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USNA "Budget" Satellite Launched and Functioning 190

Posted by timothy from the hey-bob-where's-my-metal-tape-measure dept.
Arpad Korossy writes: "Hey, you ran a story on this earlier, and some people expressed doubt whether a sattelite made for a tenth of the usual cost using mostly components from Radio Shack would work; well, it has. The best line in the whole article has to be 'Instead of a $50,000 antenna system, the group used a metal tape measure.""
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USNA "Budget" Satellite Launched and Functioning More

USNA "Budget" Satellite Launched and Functioning

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  • NASA adopts innovative procedures (Score:5, Funny)

    by Alsee ( 515537 ) on Friday November 09, 2001 @03:53AM (#2542352) Homepage
    Instead of a $50,000 antenna system, the group used a metal tape measure.

    Nasa thought it was such a good idea they have placed a $1,000,000 order for 20 metal tape measures.
    • Hams and researchers have been using the material used in tape measures (including sometimes using tape measures from the local hardware store) since at least the AMSAT Microsats (1991, IIRC).

      For low gain end-fed whips and dipoles for HF up to 70cm, they make great antennas - self deploying, keep the correct shape, and CHEAP.

      NASA has used similar materials WHERE IT IS APPROPRIATE. I would not, for example, use a tape measure dipole for an S-band system for high data-rate communications from Mars. I might use it as a UHF ground-link antenna on a surface rover.

  • Radio Shack? (Score:4, Funny)

    by anotherone ( 132088 ) on Friday November 09, 2001 @03:55AM (#2542357)
    These guys made a working satilitte from RADIO SHACK stuff?

    This has got to be some sort of a record- Radio Shack stuff working!

    • I am just thinking about the Radio Shack employees who made his commision for the day when they navy guys showed up and bought up half the store.

      I am sure Radio Shack will now be having Satellite Discount promotions now.

    • And so they got it all for $50,000 off Radioshack parts?

      Damn, so for $20,000 they could have a satellite working if they went to an electronics shop with reasonable prices!! =)
    • This has got to be some sort of a record- Radio Shack stuff working!

      You mean RS-bought items have a reputation for NOT working? Hmm. Maybe that Realistic stuff I bought doesn't actually work, and my office door just stays open all on its own! Thank you, kind stranger! I am off to find out my doors need, or lack of it, for a doorstop!
    • Was there any Duct Tape involved? I wonder. Now if only we could get this under $500.00, then we coudl build our own!
    • What I want to know is why they went to Boeing for the grant. I would imagine that Radio Shack would have given them the parts for free just for the publicity it generates.
  • This type of initiative is what will lead to the eventual commercialization of space.

    Let's face it, it *shouldn't* cost half a billion bucks to build something that will survive in low earth orbit. Inside the magnetopause the hazard to electronics just isn't that huge.

  • Proof that over the years NASA has not "cut corners" but, has over spent on their projects. If a group of undergraduates can make a space survivable craft then what has NASA been doing for the last 40 years. Although I am bashing their budgeting practices I do give them credit for some of their overspending. They did pratically invent space travel and more then likely they were responsible for putting the Radio Shack advertisment in space anyway.....

    • Re:Proof (Score:5, Insightful)

      by astrophysics ( 85561 ) on Friday November 09, 2001 @04:16AM (#2542405)
      Realize that they didn't pay for launch costs. They got a free ride. That's significant, because if you're spending $100,000,000 for a launch it doesn't make sense to save $50,000 by using a cheap antenna which is more likely to break. If you're going to pay for your own launch (like most NASA missions), then spending several times as much for the actual satellite hardware to make sure it's triple tested makes sense.
      • yes but if that, $10000 antenna thats tested really is $9500 profit for the maker, then we know how is ripping of who.

      • emmmm.

        payload cost on the shuttle is $5000 per pound. not 1,000,000 per launch.

        Anyways, the Europeans and Russians do it for a lot less anyways.

        Use Perl

        use SVG [roasp.com]

        .
      • if you're spending $100,000,000 for a launch it doesn't make sense to save $50,000 by using a cheap antenna which is more likely to break.

