Re: space shuttle obsolete
--- Doug Pensinger <[EMAIL PROTECTED]> wrote: > Gautam wrote: > > > He thought, IIRC, that he and his grad students > could, if > > they chose, build a rocket that could put 10 kgs > in > > LEO for about $50,000. It was just mindblowing - > I > > wish I had a tape of the presentation so I could > show > > it to people. > > Fascinating stuff, Gautam, but why _wouldn't they > choose to do it? > > Doug Well, among other reasons, because I think it might be illegal, as such a rocket would also qualify as an ICBM :-) In all seriousness, I don't actually know. He said they've actually gone ahead and designed all the hard parts, and actually built some of them, so he didn't feel it was much of a challenge. OTOH, I'm not sure what _use_ putting 10 kgs into LEO would be right now. 10 kgs isn't that much. If someone were to right him a check for the amount, he seemed very confident he could do it. My guess is that scaling it up to launch heavier payloads is a bit more of a challenge, but, judging by his talk (I am not, after all, a specialist in nanotech) eminently doable. Gautam Mukunda [EMAIL PROTECTED] "Freedom is not free" http://www.mukunda.blogspot.com Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: space shuttle obsolete
Gautam wrote: He thought, IIRC, that he and his grad students could, if they chose, build a rocket that could put 10 kgs in LEO for about $50,000. It was just mindblowing - I wish I had a tape of the presentation so I could show it to people. Fascinating stuff, Gautam, but why _wouldn't they choose to do it? -- Doug ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: space shuttle obsolete
--- Dan Minette <[EMAIL PROTECTED]> wrote: > In what sense would these be nuclear powered? > Nuclear propulsion is > practical for long, slow accelerations, not lifting > off a massive body like > the earth. Relatively little progress has been made > in that area because > the physics is straightforward, and the chemistry > basically just chemical > engineering. I think material science is probably > the area where the > advances would be most useful. The next most > important advance would be > rugged electronics. In my own limited field, we > subject electronics to far > greater stresses than anything one would expect > going to space. Let me toss in a different technology - nanotech. The single most interesting thing I attended in my year at MIT was a talk by an aeronautical engineering professor here on the aerospace implications of nanotech - in particular, the nanotech developments _already working in his lab_. One of the things that he showed us were massive increases in the efficiency of jet and rocket engines. He actually handed out a working jet engine about the size of my thumb. The engine for the F-22 - probably the most advanced "normal" jet engine in the world has (IIRC - it's been several months now) an 8:1 power to weight ratio, which is pretty good. This little thing, a first generation engine using nanotech, has a 50:1 power to weight ratio. It was astonishing - one of the most interesting hours of my life, really. I've never seen a presentation anything like it - and it was most impressive not because it was all "blue sky" projects but because everything he was talking about was either _already working_ or very close to being so. He thought, IIRC, that he and his grad students could, if they chose, build a rocket that could put 10 kgs in LEO for about $50,000. It was just mindblowing - I wish I had a tape of the presentation so I could show it to people. Gautam Mukunda [EMAIL PROTECTED] "Freedom is not free" http://www.mukunda.blogspot.com Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: space shuttle obsolete
- Original Message - From: "Jon Mann" <[EMAIL PROTECTED]> To: Sent: Saturday, July 30, 2005 1:40 AM Subject: space shuttle obsolete > Use tried and true disposable solid fuel boosters to launch satellites, > robotic missions, scientific experiments, etc. And when necessary, > human astronauts to work on the space station, make repairs on the > Hubble, etc. Rather than using an antiquated shuttle system it would > by more practical to develop nuclear powered smaller vehicles that > could be launched like the Mercury, Gemini and Apollo Capsules, but > with better propulsion and maneuvering technology. In what sense would these be nuclear powered? Nuclear propulsion is practical for long, slow accelerations, not lifting off a massive body like the earth. Relatively little progress has been made in that area because the physics is straightforward, and the chemistry basically just chemical engineering. I think material science is probably the area where the advances would be most useful. The next most important advance would be rugged electronics. In my own limited field, we subject electronics to far greater stresses than anything one would expect going to space. >It could remain > docked to the space station, providing additional living space, and > available for interorbital missions, such as repairing the Hubble and > eventually returning to the moon. It is impractical to launch heavy > shuttles out of the gravity well and then return them to earth, > subjecting them to re-entry damage and endangering the lives of our > hero astronauts. No matter how you slice it, space travel is still a risky business. I would hope that the advances in technology of the last 30 years would allow us to build a safer means of transport. Especially since manned space fight is still in the PR stage, so very little in terms of scientific advances can be attributed to it. Dan M. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: NASA Concerned Over Approaching Asteroid
