I hate getting into arguments over numbers, especially when they are speculated and hearsay.
I can't disagree, but some of those numbers are the ones the US Congress has to use to decide whether or not to fund the program... <g>
Let me just point out that according to these off-the-cuff calculations you use, the cost per launch is half a billion. The cost of the shuttle is roughly $1.3 billion (wiki), meaning that the new vehicle is almost 1/3 the cost.
According to the reference cited in Wikipedia, the $1.3 billion figure includes development costs. The operations costs are more difficult to estimate, but the same article has a table of five-year averages which yields per-flight costs ranging around $500-800 billion.
This indicates that the costs are largely fixed, they don't depend much on the number of flights per year. If you look at the annual budget, it remains around $3-5 billion a year for the last decade. The Transterrestrial article cites yearly operation costs of $3 billion for the CEV alone. Therefore it should cost about the same, maybe a little less, barring any budget overruns...
Oh, and the vehicle can carry cargo too. It can carry 6 crew, or partial crew and some cargo, or no crew and a space shuttle load of cargo.
... compared to cargo and crew for the shuttle, roughly at the same price.
As for why this is the right way (as opposed to Apollo or Shuttle), this provides a heavy lifter to quickly build large space structures
Cheaper than buying a bunch of light/medium boosters and developing a space tug? See
my other post on launch rate.
provides a cheaper way to get people into space
Not necessarily, as stated above.
can be reconfigured for different mission scenarios (which Apollo couldn't do),
I'd think that many light boosters would be even more versatile. And why couldn't Apollo be reconfigured for other missions? It did launch Skylab, after all.
Re:I like it, but I also have questions and doubts
on
NASA's New Shuttle
·
· Score: 1
The Delta 4 is not rated for human spaceflight, and probably cannot be without huge changes in technology and redesign.
The Delta 2 and the Ariane 4 were not man-rated either. The Shuttle and Ariane 5 are/were supposed to be. Given their failure rates, which would you rather be on? With an escape tower-equipped capsule?
More cynically, when a company designs a rocket, are they going to take more precautions to safeguard a billion-dollar satellite, or a few astronauts (with no shortage of volunteers)?
It seems very likely that the per flight cost will be much lower than the shuttle too, since the vehicle is less complicated than the shuttle, doesn't try to do everything for everybody all at the same time, and can be modified for each flight to only take up what is needed for that mission.
... yet, from the Transterrestrial Musings article I was referring to:
[...] let's just look at the CEV itself. I've seen estimates of annual operating costs for the system of three billion (and it's not clear whether those are fixed costs, or total). If they're only fixed costs, and it flies six times a year (say, in support of ISS), that comes out to half a billion dollars per flight. [...] This for something that only delivers crew to the station and returns them--no cargo capability. In other words, we're going to be spending as much on a LEO crew mission with the new architecture as we are currently on an entire Shuttle flight, including payload delivery and return.
Earlier in the article, the cost for a full lunar mission is estimated to be 3-4 billion dollars. I suspect that the "half of the Apollo program" part means that, as with the Shuttle, up-front development costs are minimized at the expense of operation costs...
As for the permanent base or other future plans, there was nothing specified. But if you look at what is being built, the HLV and CEV form a very good infrastructure to build on. With the HLV, a new space station, moon base, or Mars vehicle could be built with just a few (~5) launches. The plan is to get to the Moon the right way, with a scalable solution for future work.
But how is this more scalable, more "the right way" than Apollo, which was scrapped after a few flights? Why wouldn't the same thing happen in, say, 2020?
Re:I like it, but I also have questions and doubts
on
NASA's New Shuttle
·
· Score: 2, Informative
NASA have needed a heavy lifter
Actually, I've heard about studies stating that the main driver for launch cost is neither the total payload nor the technology but the launch rate. That is, for the same payload weight, a light booster that flies a hundred times a year will probably be cheaper than a heavy lifter that flies only a few times a year. It doesn't really matter if they are expendable, reusable, cryogenic or whatever.
See for example this 1994 study ("This indicates a potential paradox in the commercial space transportation market. High flight rates appear to be necessary to reduce the price per flight. However, reduced prices per flight reduces the revenue per flight, and consequently the cash flow available for investment payback.") or A Rocket a Day Keeps the High Costs Away.
Sure, a lower payload capacity means more orbital assembly required, more modular systems, which will make them heavier. But they will be more versatile, possibly cheaper, and the lower launch cost will offset the added weight.
