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PBS's "Nova" and MER
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#22
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PBS's "Nova" and MER
Pat Flannery wrote: About the time they started talking about sending the finished landing software to the spacecraft _after_ they launched, a feeling of deja-vu hit me; Perhaps because this isn't all that uncommon for planetary spacecraft. I believe Magellan did the same thing for one. - Matt |
#23
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PBS's "Nova" and MER
"Hallerb" wrote in message
... of course we both have dogs. Don't talk about your "gamily" that way! -- If you have had problems with Illinois Student Assistance Commission (ISAC), please contact shredder at bellsouth dot net. There may be a class-action lawsuit in the works. |
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PBS's "Nova" and MER
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PBS's "Nova" and MER
I don't think it was this kind of software. Software that directly interfaces with the hardware (like an operating system on your PC) is one thing, higher level software (that interprets images and makes onboard decisions etc) is another. my understanding was that they had the basic hardware interface system, but the higher level autonomy software was still being developed. I am not sure it would have been possible for them to to go with the basic hardware interface undone. Higher level software is much more flexible and can and will be changed even as the mission is on the planet. Basically the went up with a loaded beta OS and no programs. In flight they loaded OS service packs and programs they wanted to run. if the program did not work with the OS, and therefore the hardware, they just re-wrote the program. The comfort level with hardware/software interfaces is such that this was possible. In article , says... What happens if you launch them, and then run into some software-spacecraft compatibility problem that can't be fixed before the time that the software is needed, due to a compatibility problem that can't be fixed in-flight; but could have been found via ground testing of the systems and software on the ground prior to launch? If that had happened on the two MER flights they would have had no way to get them ready for landing. |
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PBS's "Nova" and MER
"Pat Flannery" wrote in message ... The only big-budget long-span program semi-flop we have had was Galileo; and its problems were as much due to a hurried redesign of its launch method and trajectory as anything else, and it still got a lot of its job done at Jupiter. In comparison to this, our lower-cost fast timeline missions are running around 50% as to success rate. While agreeing with your main point, I also nominate MO as an expensive project that wasted money by failing. |
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PBS's "Nova" and MER
"Diane Wilson" wrote in ... Diane -- Pearls of wisdom -- heck, an entire necklace of such pearls -- such as yours is one of the highlights of these discussions. Thanks for sharing your experiences and insights. It was a keeper! jim |
#29
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PBS's "Nova" and MER
In article ,
Brett Buck wrote: ... The technology and missions are so unforgiving that even tiny problems have to be addressed, and beaten to death. That takes time and money - there's no getting around it. Actually, it's perfectly reasonable to simply accept a modest amount of risk... especially since you are *always* doing that anyway, because you can never anticipate all the problems. (At no time did Apollo planning ever consider the possibility of losing all oxygen and all electrical power in the CSM; studies of the "LM lifeboat" were confined to using the LM *engine* to cover for a CSM propulsion failure.) A sense of proportion is needed; you can waste unlimited amounts of money on unlikely what-ifs. The need for *adequate* funding does not imply a need for NASA-megaproject funding levels. (However, it *does* mean that if you don't have NASA-megaproject funding levels, you can't use the NASA-megaproject management style.) ...You are correct that cheaping out or funding or schedule, or simply ignoring this essential fact, is exactly why there are so many failures in all sorts of aerospace projects. Nonsense. There have been numerous failures in aerospace projects which had ample funding and schedule. The evidence is strong that the bulk of the failures are simply independent of cost and schedule, at least within broad limits. For every Mars Climate Orbiter there's a Mars Observer. ...Those "dinosaur" aerospace companies actually know some things about how to conduct projects that lead to their "exorbitant" bids. Yeah: they know how to run projects so as to maximize effort -- as opposed to results -- because that's what they get paid for. When Max Faget, who had more than a little experience dealing with the dinosaurs, was trying to get his private-venture Industrial Space Facility off the ground, his major ground rule when looking for an industrial partner was "no aerospace companies". ...Most of the proposed budgets for the "stunts" like Roton aren't enough to cover even the contingencies that will arise, much less the entire program. That's why they fail. Name three private launcher projects that have failed by overrunning their budget estimates. (Hint: to overrun its estimated budget, such a project would first have to *have* funding somewhere close to the estimated amount.) -- MOST launched 30 June; science observations running | Henry Spencer since Oct; first surprises seen; papers pending. | |
#30
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PBS's "Nova" and MER
Scott Ferrin wrote:
Even if that is the case (it's been a while since I saw the show about the construction of the Truman but I'd have sworn they were outdoors when they bolted the sections together) that is still a far cry from "the levelest and flattest floor in the world". Sorry, you are *WRONG*. Don't confuse the assembly of the shaft segments (which is done on the pier) with the alignment of the shaft segments and the alignment of the shaft itself, which is done once installation is complete. 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. |
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