At 08:11 AM Saturday 7/30/2005, you wrote: This is the same asteroid that they thought would hit the Earth in 2029 and then they retracted that statement a few days later. If the probability of impact does go up, I wonder just how much political fighting there will be over budgets, methods and the actual need to try to divert this asteroid. There's always going to be someone that disagrees that it will actually hit Earth. Not that I think there is a conspiracy, but the timing of this news is very coincidental after the successful comet impact. If I were going to try to win support for a mission to divert an asteroid, I think I would have waited until after a successful mission too. Or maybe the solar system is shooting back. BTW, I wonder if that Russian astrologer who sued over the Deep Impact mission already knew about and took into account the "tenth planet" announced yesterday? --Ronn! :) I always knew that I would see the first man on the Moon. I never dreamed that I would see the last. --Dr. Jerry Pournelle ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Data Cuts, Normalization, and Analysis for Politics L3
- Original Message - From: "Dan Minette" <[EMAIL PROTECTED]> To: "Killer Bs Discussion" Sent: Monday, July 25, 2005 3:50 PM Subject: Data Cuts, Normalization, and Analysis for Politics L3 1) Even reports which, as given, could not be true can be mined for critical information: The application to politics is two fold. First, even when one has good suspicion that there is some bias in a report, one should still accept the presentation of that report as a fact. In some cases, like the National Inquirer, the fact that there is a report of a secret prophecy that Bigfoot will marry Elvis, who's been living with space aliens, probably has minimal correlation observables. In other cases, one finds a much better correlation between observations and reports, after things have time to be sorted out. I'll give an example involving the president GWB's DWI was quickly confirmed, while the report based on forged records of GWB's National Guard duty had to be retracted. Taken together, we have a discernable pattern. I realize that folks on the right state that the liberal media has it in for GWB and thus finds spurious things to accuse him of. But, it was the same liberal media which reported the stories questioning the accuracy of the report. Articles were written both attacking and supporting the position that the forged report was trueuntil the propensity of the evidence required a conclusion. It doesn't always work out this well, mind you, but it this is not the behavior of a group that is ideologically bent on getting one message out. Instead, the data seems to support a different hypothesis: news organizations are very interested ratings, readership, taking the lead in stories. So, they look for scoops that will raise their rating. This holds particularly true for news magazine shows, I think. I've developed a model that's fairly consistent with observations that indicates that news shows, in general, are biased towards stories that create buzz. Given this, we can develop a rule of thumb concerning revelations. When they first come out, they should be taken with a grain of salt. After other organizations get their teeth into the revelation, one should quickly see if it is immediately confirmed, if it will take a while to confirm, or if questions are immediately raised. One advantage of using this technique should be clear: it is not based on the ideological impact of the news. Therefore, it is fairly well insulated against the risks of confirmation bias that may exist with the person using the technique. While there are additional aspects to this, they probably fit better under the points listed below, so I'll cover them there. 2) Having a teammate with a significantly different perspective look at the problem is usually very helpful: Translated to politics, this involves having friendly debate partners who have different outlooks than your own. Two of mine are my Zambian daughter, Neli and Gautam. When I come up with a reading of the data, I often determine how I could defend it with data in such a manner that my debating partners will see the merit of the argument, even if they read things differently. So, they help me, even before I discuss things with them. > 3) What I have found successful is establishing a hierarchy of likely causes. There are a couple of obvious carry overs from engineering to politics here. First, the hierarchy doesn't actually reject possibilities; it assigns lower probability to them. Second, as described in my previous post, the ranking of the probabilities is adjusted as more data comes in. Thus, as data comes in, one is guided by technique to reconsider one's own position and, perhaps, modify it slightly to better fit the expanded data set. 4) Calibrating against past observations is very helpful. In particular, it is helpful if as many observations as possible are included in the calibration. If one suspects a bias towards a