On Oct 30, 6:37 pm, Brian Thorn <
bthor...@suddenlink.net> wrote:
> On Tue, 30 Oct 2012 14:55:56 -0700 (PDT), bob haller <
hall...@aol.com>
> wrote:
>
> >
http://www.space.com/18275-nasa-sls-rocket-potential-missions.html
>
> So NASA is dreaming about SLS payloads, too...
>
> Brian
Very exciting astronomy missions become possible also with the SLS:
SLS Useful for Science Missions, Too, STScI Director Tells House
Panel.
Marcia S. Smith
Posted: 17-Sep-2012
[quote]
The new Space Launch System (SLS) NASA is developing is useful for
robotic science missions as well as human spaceflight according to the
director of the Space Telescope Science Institute (STScI).
Testifying to a House subcommittee last week, Matt Mountain said that
SLS could enable launching telescopes much larger than the Hubble
Space Telescope or the upcoming James Webb Space Telescope (JWST).
STScI operates Hubble and will operate JWST after it is launched in
2018. Mountain described telescopes with primary mirrors 15-25
meters across -- three or four times the size of JWST -- that might be
able to detect life on planets around other stars that would be
enabled by a launch vehicle the size of SLS coupled with "human or
robotic infrastructure to assemble such a system in space." [/quote]
http://www.spacepolicyonline.com/news/sls-useful-for-science-missions-too-stsci-director-tells-house-panel
Telescopes with mirrors 15 to 25 meters across might be too ambitious
since we don't have those even for ground scopes yet. But we can
certainly imagine 10 meter telescopes. I looked up some costs of the
largest ground scopes and was surprised by how low cost they were
compared to typical space missions. The Keck 1 and Keck 2, which are
each 10 meter scopes, cost in the range of $100 million each in 1993
dollars. And the Large Binocular Telescope(LBT) whose twin 8.4 meter
mirrors give it the collecting power of a 11.9 meter scope cost only
$120 million in 2005 dollars. This compared to the likely billion
dollar launch costs of the SLS.
There would be additional costs at making these scopes space
qualified, but on the other hand you don't have the large costs of
constructing the buildings to house such large telescopes on the
ground.
The LBT case is especially interesting in that the twin mirrors if
they could be used together to create a single image they would have
the resolution of a 22.8 meter telescope. This would put it in the
range able to detect life on extrasolar planets. According to the
Wikipedia page on the LBT, this image synthesis mode has been tested
but has not been part of the regular use. Likely cost has been a
limiting factor. However, the National Reconnaissance Office has an
ever increasing need for better and better imaging resolution from
space. Reportedly they already have launched billion dollar
satellites. Then they could be a source for the funding to perfect the
image combining methods.
Bob Clark