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The Next Falcon Heavy Will Carry the Most Powerful Atomic Clock Ever Launched (space.com)

schwit1 shares a report from Space.com: This isn't your average timekeeper. The so-called Deep Space Atomic Clock (DSAC) is far smaller than Earth-bound atomic clocks, far more precise than the handful of other space-bound atomic clocks, and more resilient against the stresses of space travel than any clock ever made. According to a NASA statement, it's expected to lose no more than 2 nanoseconds (2 billionths of a second) over the course of a day. That comes to about 7 millionths of a second over the course of a decade. n an email to Live Science, Andrew Good, a Jet Propulsion Laboratory representative, said the first DSAC will hitch a ride on the second Falcon Heavy launch, scheduled for June.

Every deep-space mission that makes course corrections needs to send signals to ground stations on Earth. Those ground stations rely on atomic clocks to measure just how long those signals took to arrive, which allows them to locate the spacecrafts position down to the meter in the vast vacuum. They then send signals back, telling the craft where they are and where to go next. Thats a cumbersome process, and it means any given ground station can support only one spacecraft at a time. The goal of DSAC, according to a NASA fact sheet, is to allow spacecraft to make precise timing measurements onboard a spacecraft, without waiting for information from Earth. A DSAC-equipped spacecraft, according to NASAs statement, could calculate time without waiting for measurements from Earth -- allowing it to make course adjustments or perform precision science experiments without pausing to turn its antennas earthward and waiting for a reply.

128 comments

  1. Forgive my ignorance by GeekWithAKnife · · Score: 3, Insightful


    ...but what does "the most powerful" atomic clock do as opposed to just a "powerful" one?

    "powerful" is not something I can immediately quantify when it comes to time keeping. :-|

    --
    A 'singular oddity' is an event that cannot be explained and only happens when you are alone.
    1. Re: Forgive my ignorance by Anonymous Coward · · Score: 5, Funny

      It's going to send out such a powerful 'dong' that the whole earth will resonate in unison.

    2. Re:Forgive my ignorance by Anonymous Coward · · Score: 5, Informative

      You need to think of power like a superhero's power. From the Oxford Dictionaries website the first definition of power is: The ability or capacity to do something or act in a particular way.

      Obviously, an atomic clock's power is to measure time accurately using atomic behavior. So this is indeed the most powerful atomic clock launched.

    3. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      It's gonna count Grandfather Time back into the stone age

    4. Re:Forgive my ignorance by Katatsumuri · · Score: 1

      They should have gone with precise and robust.

    5. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      A power clock would be something like Dr Who Tardis. So I presume Musk wants to do time travel as well as space travel.

    6. Re:Forgive my ignorance by nagora · · Score: 1

      Nothing to forgive, the headline is just bad English, although technically allowable.

      --
      "Encyclopedia" is to "Wikipedia" what "Library" is to "Some people at a bus stop"
    7. Re:Forgive my ignorance by famebait · · Score: 2

      ...but what does "the most powerful" atomic clock do as opposed to just a "powerful" one?

      I goes faster, of course!
      Duh.

      --
      sudo ergo sum
    8. Re:Forgive my ignorance by dohzer · · Score: 2

      The battery will go flat faster.
      It also has a calculator function. Neat!

    9. Re:Forgive my ignorance by GeekWithAKnife · · Score: 1


      Oh, I get it! Because it goes around the world, really fast.

      --
      A 'singular oddity' is an event that cannot be explained and only happens when you are alone.
    10. Re:Forgive my ignorance by GeekWithAKnife · · Score: 1


      It's probably the most allowable bad English headline...is this what Trump would call "Fake English"?

      I intend to help fund the centre for kids who can't read good and cannot do other stuff good too.

      --
      A 'singular oddity' is an event that cannot be explained and only happens when you are alone.
    11. Re:Forgive my ignorance by IsaacGrimnebulin · · Score: 1

      To be honest thought you guys were being way too nitpicky about the title but after reading the article I'm starting to wonder if the typewriter got stuck on those letters, in that order, somebody must have seen an early screening of Black Panther. More concerning though is that the author thinks atomic clocks are a rarity in space. I mean they were created to solve the problem of "astronomical time". That's a bit of a hint you'd think but the fact that every single navigation system satellite has several atomic clocks for each individual satellite might be worth looking into. It's kind of sad coming from a website that you'd think would know more than the average newspaper.

