they have not been launched and returned as we have had no missions capable of performing such a task) and have gifted them to NASA. The question now is what to do with these 2 potential Hubble replacements, lest the gift be wasted.
Now these things aren’t exactly ready to fly satellites, they’re basically skeletons ready to be molded into whatever shape NASA wants them to be in. So the basics are there like the housing and the primary (and secondary, something Hubble didn’t have) mirror array but it’s missing crucial parts like the sensors, communication systems and I’m guessing stationkeeping equipment. So there’s a large parcel of work that’s already been done, and no doubt anyone who was looking to build a satellite would love to have this much done for them for free, but to actually get these things flight ready will take quite some time and, most importantly, some budget. If the required funds were found immediately NASA believes they’d be ready to launch no earlier than 2020, or a turnaround time of about 8 years.
Personally I believe that we’d be best served by configuring both telescopes to be identical and then launch them as a stereoscopic pair that could perform in space interferometry. This would allow us to surpass the capabilities of Hubble significantly and would open up imaging opportunities that just weren’t available otherwise. Of course we’d probably be better suited designing a whole new telescope with an even larger mirror array than the two combined but with NASA struggling to complete the JWST on time I can’t see that happening for anytime in the near future. Using these two proto-Hubbles would be an excellent solution for the interim however.
It’s not often that some like this happens so it will be very interesting to see what NASA does with these skeleton telescopes. I would love to see a visible spectrum telescope up there to replace the Hubble after it returns to Earth in a fiery blaze of glory but there are just as many other worthwhile goals for these little beauties. Whatever their fate I’m glad that they’re now in the hands of NASA as they’ll do a lot more good for mankind as science vessels than they ever would as spies.