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ESA Satellite Recovers: Total Loss To Geostationary

Posted by timothy on from the falling-forward-all-the-time dept.

Slimbob writes "About 2 years ago an Ariane 5 rocket malfunctioned and left a very expensive Artemis satellite in an unusable orbit. Well, over the course of 18 months, the European Space Agency actually managed to push the satellite into a usable orbit using measly 15mN ion thrusters! They managed the feat by reprogramming about 20% of the original control software and uplinking the patches to the satellite! See the ESA press release . Achievements include the first first major reprogramming of a telecommunications satellite, the first orbital transfer to geostationary orbit using ion propulsion, and the longest ever operational drift orbit."

47 comments

  1. Fuel by GigsVT · · Score: 3, Interesting

    The article says they used up almost all the ion fuel, but yet it will still have enough for 10 years of trim thrusting, was the original planned life much longer, or did it just have that much extra fuel?

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    1. Re:Fuel by Simon+Field · · Score: 4, Informative


      The article makes a distinction between the Xenon ion thrusters and "chemical propellant". The last orbital adjustments were made with "small chemical propellant thrusters, activated for the first time since launch".

      It looks like the 10 years number does not refer to the Xenon ion thrusters.

      --

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    2. Re:Fuel by phobonetik · · Score: 2, Interesting

      I've been reading a few recent slashdot articles on Ion thrusters (e.g. the space ladder, I think). Where's a good intro on the things? I'm almost pleased they exist, sounds nice and sci-fi, even if i'm 21 :)

    3. Re:Fuel by warpSpeed · · Score: 3, Interesting
      The article says they used up almost all the ion fuel, but yet it will still have enough for 10 years of trim thrusting, was the original planned life much longer, or did it just have that much extra fuel?

      Since the operational drift is so much longer then what was originaly antisipated, I would be that they are consuming much less propellent then originaly expected, so they are able to get "10 years" out of what is left.

      GStar 3 or 4, put up by GTE in the late 80s, had a simmilar fate. It was lobbed into a bad orbit, written off (paid for), and then slowly (very slowly) moved into a "usable" orbit. The satellite had less propellent avaiable to it, so it was allowed to drift up and down, and side to side.

      GTE sold cheap time on the satellite since you could only get 5 to 20 minutes at a time without re-aiming your uplink antenna. A friend of mine wrote the software (in basic) that people used to aim thier uplinks antennas. However, since the satellite was paid for already, any money coming in was gravy at that point.

    4. Re:Fuel by Simon+Field · · Score: 2, Informative


      A Google search for "ion thrusters" returned a wealth of information, much of it suitable for an introduction. An excellent one is here.

      These devices are not new -- they have been in use for years.

      --

      Free book: Science Toys You Can Make

    5. Re:Fuel by PortWineBoy · · Score: 2, Informative

      I love ion thrusters too. I think you'll be seeing more and more of them. Dr. Mark Raymond of JPL kept up a mission log on the Deep Space 1 mission which used Ion propulsion to meet and dramatically exceed its design criteria. Some great photos of that Ion engine are here.

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    6. Re:Fuel by hubie · · Score: 1

      One that I like can be found here.

  2. I stand in awe... by HotNeedleOfInquiry · · Score: 1

    of these guys and their accomplishment. Some fsking stand-up engineering for sure.

    --
    "Eve of Destruction", it's not just for old hippies anymore...
  3. This isn't the first innovative satellite recovery by Sierran · · Score: 4, Informative
    A few years ago, Hughes Communications engineers used a lunar orbital slingshot maneuver to recover AsiaSat 1, which had been stranded in an unusable orbit. The insurance consortium that had already paid out for the satellite accepted a salvage deal with Hughes, who had manufactured it in the first place (it was launched on a Proton out of Baikonur). While they were using the designed maneuvering engines, as opposed to the stationkeeping thrusters, they ended up sending the satellite completely out of cislunar space in order to make the save.


    Reference: Flug-Revue

    --
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  4. "15mN ion thrusters" by rthille · · Score: 3, Funny

    15mN ion thrusters
    See honey, size doesn't matter!

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    1. Re:"15mN ion thrusters" by MrPeach · · Score: 5, Funny

      It's not the size of the thrusters, it's the length of it's operation!

    2. Re:"15mN ion thrusters" by Theaetetus · · Score: 1

      It's not the size of the satellite, but the perturbation of the gravitation?

    3. Re:"15mN ion thrusters" by SatanicPuppy · · Score: 1

      It's neither the size of your thrusters, NOR the length...It's how you USE them that counts!

      --
      ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
  5. Don't understand their error rate calculations by dabuk · · Score: 1
    Link quality was almost perfect: a bit error rate better than 1 in 109 was measured. This means that 1 bit at most is received erroneously per 1 000 000 000 bits transmitted.

    I don't get this bit. If the bit error rate was measured at 1 in 109, surely that means that there should be approximately one bit received erroneously per 109 bits? How do they get a billion? Or is that in conjunction with an error correcting code?

    1. Re:Don't understand their error rate calculations by ptaff · · Score: 1

      I guess there has been a misprint and 109 is really ten to the ninth power.