    12. Re:Forgive my ignorance by PolygamousRanchKid+ · · Score: 1

      "powerful" is not something I can immediately quantify when it comes to time keeping. :-|

      It has a Dr. Who inside.

      Jodie Whittaker has complained that Apple's newest update slowed her down.

      --
      Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
    13. Re:Forgive my ignorance by mrbester · · Score: 5, Funny

      Other atomic clocks accuracy only goes up to 10. This one goes to 11. It's 1 accurater.

      --
      "Wait. Something's happening. It's opening up! My God, it's full of apricots!"
    14. Re: Forgive my ignorance by Anonymous Coward · · Score: 1

      huh, I'm guessing it's not using NTP then?

    15. Re:Forgive my ignorance by Anonymous Coward · · Score: 1

      Per the summary, this clock is meant to drift by no more than 2 nanoseconds per day. Current GPS clocks drift by 10 nanoseconds per day (ref). So this clock can tell you the time with an uncertainty one-fifth that of current space-based clocks.

    16. Re:Forgive my ignorance by excelsior_gr · · Score: 1

      More power, more better.

    17. Re:Forgive my ignorance by DrTJ · · Score: 2, Informative

      But this is actually relevant (well, almost)!

      I don't know the orbital speed of this clock, but if it goes as fast as ISS, it's about 8 km/s.

      The time dilation relative to an earth observer will be approximately
      t/t' = 1/sqrt(1-v^2/c^2) = 1/sqrt(1-(8/300000)^2) ~ 1.000000000355

      That corresponds to 0.355 ns per second, so if the expected drift is ~2 ns/s, they are actually homing in to the relativistic limit for how much two observers can agree on in this setting. I.e. it would be kind of pointless to make it 10x more accurate.

    18. Re:Forgive my ignorance by K.+S.+Kyosuke · · Score: 5, Funny

      Meh. Most clocks go up to at least 12.

      --
      Ezekiel 23:20
    19. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      My clock goes to 23.

    20. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      Obviously, an atomic clock's power is to measure time accurately using atomic behavior. So this is indeed the most powerful atomic clock launched.

      It will also need to broadcast that signal so the spacecraft can make use of it.

      Having an atomic clock is useless if you can't be sure the things which need to use it can receive the signal.

      That may be part of their use of the word 'power'.

    21. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      ...but what does "the most powerful" atomic clock do as opposed to just a "powerful" one?

      The volume control goes to 11

    22. Re:Forgive my ignorance by GS1 · · Score: 5, Informative

      I believe this clock is accurate up to ±2ns per day, not per second. In fact I would be shocked if it were per second.

      Plus, this has to be understood as a random walk of time keeping. When a clock "looses" a second, it's not necessarily slower than some other reference. It may be faster.

      Now, if relativity states time dilation slows clocks (from the point of view of Earth-based observers), this is something we can agree upon and take into account. This is not clock imprecision of random loss (or gain) of time. It has in fact and must be taken into account for the GPS system to work at all.

      See: https://physics.stackexchange....

    23. Re:Forgive my ignorance by Mister+Transistor · · Score: 1

      It's going to shoot the most powerful "Arrow of Time" ever!

      --
      -- You are in a maze of little, twisty passages, all different... --
    24. Re: Forgive my ignorance by DickBreath · · Score: 1

      As long as the resonance does not break anyone's jaw, that sounds great.

      --

      I'll see your senator, and I'll raise you two judges.
    25. Re:Forgive my ignorance by hcs_$reboot · · Score: 1

      In this case, you have also to take into account the speed of Earth around the Sun, the speed of Sun within the Galaxy, the Galaxy within its cluster and the whole Universe is maybe moving somewhere...

      --
      Slashdot, fix the reply notifications... You won't get away with it...
    26. Re:Forgive my ignorance by hcs_$reboot · · Score: 1

      oh and gravity has an impact on GPS ...

      --
      Slashdot, fix the reply notifications... You won't get away with it...
    27. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      no you do not. Speed is not absolute. It is about a relative difference.