        Is $100M what it costs to launch the Shuttle? (It seems like the right order of magnitude.) But the USNA satellite didn't ride the shuttle, it shared a small single-use rocket with 3 other satellites. Launch cost was much less, maybe around $1M, and since it was sharing a ride with other, larger items, it's share of the launch cost may have been as low as $100K. (Probably the Navy didn't have to pay it.) Note that the most common cost quote is $5000/lb; the satellite was "the size of a TV set", so maybe it was 20 lb weight = $100K cost. And it probably would have made more sense to spend more to get longer lasting electronics, but since the thing was designed by college students maybe expensive parts would not have been that well utilized.

        AFAIK, the Shuttle can carry up to 60,000 pounds payload, so if you can load it fully and it costs $100M to launch, this works out to $1667 per pound. However, 60,000 pound loads are pretty rare (maybe major pieces of the ISS), the rest of the time it carries as many smaller satellites and on-board experiments as can be deployed or ran in one flight, the total payload is considerably less, and the cost per pound considerably more. In addition, a significant part of the inflated launch cost comes from keeping the 500 or more people needed to launch it on salary for months between each launch; if you had the shuttles and the payloads to launch every few days, the per launch cost would go down quite a lot. In other words, the Shuttle is too damned big for efficient operations, unless you are building something BIG up there (cough, **starwars, cough).

        By the way, a metal tape-measure sounds like a quite good solution when you want a simple quarter-wave-dipole antenna in space. It's cheap and stores compactly. By removing the case and mounting it properly, I think you could get the spring action of the tape to provide the motive power for deployment (uncoiling). It's unlikely anything would bump it in space, but if it did a tape measure would bend and then spring back, where a telescoping antenna would break.
        • I think it's more like $400M a launch, which works out to about $6000 per pound. And you're right, much of that cost is due to salaries of engineers and technicians and whatnot (fuel is comparitively cheap), but they don't spend all their time on their bums. They have to practically rebuild the friggin thing after every launch.

    • Re:Proof (Score:2, Informative)

      by dbolger ( 161340 )
      They did pratically invent space travel

      *cough [friends-partners.org]* Sure they did.

    • Re:Proof (Score:5, Insightful)

      by MikeyNg ( 88437 ) <mikeyng.gmail@com> on Friday November 09, 2001 @04:26AM (#2542433) Homepage

      Proof that over the years NASA has not "cut corners" but, has over spent on their projects. If a group of undergraduates can make a space survivable craft then what has NASA been doing for the last 40 years. Although I am bashing their budgeting practices I do give them credit for some of their overspending. They did pratically invent space travel and more then likely they were responsible for putting the Radio Shack advertisment in space anyway.....


      It costs an awful lot to blaze trails, and alot less than that to follow the lead.


      NASA may have spent quite a bit more money than these folks, but R&D is expensive. Plus, they're about the only people who are actually in the space business right now. Before people get on NASA for overspending, think about it. What would happen if NASA does reduce spending and the growth of the frontier of space travel becomes stunted accordingly?


      People like these are worthy of praise because they're helping make space accessible to the more common folk. That can only be a good thing. As more and more people get involved in bridging the gap between where we are now and where NASA is, it will make space that much more accessible.


      As one of my friends in college used to say, "I may not be smart enough to be at the boundary of science, but I can help fill in the gap." These people are filling in the gap, but NASA is at the boundary.

      • Re:Proof (Score:3, Interesting)

        by justin_schoeman ( 203052 )
        I may be completely off the mark here, but I would guess that one of NASAs primary goals at the time was to _spend_ money. Any time a government can get a legitimate reason (that the general populace will actually support) to shove a huge amount of money into the economy, they will do it. This way they get to build both technical superiority, and a stronger econony at the same time.

      • Re:Proof (Score:3, Interesting)

        by 4im ( 181450 )
        Plus, they're about the only people who are actually in the space business right now.

        So I guess all the others out there don't count? What about ESA, Russia, India, China, Israel etc.? ESA with Ariana has sth. like half of the launcher business.

