"Better-than-Hubble" is flat out wrong here, the only correct interpretation is "with larger apertures than Hubble", but there is so much more to a telescope, especially one in Hubble's class. A spysat is optimized for taking only exposures lasting a fraction of a second, for example, whereas Hubble is optimized for taking exposures that last many minutes at a time, with guidance that keeps Hubble pointed in the same direction to sub-pixel precision.
Let's take a moment to walk down the aisle with the label "Current Hubble Science Instruments". First, we come upon WFC 3, a 4k x 4k high quantum efficiency CCD imager with a wide field of view, spectral coverage from the near-UV through visible spectrum and with 63 different narrow and wide-band filters. Oh, and with a set of grisms and prisms for taking spectra, and with a separate 1k x 1k IR sensor with 17 of its own filters. Next up is NICMOS, an IR imager and spectrometer with a spectral range of 0.8 to 2.4 microns, this instrument alone places Hubble into the rankings as one of the top 3 or 4 most productive and capable Infrared telescopes in history all on its lonesome. Then there is STIS, a 3 CCD sensor with coverage from far-UV through near-IR wavelengths which is capable of taking high resolution spectra for 500 separate points simultaneously while also taking a full frame image, this instrument alone is responsible for much of all of the astronomical observations in the UV-range throughout all of history. And there are several other equally impressive instruments I have not mentioned.
The point is, none of these instruments or capabilities are going to be on a spysat. And they make up the vast majority of the value of a space based observatory. If a space telescope was nothing more than a big mirror, some guidance, and an imager then we could save billions of dollars, but they are so much more than that.
I honestly don't know the answer to this, so perhaps somebody can provide some info: Does it cost more to produce the mirror or to produce the various CCD imagers and science instruments?
It would seem to me that the CCD's should be cheaper - we have a LOT more experience producing CCD's than we have producing 3 meter mirrors capable of being launched into orbit. Surely the huge amount of research being put into producing low noise CCD's for cameras and phones would have the effect of making it easier and cheaper to produce the science instruments for a space telescope?
It's not got a mirror flaw that you need to work around which loses light, and the secondary is steerable. So the optics are definitely better than the Hubble we have. Just taking those instruments you mention and putting them on this NRO bird would give better results than the Hubble.
Maybe you missed what I was saying. Those instruments are the heart of what makes Hubble a world-class observatory, and they are far from off the shelf components.
That's my point. These aren't "better than Hubble" telescopes, they're just optical assemblies. That's more than nothing but it's hundreds and hundreds of millions of dollars of equipment short of a Hubble equivalent observatory.
Let's take a moment to walk down the aisle with the label "Current Hubble Science Instruments". First, we come upon WFC 3, a 4k x 4k high quantum efficiency CCD imager with a wide field of view, spectral coverage from the near-UV through visible spectrum and with 63 different narrow and wide-band filters. Oh, and with a set of grisms and prisms for taking spectra, and with a separate 1k x 1k IR sensor with 17 of its own filters. Next up is NICMOS, an IR imager and spectrometer with a spectral range of 0.8 to 2.4 microns, this instrument alone places Hubble into the rankings as one of the top 3 or 4 most productive and capable Infrared telescopes in history all on its lonesome. Then there is STIS, a 3 CCD sensor with coverage from far-UV through near-IR wavelengths which is capable of taking high resolution spectra for 500 separate points simultaneously while also taking a full frame image, this instrument alone is responsible for much of all of the astronomical observations in the UV-range throughout all of history. And there are several other equally impressive instruments I have not mentioned.
The point is, none of these instruments or capabilities are going to be on a spysat. And they make up the vast majority of the value of a space based observatory. If a space telescope was nothing more than a big mirror, some guidance, and an imager then we could save billions of dollars, but they are so much more than that.