Ashes to ashes, stardust to stardust

By Phil Plait | April 12, 2011 7:00 am

On March 24, the NASA mission Stardust ran out of fuel and sent its last data to Earth. At 16:33 Pacific time the mission was officially ended.

Launched in 1999, Stardust became a wildly successful mission. It passed by the asteroid Annefrank, sampled the dust from one comet (Wild 2) — returning those samples to Earth in a special re-entry container while the spacecraft itself flew on — and looked closely at another (Tempel 1) to see the crater left by the Deep Impact mission.

It’s always sad to see a mission end, but I like to also keep my eyes ahead. Stardust may be done, but Rosetta flies on, heading toward a rendezvous with a comet where it will deploy an actual lander. The Dawn spacecraft will enter orbit around the main-belt asteroid Vesta later this year as well. And, of course, MESSENGER is now orbiting Mercury and returning data.

We learned a lot from Stardust, and we get better with this endeavor of solar system exploration as a result.

And that’s the whole point, isn’t it?

Image credit: NASA/JPL-Caltech


Related posts:

Followup: Deep Impact crater on Tempel 1
Stardust snaps close-ups of a second-hand comet!
A comet creates its own snowstorm!
The return of Stardust
Stardust@Home starts NOW

CATEGORIZED UNDER: Astronomy, NASA, Space
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Comments (19)

  1. Any idea where Stardust is headed? What sort of general direction is it going? Toward the sun to crash into it? Just generally shooting out into deep space? In or out of the plane of the ecliptic? I’m curious…

  2. Sam H

    Phil, have you seen Google this morning? It’s the 50th anniversary of the Gagarin flight!! 50 years since one brave man, strapped into a tiny, uncomfortable ship, was launched at thousands of miles per hour OFF THE PLANET (the first time that anyone had ever done it in human history), and became the first to see the fantastic landscapes of our fragile home from far above, and see the multiple sunrises and sunsets in a realm without air…
    Just sayin’ you should write a commemorating post today. :)

  3. So Stardust’s final mission was to see how much gas it left in the tank by burning it all? It seems like there should be some manner of gauging fuel left in a zero G spacecraft. What type of fuel is it? Do they use the same liquid oxygen/hydrogen that the space shuttle uses? Or is it something like the orbital maneuvering system and whatever that is?

    I’m also assuming that with a randomly timed burn, they didn’t really anticipate putting this spacecraft into and specific orbit or direction… so I’m also wondering where it’s going.

  4. I echo Sam H’s post!

    I also recommend this page: http://www.firstorbit.org/watch-the-film

  5. Nigel Depledge

    Well, I guess the guys on the Stardust team would have had some idea how much fuel it had left, and so would have had some idea of where Stardust’s orbit would end up. It seems likely it’ll be in a heliocentric orbit, but is it near-circular, or quite eccentric? Is it just another tiny piece of matter in the vast emptiness of the Asteroid Belt?

  6. angelo

    actually, IIRC, the point was to validate their fuel consumption models

  7. Chris A.

    Small world. A few weeks ago I found myself taking lessons from a former Stardust/Genesis mission scientist, who’s now teaching skiing in Jackson Hole. I wish I had known about Stardust’s impending swan song so I could have asked him how he felt about it.

  8. chris j.

    stardust, dawn, messenger, rosetta, deep impact… i long for the days of mariner, pioneer, and voyager.

    i know the reality of anti-science budget cuts that have crippled NASA’s ability to develop and maintain space programs, and not just individual spacecraft. but even if the reality is that each craft is something of a one-off, i think there’s something evocative to the idea of naming them as if they are part of a program. it makes you feel like there are more to come.

    this doesn’t apply to the orbiting observatories, which in my opinion are aptly named to honor historic astronomers (hubble, kepler, spitzer, etc.).

  9. OtherRob

    They did put a fuel gauge on Stardust, but it’s just too hard to read from here…

  10. toasterhead

    Endyo Says:
    It seems like there should be some manner of gauging fuel left in a zero G spacecraft.
    —–
    There is, but it’s complicated. Gravity has a nice way of uniformly squeezing fuel into the bottom of a tank so a sensor can read the level. In zero-g you have to be more creative.

    The Space Shuttle’s OMS pods use a combination of tank pressure gauges and in-tank sensors to estimate fuel quantity, but it’s only possible for the sensor to read the amount of fuel when the engine has been burning for 14.8 seconds – this is how long it takes for acceleration to push the fuel into the aft end so it can be measured. There’s also a blind spot between 30-45% due to a bulkhead in the middle of the tank.

