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SEXTANT, a "GPS System" for Deep Space

01/14/2018 1:04 PM

Pulsars are spinning neutron stars. Neutron stars generally have very intense magnetic fields and charged particles falling to the surface will follow the magnetic field lines producing two intense sources of radiation. As the pulsar spins on its axis, these two sources of radiation radiate out into space like searchlights. Any observer in the direction of the searchlight beam will see a pulse of radiation as the pulsar rotates. The spin of these pulsars is extremely stable and the arrival of the pulse of radiation can be predicted within microseconds well into the future.

https://phys.org/news/2016-10-millisecond-pulsars.html

Using four pulsars, the time of arrival of the radiation pulses can be used for navigation in deep space. This capability has been demonstrated by NASA this past year with the SEXTANT (Station Explorer for X-ray Timing and Navigation Technology ) utilizing the NICER (Neutron-star Interior Composition Explorer) satellites.

"In a technology first, a team of NASA engineers has demonstrated fully autonomous X-ray navigation in space -- a capability that could revolutionize NASA's ability in the future to pilot robotic spacecraft to the far reaches of the solar system and beyond.

The demonstration, which the team carried out with an experiment called Station Explorer for X-ray Timing and Navigation Technology, or SEXTANT, showed that millisecond pulsars could be used to accurately determine the location of an object moving at thousands of miles per hour in space -- similar to how the Global Positioning System, widely known as GPS, provides positioning, navigation, and timing services to users on Earth with its constellation of 24 operating satellites."

NICER's mirror assemblies concentrate X-rays onto silicon detectors to gather data that probes the interior makeup of neutron stars, including those that appear to flash regularly, called pulsars. Credit: NASA's Goddard Space Flight Center/Keith Gendreau

https://www.sciencedaily.com/releases/2018/01/180111223914.htm

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#1

Re: SEXTANT, a "GPS System" for Deep Space

01/14/2018 4:02 PM

I thought NASA was also going to provide the manned Mars mission with old-fashioned nautical sextant and star-charts...albeit packaged in a smart-phone display package.

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#2

Re: SEXTANT, a "GPS System" for Deep Space

01/14/2018 7:19 PM

That idiot Carl Sagan included charts on Pioneer 1 and 2 with pulsars shown on them to help aliens from space triangulate and locate Earth. Like, 'Here we are. Come destroy us.'

Moron.

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#4
In reply to #2

Re: SEXTANT, a "GPS System" for Deep Space

01/15/2018 8:06 AM

Well, interstellar space is very big, those probes are pretty tiny, and from what we know, there is not a lot of traffic out there, so the odds of ETs finding one of them and figuring out what our interstellar graffiti means is extremely remote. And, in any case, they could probably trace the trajectory back to our solar system. We are far more likely to be discovered by the radiation we send out from radio and television broadcasts, although some have postulated that the quality of the programming is likely to keep them away.

However, on the downside, judging from our own species, a superior species might either study us, keep us as pets, or eat us. It would be better to be on the end of a leash than in a zoo, a dissecting table, or on the dinner plate. Life is not so good when you're no longer at the top of the food chain.

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#5
In reply to #4

Re: SEXTANT, a "GPS System" for Deep Space

01/15/2018 3:07 PM

Also, Pioneer 10 & 11 (the two with the plaques) have only gotten to the Heliopause(1) so far. Distance-wise, that's like standing on your front porch and hurling a baseball, only for it to stop at the curb, the near side of the curb, not even technically in the street yet.

Notes:

  1. The point where the solar wind is balanced out by the pressure of the outside universe. It is considered to be the "outer edge" of the Solar System.
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#6
In reply to #5

Re: SEXTANT, a "GPS System" for Deep Space

01/15/2018 4:04 PM

Yes, as of now there's not much question of where they came from! I doubt that any advanced civilizations that can travel among the stars are too worried about us just yet.

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#7
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Re: SEXTANT, a "GPS System" for Deep Space

01/16/2018 9:22 AM

Yeah, if there is a Galactic Federation or similar, they're probably waiting for us to grow up a bit more before initiating first contact. It only makes sense, you don't invite immature kids to a fancy dress ball or an important trade meeting.

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#3

Re: SEXTANT, a "GPS System" for Deep Space

01/14/2018 8:17 PM

I wonder if the Tesla that Elon is sending to orbit Mars has this type of guidance system?

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#8

Re: SEXTANT, a "GPS System" for Deep Space

01/16/2018 2:27 PM

Seems pretty clever to me.

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