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NASA Science

NASA To Test New Atomic Clock 79

edesio writes "Many satellites and spacecraft require accurate timing signals to ensure the proper operation of scientific instruments. In the case of GPS satellites, accurate timing is essential, otherwise anything relying on GPS signals to navigate could be misdirected. The third technology demonstration planned by NASA's Jet Propulsion Laboratory is the Deep Space Atomic Clock. The DSAC team plans to develop a small, low-mass atomic clock based on mercury-ion trap technology and demonstrate it in space."
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NASA To Test New Atomic Clock

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  • by Anonymous Coward

    Maybe this one will be able to do something as simple as timing neutrinos properly.

  • by Anonymous Coward

    I'm not so sure that I can support anything radioactive while the poor people in Japan are dealing with their atomic disaster and remember Chernobyl? people can't live there anymore. All because of atomic clocks

    • by bmo ( 77928 )

      You know what's frightening?

      Many people would actually believe you.


      • by Cryacin ( 657549 )
        Thankfully with this audience, you'd need an atomic clock to measure the time it would take to realise that the GP is a troll.
      • No, nobody would believe them. That's why they had to make it up, and get another clown to say many people would believe them.

        You nuke fetishists are so desperate now that Japan nuked itself that you have to invent people to believe the BS you make up, even when that BS is against yourselves.

    • An atomic clock could just measure radiation as harmless as the one the sun sends out your way... every second of every day... Billions of times...

      I know you were trying to be ironic, but the "it's atomic so it must be bad" just irks me.

      As for energy... Solar and Fusion's the way to go, it's just more complicated to do it "Right".

      We never seem to get things "right" we always stop at getting the shortcuts... and then we complain we have problems...

    • by khallow ( 566160 )
      To be safe, you probably ought to keep your sincerity in your Mom's basement until it decays into undetectable quantities, say within three days. Make it "movie weekend" and you'll have a plausible cover story.
    • by Kaenneth ( 82978 )

      You can't hug your children with Nuclear Arms.

      • You can't hug your children with Nuclear Arms.

        I don't see why not -- just take your nuclear arms, gently put them around the child, and there you go. Is it because it's too difficult to make a tactical nuke small enough that the human skeleton and shoulder muscles would be able to lift it? If we're replacing the arms with nukes anyway, why not enhance the rest of the body so that it could? Seems like an engineering problem to me.

        Wait, I get the feeling I'm missing something...

      • But you can deliver the Mother Of All Spankings.
    • Because of the mercury ions, use will be banned in the EU and California.

  • about time... (Score:5, Interesting)

    by evangellydonut ( 203778 ) on Wednesday October 19, 2011 @06:27PM (#37768336)

    Having once worked on GPS Satellite's clocking system, I was surprised that the AF was so against usage of atomic clocks phased-locked to crystals for accurate timing. Maybe the latest news about Galileo using atomic clock changed their mind?

    • by kod3l ( 2173912 )
      I would assume they would want something more mechanical. Semiconductors longevity is usually not very high.
    • by JohnnyComeLately ( 725958 ) on Thursday October 20, 2011 @05:35AM (#37772070) Homepage Journal

      Were you a Payload Officer at 2 SOPS? And, are you referring to the Space or Ground segment? If you mean the backup clocks in the Mod, then that's slightly outside my knowledge. As far as the Space Segment, they've been reliably using Cesium and Rubium (atomic) clocks for over 3 decades. They don't want to change because it's known, reliable, etc. I was curious to note the newest generation of satellites dropped the 4th clock, and now launch with only 3. Since each clock is only usable a number of years (varies too much for me to generalize), I'd have thought they kept all four just in case the electrical system outlives normal design life, and you end up needing to go with a 4th clock when the 3rd one becomes too "deviant".

      I think the GPS relevence is buried at the bottom of the article. Cesium and Rubidium clocks are both accurate to the nanosecond. That's just about as accurate as can be practical. The new atomic clock, however, they're saying is accurate LONGER. On GPS Satellites, the original satellites (Block I, II, IIA, IIR) launched with Cesium and Rubidium, 2 each. Usually you have one operational, sometimes one on "ready standby", and the other two off. As each atomic clock reaches the end of its mission-usable life, it's turned off. It become's "mission-unusable" (not a real term, I just made that up) when it's signal varies outside a normal window of acceptable predictability in terms of its output signal. There are design differences, such as Rubidium clocks have to stay within a tenth of a degree (F) in temperature stability (if memory serves correct). So, if they can create a clock that's more stable, for a longer period of time, this has huge potential for future GPS satellites. However, since we just awarded contract to Boeing the contract for IIF birds, with only 2 of 12 launched, it's going to be a very long time (decade at best) before you'd see this in a GPS satellite. Design life has also expanded from 7 to 12 years for each satellite (for point of reference Block I only had a design life of 3 years since they were R&D), so this pushes any usage even farther out since we're going to go longer before replacements need to be launched.