      Probably attained with error-correction, too.

    2. Re:Don't understand their error rate calculations by Merlin42 · · Score: 5, Informative

      I think that instead of 109 it should have read 10 to the 9 or 10^9 ... now it makes perfect sense.

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    3. Re:Don't understand their error rate calculations by Daniel+Wood · · Score: 1

      Indeed. Where I work we consider 10^6 to be an ideal BER.

    4. Re:Don't understand their error rate calculations by retrac · · Score: 1

      wish we could be that sloppy. we shoot for 10^12

    5. Re:Don't understand their error rate calculations by Anonymous Coward · · Score: 0

      As others have said it's probably 1 in 10^9. Still, you can always use ECC to get as low an error rate as you want. The big problem is, you get slow and slower transfers.

  6. Cool Hack by JGski · · Score: 3, Insightful

    This kind of hacking has been going on for >30 years by NASA and the military to save satellites. Certainly saving expensive spacecraft is one of the clearly positive aspects of hacking and hacking talents.

  7. Great by tsa · · Score: 1

    What a fantastic achievement. Let's give three hurrays to Sir Isaac Newton, who made this all possible.

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    1. Re:Great by Anonymous Coward · · Score: 0
      Huh?

      It wasn't possible before his life or right after either. He also doens't seem to me to be the most important person either. Newton did a lot, but giving him full credit seems crazy to me. It's not like he invented gravity, orbits, computers, and, ion drives.

      Is this some kind of pro-Newton cult I wasn't aware of or a post by someone with nothing to say who just happens to know that Newton came up with the math to explain gravity.

    2. Re:Great by Anonymous Coward · · Score: 0
      One should note that the math Newton came up with explains dynamics, not just gravity, and it is this same math that is used to do the orbit calculations in the first place. In fact it was Newton that came up with the calculation for the velocity of an orbiting object. He also exactly solved the two-body problem and proved that the orbits are conic sections (elliptical, in this case). He also did a whole lot of other things which are quite impressive and amazing, but hey, you've got fingers, you look it up.

      Note also that even today, satellite orbits are still calculated using only Newton's Laws.

      Man, don't they teach you kids anything these days?

    3. Re:Great by FatigueStrain · · Score: 1

      Hmmm. I'm pretty sure that Kepler was the first guy to come up with the elliptical orbit idea (Kepler's Laws anyone?). Newton just ("just!" i should be so lucky [grin]) showed how this is derivable from an inverse square gravitational force. Oh yeah, and he invented calculus.

    4. Re:Great by hubie · · Score: 1
      Kepler stated that the planets move in ellipses. Newton showed (derived) that for a central force the resulting orbits (for the two-body problem) are conic sections, and in particular he showed that for an inverse square force in a two-body system that the resulting orbit is an ellipse.

      Basically Kepler made postulates (planets follow elliptical orbits with the Sun at one of the foci; planets sweep out equal areas in equal time; planet orbital period relationship to the orbital radius) that fit the data pretty well. Newton mathematically derived these from first principles and added corrections (e.g., the planets don't orbit the Sun, the Sun and planets orbit each other) that fit observations even better. Newton also starting working on the higher order correction terms to describe planetary motion when other bodies are present, which is the three-body (and higher!) problem (the three-body problem, by nature of not being integrable, has occupied the minds of some of the biggest names in mathematics ever since). I believe that above statement is true, that how satellite/spacecraft orbits are calcuated is essentially the same method that Newton was using when working on planetary orbit corrections.

  8. Expect more ions in the future by TheSHAD0W · · Score: 4, Interesting

    The results of this botched lofting actually bode well for future satellite installations. Admittedly, using ion thrusters for final delivery would take much longer than using standard rocket technology, but it would also be enormously less expensive. The weight savings would be large, at a stage where weight is the most expensive part of the flight.

  9. Wow by robbo · · Score: 3, Funny

    Imagine trying to do that to a windows box. With each patch you'd have to engineer a probe to go up and hit 'Ok' when it reminds you to reboot. ;-)

    --
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    1. Re:Wow by alexpage · · Score: 1

      Nah, you just get one of those l33t TCP-KVM things. Plug in PS/2 keyboard and mouse, and VGA, then VNC into it :) It's the best way to turn commodity PC hardware into something resembling a serious server.

  10. Ah, that's what they *want* you to think... by Samrobb · · Score: 1
    About 2 years ago an Ariane 5 rocket malfunctioned and left a very expensive Artemis satellite in an unusable orbit. Well, over the course of 18 months, the European Space Agency actually managed to push the satellite into a usable orbit using measly 15mN ion thrusters!

    Damn. It's obvious that Planetary's efforts on behalf of mankind have been negated yet again...

    "Why do I even have to say this? Why do I have to say
    'Get off the unique and probably alien plinth that zaps the
    unwary?' What is wrong with my life that I have to say
    these things out loud to someone?"

    - Jakita Wagner, Planetary #4
    --
    "Great men are not always wise: neither do the aged understand judgement." Job 32:9
  11. On patching satellites by bill_mcgonigle · · Score: 2, Interesting

    Does anybody know what kind of authentication they use and how they deal with failed patches?