particular viewpoint, it is not enough to catalog past instances that support that view of the bias. One must also accept past instances that are inconsistent with that view. Let me give an example. We can compare reports on conventional fighting that have come from the administration vs. scoops that have come from various people. Among them was Seymour Hearsh, who claimed that the US had many more people killed at the start of the Afghanistan war than reported...and that the Ranger raids were disasters. On the whole, if you compare the predictions of the Administration with those of the various pundits; the Administration's predictions were superior. Allowing a modest error bar for the fog of war, you would see that the GWB administration did a pretty good job representing the progress of the conventional war phases of both the Afghanistan and Iraq conflicts. Now, a good Bush Republican will point this out as a stellar example of media bias. They might argue that the media always seems to be loo
RE: space shuttle obsolete
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jon Mann Sent: Saturday, July 30, 2005 4:10 AM To: brin-l@mccmedia.com Subject: space shuttle obsolete Ever since the Space Shuttle Challenger exploded on takeoff I realized NASA technology is neither safe nor cost effective, but a multi billion dollar business. I believe that the Russian approach to orbital launches is cheaper and far less dangerous. It appears the Chinese will also be relying on rocket launches rather than expensive and inefficient orbital vehicles. Here is my idea that I have proposed to friends who have far more knowledge and expertise than a layman such as myself. Use tried and true disposable solid fuel boosters to launch satellites, robotic missions, scientific experiments, etc. And when necessary, human astronauts to work on the space station, make repairs on the Hubble, etc. Rather than using an antiquated shuttle system it would by more practical to develop nuclear powered smaller vehicles that could be launched like the Mercury, Gemini and Apollo Capsules, but with better propulsion and maneuvering technology. It could remain docked to the space station, providing additional living space, and available for interorbital missions, such as repairing the Hubble and eventually returning to the moon. It is impractical to launch heavy shuttles out of the gravity well and then return them to earth, subjecting them to re-entry damage and endangering the lives of our hero astronauts. Continue to use them in orbit and return the astronauts the old fashioned way. The logistics should not be difficult. ___ http://www.mccmedia.com/mailman/listinfo/brin-l I'll say this First before I go farther, I really don't want to be a nay sayer to your idea as I have similar views about the current and future manned space exploration outlook. However, there are several things that I would like to highlight from your post as some food for thought about it. "I believe that the Russian approach to orbital launches is cheaper and far less dangerous. It appears the Chinese will also be relying on rocket launches rather than expensive and inefficient orbital vehicles." Though I do agree that "now" this approach is a safer bet for crew survivability, there were quite a few launch failures with loss of payload and crew, the US shuttle program can only see 2 massive failures to date Challenger and Columbia. Before I make my next point off of this I will make some admissions, I will not argue that the Shuttle is tres expensive. However at the time it was built is was the cutting edge in technology, and as was said in a previous post if you were to ask a shuttle engineer if they thought the shuttle would be flying in '05 they would laugh, the thing simply was not meant to be in operation for 30+ yrs. (yes I know they all didn't come out in '75 but the design has been around since the) The reason why the vehicles themselves are cheaper is because they are toss away, im sure someone with more knowledge will tell me that they salvage much of the electronics from one Soyuz for one under construction replacing as needed to reduce cost, but I don't know that for sure. The shuttle was designed to be a multi task vehicle, which it still is, what is needed is a modular system with a return to earth capability something again modular but in the sence that the payload module can be launch automated and return to earth automated after dropping off its payload, and have a reuse of say 15+/- flights. I would want the option that the crew module can launch and return on its own, so if you have to do a crew change on the ISS you don't have to launch an entire vehicle. In the same breathe I would want it to have the option of launching with the payload module. " Rather than using an antiquated shuttle system it would by more practical to develop nuclear powered smaller vehicles that could be launched like the Mercury, Gemini and Apollo Capsules, but with better propulsion and maneuvering technology." Ok here I go sounding like a crazy scared old nuclear watch dog.. I think that giving a larger power source to manned and unmanned missions is a great idea, and very necessary as it takes away power limits for scientific payloads on DS missions. However the more you launch them and return them the higher the chance of a catastrophic failure and we have a nuclear could falling over the world. even as you have put it they would stay docked to the ISS there has to be away for the crew to return home, so they have to have reentry capability, and poking a nuke on a one hop capsule to me just isn't cost effective. Granted as I said above you can salvage from each cap. And drop cost but I'm still wary about having a crew return vehicle that has a nuke on board. Before you say well we can have it removable in orbit and it can be connected to the ISS for additio