        And there are quite some private companies also in the business (Sea Launch...); even in the US (if you don't check beyond your borders) there's more than just NASA. Indeed, some say that NASA has actually stifled private competition (Delta-X, Rotary etc.). Maybe it's even a good thing if NASA tunes down some, provided private companies pick up where NASA left off, and are allowed to actually do business. Leave NASA with the basic scientific research stuff... that's what they're supposed to do anyway.

      • You are not talking of Space Business, I hope
        because lots of people are in it. If you are
        talking about spending money just for the fun of
        exploration then NASA is probably about the only
        one, I don't know enough to vouch for it though.
        I am not against NASA doing the dirty work, somebody
        has to do it, and USA having the most money should
        probably do it. When they can spend so much money
        building nukes they should spend some money
        helping science.
      • People like these are worthy of praise because they're helping make space accessible to the more common folk.

        if by 'more common folk' you mean the super rich, i agree. you (and i), however, are never going into space (unless you go like gene roddenbery [space.com]).

        the research done at NASA and its contractors may produce some results applicable to us but a better return on our investment would be researching (and implementing) technology whose application lies on earth. i'm not saying NASA should be dropped outright but we should re-evaluate our goals in space.
      • What would happen if NASA does reduce spending and the growth of the frontier of space travel becomes stunted accordingly?

        A decade or so back, when several startups were trying to develop private enterprise launch systems, they couldn't get the aerospace manufacturers to sell them components (space-rated cryogenic-liquid valving, guidance components, etc.). One manufacturer's rep said (in confidence) that they had been told by NASA administrators that if they sold to the private launch companies they wouldn't sell to NASA again.

        So they made do with NON-space rated components and other kludges.

        Some of this worked really well. (For instance: The virtual control panel hacked up on a Mac was a LOT cheaper and more functional than the roomfull of one-of control equipment it replaced, much to the amazement of the NASA engineers who watched the engine test.)

        But some of it was a disaster. (For instance: The liquid oxygen valve on a hybrid engine failed in a mode that created the second worst possible disaster {behind guidance failure} for a hybrid engine vehicle: It stuck at 10% during engine startup. Too little thrust to get off the pad, but they couldn't turn it off so the rocket burned itself up. The test was a failure and the company was unable to raise money for a second try and folded, taking the safest known rocket technology down with it.)

        "What would happen if NASA does reduce spending...?" Well, for starters they wouldn't HAVE the kind of clout with suppliers to deny components to the private market, while the suppliers would have a big drop in sales until they found other customers.

        It could be the best thing ever to happen to space technology.

    • Re:Proof (Score:5, Informative)

      by xX_sticky_Xx ( 526967 ) on Friday November 09, 2001 @04:38AM (#2542449) Homepage Journal
      If a group of undergraduates can make a space survivable craft then what has NASA been doing for the last 40 years.

      Oh, [nasa.gov] not [nasa.gov] much [nasa.gov] really [nasa.gov].

      I'm [nasa.gov] sure [stsci.edu] some [nasa.gov] searching [nasa.gov] would [nasa.gov] reveal [nasa.gov] some [nasa.gov] details [nasa.gov] though. [nasa.gov]

    • PCSAT works. "Survivable"? That depends. The core of the spacecraft electronics are two off-the-shelf Kantronics TNCs. They have reset a few times, and I have no idea if the ROMs were replaced with rad-hard units or not. Time will tell how well they hold up in the space radiation and thermal environment.

      There are a number of successful amateur spacecraft using commercial chips and RF components. All operate in LEO where they receive some radiation protection from the Earth's magnetic field.

      NASA using similar components and design techniques in a low cost LEO mission may make sense. The same techniques in a high-risk or deep space mission would be foolhardy.
  • I like how anyone can just send transmissions to it.
    Let's see if we can /. it!