    28. Re:Forgive my ignorance by XXongo · · Score: 2

      Yes, atomic clocks (including the ones that support GPS) routinely incorporate the relativistic corrections-- both special and general.

    29. Re:Forgive my ignorance by mrbester · · Score: 1

      "Other atomic clocks accuracy..."

      My Swatch clock goes up to 999.

      --
      "Wait. Something's happening. It's opening up! My God, it's full of apricots!"
    30. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      "powerful" is not something I can immediately quantify when it comes to time keeping. :-|

      I gather that you've never forgotten your wife's birthday!

    31. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      No the idea is that a spacecraft would carry it's own clock, the same as ships used to carry chronometers now all of that is automated via GPS for ships but this will do the same for spacecraft at a much larger scale.

    32. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      Superb!

    33. Re:Forgive my ignorance by Verdatum · · Score: 1

      "Powerful" is apparently now another word for "accurate", only with more ZAZZ. (But yeah, this bugged me too)

    34. Re:Forgive my ignorance by budgenator · · Score: 2

      The idea is to use them on interplanetary spacecraft, where atomic clocks are much rarer. When a spacecraft is several lightminutes away, getting the clocks synced and navigation commands sent, received and confirmed is much more challenging than doing the same in LEO or GEO. By having that accurate of a clock on our spacecraft they can eliminate the sync portion.

      Having that precision on GPS would be a boon to robotic vehicles as well.

      --
      Apocalypse Cancelled, Sorry, No Ticket Refunds
    35. Re:Forgive my ignorance by careysub · · Score: 1

      Furthermore the NASA article states that this is a prototype mercury ion trap clock that is expected to reach an accuracy of 0.3 nanoseconds a day with some more refinement, which will make it 30 times as precise as GPS satellite clocks.

      The stability of this clock is at least 2E-14, and the future version will be 3.5E-15. For comparison the US national standard clocks (NIST-F1 and NIST-F2) has a stability of about 1E-16, so this is pretty darn good for compact, low energy consumption, system for long term unattended space operation. So far the best clock in the world has an precision of 3E-18.

      --
      Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
    36. Re: Forgive my ignorance by Anonymous Coward · · Score: 0

      My clock goes to 23

      Mine does all 24.

    37. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      Atomic batteries go flat faster than, what, alkalines?

    38. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      The better explanation is that the article writer is a "science journalist" and that's all you really need to know.

    39. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      so that is why it is called the theory of absolutivity!

    40. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      ok, serious question, how can they calculate that the clock is that accurate when the scale is our own invention to begin with and time moves differently for every single observer in the universe due to relativity?

    41. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      Did you allow for the fact that, due to its orbital altitude, the local gravitational field will be less? (Therefore the clock will run faster, but not as much as its speed slows it down.)

    42. Re:Forgive my ignorance by Dread_ed · · Score: 1

      Think of atomic clocks as time machines that transport observers to a very specific time in the present. This one is more powerful, so it is better at transporting the observer to the present than previous versions.

      --
      When the only tool you have is a claw hammer every problem starts to look like the back of someone's skull.
    43. Re:Forgive my ignorance by Bruce+Perens · · Score: 1

      Thanks to the people on this thread for atempting to impart some content to this otherwise content-free discussion. Science needs accurate timebases for interferometry and physics observations, among other things. Just as accurate as we can make them.

    44. Re:Forgive my ignorance by Zaiff+Urgulbunger · · Score: 1

      ...but what does "the most powerful" atomic clock do as opposed to just a "powerful" one? "powerful" is not something I can immediately quantify when it comes to time keeping. :-|

      Essentially, everything you think you understand about clocks is wrong. Clocks don't measure time... they actually warp the fabric around what the clock face shows, hence, a more powerful clock is capable of warping time more accurately and/or over a wider area.

    45. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      UK and military clocks are even double that!

    46. Re: Forgive my ignorance by Anonymous Coward · · Score: 1

      A powerful dong with a small DSAC? Is that what happens when a steroid junkie takes a lot of viagra?