RE:Harry Potter Discussion (Spoilers!!!) L3
I am jumping in a bit late but what with one thing or the other, I didn't get around to reading this thread until this morning. Gautam wrote: > In this book, however, the situation is different - > and here, in a real sense, I am more impressed. Now, > Harry is the king of Hogwarts. A hero to most of his > peers, adored by girls, the favorite of most of the > teachers, captain of the Quidditch team. Harry isn't > the downtrodden outcast. He's the elite. What does > he do? He (in my single favorite moment of the book) > invites Luna Lovegood to a prestigious party. Now > that the books are being read by everyone, I think > Rowling is taking advantage of this popularity to send > a new, much rarer message. Now, knowing that the > kings of the school will also be reading her books, I > think Rowling is trying to teach _them_ something. > This is how you should behave. You reach out to the > poor kids, the unpopular kids. That's not a common > message, because most kids lit doesn't have the > popular kids as the heroes. I disagree on two points here. First, I don't think Harry's invitation to Luna was any kind of a big deal. Harry couldn't invite the girl he wanted to invite, was pre-occupied, and invited the first girl he considered a friend. All I could see in his actions was convenience. Not that Harry doesn't take a stand on the issue, but that happens right at the beginning of the term, on the train to Hogwarts as a matter of fact. And there, I found the message to be not that popular kids should reach out to the unpopular kids, but that popularity is an ephemeral thing, and that friendship and loyalty matter more than the appearance of being 'cool'[the entire exchange in the train when Harry is questioned about his companions, his answer, Luna's comment and Harry's response to the same]. And that brings me to the second point of disagreement - I don't think Rowling [through her characters] was advocating that the popular kids to reach out to the poor, unpopular kids [the notion has a uncomfortable tinge of noblesse oblige to me], but was pointing out that the kids unpopular in school have their own good points, points well worth appreciating. Harry, although somewhat uncomfortable and embarassed around Luna, still appreciates the fact that she fought by his side. Ron is on the way to becoming a fan of her Quidditch commentary. > 3. Finally, briefly, and inextricably from the above, > I think there is some level of political allegory > involved. Definitely. My favourite part was when Harry tells Scrimgeour that he has no desire to be affiliated with a Ministry which doesn't ensure people's innocence or guilt before chucking them in prison. And I really liked the fact that he relayed pertinent bits of that conversation to Dumbledore. :) Ritu ___ http://www.mccmedia.com/mailman/listinfo/brin-l
NASA Concerned Over Approaching Asteroid
This is the same asteroid that they thought would hit the Earth in 2029 and then they retracted that statement a few days later. If the probability of impact does go up, I wonder just how much political fighting there will be over budgets, methods and the actual need to try to divert this asteroid. There's always going to be someone that disagrees that it will actually hit Earth. Not that I think there is a conspiracy, but the timing of this news is very coincidental after the successful comet impact. If I were going to try to win support for a mission to divert an asteroid, I think I would have waited until after a successful mission too. NASA Concerned Over Approaching Asteroid Large Space Rock May Collide With Earth in 2036 By PETER N. SPOTTS Jul. 26, 2005 - Humans live in a vast solar system where 2,000 feet seems a razor-thin distance. Yet it's just wide enough to trigger concerns that an asteroid due to buzz Earth on April 13, 2029 may shift its orbit enough to return and strike the planet seven years later. The concern: Within the object's range of possible fly-by distances lie a handful of gravitational "sweet spots," areas some 2,000 feet across that are also known as keyholes. The physics may sound complex, but the potential ramifications are plain enough. If the asteroid passes through the most probable keyhole, its new orbit would send it slamming into Earth in 2036. It's unclear to some experts whether ground-based observatories alone will be able to provide enough accurate information in time to mount a mission to divert the asteroid, if that becomes necessary. So NASA researchers have begun considering whether the United States needs to tag the asteroid, known as 99942 Apophis, with a radio beacon before 2013 Complete article http://tinyurl.com/7hybu http://makeashorterlink.com/?C21A2268B http://abcnews.go.com/Technology/CSM/story?id=976463&page=1 ___ http://www.mccmedia.com/mailman/listinfo/brin-l