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ESA to Give New Life to Old Satellites 119

Posted by chrisd from the space-is-still-pretty-cool dept.
JPNews writes "The European Space Agency is designing a program (www.esa.int) to re-configure dying television transmission satellites to be used as a XM Radio-like satellite radio network. 'Once in position, 35,000 km away in space, TV satellites will remain in orbit forever, but their useful life amounts to 15 years or less... further life can be squeezed from a low-propellant TV satellite switched over to mobile digital radio broadcasting where precision position control is less important.'"
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ESA to Give New Life to Old Satellites More

ESA to Give New Life to Old Satellites

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  • ...the N-Gage was going to wipe out satellite radio?
  • Since when has 'precision position control' been more or less important? Sounds like marketing hype to me. Wouldn't it then be called 'sloppy position control', and thus deemed important once again? trying not to laugh...

    • Re:Excuse me? (Score:5, Informative)

      by jovlinger ( 55075 ) on Wednesday February 05, 2003 @11:56PM (#5238099) Homepage
      Never used a TV satelite dish have ya sonny? You have to aim the dish fairly accurately at the satelite, which kinda requires that it be where it should. Since you never get perfect geosynch (IANAOrbitalEngineer, but stands to reason), you need to use little spurts of attitude jets to keep in place. You'll also need these to despin the gyros that maintain attitude from time to time.

      The punchline is that these XM radio receivers, like GPS, don't require a dish to be pointed at the satelite, so it's free to stray further from it's assigned station. This allows you to use less fuel in staying in place.

      But then, you're probably a troll, so I just wasted my breath.

      • Re:Excuse me? (Score:3, Informative)

        by tanveer1979 ( 530624 )
        I would like to add here that many times communications satellites used for TV also are used for VSAT communications. On TV if the satellite has wobble booters in the receiver can compensate, but such satellites are pretty much useless for internet(VSAT).

        We has a 128kbps VSAT terminal at college supplied by aging ernet satellite. Data rates used to come down to 2kbps yes kilo BITS. Such satellites are normally space junk, however this may allow us to sqeeze the last bit of life from the satellite, and this will result in cost of cummunications to come down pretty much. I wonder why didnt they think of it before!

      • Re:Excuse me? (Score:3, Informative)

        by Animats ( 122034 )
        There's a definite fuel penalty associated with holding geosynch position tightly. Some comsats have only 20Kg or so of on-orbit maneuvering fuel. There's a trick called a "COMSAT orbit" (because it was invented by somebody at COMSAT Corporation) to allow more of the deviation caused by the moon to be tolerated. The satellite moves around a few degrees relative to the earth, instead of holding geosynch position tightly, but long-term error isn't allowed to accumulate.

        I'm not really up on this, but I used to work at a place that made the Intelsat satellites, and some of the people around me were working on this stuff.

        • You probably mean the Comsta maneuver , in which the orbit inclination is not only corrected but overcompensated so that the orbit after the maneuver is inclinde in the opposite direction. so instead of letting the satellite orbit to drift to X degrees and then correct it back to 0 inclination (parallel to the earth's equatorial plane) the orbit is set to an inclination of -X and let to drift all the way back to X at which time the maneuver is applied again.
      • Wouldn't these satellites still need to be kept in position in order to prevent them from wandering off in neighboring orbital positions (where they might collide with other satellites, which are still operational?)
        • Not really. Satelites are hundreds to thousands of miles apart. Even satellites that appear to be in the same location (like the 3 main DirecTV satellites for example) are a few hundred miles apart. So as long as you maintain some kind of reasonable control, there is no real concern about them colliding.

  • less space trash (Score:4, Interesting)

    by trmj ( 579410 ) on Wednesday February 05, 2003 @11:13PM (#5237855) Journal
    It's good that they are looking at reusing some of the old junk that we can't effectively remove from space.

    Perhaps NASA could sell off some of their old, unused satellites to get (some of) the funding the need?

    • Just a guess, but I don't think that most of the satellites (save a few) are the property of NASA.

      Launch service:

      NASA launches some, the military does some of their own, and commercial lauch providers do the majority.