  • It figures... (Score:3, Funny)

    by CrayBeast ( 521458 ) on Friday November 09, 2001 @04:01AM (#2542372) Homepage

    ...I've been using a metal coathanger to pick up TV for years :)

  • Metal tape antennaes already on AMSAT AO-40 (Score:4, Interesting)

    by dg1kjd ( 159535 ) on Friday November 09, 2001 @04:02AM (#2542373) Homepage
    The metal measurement tape omnidirectional antenna system was already used on the AMSAT AO-40 hamradio satellite slashdot already posted news stories about a couple of times. The interesting part is that both antennaes which used that system failed mysteriously (or alternatively the transmitters did, this is not for sure yet).
    • And prior to that on the AMSAT Microsats (AO-16, DO-17, WO-18, LU-19), IO-26, AO-27, the two Univ of Mexico satellites, and probably a few other university and amateur satellite projects.

      It's a simple and effective technique well-known in the amateur satellite community.

  • a satellite built by Naval Academy midshipmen with off-the-shelf parts from Radio Shack is exceeding all expectations

    And it's exceeding mine too. :-) Approximately 3 out of every 5 things that I've gotten at radio shack have either been broken when I got them home or they broke shortly later. I can recall a CD player that *melted*, audio cabling that had breaks in the wires, and broken rj-45 connectors off hand...

    If this thing can go another week, i'll be really impressed.

  • Innovative=expensive (Score:5, Interesting)

    by tony_gardner ( 533494 ) on Friday November 09, 2001 @04:10AM (#2542394) Homepage
    I'd like to point out to all thos who think that NASA overspends its budget the vast cost difference between developing something new, and buying a consumer product. The rocket engine which cost 20 billion for the first one is available "off the shelf" for 200,000 today. Same for "space rated" electronics, valves, cameras, etc. It's perfectly feasable to get a reliable payload working today for very little. It probably won't, however, do anything very innovative, because doing innovative requires high precision equipment which costs a lot on earth. The equipment also has to survive the takeoff, which is another matter.

  • Space junk (Score:5, Insightful)

    by tony_gardner ( 533494 ) on Friday November 09, 2001 @04:18AM (#2542408) Homepage
    A lot of people frown on cheap satellites because what the expensive ones are paying for is in large part reliability, long life, and accessories like the ability to de-orbit at the end of its working life. If NASA started to put up loads of cheap satellites with an unknown, but short, working life and no ability to deorbit we'd be on their backs in a minute accusing them of creating space junk, so why are we applauding it here? Yes, it's great that the satellite is working, but lets keep the eyes on the ball. Cheap satellites increase the hazard for everyone else, and that's where my patience stops.
    • why cant they design one GOOD multipurpose probe, with all the goodies/cameras/scanners/optics/ION engine, VOyager3 or something....

      Make 100 of the puppies, then launch them all with in 2 years, and send em on their way .... 3 per planet, and 1 each to a dozen moons, and place 2 in perm orbit around our moon.

      • Re:Space junk (Score:2, Informative)

        by ThePilgrim ( 456341 )
        Because of physics, and some economics.

        You can only launch at certain planets at certain times if you want to be able to slow the space ship down enougth to get into orbit at the far end.

        If you get out side tht launch window the cost/mass of carrying extra fuel becomes prohibative.
    • Sputnik, Tellstar, la, la la, all junk now. Sure, it sucks but people learned from it.

      Cheap is good because it spreads out the knowledge base. We want to get at resources beyond our planet sooner than later. This will help.

    • So?

      When it stops working, the orbit will decay and it will fall back into the atmosphere. Since it's the size of a TV, it will burn up in reentry.

      So what's the problem?

      D
      • So what's the problem?
        The problem is that low-Earth orbit (LEO) is getting to be very crowded, and it takes a lot longer for the orbit of a satellite at an altitude of 150 miles to decay than it does for the "standard orbit" of the Enterprise to do the same thing. I think this is caused by the fact that the plot of an LEO satellite doesn't need to be resolved in a one hour episode.

        There are still bits of junk floating around in fairly low orbits from the '60's. A really useful cheap satellite would be something that sought out space junk, captured it, and then de-orbitted after collecting a couple hundred pounds. Anyone besides me remember Quark?

        • Well, obviously there is a very straightforward solution to this problem.

          Create a one-hour TV show about LEO satellites.

          But what would happen if it got cancelled?

          Okay, okay.

          Does space junk have any value? Most of it was pretty expensive when new, could it be collected and saved for use in new satellites?

