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NASA Moon

NASA Finds Lunar Spacecraft That Vanished 8 Years Ago (cnn.com) 56

An anonymous reader shares a CNN report: It made history as India's first unmanned lunar spacecraft. Then it vanished. Nearly a decade later, NASA has located two unmanned spacecraft orbiting the moon, including India's Chandrayaan-1, which went quiet in 2009. Scientists used a new ground radar to locate the two spacecraft -- one active and one dormant, NASA said Thursday. "We have been able to detect NASA's Lunar Reconnaissance Orbiter [LRO] and the Indian Space Research Organization's Chandrayaan-1 spacecraft in lunar orbit with ground-based radar," said Marina Brozovic, a radar scientist at NASA's Jet Propulsion Laboratory in Pasadena, California. "Finding LRO was relatively easy, as we were working with the mission's navigators and had precise orbit data where it was located."
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NASA Finds Lunar Spacecraft That Vanished 8 Years Ago

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  • by xxxJonBoyxxx ( 565205 ) on Friday March 10, 2017 @12:53PM (#54013071)
    I need to find a satellite the launch team stood up in 2009. Can you please send me the commands to find the satellite and restore communication with it. This mission is most needful!

    Your greatest help is mostly appreciated!!!
    • Sure I can help you. First let's start up a Webex and you can show me the environment and describe how things appeared to work before the problem happened. We will then collect any relevant information for further analysis and determine the next best course of action.

  • by Anonymous Coward

    "Finding LRO was relatively easy, as we were working with the mission's navigators and had precise orbit data where it was located."

    So it was easy for NASA to find something that they knew the location of.

    Okaaaaaay.

    • Finding LRO [with ground-based radar, as implied by the entire point of TFA] was relatively easy, as we were working with the mission's navigators and had precise orbit data where it was located

      So yes, it was easy to confirm the position of a lunar satellite using Earth-based radar given a position pre-calculated with high confidence.

      Hopefully, at least now that it's been spelled out for you, you can grasp why this is interesting and not some kind of joke only were clever enough to spot.

      • Actually I am surprised that a lunar orbit was stable enough for that to work. The moon is lumpy with old impactors, and some orbits are stable for a month or two at best.

    • by TWX ( 665546 ) on Friday March 10, 2017 @01:10PM (#54013195)

      That's how the development process works.

      First you start by establishing conditions that are entirely known and are as close to within-your-control as possible. You confirm that you get the expected results this way. After that, then you pursue something that is known to an extent but is not entirely known. The Indian satellite in this case works, its orbit prior to its failure was reasonably well known and I assume that those who do orbital mechanics for a living would be able to extrapolate a reasonable position assuming that nothing unknown has influenced it.

      These tests don't necessarily tell you that your system is working properly, but they do tell you that the system has some degree of expected function. For a next test you'd have to place something into orbit without telling the team where it is but that something is there, and ask them to find it. If that succeeds then you can start testing with things put into orbit that the team is expected to look for but where they have no specific knowledge, so that they get used to looking and scrutinizing their dataf without any advance notice.

    • So it was easy for NASA to find something that they knew the location of.
      Okaaaaaay.

      You calibrate your methods using known values, then you try for the experimental.

      #researchmethods

    • by jaymemaurice ( 2024752 ) on Friday March 10, 2017 @02:17PM (#54013817)

      Feeding a troll but to put this into perspective they located a satellite last seen in 2009 by basically sending a signal into space and catching it's echo... all while that satellite is rotating around another giant satellite that is rotating around us...

      Let's pretend that you know the old rotation...
      Forget what amazing technology radar is and how even decently catching the reflection of sun off the moon in a camera is difficult...
      Forget about the problems of all the other stuff that can bounce the signal back... forget that in 8 years the orbit could have changed so significantly you might not even know when the satellite will be eclipsed by the moon!! Also, the moon is only over the horizon for as long as the sun so you have 8 to~14 hours of time then the moon isn't eclipsing the satellite where a particular ground station could even hit the satellite with a signal.

      The moon is 384,400 km away and orbits the earth at a speed of 3,683 km/h! It takes ~1.3 seconds for the signal to make it roughly to the moon and ~1.3 seconds to make it back! in that time the moon (and things orbiting it) have moved over a kilometer in relation to the earth!!! That's just in the time it took the radar signal to reach! Another kilometer for the return signal!

      They sent the signal from one ground station and received a reflection of that signal on another, were able to correlate the exact time the signal was sent vs. when it was received, compare it with the location of other signal reflections, figure out where to point a telescope and verify this tiny little thing the size of a smart car is in fact Chandrayaan-1.

  • by sl3xd ( 111641 ) on Friday March 10, 2017 @12:59PM (#54013105) Journal

    Given the distance involved and the size of the sattelites, this is some pretty impressive work.

  • V'ger (Score:1, Troll)

    by houghi ( 78078 )

    This space left blank intentionally.

  • It made history as India's first unmanned lunar spacecraft.

    Was there an earlier manned one from India then?

  • by mrbester ( 200927 ) on Friday March 10, 2017 @02:32PM (#54013983) Homepage

    And it wants to be known as "The Excession"...

  • by dvase ( 1134189 ) on Friday March 10, 2017 @02:35PM (#54014013)

    https://www.nasa.gov/feature/j... [nasa.gov]

    The NASA link has more technical details than the CNN link in the summary above.

  • Unmanned (Score:4, Funny)

    by B1700 ( 4884853 ) on Friday March 10, 2017 @02:36PM (#54014025)
    Good thing they were unmanned. I would hate to think we forgot about someone up there.
  • They probably lost it because something weird showed up in the video feed and NASA cut the video link.
  • Is an orbit around the moon, unmanned, even possible?

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