Tuesday, June 12, 2012

Low cost development and applications of the new NRO donated telescopes, Page 2.

Copyright 2012 Robert Clark 
Credit: NASA simulated image of extreme Solar System bodies

Hubble-class scopes can be placed at GEO rather than a Lagrangian point.

The Planetary Resources, Inc. version of such an infrared scope would operate in low Earth orbit. Then it quite likely could be launched by a Falcon 9, at a ca. $50 million launch cost. However, the plans for the Wide Field Infrared Survey Telescope (WFIRST) that these NRO scopes could be used for would be to place it at a Sun-Earth Lagrangian point millions of miles away. But according to this article the large size of these new scopes would allow them to be placed much nearer, in geosynchronous orbit:

Ex-Spy Telescope May Get New Identity as a Space Investigator.
Published: June 4, 2012

The telescope’s short length means its camera could have the wide field of view necessary to inspect large areas of the sky for supernovae.
Even bigger advantages come, astronomers say, from the fact that the telescope’s diameter, 94 inches, is twice as big as that contemplated for Wfirst, giving it four times the light-gathering power, from which a whole host of savings cascade.
Instead of requiring an expensive launch to a solar orbit, the telescope can operate in geosynchronous Earth orbit, complete its survey of the sky four times faster, and download data to the Earth faster.
Equipped with a coronagraph, which blocks light from the sun’s disk to look for exoplanets, another of Wfirst’s goals, the former spy telescope could see planets down to the size of Jupiter around other stars.

 Then they could be launched at least by a Falcon Heavy at a $100 million launch cost. The colder temperatures out at GEO compared to LEO would make the PRI asteroid search more sensitive also.

Cost advantage of a single large scope compared to multiple small scopes.

 In regards to PRI financing the development of such a scope, PRI has announced plans to make small telescopes of about 9" diameter to be sold for Earth imaging purposes and to combine hundreds to thousands of these for the asteroid search:

APRIL 26, 2012
Planetary Resources could take megapixel images of exoplanet and makes billions by 2020 before mining anything.

However, linking up optical or infrared telescopes in orbit to form a single coherent image has not been done before and likely will add significantly to the price of the individual scopes. If it does work then the resolution will be as the widest distance between the scopes. However the light collecting area, which is what is needed for the sensitivity of an asteroid search, will only be as the sum of the areas of the scopes.
 The new NRO scopes have 11 times the diameter of the planned PRI telescopes. So it would take 121 of the PRI scopes to make up the sensitivity of a single one of the NRO scopes, assuming they are able to get a single coherent image from the combined scopes. 
 PRI has said they expect to cut the costs of their scopes by 1 to 2 orders of magnitude below that of, for example, a telescope as on the WISE mission. This would make them in the $3 to $30 million dollar range. With the complexity of the wide scale link up of the scopes at hundreds to thousands of kilometer distances,  it seems likely it would be closer to the higher range. Even if the Arkyds amount to $10 million each including launch costs, that would still be over a billion dollars to match the sensitivity of a single one of the NRO  scopes. In that case a single one of the NRO scopes at a few hundred million dollar cost would be advantageous.

The Hubble-class scopes properly instrumented can serve as upgrades both for the WISE and WFIRST scopes. 

 Interesting articles here about the WISE capability to detect large unknown planets at the very fringes of the Solar System:

Up telescope! Search begins for giant new planet.Tyche may be bigger than Jupiter and orbit at the outer edge of thesolar system. BY PAUL RODGERS SUNDAY 13 FEBRUARY 2011

About that Giant Planet Possibly Hiding in the Outer Solar NANCY ATKINSON on FEBRUARY 16, 2011

 The 40 times greater collecting area means the Hubble-class scopes could perform a much more sensitive search than WISE for these extreme Solar System planets.
 Another possible use would be the search for nomad or rogue planets which are planets in the interstellar space between star systems:

Researchers say galaxy may swarm with 'nomad planets'. A good count, especially of the smaller objects, will have towait for the next generation of big survey telescopes, especially thespace-based Wide-Field Infrared Survey Telescope and the ground-based Large Synoptic Survey Telescope, both set to begin operation in theearly 2020s. A confirmation of the estimate could lend credence to another possibility mentioned in the paper - that as nomad planets roam theirstarry pastures, collisions could scatter their microbial flocks to seed life elsewhere. February 23, 2012 BY ANDY FREEBERG

 Again the Hubble-class scopes would have much better sensitivity to detect them than the Wide-Field Infrared Survey Telescope(WFIRST) scope mentioned.
 It has been speculated such nomad planets could have life in subsurface water. Since some of these nomads are believed to be ejected from other star systems, nomads near to us or captured by our Solar System would provide a more near term route to search for life in other star systems.
 Because of the interest in the search for extraterrestrial life, you could have another source for private funding for such scopes. One could have for example the scope named after a foundation or individual who provided a large portion of the funding, like the Keck telescope.

   Bob Clark

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