          D

  • Radiation hardening? (Score:4, Insightful)

    by justin_schoeman ( 203052 ) on Friday November 09, 2001 @04:27AM (#2542434)
    This is all well and good. But I'm pretty sure you can't buy radiation hardened components off the shelf. The satellite will probably function perfectly well until the first decent solar flare. , after that, all bets are off.

    A large proportion of the cost of space borne systems is taken up by the radiation hardening. Both the microchips themselves, and the support circuitry, need to be hardened against the random bit changes, and the long term physical degradation caused by radiation.
    • so... just buy those Intel RAD harderned CPUs, its all OFF THE SHELF... package the computer in a lead casing , who cares if its 10 pounds....

      Its the temperature also which is more important.
    • Think "below the magnetosphere" and all will become clear.
    • "...until the first decent solar flare"
      I keep telling them that they should only fly these things at night, and avoid the hazards of the sun.
    • The satellite will probably function perfectly well until the first decent solar flare.

      You mean like this one [cnn.com] from last Sunday?

  • Innovation (Score:3, Insightful)

    by pieterh ( 196118 ) on Friday November 09, 2001 @04:49AM (#2542466) Homepage
    The lesson that small budgets do not need to restrict your ambitions. Indeed, large budgets seem to constipate ambition. Small disposable satellites are a wonderful idea. Cheap communications can revolutionise societies. On a global scale the potential is... big.

    Somewhere there are groups of people figuring out how to lower that launch cost from $100m to $1m.

  • Chicken and Egg (Score:4, Insightful)

    by Baldrson ( 78598 ) on Friday November 09, 2001 @05:03AM (#2542483) Homepage Journal
    Have to have expensive satellites 'cuz they have to be reliable on orbit. They have to be reliable on orbit 'cuz launching them is so expensive. Launching them is so expensive because the rockets are expensive. The rockets are expensive 'cuz they have to be so damn reliable or else the insurance is WAY too expensive. Can't get walking on down the cost/risk ratio learning curve because we're launching rockets so infrequently that we slide back on the slope before launching the next one...

    Hey, I have an idea:

    Fly more rockets [arocket.net] using all that computer and electronics skill for cool hacks in guidance and control [armadilloaerospace.com] maybe even with some rocket races [xcor.com] and some rocket designs that can use the guys in high performance automotive shops to lower cycle times on design and development [geocities.com].

  • 1 out of 3 geeks can make it work (Score:1, Interesting)

    by Anonymous Coward
    Well, all I could say is it's a very cool project. I am happy for those who had success.

    To the argument that it could be zapped by a solar flare.. heck man, we already have bigger birds that get fried by the same thing.

    I wonder how much those rockets cost, as that seems to be the method to put em up.

    I remember getting interested in this kind of stuff when I was in elementry school Back then it was all about the future space shuttle and what it would look like and this and that.

    With what at least the first 100 missions being military missions, and me hitting my teen years, I lost all interest in science. (I had it in my blood when I was in diapers eating hamburger and corn watching them land on the moon though.)

    A thing like this could do us good. It could get me interested in science again. I never liked college much, they just don't seem to have common sense about reality and the real world. Maybe the younger generation will get their youthful imaginations inspired by projects like this. Even to teach them about electronics, transmitters, receivers, microwave, and a little common sense physics could do this country some good. For one thing I would hope they start teaching American History again, instead of requiring all these other (I won't say stupid) non-american history. I am sick of the liberals and the tenyear professors who push their agenda on people. (I hated that crap!)

    Remember one day these kids grow up, if they can't think for themselves, engineer a radioshack surface mount CB radio, or at least know how to repair it, or create or fix older stuff (ahh I hated the day surface mount came), I think we are screwed as a country. All the lawyers and laws, and junk that has passed lately is just dumbing down our children and ourselves, and were setting ourselves up to be a brain dead slave society who gives away all our constitutional rights, unless something changes with the education. (There is no accountability in government and that needs to change!)