    47. Re:Forgive my ignorance by repka · · Score: 1

      And my microwave oven goes to 99:99

    48. Re:Forgive my ignorance by Ungrounded+Lightning · · Score: 1

      [powerful?!]

      They should have gone with precise and robust.

      Or "accurate".

      Even though "precise" (measures intervals well) is more correct than "accurate" (closeness to the standard, i.e. both precise and properly set), when you're getting technical, it's in more common use and gets the meaning across a lot better than "powerful".)

      When I hear "powerful" I get "this thing uses a lot of power". NOT what you want in an instrument on a spacecraft.

      (Reminds me of a satire of golden age science fiction, where the aliens have been monitoring our radio transmissions from afar with "crystal sets of enormous power".)

      --
      Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
    49. Re:Forgive my ignorance by Anonymous Coward · · Score: 0

      Well only 17% faster.

    50. Re:Forgive my ignorance by K.+S.+Kyosuke · · Score: 1

      Well of course; your superiors wanted you to do things on the double so often that the clocks had to be adjusted.

      --
      Ezekiel 23:20
    51. Re: Forgive my ignorance by Anonymous Coward · · Score: 0

      A cpu could be considered powerful but a clock should be considered accurate.

    52. Re: Forgive my ignorance by Anonymous Coward · · Score: 0

      When a clock "looses" a second

      OMG! There's a loose second! Find it before somebody steps on it!

  2. Re:Launch Trump into deep space forever by Anonymous Coward · · Score: 0

    ... whether you can hear it or not,
    The Universe is laughing behind [his] back.

  3. Most powerful... 13? by billybob2001 · · Score: 5, Funny

    Nigel Tufnel: The numbers all go to thirteen. Look, right across the board, thirteen, thirteen, thirteen and...

    Marty DiBergi: Oh, I see. And most clocks go up to twelve?

    Nigel Tufnel: Exactly.

    Marty DiBergi: Does that mean it's timelier? Is it any timelier?

    Nigel Tufnel: Well, it's one timelier, isn't it? It's not twelve. You see, most blokes, you know, will be timing at twelve. You're on twelve here, all the way up, all the way up, all the way up, you're on twelve on your craft. Where can you go from there? Where?

    Marty DiBergi: I don't know.

    Nigel Tufnel: Nowhere. Exactly. What we do is, if we need that extra push over the event horizon, you know what we do?

    Marty DiBergi: Put it up to thirteen.

    Nigel Tufnel: Thirteen. Exactly. One timelier.

    Marty DiBergi: Why don't you just make twelve timelier and make twelve be the top number and make that a little timelier?

    Nigel Tufnel: [pause] These go to thirteen.

    1. Re:Most powerful... 13? by wbr1 · · Score: 2

      My kingdom for mod points.

      --
      Silence is a state of mime.
    2. Re:Most powerful... 13? by Anonymous Coward · · Score: 0

      "One timlier."

      Thank you, thank you so much for this.

    3. Re:Most powerful... 13? by bosef1 · · Score: 2

      Excellent... if only we could get the moderation to go to 6.

    4. Re:Most powerful... 13? by zeugma-amp · · Score: 4, Funny

      Excellent... if only we could get the moderation to go to 6.

      Yes! The post could then be modlier!

      Woot!

      --
      This is an ex-parrot!
  4. ... Will Carry the Most Powerful Time Machine ... by TimSSG · · Score: 3, Funny

    How did the miss this title? "The Next Falcon Heavy Will Carry the Most Powerful Time Machine Ever Launched" Tim S.

  5. Clock in space, money well spent by Anonymous Coward · · Score: 0

    Yes, let's put a atomic clock into space. Already put a car and fake spaceman into space so this at least has some function.

    1. Re:Clock in space, money well spent by Megol · · Score: 2

      There are many atomic clocks in space already. Just the satellite positioning systems alone adds up to more than 100 clocks.

    2. Re:Clock in space, money well spent by Bengie · · Score: 1

      Elon said he thought there was about a 50% chance of the Falcon Heavy blowing up on the pad and even less chance of making the payload into orbit. There was a reason there was no payload of real value.

    3. Re:Clock in space, money well spent by Anonymous Coward · · Score: 0

      and for that matter the payload had some scientific value. supposedly they used it to run some tests on the spacesuit.