    I’m not sure what the system is like for a probe like Stardust, but it would seem that the fuel sensors in the hydrazine tanks would be an unnecessary addition of weight, when managers can simply calculate the amount of fuel burned and subtract it from the initial volume. Especially if the engine has to be burning for the sensor to work.

  11. Craig

    Phil: PLEASE research and tell us where Stardust is now headed. That Neil Guy isn’t the only one curious about this.

  12. DennyMo

    I’m intrigued to learn that there’s an asteroid named Annefrank. Are there many asteroids named for Holocause victims?

  13. Keith Bowden

    Here’s a link to First Flight, a real time recreation of Yuri Gagarin’s first orbit, from his POV:

    http://www.youtube.com/watch?v=RKs6ikmrLgg&feature=player_embedded

    The odd thing? I found this on a Google search for something appropriate to post on my Facebook page to commemorate the day. It was on Fox News!

  14. Joseph G

    So Stardust isn’t slated for any lithobraking maneuvers? It’s just going to orbit the sun more or less indefinitely? If so, that’s doubly cool.
    I was one of the many folks who got their names saved on a DVD aboard Stardust. It’s pretty amazing to think that a million years from now, when no human structure currently on earth could possibly have survived weathering and geological change (and possibly humans and nukes), Stardust will still be out there. With my name on it (among others) 😀

  15. Joseph G

    @12 DennyMo: Asteroids are named after all manner of notable people. Including our friend Dr. Plait :)

    @10 Toasterhead: It’s funny, it sounds on the face of it like such a simple problem (measuring fuel levels) and yet…
    I wonder if you could just rotate the whole spacecraft and then have strain gauges on the fuel tank mountings that tell you how much force the tank’s exerting on the spacecraft as it swings around? You’d still use RCS propellant, but you’d need a whole lot less juice then burning the OMS engines for 15 seconds. You wouldn’t need to spin very fast, and you could take plenty of time for the tank to settle. If you’ve got a reaction wheel, you don’t even need to use the RCS.
    Of course, if you’re using this technique on a crewed vehicle, you might need to pack some extra barf bags 😀
    Actually, given the sensitivity of the strain gauges they have these days, I’ll bet that you wouldn’t need to rotate the craft very fast at all. And the bigger the ship, the lower RPMs you’d need. Just enough to drown out tidal forces and then some.

  16. db26

    They should have used the Mr. Fusion energy source from the back of Doc Brown’s Delorean. Those things last forever…

  17. Vex

    @14 Joseph G:

    That is pretty cool!! It’s offers a small feeling of immortality :)

  18. Messier Tidy Upper

    Thankyou Stardust and farewell.

    Lost in independent solar orbit
    To wander for aeons
    Passing who knows what
    A flying spaceprobe silent
    But enduring.

    I wonder if we’ll ever recover you in the far, far, distant future

    What the world -or better worlds -willbe like then?

    Or if you’ll fly forever until the protons decay and the cosmos grows cold.

    Thankyou Stardust and farewell.

  19. Nigel Depledge

    Toasterhead (10) said:

    Gravity has a nice way of uniformly squeezing fuel into the bottom of a tank so a sensor can read the level. In zero-g you have to be more creative.

    The Space Shuttle’s OMS pods use a combination of tank pressure gauges and in-tank sensors to estimate fuel quantity, but it’s only possible for the sensor to read the amount of fuel when the engine has been burning for 14.8 seconds – this is how long it takes for acceleration to push the fuel into the aft end so it can be measured. There’s also a blind spot between 30-45% due to a bulkhead in the middle of the tank.

    I’m not sure what the system is like for a probe like Stardust, but it would seem that the fuel sensors in the hydrazine tanks would be an unnecessary addition of weight, when managers can simply calculate the amount of fuel burned and subtract it from the initial volume. Especially if the engine has to be burning for the sensor to work.

    Yeah, the Saturn V and Apollo spacecraft had separate little motors to give the spacecraft a kick so that the fuel would move to the part of the tank where the pipes could draw it off and feed it into the main engines. This process is known as ullage, and the motors as ullage motors.

    If you look carefully at some of the footage of a Saturn V staging, you can see the ullage motors burn briefly (they only burn for a few seconds) before the next stage motors light.

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