    At one time I used to spend as much as 500 dollars a week at Radio Shack, for electronic parts (not gear and stereos duh.)
    But you know another person that I agree with (in part) is Wayne Green (I don't agree about the "we haven't been to the moon." part.) I do agree with what he says about getting our children interested in ham. We really as a society need to think, and encourage children to think and create, and stop making them pay for it.(legally) Let them do what they want, guide them, but don't force them into loosing that innocence that spawns the unlimited energy and creativity they have. Seems like I am harping on this a lot, but I already see things I do not like happening in this country.

    So hey Naval Academy midshipmen, Radio Shack, well job done. I come to attention, and I give you an AirForce Salute!

  • sputnik (Score:2, Interesting)

    by tony_gardner ( 533494 )
    On the topic of cutting edge vs everyday.

    Anyone got an estimate of how much it would cost to launch Sputnik today (83kg /184lb, Low earth orbit), compared to what it cost then?
  • "Solar panels costing $20,000 apiece? The students used the panels that power emergency phones in deserts and national parks. Cost: $25 each."

    And people ask why nasa runs over buget so often.

    • Re:NASA (Score:3, Insightful)

      by dbolger ( 161340 )
      Why? Because these guys were amateurs/academics who only stood to lose their pride if the entire thing screwed up. When NASA sends a sattelite up, there are usually several million dollars worth of of R&D/net equipment costs associated with it that just can't be wasted. In short, while its cool that the midshipmen managed to do this, the chances of the entire thing blowing up in their faces (figuratively) are far too high for NASA to be able to use "radio shack" materials, or as they have often been accused, to 'cut corners' like this group were able to.

      • Re:NASA (Score:2, Informative)

        by BDew ( 202321 )
        Exactly. Also, the 30% efficiency of NASA panels vs the 5% efficiency of the Radio Shack ones also makes a difference.

  • $50000 (Score:5, Insightful)

    by mike_g ( 24445 ) on Friday November 09, 2001 @05:46AM (#2542557) Homepage
    Instead of a $50,000 antenna system, the group used a metal tape measure.

    This statement is misleading. The metal tape measure is a toy compared to a well designed NASA antenna system. The transmitter on the Cassini space probe uses only 20 watts of power to transmit a signal from Saturn to Earth. This is most likely less than one third of the power used by a single light bulb illuminating the room you are currently in.

    Don't get me wrong, the USNA team accomplished an amazing feat with their satellite, but we must keep things in perspective.

    • Re:$50000 (Score:5, Insightful)

      by tony_gardner ( 533494 ) on Friday November 09, 2001 @05:54AM (#2542569) Homepage
      Exactly. Perhaps it should have read that instead of a $50,000 low power, directional, narrowband antenna, they used a high power, broadband, nondirectional antenna, not permitted for commercial use due to the interference it causes, as well as not useful because of the power drain.

      Similarly for the solar arrays, they used a commercial array with an efficiency under 5%, compared to a high quality array with an efficiency over 30%.

      There's a reason why people spend the money, and its not because they're complete idiots. It's like comparing a 2GHz Pentium to a 200 Mhz Athlon. Oh wait...

      • Re:$50000 (Score:3, Informative)

        by rand.srand() ( 243903 )
        The metaphor is closer to comparing a group that builds an XT from spare parts and having it boot up in DOS compared to a new P-4 out of the box from a store running SETI@home. Would anyone claim the P-4 user was crazy when he could have cobbled together the XT for so much less?

        Besides the fact that without the research that went into producing the 30% efficiency panels, the 5% panels would not be as cheap as they are. Show me a group that launches a same technology/capability/longevity bird for reduced price and then we're talking.

      • Re:$50000 (Score:2, Interesting)

        by Muad'Dave ( 255648 )

        ...not permitted for commercial use due to the interference it causes...

        Huh? Antennas don't cause interference. You must use the proper antenna for the task at hand. There are plenty of commercial uses for omnidirectional antennas.

        Comparing a $50,000 narrowbeam antenna to a tape measure quarter- or half-wave whip is illogical in the first place. Those $50,000 arrays are made to communicate from a spacecraft very far away to a tiny little speck of dirt called earth using as little power as possible due to the extreme distance from the sun. The tape measure variety are made to pick up signals from earth while in earth orbit - necessitating a wide receive and transmit pattern. Apples and oranges, and all that.

