ISS boosted by Jules Verne

By Phil Plait | April 26, 2008 12:00 pm

Space, especially in near-Earth orbit, is not really a vacuum. The atmosphere is thin, sure, but it’s there. Any object orbiting the Earth only a few hundred klicks up is plowing through that ethereally thin stuff, which causes drag on it. This robs the object of energy, and the orbit lowers. That in turn drops it into thicker air, which increases the drag, which speeds up the process. Unless action is taken, a fiery fate awaits.

The International Space Station is in such an orbit. Every day it loses altitude due to drag, and left on its own would burn up in the Earth’s atmosphere in a matter of years. The European Space Agency, however, has built the Jules Verne Automated Transfer Vehicle, which is capable of boosting the orbit of ISS to safer heights. And that’s just what they did a few days ago, lifting the station’s orbit by 4.5 kilometers.

Universe Today has all the details. This is a cool story, and if you like it, Digg it! More people should read about space success stories.

CATEGORIZED UNDER: Space

Comments (23)

  1. For more information, see the ESA video “ATV: a very special delivery” – http://www.esa.int/esaMI/Space_In_Bytes/SEMH6XJ26DF_0.html

    Disclosure: one of the authors of the video is a friend of mine.

  2. This is what is better known as “micro-gravity”, right?

    I have heard that term used in describing what the shuttle has to deal with by being in the relatively low orbit it usually flies in.

  3. Tim G

    “Micro-gravity” is a colloquial term. It’s the station’s acceleration relative to the acceleration due to gravity that is tiny.

  4. Yoshi_3up

    That’s the same that happened with USA 193, right?

  5. Sarah Anderson

    And great title as well. I’m sure Jules would be a booster.

    “Mr. Sulu, enter a parking orbit”

  6. Max Fagin

    The link says that Jules Verne “provided a thrust of 2.65 m/s.”

    Does that mean Verne gave a total delta-V of 2.65 m/s to the station?

    Or does it mean the boosters on Verne are capable of accelerating the station at 2.65 m/s^2?

  7. Ed Davies

    Max Fagin: I don’t think the 2.65 can be m/s² as that would be over a quarter of a gravity – I can’t imagine the ISS would hold together under that. Also 2.65 m/s² for 12 minutes 20 seconds would change the speed by 7000 km/h which is a huge amount; the orbital velocity is around 27 000 km/h.

    A delta-V of 2.65 m/s², on the other hand, would increase the orbital velocity of, say 7400 m/s² to 7402.65 m/s² (Just rough guess based on circumference of the Earth of 40 000 km and orbital period around 90 minutes). Using ½mv² that corresponds to an increase of energy of 19 600 J·kgâ?»Â¹. With g at that altitude of, I’m guessing, 9.5 m·sâ?»Â² the reported increase of altitude of 4.5 km corresponds to an energy increase (using mgh) of 39 900 J·kgâ?»Â¹. As I understand it, when you raise an orbit half the extra potential energy for the extra height comes from the work you actually need to do to raise the orbit and half comes from the reduced kinetic energy of the slower speed in the higher orbit so that looks about right for the 2.65 m·sâ?»Â¹ being the delta-V.

  8. Reed
  9. Jeffersonian

    The solution is cool in its relative simplicity. Solved!

  10. Sili

    GO EUROPE!!

    I know this has nothing to do with the EU (yet), but I still want to feel a little proud of it.

    Thank you, Paolo, that was a very nice video. I guess it’s unavoidable, but it’s still troublesome that we need a 20 tonnes vehicle to deliver 6 tonnes of goods. Very wasteful.

  11. It really has nothing to do with EU, and probably never will. EU and ESA are two different organizations, with widely different goals and somewhat different memberships, although the solid core of both are the same countries.

    My own country became a full member of ESA only recently, despite being an EU member for 20 years now. So recently, in fact, that it doesn’t even take part on the ESA effort in the space station… :(

    Europe’s various levels of political, scientific, economical, military, you-name-it, integration are not for the faint of heart. Things can get pretty confusing real quick.

  12. Ed Davies

    Sorry. I won’t use Unicode here again. Racist :-). Mostly I was trying to use middle dot for multiplication (which sort of worked with an accented A before it) and superscript minus, one and two.

  13. Astro

    Heavens Above website gives the height variation of the ISS:
    http://www.heavens-above.com/IssHeight.aspx

  14. Quiet Desperation

    How high could they raise it and still have the ISS reachable by the Space Pickup Truc- er, I mean, Space Shuttle?

