KBO encounters |
KBO encounters |
Aug 2 2008, 12:53 PM
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#501
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Newbie Group: Members Posts: 6 Joined: 1-August 08 Member No.: 4280 |
Hi,
I’m regular follower of NH and I’m also interested in the 2nd leg of the mission, i.e the 2016+ KBOs encounters. Does anyone know when operations about this leg (starting with searching objects of interest with HST or some other earth-based means, I suppose) are expected to begin ? |
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Jan 9 2019, 04:16 PM
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#502
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Senior Member Group: Members Posts: 1669 Joined: 5-March 05 From: Boulder, CO Member No.: 184 |
Maybe we need a rather nearby supernova to provide the flash? Unsure though if a potential one like Betelgeuse would be bright enough.
-------------------- Steve [ my home page and planetary maps page ]
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Jan 9 2019, 07:09 PM
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#503
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Member Group: Members Posts: 684 Joined: 24-July 15 Member No.: 7619 |
Maybe we need a rather nearby supernova to provide the flash? Unsure though if a potential one like Betelgeuse would be bright enough. -Flash-of-inspiration- We don't need a supernova. We need to reverse our thinking: How about using the biggest dish on New Horizons, the high gain antenna, like radar? NH can detect a-millionth-of-a-billionth-of-a-watt of radio waves with the high gain radio antenna. Turn NH forward and use the spin stabilized high gain antenna to listen for KBOs using radar pings. NH could broadcast radio pings at around 12 watts. DSS-43 in Canberra could broadcast radio pings at 400 kW (IIRC, nobody has ever tried it at full power). Arecibo could broadcast radio pings at around 1 million watts. Using the low gain antenna, order New Horizons to turn the high gain antenna FORWARD in spin-stabilized mode. Turn the volume on Arecibo and the Canberra 70-meter scopes up to 110% and blast out a ping aimed AHEAD of New Horizons. Have NH listen for reflected pings with the high gain antenna - the only thing out there that could reflect a 1 km radio wave is a nearby KBO that is bigger than 1km. (might need to use some Cassini/Huygens doppler shifting magic to differentiate between red-shifted-outbound radio signals and blue-shifted-reflected-incoming radio signals) If you detect a ping, then start slewing the spin axis during the pings so that the high gain dish samples a point, then a small circle, then wider circles, and track which azimuth offset (circle size) corresponds to the biggest increase in reflected radio waves. Then a pattern of timed pings could determine where along the circle the reflection is the strongest, i.e. that the KBO is located at, for example 4-o-clock on that circle. Follow up with a spin-stabilized search with a sweep of x-band frequencies to determine likely KBO size. -- All of this AFTER NH is done downloading the Ultima Thule data, of course. |
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Jan 11 2019, 03:42 PM
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#504
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Member Group: Members Posts: 684 Joined: 24-July 15 Member No.: 7619 |
-Flash-of-inspiration- We don't need a supernova. We need to reverse our thinking: How about using the biggest dish on New Horizons, the high gain antenna, like radar? NH can detect a-millionth-of-a-billionth-of-a-watt of radio waves with the high gain radio antenna. Turn NH forward and use the spin stabilized high gain antenna to listen for KBOs using radar pings. NH could broadcast radio pings at around 12 watts. DSS-43 in Canberra could broadcast radio pings at 400 kW (IIRC, nobody has ever tried it at full power). Arecibo could broadcast radio pings at around 1 million watts. Using the low gain antenna, order New Horizons to turn the high gain antenna FORWARD in spin-stabilized mode. Bump, Found some discussions about using radar from -DSN- at Ultima Thule For both trajectories, we chose the nominal close approach time to be 05:33 UT on 1 January 2019. The flyby date was selected to minimize propellant consumption. The flyby time on that date is about an hour earlier than the uncontrolled (minimal propellant usage) arrival time, to allow the spacecraft to receive uplink signals from both the NASA Canberra and Goldstone Deep Space Network (DSN) stations to attempt a bistatic radar measurement of MU69 shortly after closest approach. Found some prior info about NH using at Pluto expecting to use radar from Arecibo and DSN to reflect off Pluto and be imaged by REX camera- http://www.planetary.org/blogs/guest-blogs...tes-part-1.html https://www.lpi.usra.edu/opag/meetings/sep2...tions/Stern.pdf About 30 dB advantage for NH at Pluto using REX Details about NH and REX as page 73 of Advances in Bistatic Radar Has anybody published any results based on NH using radar signals from DSN to study Pluto's atmosphere, or surface roughness? |
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