    4. Re:Clock in space, money well spent by Anonymous Coward · · Score: 0

      Not only that, but SpaceX made the offer to NASA and others to put a payload on FH for the test, for free. They didn't get any takers.

      Not surprising, because spacecraft cost real money.

    5. Re:Clock in space, money well spent by Anonymous Coward · · Score: 0

      The scientific value is its mass. Spacex demonstrated Van Allen belt maneuvers on behalf of the US military. Seems they had some problems with this as well.

  6. I wonder how long before some CND halfwit... by Viol8 · · Score: 4, Funny

    ... reads "atomic" and starts River Dance style knee jerking and protests against it. Until one of his compatriots who was assigned the working braincell for the day points out his mistake to him.

  7. Powerful Clock! by 140Mandak262Jamuna · · Score: 4, Funny

    I am sure it would be carried aloft by the most accurate rocket.

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
    1. Re:Powerful Clock! by billybob2001 · · Score: 1

      Precisely!

  8. MUHAHAHAHAHA by Togden · · Score: 1

    Finally my master plan to destroy all of time will be realised!

  9. Time is an illusion by andrewbaldwin · · Score: 2

    ...lunchtime doubly so.

    Ford Prefect (or rather his creator, Douglas Adams) was not entirely flippant.

    I'm sure much brighter people than I have addressed this but it would be nice to know what the time is measured against / where is the datum.

    In 'normal life' any discrepancies caused by the relative motion of clock and observer can be ignored - they're too small an Newtonian mechanics is fine.

    However even at low earth orbit conditions, GPS satellites and receivers need to make relatavistic adjustments.

    When we're measuring to such (almost incredible) levels of detail and talking about movements in various gravity wells surely an agreed well defined datum is required otherwise how can any sensible measure be taken.

    1. Re:Time is an illusion by jfdavis668 · · Score: 1

      The wave harmonic theory of historical perception, in its simplest form, states that history is an illusion caused by the passage of time, and that time is an illusion caused by the passage of history.

    2. Re:Time is an illusion by Anonymous Coward · · Score: 0

      C (speed of light) is inverse to "time". Meaning, anything and everything in the universe already happened, will happen, and has happened already. The universe is a singularity unto itself. But, something happened. Something that provides that extra dimension which we perceive as time. We have a since of scale via C. In reality, it's not that the speed of light is limited (because from a photon perspective, the universe is still a singularity), rather, it's rate limited while observing the speed of light while in the extra dimension known as space-time.

    3. Re:Time is an illusion by mysticgoat · · Score: 1

      As has been said before, time is Her way of keeping everything from happening all at once.

    4. Re:Time is an illusion by Anonymous Coward · · Score: 0

      "People assume that time is a strict progression of cause to effect, but actually — from a non-linear, non-subjective viewpoint — it's more like a big ball of wibbly-wobbly... timey-wimey... stuff."
              -- The Doctor, in Blink (by Steven Moffat)

  10. Gravitational time dilation by Anonymous Coward · · Score: 0

    Gravitational time dilation, I Am wondering, how they compensate for that phenomenon?

    1. Re:Gravitational time dilation by olsmeister · · Score: 1

      The plan is to avoid black holes.

    2. Re:Gravitational time dilation by Anonymous Coward · · Score: 0

      You know, black holes matters!

    3. Re:Gravitational time dilation by Matt_Bennett · · Score: 0

      This is well known and already compensated for in GPS (it must be, or GPS would not work).

    4. Re:Gravitational time dilation by DickBreath · · Score: 3, Informative

      You don't compensate for it. You want accurate time measurement within the orbiting clock's frame of reference. The value comes from comparing it to other clocks in their respective frames of reference. A translation between frames of reference can be done to take advantage of the accuracy of whatever is considered to be the most accurate clock.

      On the subject of accuracy, about that 7 microseconds per decade -- does that assume that all errors accumulate in the same direction? Or might some oscillation errors be in different directions from other errors. (eg, an extra "tick" or a missing "tick".)

      Even if all errors accumulate in the same direction, it is probably not enough for slow, inefficient, puny humans to notice. The length of sprints do not need to be adjusted to compensate, and thus no effect on the release schedule.