      Actual satellites:

      The satellites themselves are owned by the entities that wanted them up there.

      - Commercial (consortiums of telcoms, TV)
      - Military (DOD, NRO)
      - Other non-NASA governmental entities (NOAA, climate).

      Only a few would be NASA's (astrophysics, comsology, etc.)

  • how about making the satellites do starband or richochet internet?

    • Re:internet (Score:4, Funny)

      by Anonymous Coward on Wednesday February 05, 2003 @11:20PM (#5237898)
      I wouldn't want internet access from an elderly satellite that's going to be wobbling all over the place in its orbit after running out of propellent.

      I can get just as unreliable access down here on the ground, thanks.

  • Sounds interesting (Score:2, Interesting)

    by amigaluvr ( 644269 )
    I am a little suspicious of motives and lock-in though.

    If these are up for a further 15 years, is there any more support after that?

    Or would we be locked-in to using a system that by then is even more out of date.

    Interesting idea, but care needs to be taken

  • A Primer on the ESA (Score:5, Informative)

    by use_compress ( 627082 ) on Wednesday February 05, 2003 @11:15PM (#5237871) Journal
    from: http://www.space.com/news/spaceagencies/esa_25year s_000602.html [space.com]
    However, ESA's biggest achievement of all, explained Bonacina, lies not in any one particular space project. Rather, it's the fact that 15 European nations have successfully worked together, and in cooperation with other non-European space programs, to reach a common goal.

    It's amazing how little a program this wide in scope accomplishes :)
    • I agree, we need another space race to get the US to give NASA more funding and a kick in the pants. After all, competition is better than a monopoly for consumers.
    • However, ESA's biggest achievement of all, explained Bonacina, lies not in any one particular space project. Rather, it's the fact that 15 European nations have successfully worked together, and in cooperation with other non-European space programs, to reach a common goal.

      That is just politically correct rubbish. The taxpayers of those 15 countries don't care that all the ESA employees have a group hug every morning, we care about actual results and effective use of resources. It's like telling an athlete that "it's not the winning that counts". Hell, get any bunch of people together from 15 countries, give them a budget of billions and tell them to have a good time, and they'll "cooperate" just fine!

  • Precisely the kind of ideas aerospace needs now... (Score:5, Insightful)

    by coupland ( 160334 ) <dchaseNO@SPAMhotmail.com> on Wednesday February 05, 2003 @11:18PM (#5237889) Journal
    With NASA giving the one-fingered salute to the unfairly maligned "faster-better-cheaper" programme it's nice to see the ESA taking a more pragmatic approach to things. I have a great deal of respect for NASA but I also want to see Europe, China, India and others up the ante, and this seems like a perfect example.
    • I'll agree. Looking back on history, it just seems like there was no motivation like competition.

      David Brin points out America is a peculiar society in that its populace considers its golden age to be in the future. But I wonder if that is really so. We already say "back in the day we were on the Moon".

      I'm not saying we are past our peak, but I wonder if something like going to the moon will be where historians put American's peak or if we are going to have the courage to do more.

      -------------------
      OnRoad [onlawn.net]: Reporting what happens in America when the police get out of hand.

    • Re: (Score:2, Insightful)

      by account_deleted ( 4530225 )
      Comment removed based on user account deletion
    • Well the ESA is at least cheaper.

  • Just when you thought it was safe (Score:5, Funny)

    by Anonymous Coward on Wednesday February 05, 2003 @11:19PM (#5237894)
    Dammit. Where'd I put my tinfoil hat.

  • To summarize (Score:5, Informative)

    by mlyle ( 148697 ) on Wednesday February 05, 2003 @11:22PM (#5237901)
    Most older communications satelites have what are called "transponders"-- they take everything that comes in on a certain band of frequencies and plays it out on another set.

    Because usually relatively high-bandwidth analog signals with high quality requirements are sent through these transponders, and the satelites have a relatively small amount of output power, high gain antennas (big satelite dishes) are required to recover the signal, which must be very precisely pointed.

    By using digital signals and audio compression technology, suddenly the signals can be narrower bandwidth. Noise is proportional to bandwidth, and since the signal is narrower, signal/noise ratio is improved. This means high-gain antennas may no longer be strictly necessary, and thus the position of the satelite becomes less critical as the orbit decays.