      • Perhaps it should have read that instead of a $50,000 low power, directional, narrowband antenna, they used a high power, broadband, nondirectional antenna, not permitted for commercial use due to the interference it causes, as well as not useful because of the power drain.


        Hmm. Like the high-power, broadband (since when is a 1/4-wave end-fed antenna broadband anyway) omnidirection antennae used for satellite TV transmissions?

        For the kind of work they're doing, they need fairly broadband, omnidirection antennae. Go and get a scanner and listen to how it's done, then post. Why not ask a licenced radio amateur to show you? They don't bite, they're hackers just like us but they use radio instead of computers.

    • Re:$50000 (Score:3, Informative)

      by krystal_blade ( 188089 )
      The transmitter on the Cassini space probe uses only 20 watts of power to transmit a signal from Saturn to Earth.

      While this is true, a few things must be taken into account. 1st, electromagnetic waves can travel an infinite distance in an area that has zero air loss to account for. So, while 10 watts may get you 15 to 20 nautical miles in an omni-directional antenna, at approximately -97.5 dbm, in space, the same power level can literally travel MILLIONS of miles and achieve a higher dbm level. Using a directional antenna compounds the benefits of an airless medium, just as it does here on earth.

      The Cassini spacecraft is capable of doing what it does with the power level it transmits at because those signals are either picked up by DEDICATED dishes specifically tuned to said frequency, or because they are picked up by orbiting re-trans sattelites in orbit around earth. The second option takes ANY airloss out of the question.

      I worked at an uplink station once that transmitted off of a geo-synchronous sattelite. To saturate the transponder with a directional, wideband signal, with minimal bit errors, we had a set output level of 75 watts. That allowed for any air loss, with 100% signal reception. If a thunderstorm or heavy clouds were in the area, we would have to jack up our signal strength to reach saturation.

      Cassini doesn't have that problem. The Ham Radio sattelite (aka budget sattelite) does.

      krystal_blade

      • Re:$50000 (Score:3, Informative)

        by ChuckDivine ( 221595 )

        Gulp. Air loss?

        The physicist in me cringes at krystal_blade's message and it's rating.

        OK, what problems do we have in communicating with deep space probes? Ones that come to mind include:

        • The inverse square decline in signal strength. Check out an electricity and magnetism text for a full explanation. Briefly, signal strength decreases at the rate of 1/r**2. It's a long way to Saturn.

        • Background noise. Space isn't quiet.

        • Interference from various electromagnetic phenomena between the source and us.



        Air loss? Please.

    • "Instead of a $50,000 antenna system, the group used a metal tape measure."

      Not an original idea. In 1961 radio amateurs put their first satellite into orbit. OSCAR-I (that's "orbital satellite carrying amateur radio") used four pieces of steel tape measure blades as an antenna. The blades were wrapped around the satellite and sprung out into place when the satellite was ejected from the booster it was riding piggy back on.

    • The metal tape measure is a toy compared to a well designed NASA antenna system.

      Oh, you mean like the high-gain antenna on Galileo? Yeah, that's working really well.

      For those not keeping track, the high-gain antenna on Galileo failed to deploy, severely cripping the probe's ability to send back science data. The mission wasn't completely ruined because the low-gain antenna still works.

  • $$ (Score:2, Funny)

    by saqmaster ( 522261 )
    One thing this article fails to mention is how much it actually cost to get this thing into space..

    I know the government do some projects, however I don't know the specifics, for schools/education environments.. Saw something on slash a while back on this.. But sure, this device may have cost 1/10th the cost of a full NASA satellite, but the launching costs would have been the same, which in all reality is probably more than the cost of the proper version satellite in the first place!
  • "This satellite has already surprised us," Smith said, "and it will probably continue to."

    Is he saying "I wouldn't be surprised if this satellite surprises us again"? :)

  • RadioShack (Score:5, Funny)

    by Ratbert42 ( 452340 ) on Friday November 09, 2001 @07:42AM (#2542710)
    Yeah, but did they have to give their name & phone number to RadioShack to buy those parts?