      --

      I'll see your senator, and I'll raise you two judges.
    5. Re:Gravitational time dilation by careysub · · Score: 1

      On the subject of accuracy, about that 7 microseconds per decade -- does that assume that all errors accumulate in the same direction? Or might some oscillation errors be in different directions from other errors. (eg, an extra "tick" or a missing "tick".)

      All such x number of fractional seconds per mega-fortnight or what-have-you is a way of expression the stability by multiplying the "mega-fortnight" by the stability factor (1E-15, 3E-16 and so on) for public consumption. You are right that these errors are random walks (otherwise they could be compensated for) and that the actual drift with time will be significantly smaller.

      --
      Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
    6. Re:Gravitational time dilation by Anonymous Coward · · Score: 0

      Their baby-daddys don't think so

  11. Uncertainty principle by shayd2 · · Score: 2
    The article doesn't explain how knowing what time it is tells the clock WHERE it is

    Orbital failure

    It was exact 00:00.999891 when I slammed into the target

    1. Re:Uncertainty principle by rkordmaa · · Score: 1

      As long as you know the time precisely you can calculate your location using observations of solar system objects. It works a lot like marine navigation of olde, development of marine chronometer was a major advancement then too.

    2. Re:Uncertainty principle by Anonymous Coward · · Score: 0

      ... to make precise timing measurements onboard a spacecraft ...

      It doesn't talk about cameras and constellation recognition (is machine learning that smart?). I think it's using dead reckoning: It's been travelling along this map for this duration at this speed, so it must be at point X. That means it must have a way of determining it's speed: Magnetic and gravity fields, perhaps. Also, pray they're not using Apple maps.

    3. Re:Uncertainty principle by Mister+Transistor · · Score: 1

      The satellite doesn't need to know where it it, that's the reciever's job. You compare the time difference of arrival from 3 or more satellites, and the GPS receiver determines where it is from that. The ground control system keeps track of where the satellites are at for navigation purposes and to keep them in orbit, but the atomic clock for the GPS time signal doesn't keep track of where the satellite is at, specifically - it just broadcasts it out. Others do the "where am I" (or "you") calculations externally.

      I have my own Atomic Clock on my bench - It is a 10 MHz Rubidium source from an old NexTEL site (cheap on eBay) that is routed to all my test equipment, signal generators, frequency counters, etc. Accuracy on them is to about 1/10 of 1 Hz!

      --
      -- You are in a maze of little, twisty passages, all different... --
    4. Re:Uncertainty principle by careysub · · Score: 1

      It would seem that with this clock the probe would receive a time signal from Earth and directly calculate its distance itself.

      --
      Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
    5. Re:Uncertainty principle by shayd2 · · Score: 1
      it's been traveling along this map for this duration at this speed ...

      If clock carrier knows precisely what map it is following, there wouldn't be a need for course corrections.

      Locating 3D position won't work very well if the clock is in the Kupier belt and the satellites are close to the sun

    6. Re:Uncertainty principle by careysub · · Score: 1

      I think it's using dead reckoning: It's been travelling along this map for this duration at this speed, so it must be at point X. That means it must have a way of determining it's speed: Magnetic and gravity fields, perhaps.

      You have it rather backwards, the distance they know accurately from direct measurement using the time signal transmitted. Speed can be obtained as a derived quantity, the distance at two different times. But they can also measure speed directly via the doppler shift (this is probably only done Earthside).

      The position in the sky (providing the other two coordinates required for a complete position and velocity solution) is determined from Earth by a combination of time signal differences (just like with GPS) and long baseline interferometry. All of these different measurements are put into a model to calculate the state.

      --
      Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
    7. Re:Uncertainty principle by Anonymous Coward · · Score: 0

      Spacecraft have been using stars for attitude sensing since the 1960s, if not 50s. Typically bright stars like Canopus or Sirius. Line up three different stars in different sensors and you know your exact attitude. (The sun, moon, etc are too big -- you need point sources.)

    8. Re:Uncertainty principle by budgenator · · Score: 1

      The spacecraft uses the clock to tell the Earth station exactly what time it sent the signal, we know what time we received the signal and therefore know how far away it is to +- 1m. With the new clock we don't have to worry about keeping the clocks synchronized like we do with the current clock. The new clock is being tested for interplanetary vehicles, with use in GPS satellites is a side benefit.