    Note that this does not lock us in to a proprietary standard-- if the spectrum is allocated for this purpose, smarter digital transmitters can be put into space for the same purpose later.

    Still important is attitude control-- the satelite's antenna must be pointed down and the solar panels pointed in a useful direction. But this often uses gyroscopes, reaction wheels, and magnetic systems-- which do not use propellant.

    Finally, battery life is a question. No communications satelite is constantly receiving solar power, so if the satelite is operated while not in view of the sun, batteries on the satelite discharge. Satelites can withstand a limited number of charge cycles before they fail, and this is likely to form the true upper bound on satelite lifetime.

    In all, it's a good idea. I imagine we'll see lots of clever ways to emerge on how to use legacy hardware we've put in space, as launch costs remain so expensive.
    • "I imagine we'll see lots of clever ways to emerge on how to use legacy hardware we've put in space, as launch costs remain so expensive"

      Sound point(s) that enforce the call for less emphasis on romantisized manned missions and more funding and focus on unmanned drones, robot probes and satellites.
      • Honestly, I really hope so.

        I don't think we should completely abandon manned space missions, but the ISS is going to cost $100B over its lifetime-- figuring that the cost of a 4 year university education is $100k, we could create a million more scientists on earth-- and think how much that could do to solve the autonomous control and robotics problems that currently limit unmanned missions.

        Right now, basically 2 of the 3 members of the ISS crew are dedicated to doing things to keep the ISS running. Surely with $100B we could get as much real space science done as that one individual who's concentrating on science on the ISS over these next 10 years can, right?

        Let's learn what we can now cheaply, and regroup in 10-25 years and go to Mars, or form a colony on the moon, or do something else really radical that broadens the future for mankind.

        • Let's learn what we can now cheaply, and regroup in 10-25 years and go to Mars, or form a colony on the moon, or do something else really radical that broadens the future for mankind.

          The problem is not now, nor has it ever been, a lack of technology or science.

          The problem has been, since the days of Skylab, one of money. (Trivia question: what was the first scheduled shuttle mission? A _BOOSTER_ for skylab. Had the shuttle + booster been built in time, we'd have had a space station in orbit for quite possibly just as long as the Russians.)

        • The Bush Administration would like to spend $200-300B for Gulf War 2. If we spent the money educated a few million scientists, they'd have the ability to do a huge amount of good for society, which won't happen if we spend the money taking people away from productive jobs to bomb other people, or turn a good chunk of US factory production into making missile and tank engines instead of car and Cessna engines. That doesn't even begin to count the costs of the destruction done to Iraq during Gulf War 1.0, or the ~200,000 people killed directly during that part (that was the US government estimate), or the ~500K-2M people who died during the decade of Gulf War 1.1 (UN estimates), mainly from bad water (because we bombed their water systems) or starvation (because the destruction further trashed their economy, as well as killing off a lot of productive people, and because the embargo prevented them from getting medicine or imported food or water system repair parts.

          I'd rather have privately-built space stuff, but even blowing the $100B on the space station or a really great fireworks show would be better than blowing it on a war. And if we don't buy college educations for a million or two scientists, we can just as well buy college educations for a million or two liberal arts students so we'll get better literature or at least better-written computer manuals and television shows...

    • good points.

      One thing: when the battery dies, could you just use the bird when it's in sunlight? what's the orbit period like up there? would you have the content dropping out in the middle of the transmission, or could you hand it off to another old bird that just passed the daylight terminator?

      • Re:To summarize (Score:2, Informative)

        by Captain Nitpick ( 16515 )
        One thing: when the battery dies, could you just use the bird when it's in sunlight? what's the orbit period like up there? would you have the content dropping out in the middle of the transmission, or could you hand it off to another old bird that just passed the daylight terminator?

        Since they're talking about old tv satellites out at 35000km, it looks like these are geosynchronous orbits. This means that an orbit takes 24 hours. A geosynchronous satellite should only be in Earth's shadow for a brief time each day (too lazy to look it up/do the math).