  • Interesting development, but not revolutionary (Score:5, Interesting)

    by f00zbll ( 526151 ) on Friday November 09, 2001 @07:52AM (#2542724)
    First off I am pretty impressed such a cheap satellite is able to stay up for a month. Although it shows it is possible to build a functional satellite from off-the-shelf parts, it isn't going to revolutionize the space industry. More likely than not, it will drastically change how schools teach engineering, physics and astronomy. As others have mentioned, big expensive satellites are engineered to a different reliability standard. If our national telecommunications infrastructure was built with a bunch of small cheap satellites, I doubt our phones and television would be as reliable.

    Where all this really matters is with the next generation of engineers, scientists and inventors entering college in the next few years. They are the ones that will benefit from this type of experimentation. Not only will students be able to get valuable hands on experience about real world engineering, but they will get others interested in the field. Developments like these bring exotic technologies down to earth and show students they can do something really challenging. With so many posts on /. about burning out, boring classes, and disillusionment, this may bring in a breath of fresh air.

    The down side of having a lot of students launching small satellites is it polutes space and makes the job of tracking dangerous objects more difficult for NASA. All of these developments aren't free, because there are a lot of other financial, political and environmental concerns attached to satellites.

  • Why don't we get these undergrads, Martha Stewart, and the writers of MacGyver together to improvise a working missile-defense shield?

    It'll be done on time and under-budget, it'll coordinate with all the other satellites, and it'll be made solely of a shoe polish tin, duct tape, a foot of rope, and a thumbtack!

  • I wonder... (Score:1, Funny)

    by Anonymous Coward
    Do you think they included a CueCat on the satellite that Radio Shack built? It could be 230 miles above you right now, stealing your privacy! Frightening.

  • Well Great.... (Score:2, Funny)

    by RiscIt ( 95258 )
    There goes the price of metal tape measures...

  • NASA is expensive because its political... (Score:3, Insightful)

    by Patoski ( 121455 ) on Friday November 09, 2001 @09:18AM (#2542933) Homepage Journal
    Let's be honest with ourselves here... NASA is not as costly as it is because of the innovations it comes up with but rather because at its heart NASA is a political beast. I give you the Space Shuttle as evidence. This 30 year old technology costs about $470 millon dollars to launch one shuttle, one time. That cost skyrockets to 1.7 BILLON dollars if you factor in R&D (although R&D costs are spread out over subsequent missions). There are _far_ more cost effective means of getting things into space so why doesn't NASA use them? Easy... The shuttle program is popular and very well known by the public.

    Does anyone else remember all the savings that we were told were going to be realized because of the shuttle's ability to reuse it's solid rocket boosters and the orbiter? Unfortunately, quite the inverse occurred. Costs ballooned and NASA didn't even blink. In fact until relatively recently (the past 10 years or so) NASA hasn't even seriously tried to find a replacement for the aging shuttle fleet. In the eyes of congress NASA is just another special interest looking for their turn at the budgetary feeding trough and quite frankly that's how NASA acts. This makes NASA do things that doesn't make sense economically but make lots of sense politically. While this does explain their behaivor it does not change the fact that NASA is wasteful with the money that they are given. NASA does cool geeky stuff and has come up with a lot of innovations but given the amount of cash they're given one would think they could do more. Looking at where we are technologically and watching how NASA burns through cash I'd say there is a pretty compelling arguement for pushing efforts for privatized space flight even harder than we have until now.

  • Amsat (Score:3, Informative)

    by Anonymous Coward on Friday November 09, 2001 @09:24AM (#2542954)
    Take a look at the history of AMSAT [amsat.org] and Amateur Radio satellites. This whole concept (tape measure, off-the shelf components, hitch-hiking on the boosters) was done by amateur radio operators in the 60's. Many of those satellites were operational for years.
  • How much of their savings were made by using parts from free CueCats and Flashlights?

  • Extra, random links (Score:2, Informative)

    by anichan ( 205614 )
    The project's page here [navy.mil] has pictures and links.

    For the curious, here's Lockheed' page about the Athena [lockheedmartin.com] rocket.

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