      --
      Apocalypse Cancelled, Sorry, No Ticket Refunds
  12. I need this accuracy! by Anonymous Coward · · Score: 0

    what is its ntp address?

    1. Re:I need this accuracy! by sl3xd · · Score: 1

      If you want something more accurate than internet-based NTP, you can try: Your own Stratum-1 NTP server (it's fun, do it!).

      This lets you connect a GPIO pin of a Raspberry Pi directly to the Pulse Per Second pin of a GPS receiver (which receives the signal from multiple satellites simultaneously, and each has multiple atomic clocks. GPS, GLONASS, Galileo, Baidu...) The receiver I use typically sees at least 15 satellites, which isn't too hard when there are four constellations in various stages of completeness.

      The big issue is that NTP isn't really accurate past a millisecond or so for network synchronization. If you need better than that, you're going to have to go with the Precision Time Protocol which can get you down to a microsecond or so - much better than NTP.

      --
      -- Sometimes you have to turn the lights off in order to see.
  13. Huh? by Anonymous Coward · · Score: 0

    More powerful?

  14. So how powerful is it? by Onymous+Hero · · Score: 1

    Neither the summary nor the title give any indication how much power this clock dissipates. 10kW? 100kW? How does this compare to previous atomic clocks? How will it be powered? These are questions we need answers to!

  15. That'll be interesting by CODiNE · · Score: 1

    Soon you'll be able to course correct satellites right into the ground.

    --
    Cwm, fjord-bank glyphs vext quiz
  16. I'm NOT impressed by Anonymous Coward · · Score: 0

    That's not very accurate for an Atomic Clock. Especially if it's so large it needs a Falcon Heavy to lift it.

  17. Hmm by bagofbeans · · Score: 2

    Shirley if it has a powerful dong it should be used to time porn films?

    1. Re:Hmm by DickBreath · · Score: 1

      DickBreath's Law: Any background music used in pr0n films is interchangeable with background music for Power Point presentations.

      --

      I'll see your senator, and I'll raise you two judges.
    2. Re:Hmm by CrimsonAvenger · · Score: 4, Funny

      Shirley if it has a powerful dong it should be used to time porn films?

      Not just no, but...no. And stop calling me Shirley....

      --

      "I do not agree with what you say, but I will defend to the death your right to say it"
    3. Re:Hmm by budgenator · · Score: 1

      DickBreath's Law: Any background music used in pr0n films is interchangeable with background music for Power Point presentations.

      Well that certainly explains an embarrassing reaction of mine at the last briefing.

      --
      Apocalypse Cancelled, Sorry, No Ticket Refunds
  18. Did anyone else hear "F**Kin Heavy"? by bjdevil66 · · Score: 1

    Forget the Falcon Heavy; I can't wait for the next F**kin Heavylaunch!

    1. Re:Did anyone else hear "F**Kin Heavy"? by quenda · · Score: 1

      No, you must be thinking of the new rocket under development, the BFR, which takes its name from the Big Fucking Gun in Doom games.

      Sometimes a Falcon is just a Falcon.

    2. Re:Did anyone else hear "F**Kin Heavy"? by david_thornley · · Score: 1

      Sometimes a Falcon is just a Falcon.

      But is it? The next project is the Big Falcon Rocket, and we all know what that sounds like. Did Musk pick "Falcon" so he could set that up sometime? It's a perfectly good rocket name, distinctive and giving the impression of speed and power, but is that all that it is?

      --
      "When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
    3. Re:Did anyone else hear "F**Kin Heavy"? by quenda · · Score: 1

      Did Musk pick "Falcon" so he could set that up sometime?

      I did consider that. Seems possible, but more likely just a coincidence, conveniently allowing the early internal 'bfr' codename to be retained for polite usage.
      Would Musk really have chosen his rocket name in order to make a weak double entendre on an obscure element of an old video game?
      He says it is named after the Millennium Falcon.

  19. Post Powerful Atomic Clock Ever Launched by linear+a · · Score: 1

    100 megatons?