        • A geosynchronous satellite should only be in Earth's shadow for a brief time each day

          Remember that the Earth's equatorial plane is "tilted" with respect to the Earth-Sun plane by ~23 degrees. So a true geosynchronous satellite (0 degrees inclination) will not experience Earth eclipses of the sun every day. These type of eclipses will only occur for a few weeks centered around the equinoxes (i.e., March and September), and can last for up to an hour or so per day. The details will depend on the orbital elements of the satellite.

          There are also those pesky lunar eclipses of the sun. These can occur at a maximum of once per 28 days. But in reality they don't occur that often, since the geometry doesn't always line up, so you're looking more at 2-4 of these per year.

          Travis
          • Upon further review, I should have said "the equatorial plane is tilted with respect to the Earth's orbital plane about the Sun". I think that makes more sense.

            Not that anyone reads comments buried this far down, but hey.

            Travis

      • Re:To summarize (Score:3, Informative)

        by mlyle ( 148697 )
        When we're talking about geosynchronous satellites, or near-geosynchronous satellites, the orbital period is going to be remarkably close to 24 hours.

        The answer: Maybe, but probably not. Usually the satellites have control computers and bringing them back up after they've been powered off can be difficult. It also depends on how the satellite's power system is arranged.

        It's also important to note that the closer it gets to midnight, the closer to the horizon (and thus, the harder to listen to) a satellite has to be to be in sunlight-- and there's not likely to be as many geosynchronous satellites over unpopulated latitudes.

        The fact that stabilization coils and reaction wheels go offline when the satellite's battery discharges means the satellite might very well begin tumbling and thus not get so much useful power when it returns to daylight-- and also not know its exact attitude to begin to recover.

        Finally, the failure mode of the battery is important. If the battery fails "closed", or shorted, it might connect the negative sides of the power bus to the positive and not allow the panel to generate any useful power.

        Basically, when power systems start to fail on a satellite, even when it's a temporary problem (e.g. an accidental discharge of the batteries because of an orientation problem), it can be pretty hard to recover from-- if it's possible at all.
    • I imagine we'll see lots of clever ways to emerge on how to use legacy hardware we've put in space, as launch costs remain so expensive.

      I have wondered in the past if it would be possible to launch kind of backpack units to help out old satelites. I was thinking of small boxes with attitude jets or whatever runs out which could bolt themselves to otherwise useless satelites. I hadn't thought of the battery problem though.

      So, this article inspired me to wonder why they don't build satelites with replaceable bits containing the consumables. A standardised box with batteries, manoevering abaility and whatever else tends to run out. These would persumably be cheaper to launch than a complete new satelite, and cheaper to build because they are standard.

      Take a clever design to give enough flexibility, but hell, that is what we have engineers for!

      • It's possible, but pointless. Satellite technology is changing fast enough that it's better to launch a new bird than try to repair the first one. It's similar to the motherboards with 'upgradable CPU' you see occasionally. No-one really upgrades the CPU, because the needs have changed.
        • It's similar to the motherboards with 'upgradable CPU' you see occasionally.

          More like throwing aay your printer when you run out of ink, with the added feature that getting the new printer delivered will cost you millions of dollarpounds.

          • The thing is, intercepting an orbit is also very very expensive in propellant (in fact, if it involves a significant change to the orbit's inclination, it's basically impossible). So it's not like you could launch multiple of these "backpacks" from one launch.

            Even though satellites are very expensive due to the (over)engineering involved, they have limited design lifetimes. And when a launch is going to cost you $50M, you're better off just replacing whatever you have with something that meets your current needs-- and something that sets the component failure lifetime clock over again.

            This doesn't even mention the difficulty of trying to hook up to the satellite's power bus, etc.
  • I thought that with digital broadcasting now that satalite radio was pretty much dead anyways.

  • Amateur Radio (Score:5, Interesting)

    by sQuEeDeN ( 565589 ) on Wednesday February 05, 2003 @11:26PM (#5237916)
    It would be quite cool, depending on the frequencies, if they could open the sattelites up to hams. There are a few sattelites here and there available for amateur use, but something launched by the ESA is probably waay cooler.
    Of course, this all depends on the ability of them to switch which frequencies the sattelites use--I imagine they weren't originally designed to use Ham frequencies. As for "sloppy" orbits, we hams typically have fairly sophisticated tracking equipment: a 486 pc, running any one the free tracking wares, connected to a dual-axis antenna rotator. Makes it a challenge!!