  • but it will take........TIME!!!!! Muahahahhahahaha!
  • by Cochonou ( 576531 ) on Wednesday October 19, 2011 @06:36PM (#37768436) Homepage
    ... you might have heard about PHARAO [], a caesium clock which is planned to fly on the ISS in 2013. Accuracy target is 1E-16.
  • ESA ACES (Score:5, Informative)

    by mbone ( 558574 ) on Wednesday October 19, 2011 @06:48PM (#37768566)

    ESA will get there first, with the Atomic Clock Ensemble in Space [] (ACES) [], intended for the ISS in 2013, which should be good to ~ 10**-16 and will include a test of relativity []. I believe that this [] is the JPL clock, which is aiming at 10**-15 stability, and a 2015 launch. (Both are fairly low earth orbits, with the JPL clock intended for an Iridium satellite.)

    So, the JPL effort is cool, and I would love to see one flown to Mars or truly deep space, but this is one case where the Europeans are in the lead.

    • by mbone ( 558574 )

      Pharao is one component of ACES (see above).

    • Time keeping is getting better and better. I just happened upon this article recently which gives some history on timekeeping and what some of the latest efforts are working on: [].

      Here's an excerpt (emphasis added):

      The metrology of time is not holding still. In the April-June issue of Reviews of Modern Physics, experimental physicist Hidetoshi Katori of the University of Tokyo and theorist Andrei Derevianko of the University of Neva

    • by Anonymous Coward

      There's a huge difference in size, mass, and power between PHARAO (which has impressive peformance) and the JPL DSAC/SpaceClock.
      The former is 91 kg and draws 114 watts and is a meter long. The Hg+ ion clock is notionally 1 liter/1kg and a few watts.

      Considering that for a deep space probe, a couple hundred kilos is the whole spacecraft and a couple hundred watts is the total power budget, that's the value of DSAC/SpaceClock.

      • by mbone ( 558574 )

        You are of course quite correct. But, ACES will still fly before DSAC does, which is something.

  • Deep Space Atomic Clock.... what does this have with "deep space"? GPS satellites are on medium Earth orbits []... or did the space constricted so much now that NASA operates no shuttles?
    (letting aside that... heck... what should it have anything to do with "space"? It's an atomic clock, does it need 0-g to function?)
    • Re:Deep space? (Score:4, Informative)

      by Nyeerrmm ( 940927 ) on Wednesday October 19, 2011 @07:01PM (#37768706)

      Its a technology demonstration for hardware that will eventually make deep space navigation better.

      This is being run out of the JPL navigation section and is intended to improve long-term capabilities with a small investment.

    • Re:Deep space? (Score:5, Informative)

      by mbone ( 558574 ) on Wednesday October 19, 2011 @07:10PM (#37768832)

      Well, first, this is a NASA technology demonstration mission for a clock needed by JPL. That means that NASA is going to validate that this clock will work in space, so that JPL can use it where they operate (i.e., deep space, the Moon, Mars and beyond).

      Second, yes, the very best modern clocks work differently with and without gravity. This is basically because the atoms used are so cold they are moving at human type velocities, and so gravity can't be ignored. The best terrestrial clocks are the fountains - take very cold atoms, moving at ~ 1 meter per second in a trap and shut off the trap. Some of the atoms (the ones that happen to be moving up) will ballistically go up, and then fall back down. (This is much like tossing your keys up 1 meter or so, and then catching them, except with single atoms.) The gravity is used to collimate the pulse of atoms going up and down, and (with timing the round trip) to select only the ultracold ones coming down. By timing the round trip, you can really select a particular set of velocities - the better constrained the velocity dispersion, the better constrained the clock read out.

      NONE of that works in zero-G, and PHARAO (I am more familiar with this clock that the JPL Hg Ion one) is completely re-designed to use fountain-like ideas in a linear beam. I am not sure it would even work on the ground, and it definitely needs zero-g to meet its performance goals.

      • by mikael ( 484 )

        Why not just put the atoms in a magnetic torus field or a circular track rather than a linear track? Seems they already use magnetic fields to sort out the atoms to get the ones in the correct phase.

        • by mbone ( 558574 )

          Why not just put the atoms in a magnetic torus field or a circular track rather than a linear track? Seems they already use magnetic fields to sort out the atoms to get the ones in the correct phase.

          You basically don't want to accelerate the atoms if you don't have to, and in a ring they would be constantly accelerating. Gravity is a little different, as it is very smooth and doesn't require contact with structure, magnetic fields, etc.

    • by hjf ( 703092 )

      Deep Space clock, AKA, Pulsar [].

  • Before they can get that TARDIS project working.

  • the deep space clock will be accurate to 1 second every umpteen million years, but will need to be reset in a couple of weeks due to the change from daylight time to standard time.

  • This project is clearly socialism.

    If you think anything a government does is socialism.

    • So you're saying this clock will pay me retirement, take care of my illnesses, repave roads, build bridges, put food on my table, educate my kids and make me coffee every morning? SWEET!!
      • Like most science, it won't do any of that immediately, but if it proves itself, it might make most of that better & cheaper.

        Taxes pay for GPS. Farmers use GPS to track crop yield so they can fertilize more efficiently. Using high accuracy GPS to repave roads, or build bridges properly is a no-brainer. GPS might help the ambulance get to you and back to the hospital seconds *before* you're dead. So yes, a better clock can improve all those aspects of your life. SWEET!!
    • Not everything a government does is socialism. Some is fascism or cronyism, and let's not forget plain old waste and fraud.

      (:-) for the humor impaired.

"This is lemma 1.1. We start a new chapter so the numbers all go back to one." -- Prof. Seager, C&O 351