  20. Re:Launch Trump into deep space forever by budgenator · · Score: 1

    Zaphod Beeblebrox never had a problem with that.

    --
    Apocalypse Cancelled, Sorry, No Ticket Refunds
  21. Powerful? by mschaffer · · Score: 1

    I could not find any mention of horsepower, voltage, current, political influence, or anything that would substantiate "most powerful atomic clock"?

  22. isMentioned("Musk") goto: UNDERWHELMED by Anonymous Coward · · Score: 0

    general purpose code for /. stories involving anything associated with Mr. Musk.

  23. not using Apple maps by Anonymous Coward · · Score: 0

    If they used Apple maps they would miss the delivery address, let alone get it in the payload module.

  24. Too Trump-like... by mschaffer · · Score: 1

    Makes me think of how Trump exaggerates things: This is the most powerful clock (hand waving)...it's the best clock (gun gesture)...you'll see how good it is (hand going in circles)...

  25. Anti-nuclear protests by quenda · · Score: 1

    After all the Luddites protesting at the Cassini launch, I wonder how many this will attract?

  26. The "so-called" Deep Space Atomic Clock? by Anonymous Coward · · Score: 0

    ... it's _actually_ called the Deep Space Atomic Clock. wtf?

    1. Re:The "so-called" Deep Space Atomic Clock? by Anonymous Coward · · Score: 0

      Yea, it's useful for solar system navigation. It's like GPS for our space probes.

  27. Re:... Will Carry the Most Powerful Time Machine . by freeze128 · · Score: 2

    Seeing that Elon Musk likes to launch cars into space, maybe it will be a DeLorean.

  28. Most powerful atomic clock by OrangeTide · · Score: 1

    This new atomic clock has a yield of 10.4 megatons (over 450 times more powerful than the bomb dropped on Nagasaki during World War II)

    --
    “Common sense is not so common.” — Voltaire
  29. Re:... Will Carry the Most Powerful Time Machine . by Anonymous Coward · · Score: 2, Funny

    Seeing that Elon Musk likes to launch cars into space, maybe it will be a DeLorean.

    They've tested this several times. But every time the rocket gets to 88 mph, the DeLorean disappears.

  30. Whose 2 ns? by scorp1us · · Score: 1

    It would seem that there's a lot of ambiguity in this clock. If you're looking at 2ns per day, then the orbital speed will have relativistic effects, not including the distance from earth as well. So who is this keeping time for?

    --
    Slashdot's rate-of-post filter: Preventing you from posting too many great ideas at once.
    1. Re:Whose 2 ns? by sl3xd · · Score: 1

      It's mostly for navigation.

      Even 18th century celestial navigation was dependent on accurate clocks - Then, as now, a more accurate clock gives you a more accurate location.

      Relativistic effects are important, and the GPS system uses all of them (as does its siblings).

      GPS Satellites subtract 45 microseconds per day due to their position high above Earth's magnetic field, and then add back 7 microseconds due to their orbital velocity -- making a rough 38 microsecond/day correction.

      --
      -- Sometimes you have to turn the lights off in order to see.
    2. Re:Whose 2 ns? by sl3xd · · Score: 1

      Earth's magnetic field

      Yeah, I meant to say gravitational field. Sorry.

      --
      -- Sometimes you have to turn the lights off in order to see.
  31. GPS by Anonymous Coward · · Score: 0

    Good point. In reading the linked article in the OP, I came across this:

    "... results have shown DSAC to be upwards of 50 times more stable than the atomic clocks currently flown on GPS."

    We all know how important a very stable geniu- er, clock is, now.

  32. Millionths? by Anonymous Coward · · Score: 0

    Disappointing to see trash journalism originating from space.com: why mention two nanoseconds in one sentence followed by seven millionths of a second in the next?

    Assuming constant drift (in the same direction) then 2 nanoseconds/day over ten years will get you 7,300 nanoseconds or 7.3 microseconds of total drift.

  33. Re:Launch Trump into deep space forever by kimvette · · Score: 1

    The People elected him; people are a problem.

    --
    The Christian Right is Neither (Christian nor right). See: Matthew 23, Matthew 25, Ezekiel 16:48-50