  • XM hacking... (Score:2, Interesting)

    by Anonymous Coward
    just wondering how long they think they can stop people from hacking the xm network...

    broadcasted stuff has almost always been 110% easier to beat (read: harder to find the pirates, arrrrrg!) than conventional cable/wired networks.

  • Great! (Score:3, Insightful)

    by megaduck ( 250895 ) <dvarvelNO@SPAMhotmail.com> on Wednesday February 05, 2003 @11:57PM (#5238104) Journal

    This kind of thinking is exactly what we need right now. Our space program has kind of a "chicken and egg" problem right now. NASA doesn't really have the budget to do the research we need. Space won't become cheaper until commercial interests get involved, and commercial interests won't touch space as long as it's so expensive.

    By eliminating or reducing launch costs, we get more people interested in joining the party. More companies == more research dollars == better space programs for everybody.

    • Re:Great! (Score:3, Interesting)

      by anshil ( 302405 )
      Well it ain`t so easy it, this way we should focus on an economic basis, instead of startrek dreams.

      For example thought economically why do you need men in space after all? Answer, you don't. To launch satellits, or to make scientific experimiments you do not need a man in space.

      IMHO the ESA has done the right decision. To focus all energies on unmanned missions. This way you can do efectivly everything the NASA can, but are cheaper and more secure. (For science automatic labours are possible, and if zou think of the place and weight saved by letting away the humans and the life support this pays of quite fast.)

  • They're great! (Score:2, Interesting)

    by acidfast7 ( 551610 )
    Anyone that can get more out of existing resources, especially those that are extremely expensive to initially render useful, is a bona fide stud in my book.

    When you get a group, such as the ESA, doing that, even better.

    Kudos to you sir(s).

  • Forever? (Score:2, Interesting)

    by Drakonite ( 523948 )
    TV satellites will remain in orbit forever Maybe it's just a show of how bad education has gotten...

    But according to my education these satellites loose power and can no longer fight earth's gravity after a while, which causes them to fall into the earth's atmosphere and dissentigrate on reentry.

    I have a friend that works with satellites for a living.. maybe I should go ask him to be sure...

    • Re:Forever? (Score:3, Informative)

      by mlyle ( 148697 )
      Things in geosynchronous orbit effectively stay up there forever. This isn't a small low-earth orbit satelite 150 miles up- this is 22000 miles up.

      No orbits are "permenant" in the real world-- but some are close enough. The earth isn't gonna fall into the sun tomorrow.
      • Yippie! There are some signs of intelligence down here :)

        In this case, whether the author of the story knows it or not, 'forever' is an approximation.
        He might be an engineer, but certainly not a mathematician.

  • Space Junk (Score:2, Interesting)

    by Fogie ( 4006 )
    Are there any regulations regarding dead satellites? Once a bird is placed in a (mostly) stable geosync orbit, it's going to remain in the general neighborhood for quite a while. I would think it wise to require these satellites to bump themselves down into the atmosphere when they've reached the end of their useful lifetime. The more junk that accumulates up there, the greater the chances for impact-related disasters. Last year ~75 civil satellites were launched.. I expect the total is higher.

    Chances are that as time goes by, our travels out into space will increase, putting more craft at risk. It'd be a shame for future generations to be stuck dodging a (relatively) thick field of high-speed objects ranging in size from marbles to large houses. Things to keep in mind...
    • Generally, some fuel is saved at the end of the satellite's life. Then, when it is decommissioned, it is set to fire out its remaining fuel, and it shoves itself up into a higher "parking orbit"...basically a satellite graveyard. Will they ever fall into the atmosphere? Yes. However, I believe we are talking about thousands of years until they even fall into the original geostationary orbit.
  • In addition to the logistical problem of keeping a really old satellite with little fuel left in a stationary orbit, it's tying up a geostationary slot that could be used for a new satellite with some real profit margin.

