Author Topic: Mission to the Gravitational Focus  (Read 30903 times)

Offline Stormbringer

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Re: Mission to the Gravitational Focus
« Reply #80 on: 04/22/2016 04:54 PM »
http://nextbigfuture.com/2016/04/stellar-echo-imaging-of-exoplanets.html

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A mission utilizing distributed-aperture stellar echo detectors could provide continent-level imaging of exoplanets more readily than interferometric techniques, as high temporal resolution detection is less technically challenging and more cost effective than multi-kilometer-baseline fringe-tracking, particularly in a photon-starved regime. The concept is viable for detecting exoplanets at more diverse orbital inclinations than is possible with transit or radial velocity techniques.
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Offline Stormbringer

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Re: Mission to the Gravitational Focus
« Reply #81 on: 04/22/2016 05:20 PM »
BESIDES (<---------Yes i am shouting) we now have a new and even better reason to go even farther and a way to do it faster.

Planet nine is thought to be further out than the minimum 500 AU distance of the beginning of the GF region. We need to send probes there (once we verify it's location.)

And thanks to new propulsion ideas slightly less sketchy than the EM drive (so far...) we could get there three to four times faster than Voyager or Pluto Express (RIP) with one method and possibly at 20 percent c with another.
« Last Edit: 04/22/2016 07:07 PM by Stormbringer »
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Offline Star One

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Re: Mission to the Gravitational Focus
« Reply #82 on: 04/25/2016 04:56 PM »
This article is very much applicable to this thread.

Starshot and the Gravitational Lens

http://www.centauri-dreams.org/?p=35486

Offline Stormbringer

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Offline hop

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Re: Mission to the Gravitational Focus
« Reply #84 on: 02/26/2018 06:40 AM »
Direct Multipixel Imaging and Spectroscopy of an Exoplanet with a Solar Gravity Lens Mission

Final Report for the NASA's Innovative Advanced Concepts (NIAC) Phase I proposal.

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The remarkable optical properties of the solar gravitational lens (SGL) include major brightness amplification (~1e11 at wavelength of 1 um) and extreme angular resolution (~1e-10 arcsec) in a narrow field of view. A mission to the SGL carrying a modest telescope and coronagraph opens up a possibility for direct megapixel imaging and high-resolution spectroscopy of a habitable Earth-like exoplanet at a distance of up to 100 light years. The entire image of such a planet is compressed by the SGL into a region with a diameter of ~1.3 km in the vicinity of the focal line. The telescope, acting as a single pixel detector while traversing this region, can build an image of the exoplanet with kilometer-scale resolution of its surface, enough to see its surface features and signs of habitability. We report here on the results of our initial study of a mission to the deep outer regions of our solar system, with the primary mission objective of conducting direct megapixel high-resolution imaging and spectroscopy of a potentially habitable exoplanet by exploiting the remarkable optical properties of the SGL. Our main goal was to investigate what it takes to operate spacecraft at such enormous distances with the needed precision. Specifically, we studied i) how a space mission to the focal region of the SGL may be used to obtain high-resolution direct imaging and spectroscopy of an exoplanet by detecting, tracking, and studying the Einstein ring around the Sun, and ii) how such information could be used to detect signs of life on another planet. Our results indicate that a mission to the SGL with an objective of direct imaging and spectroscopy of a distant exoplanet is challenging, but possible. We composed a list of recommendations on the mission architectures with risk and return tradeoffs and discuss an enabling technology development program.

Offline stefan r

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Re: Mission to the Gravitational Focus
« Reply #85 on: 02/26/2018 04:19 PM »
(Hmmm, what kind of lateral movement would be required to target exo-planets around Alpha Centauri A and B? (And Proxima?))
Once you are outside of the lensed region, shouldn't it just be the angle between the targets, projected on a 550(+) AU radius circle?
D = ~3500 AU = 9.5 AU/deg = 0.0026 AU / arcsec = roughly the earth / moon distance.... which doesn't actually seem that bad. With the incredible magnification, any targets of opportunity you passed over while slewing would be good science.

Alpha centaur A and B vary between 2 and 22 arcsec, while Proxima is a whopping 2.2 degrees away.

Of course, if you got to 550 AU in a reasonable time, you'll be moving outward at tens of AU per year.

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The published resolution for HST is 0.05 arcseconds. At 550AU, that gives you a resolution of 20 thousand km.
So a diffraction limited single telescope in the tens of meters range would really be very good.

550 au is 1/115 light years.  Alpha centuari is 4.37 ly.  so a ratio 1:503.  At its furthest orbit Alpha Centuari A and B are separated by 36 au.  So 0.072 au separation. 11 million km. 

A 0.1 mm diameter tether would have around 110 kg mass. 

edit, corrected typo
« Last Edit: 02/26/2018 04:40 PM by stefan r »

Offline Paul451

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Re: Mission to the Gravitational Focus
« Reply #86 on: 02/26/2018 04:30 PM »
Alpha centuari is 3.7 ly.

Well, I didn't get that memo.

Offline stefan r

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Re: Mission to the Gravitational Focus
« Reply #87 on: 02/26/2018 04:45 PM »
I hope NASA does not use a public online forum to calculate propellant.

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