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fbc, moores law, and planning cycles
In message
Jonathan Silverlight wrote: In message , OM om@our_blessed_lady_mary_of_the_holy_NASA_researc h_facility.org writes On Mon, 29 Dec 2003 02:25:19 GMT, (Derek Lyons) wrote: I think the argument could be made that the equiment needed to make a credible space probe could be assembled from components purchased at radio shack. Um, no. There is no evidence in support of such a notion. ...I think there's quite a few OSCAR variants whose Elmers and OMs would disagree with you there, Derek. Guildford University's early UOSATs were also built using off-the-shelf parts. In particular, to get the NiCad batteries with the right specification they simply bought a whole lot and tested them. [University of Surrey rather than Guildford University] They did something similar with the solar panels for one of the satellites. When they went back for some more for the next one they found the price had gone up dramatically because they were now "space qualified"... Anthony -- | Weather prediction will never be accurate until we | | kill all the butterflies | |
#23
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fbc, moores law, and planning cycles
um, no. refer to moore's law. every space probe that took more than two
years, (from lock down to reaching the target) by definition was significantly behind by the time it arrived on target. About 10 years ago I toured the attack nuclear submarine USS Jefferson City, based in San Diego. Some of the ship's electronic systems used an XT-level computer (literally -- there was an XT sitting there, connected to whatever electronic system we were viewing), and one of the systems used a 386 which had been bought by the crew. The officer giving the tour explained that there's such a long period between design and commission of such a ship, that specified and installed components often become obsolete. This is not to say, of course, that these "obsolete" computers weren't perfectly adequate for their required tasks. -- Curtis Croulet Temecula, California 33° 27' 59" N, 117° 05' 53" W |
#24
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fbc, moores law, and planning cycles
"Giovanni Abrate" wrote:
"Derek Lyons" wrote in message ... Camera's No UV or deep IR at the Shack... Gyroscopes suitable for inertial nav? Not at the Shack. Rad-hard computers? Not at the Shack. Just one point: there are now guidance gyroscopes that are available to the general public (for instance to aero modellers) and that cost under 100 dollars. I am thinking of piezoelectric Gyroscopes and also of new, low cost fiber-optic laser-diode gyros. I'm aware of those, but do not believe that they are capable of performing in a launch/orbital enviroment. An effective IMU can be had, today, for unmanned applications, for under 1000 dollars and it weighs under a kilogram. And it's characteristics are? D. -- The STS-107 Columbia Loss FAQ can be found at the following URLs: Text-Only Version: http://www.io.com/~o_m/columbia_loss_faq.html Enhanced HTML Version: http://www.io.com/~o_m/columbia_loss_faq_x.html Corrections, comments, and additions should be e-mailed to , as well as posted to sci.space.history and sci.space.shuttle for discussion. |
#25
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fbc, moores law, and planning cycles
"Curtis Croulet" wrote:
About 10 years ago I toured the attack nuclear submarine USS Jefferson City, based in San Diego. Some of the ship's electronic systems used an XT-level computer (literally -- there was an XT sitting there, connected to whatever electronic system we were viewing) Guaranteed that wasn't a tactical system, but more likely was one of the nice-to-have support systems. (You started seeing some support systems being based on COTS as early as the late 1970's. In the mid-80's we had a 1978 era HP sitting next to our 1958/1978 era torpedo fire control system.) The officer giving the tour explained that there's such a long period between design and commission of such a ship, that specified and installed components often become obsolete. This is not to say, of course, that these "obsolete" computers weren't perfectly adequate for their required tasks. The computers were obsolescent, not obsolete. The latter term is all too often used when the former is what is actually meant, they are not really interchangeable. Keep in mind that the military cares less about whether the computer is the latest-and-greatest, and more about whether it will operate in it's intended enviroment, and whether it can be supported and maintained. D. -- The STS-107 Columbia Loss FAQ can be found at the following URLs: Text-Only Version: http://www.io.com/~o_m/columbia_loss_faq.html Enhanced HTML Version: http://www.io.com/~o_m/columbia_loss_faq_x.html Corrections, comments, and additions should be e-mailed to , as well as posted to sci.space.history and sci.space.shuttle for discussion. |
#26
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fbc, moores law, and planning cycles
(Henry Spencer) wrote:
In article , Derek Lyons wrote: ...the argument could be made that the equiment needed to make a credible space probe could be assembled from components purchased at radio shack. The term 'credible space program' doesn't apply (IMO) to the amateur sats. Derek, the word used was "probe", not "program". Try to pay attention. Ick, you are correct. But I still don't believe the original poster is correct. What useful science instrument can be built or hacked using Radio Shack components? (And I do mean *useful*. While lofting a digital camera into orbit is a cool hack, it's usefulness is marginal.) D. -- The STS-107 Columbia Loss FAQ can be found at the following URLs: Text-Only Version: http://www.io.com/~o_m/columbia_loss_faq.html Enhanced HTML Version: http://www.io.com/~o_m/columbia_loss_faq_x.html Corrections, comments, and additions should be e-mailed to , as well as posted to sci.space.history and sci.space.shuttle for discussion. |
#27
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fbc, moores law, and planning cycles
In message , Anthony Frost
writes In message Jonathan Silverlight wrote: Guildford University's early UOSATs were also built using off-the-shelf parts. In particular, to get the NiCad batteries with the right specification they simply bought a whole lot and tested them. [University of Surrey rather than Guildford University] They did something similar with the solar panels for one of the satellites. When they went back for some more for the next one they found the price had gone up dramatically because they were now "space qualified"... Ack! Blame a temporary short circuit between the ears :-) I live five miles from the place and I've visited several times, so I don't have any other explanation. Thanks for the story. -- Rabbit arithmetic - 1 plus 1 equals 10 Remove spam and invalid from address to reply. |
#28
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fbc, moores law, and planning cycles
In article ,
Derek Lyons wrote: But I still don't believe the original poster is correct. What useful science instrument can be built or hacked using Radio Shack components? (And I do mean *useful*. While lofting a digital camera into orbit is a cool hack, it's usefulness is marginal.) There's quite a bit that could be done in the way of radio-based science, e.g. topside sounding of the ionosphere, lightning detection, etc. That digital camera actually could be useful, not so much as a camera but as a particle-radiation sensor. Of course, in the orbits where this would be *most* scentifically useful, you'd have to have quite a bit of shielding mass around the rest of the Radio Shack electronics to give them a useful lifetime, but although that is unorthodox it is technically feasible. The dust/micrometeorite/micro-debris environment around Earth is also not as well mapped as it could be -- there are hints of structure to it, but little is known -- and a large thin metal plate with microphones bonded to it might make a usable sensor for that. Yes, it's a struggle, and I think the original poster overstates the situation somewhat, but he's not *totally* wrong. Radio Shack is a bit excessive, but you could get almost all of MOST's electronic components from Digi-Key. (In fact, a fair number of them probably came from there.) Not the solar cells or the CCDs, and maybe not a few other electronic odds and ends, and of course there's the optics. But if you're not in a high-radiation orbit (or if you can afford a lot of shielding mass), the electronic side of a spacecraft no longer needs anything very special. -- MOST launched 30 June; science observations running | Henry Spencer since Oct; first surprises seen; papers pending. | |
#29
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fbc, moores law, and planning cycles
Henry Spencer wrote: Radio Shack is a bit excessive, but you could get almost all of MOST's electronic components from Digi-Key. (In fact, a fair number of them probably came from there.) Not the solar cells or the CCDs, and maybe not a few other electronic odds and ends, and of course there's the optics. But if you're not in a high-radiation orbit (or if you can afford a lot of shielding mass), the electronic side of a spacecraft no longer needs anything very special. ISTR John Carmack saying his guidance system was less than $20,000 and consisted of Crossbow fiber optic gyros, PC104, and Linux as the operating system. -- Hop David http://clowder.net/hop/index.html |
#30
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fbc, moores law, and planning cycles
In message , Henry Spencer
writes The dust/micrometeorite/micro-debris environment around Earth is also not as well mapped as it could be -- there are hints of structure to it, but little is known That's odd, considering that missions such as Pegasus have been flying since the 1960s. But it's better than the situation for Mars, where we don't know anything, AFAIK :-) -- Rabbit arithmetic - 1 plus 1 equals 10 Remove spam and invalid from address to reply. |
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