    And XM is overrated.

    I won't go out of my way to get into the IPO.

  • How much? (Score:2, Interesting)

    by jaybird144 ( 558619 )
    I'm wondering how close to XM will this be...is it going to come with the monthly service fee? Because that's my biggest beef with XM. I understand that they need to have some way of making money, and if people are willing to shell out their hard-earned cash to get a couble hundred radio stations, that's fine with me, but I'm not willing to pay $10 a month when I have a host of perfectly viable radio stations to listen to with the equipment I have already, for practically nothing. (Except for those public radio donations. That's a good cause.) Maybe if I was a more hardcore radio listener...or if I lived somewhere that didn't have a good radio selection...I dunno. Does anyone who uses XM want to explain why they think it's worth the fee? I'm a bit curious.
    • I have the XM radio SkyFi unit - which means I pay for one subscription and can have XM radio at home, car and office. Between those three locations, I listen about 12 hours a day.

      It's all about the music - this is a service designed for true music lovers. All genres are covered and the depth of programming is simply amazing. For example, one of my favorite stations, Deep Tracks [xmradio.com], just ran through the top 4000 songs in their library. It took 4 weeks. Then they spent another week playing through suggestions from the audience.

      That's just one station - this quality of programming is repeated across all genres. Most of the stations are commercial free - a few have ads, but only 3-4 minutes an hour.

      The other thing that keeps me listening is the attitude of the hosts. They treat the audience as adults, not immature 14-year-old boys, which seems to be the target audience of commercial radio.

      For me, $10/month is a bargain, I would happily pay more.
  • www.esa.int? WTF domain is that?! The web site works, so it must be a new one?

  • RE-Fuelable Sats? (Score:2, Interesting)

    by KoshClassic ( 325934 )
    I wonder why (comm, spy) sats are not designed to dock with a small propellant containing vehicle that could be launched midway through the sats life to replenish propellant, since this seems to be one of the main limitting factors of sat. usefulness, and launching such a vehicle would probably cost a lot less than a whole new sat.

    After all, the Russian's do something very similar with their Progress cargo ships that dock automatically with the ISS and had also done this with Mir before.
    • IT's a nice idea, but flawed. The ISS is like 400 miles up, (geostationary) satellites are 22,300 miles up. The biggest cost of a satellite is the launch cost. You would still have that with this solution (granted, I guess you could have it dock with multiple satellites, but it's starting to get complex then) The other reason is by the time satellites have used up their propellant, they are usually considered obselete and not that desireable. Newer satellites offer more power (BIGGEST plus) more transponders, etc. The satellites that are near the end of their service life are effectively the cheap satellites, sorta like the roach motel. Comparing a satellite like Spacenet 3 to some modern satellite like Telstar 7, Telstar 7 was FAR more powerful (I think like 10x or something....this is going off the top of my head) and C-band transmissions from it can be reliably received with like a 8' dish, as opposed to about a 16' dish for Spacenet 3. Even if you use the same receiving dish, it still gives you a larger Signal margin. Basically, it doesn't make economic sense to refuel satellites and try and keep using them

  • You mean you're not already using these old sats?? (Score:1, Interesting)

    by Anonymous Coward
    These TV sats are perfect for homebrew links.
    When you take a low bandwidth signal and spread
    it over the entire transponders bandwidth it
    won't raise the noise floor enough to be detectable.
    (Low bandwidth requires low power and if you spread the signal it raises the noise floor by an undetectable amount). They'll never see a 10kbit/sec signal!
  • Can I get control of some of these old sats? I want at least two for a business proposition. 1) get control of old sat 2) fill memory with banking data and open first bank without national rules 3) Profit! The Iridium network would have been good, thought about trying to get the banks to take it use it that way when they had control (for a small (=0.1%) of the ownership). But did not have enough contacts in the banking industry. Yeah radiation and data loss is a problem (which is why Iridium would have been good), whioch is why you need at at least two, and maybe a disused oil platform in international water as a ground side backup.
  • Wouldn't this just cause more space junk.... I mean if you move them to where they stay in orbit forever with minimal propulsion needed.... its just more junk up there...

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