[X] My Assistant

[dilo]

Well, I obviously hope that Hubble will be repaired/updated and will last as much as possible.
But, sometime, we will need a replacement.
The James Webb telescope will mainly work in the mid-infrared region so I would like to have also something working in the visible and UV wavelenghts in order to guarantee a continuity (in the near IR, the fast Adaptive Optics progress will soon permit to have space-like performances from Earth).
Consider also that recent Earth-observing satellites are equipped with true telescopes, with very interesting performances; see Ikonos images of Mars during opposition:
http://www.spaceimaging.com/gallery/mars/default.htm

So my "crazy" idea is to make a telescope smaller than Hubble (let say 1.2m diameter) but equipped with state-of-the-art sensors and, especially, with heliosyncronous orbit at 800Km height.
The great advantage will be that, while orbiting above illuminated Earth side, this telescope can be used for remote sensing with a stunning resolution close to 30cm/pixel (like MRO!) while in the night side will take astronomical images and spectra.
Such compact telescope should have a moderate cost and, anyway, it's commercial use could cover the initial investment!

[stevesliva]

HiRISE is 0.5m. I remember thinking that was pretty telescopic!

I think part of the focus on bigger than Hubble is because ground-based resolution is improving, but also on IR, because the atmosphere is IR-opaque. I mention this just because I think it's part of the focus on IR in space.... speaking of, how long does Spitzer have before it starts warming up?

[Del Palmer]

how long does Spitzer have before it starts warming up?

Latest estimate for helium depletion is March 2009.