  15. Reed

    @Quiet Desperation
    Depends on how much payload you want to carry. From what I understand ISS is currently being kept relatively low because there are some heavyweight payloads going up, such as the Japanese pressurized module going up on STS-124. For these missions, you couldn’t have ISS much higher and still deliver the same payload. An lightly loaded shuttle could go much higher, but AFAIK the ceiling for Soyuz is about 400km.

    Since we are near solar minimum the drag penalty for a lower orbit is reduced.

  16. The Jules Verne certainly does seem to be successful in that it is meeting its mission objectives. However, I’m disappointed that in 2008 we are still operating a 100% disposable spacecraft. I think the ISS is a great venture but if they can’t find ways to be greener with their budget and profile, what message does that send to us common folk who don’t have quite such an exciting walk to the office?

  17. Michael Lonergan

    I’m just wondering if the “Jules Verne” is a one-off, or are they planning on building more of these vehicles? Also, even though the ISS is not completed yet, what are the plans to bring it down at the end of it’s life?

  18. Arnaud

    Michael,

    The “Jules Verne” is the first of a batch of 4 vehicles, if I remember correctly. That first one was pretty much a test launch and flight which is why it wasn’t carrying as much cargo as it could have. There may be further orders coming later.

  19. John Phillips, FCD

    Michael Lornegan. The Jules Verne is already human rated and there is talk, but only talk for now, about making it a full manned launch and recovery vehicle. However, for now, it is only being used as ESA’s contribution to the ISS and so was more a proof of concept and recovery wasn’t a necessary part of the equation.

  20. Very nice video, Paolo. The only thing I would change is the simulation showing the final approach happening in the direction of travel (this has to be done cross track to keep from raising or lowering the altitude when closing).

    I have a couple of questions about this maneuver, though, that I’m sure someone here can answer.

    1) How did they do the re-boost on the ISS previously?

    2) How do they guarantee that the centerline of the thrust from the JV module passes through the CG of the ISS? With such an ungainly structure, how do they even know where the CG is? Are all the crew and their equipment stowed in specific locations? What about the trash stuffed into the other service vehicles? How accurately does all that have to be placed? I would think there are limits to how much the guidance controller on the JV would be able to compensate and keep the station from pitching when you turn on the thrusters.

    It would seem that if they’d gone with the Ley/von Braun “doughnut” station, the drag would be a lot less than with those flat panels out there, maximizing the drag :-)

    – Jack

  21. Joe Meils

    This sort of thing facinates me. If we can boost the ISS to a slightly higher orbit, is there any reason we couldn’t dock a lander or two to it, put a booster on it as well, and take the whole thing to the moon for an extended mission?

  22. JB of Brisbane

    If only NASA had thought of something like this when Skylab was sent up, but it was thought that the shuttle would be up and running before Skylab would require boosting. I wonder if any records still exist of shuttle-based solutions to Skylab’s predicament.

  23. Buzz Parsec

    Jack,

    Before the ATV, they used engines on one of the Russian modules (Zvezda,, IIRC), Progress supply ships and the shuttles to reboost the ISS.

    To keep the thrust vector aligned with the CG, I think the ATV engines are steerable and they also use its steering thrusters (and probably the stations’ gyros) to damp out any residual rotation caused by misalignment. Right now, there are two sets of solar arrays on the port end of the truss and only one on the starboard end. Compensating for that somewhat is the Columbus lab and the airlock on the starboard side. But next month they’ll be adding the Kibo lab on the port side, which means if it’s more or less balanced now, it won’t be in June, at least until they add the last set of solar wings to the starboard side, currently scheduled for December. I’m sure this was all considered in excruciating detail when they were planning the assembly sequence.

    JB – I know that at one time NASA planned to have an early shuttle flight dock with Skylab and give a reboost, but the shuttle was delayed a couple of years and the Sun was more active than expected (which causes the upper atmosphere to expand, increasing drag on objects in low orbit), and Skylab came down before the shuttle was ready.

    BTW, Jack – the Ley/Von Braun donut station was planned to orbit at 1000 miles (or Km, but it was the 50’s, I’m pretty sure they used miles in the US), which would have put it high enough that reboost wouldn’t be a serious issue, but also right in the middle of the inner Van Allen Belt. :-( BTW, I have that book that appears in the titles for Napoleon Dynamite… An endless source of amusement for my younger siblings.)

    And Joe, yes, there’s only one issue preventing that, $$$$.
    (But it would have to be a low-acceleration booster… The ISS isn’t
    that strong! Speaking of which, wouldn’t this be a perfect application for an ion engine? Scotty, give me full impulse!)

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