    Seems like somebody probably thought it through for the cost of one of these programs.

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    1. Re:On patching satellites by OneFix · · Score: 3, Interesting

      Just a wild guess, but it's probably similar to how the Tivo does its update procedure. There are 2 boot partitions on the system...when an upgrade comes through, the system tests the integrity of the upgrade, switches the boot partition and reboots...

      I would figure they probably use a more elaborate system...but it's probably the same in practice...of course, they have simulators/emulators on the ground that can accurately recreate the satelite's internal components...so, there should be no bugs in the system when the patches are sent...

      The only thing they'ld need to worry about is noise on the uplink (corrupted files) and possible hardware failure...corrupted files could be tested for prior to patching, and hardware problems can be fixed by having backup systems...

    2. Re:On patching satellites by Frans+Faase · · Score: 1

      With adding some redundancy it is possible to have a reliable communication channel. Please realize that this kind of techniques have been used for several scientifical satilites going to the other side of our solar system.

  12. Fuel: Why not... by hcdejong · · Score: 1

    include a docking port, so you can send a 'cargo satellite' after it to refuel your $10^8 satellite?

    This would be expensive [1], but a lot less so than writing off a satellite that ends up in the wrong orbit. Also, you could keep your satellite operational far longer than usual: communications satellites IIRC are written off when they run out of fuel, rather than because of mechanical/electrical failures.

    1: or would it? You'd have to launch it, but you're launching just a load of fuel with some maneuvering motors attached to it.

    1. Re:Fuel: Why not... by Theaetetus · · Score: 2, Insightful
      _much_ cheaper to use solar-cell powered ion thrusters... which is what they did. That way, your fuel is already up there.

      -T

    2. Re:Fuel: Why not... by hcdejong · · Score: 2, Insightful

      No, your energy is already up there. AFAI understand, you still need to bring something that can be ionized, then accellerated to provide the actual thrust. Advantage of the ion drive is that the exhaust speed can be higher than with a chemical rocket, so you need less fuel to produce the same thrust.

    3. Re:Fuel: Why not... by Jonathan_S · · Score: 1

      They don't include a docking port to take on more fuel, for the same reason that the Shuttle has never performed its design goal of returning a sat to earth for servicing.

      The satellites electronics go obsolete before they run out of fuel. In general it is better for a company / country to boost a whole new sat with higher bandwidth, better resolution, more accuracy (depending on the sats design goal) and move the old one into a graveyard orbit.

      The exceptions to this tend to be science sats which are hard to get funding for and / or in weird orbits. In those cases it is a choice between doing ground side changes to prolong the sats functional life or having no sat at all.

      This instance was a unusual one becuase it was a brand new com sat that failed to achieve proper orbit; not an end of life sat running out of station keeping fuel. It isn't cost effective to add expensive refueling capability (and pay for the launch of refueling 'cargo satellites') to save the rare satellite that ends up in a wrong orbit that doesn't send it back into atmosphere and whose payload is fully functional. On a cost basis it is better to just get the insurance payout and build another sat.

    4. Re:Fuel: Why not... by Theaetetus · · Score: 1
      Good point, good point - you're right.
      Should have confirmed here first.

      Still, though, signifigantly less fuel.

      -T

  13. Re:This isn't the first innovative satellite recov by Mysticalfruit · · Score: 1

    Hmm, it makes you wonder if the possibily could have saved that other huge expensive communications satelite that they decided to dump into the pacific. I'm sure a whole bunch of "why didn't we do that!" email is floating around...

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  14. Awe by virve · · Score: 1

    Wow, one should have deep, deep respect for these people. The room for error is probably very small. When trying to patch substantial parts of the satellite's software the perils are obvious: any issues communication and stabilization might cause the loss of the spacecraft. And it is a bit difficult to reach the reset button...

    Are there any means of going back to a safe version of the firmware, or are there means of automatically rebooting the on-board computer?

    virve
    --

  15. Deep Space 1 was more impressive by Spamalamadingdong · · Score: 1

    The DS1 mission also used a xenon-ion thruster, and had several recoveries from mishaps more severe than anything sustained by Artemis. See The DS1 home page.

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  16. More to the point... by Spamalamadingdong · · Score: 1

    Saving weight in the thruster section allows more solar cells, batteries, transponders and antennas for the same launch vehicle. That's where the money is made.

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  17. Been done before by Spamalamadingdong · · Score: 1
    Are there any means of going back to a safe version of the firmware, or are there means of automatically rebooting the on-board computer?
    You can bet that there is at least one level of safemode in that thing. DS1 had such, and both hardware and communications-loss watchdog timers. DS1 recovered from a total failure of its star tracker to boot, and was navigated for some time using only its science camera and on-board software hastily written and uploaded for the purpose.
    --
    Scientists restrict study to entire physical universe; creationist
  18. Re:This isn't the first innovative satellite recov by Anonymous Coward · · Score: 0

    Is it just me, or is everything2.com completely fucking useless?

    I mean, you end up with a bunch of link between things and no actual content, say describing what cislunar space is. It's like the heat death of the web or something.