OTOH, developing a heavy lifter starts from the opposite premise: a launch has to be expensive, so their number has to be minimized, with more payload per launch. This makes low flight rate a self-fulfilling prophecy and almost calls for a high cost.
The funny thing is that NASA arbitrarily set the CEV weight at 25 tonnes, just above the LEO capability of the heaviest rocket currently available (Delta 4 Heavy). Almost as if they wanted to need a new launcher, which then could be developed from Shuttle parts, keeping the existing workforce with a job, maybe even the very same job...
Apollo on steroids, how true...
on
NASA's New Shuttle
·
· Score: 3, Insightful
Mike Griffin's comment, that this is "Apollo on steroids", has more truth than it appears. It seems that no provision is yet made in that plan to actually build something on the Moon (they say that permanent bases eventually will be set up, but where is the payload for that? right now it's still flag-and-footprints, only longer); and that the operating costs will make the new program just as affordable as the previous ones, Apollo and Shuttle, i.e. barely.
First new world humans (or their emissaries) have landed on since 1976. That's one for the history books!
History books for sure, but you must be forgetting asteroid Eros, landed on by NEAR in 2001; and (depending on your definition of "land") Jupiter, whose atmosphere was visited by Galileo.
One might add the "bombing" of Tempel 1 in a few months by Deep Impact
Is it analogous to a figure skater spinning with arms extended, then pulling them in, making them spin faster?
You seem to have answered your own question: yes, the angular momentum (= angular velocity times moment of inertia) has to be unchanged short of external action; the moment of inertia has been reduced (same mass but rearranged to be closer to the spin axis); therefore the angular velocity (i.e. rotation speed) has increased.
What will be the impact of this on geostationnary satellites?
No more than usual perturbations, I suppose: geostationary satellites already tend to drift a little and need stationkeeping.
On the measuring of time?
None. The second is defined relative to quantum levels in the caesium atom, that won't change. As for keeping up with the calendar, the Earth's rotation already has small variations; since 3 microseconds is roughly 1/300 second, we might have to subtract a leap second next July or December. (E.g. straight from 2005-12-31/23:59:58 to 2006-01-01/0:00:00 UTC.)
On the GPS?
Don't know, but don't think the resolution is that precise.
We believe that Condorcet voting is the best system if properly implemented. However, as you will see at our site, the proper implementation gets very technical. (...) It's just too darn complicated.
How about each ballot being a half-grid where people write down their preferences, instead of 0/1 on your site? For instance, with 4 candidates A, B, C, D, expressing B/{A,B,C}; A/C; D/A and C vs D undecided would yield:
\ | A | B | C | D | __|___|___|___|___| A |___| B | A | D | B |_______| B | B | C |___________| . | D |_______________|
The half-matrix, of course, grows as the square of the number of candidates. But I would assume that with many candidates, people would just pick a few favorites (fill the corresponding line and column with the right letter) and--what's the word?--"antagonizers" (fill the line and column with the opponent's letter), and leave the rest undecided.
It does seems a little simpler. Would it be simple enough?
Isn't it the point of this design, that the radionucleides will have decayed by that time, so their burning up in the atmosphere will be harmless? Not all radioactive materials have millions of years of half-life (and radioactivity from those would be less intense, I'd guess...)
apparently NIS, NFS, etc., as required to integrate into a wider infrastructure, are beginning to be usable just now (even though OSX is years old and BSD-based);
remote management isn't as straightforward as conventional UNIX, and the tools and conventions aren't standard;
too many applications seem to set umask to 000 (suited to a home system, not a workstation).
Debian.
Cron apt updates installed packages on the schedule you specify. apt-proxy sits between you and the net and keeps a local mirror of the packages requested, so 100 requests = 1 outside request. Plus you can add your own custom packages to it so that your machines are configured properly. Upgrades? Well by hand it's
apt-get -y dist-upgrade. The stable branch is just that, and the testing branch is really production ready for most definitions of production.
Seconded, with reservations. We have recently transitioned from a jumbled mess of Windows, Macs, Suns, Redhat to something more manageable; that includes Debian Woody PCs, installed by FAI. No apt-proxy but we already maintain a local mirror.
The process is not complete. We are just beginning to deploy cron-apt. And apart from the difficulty of making some "historical" sysadmins to think in terms of an infrastructure instead of installing machines every which way; and the fact that we can't transition all software away from Windows (CAD tools, electromagnetic simulators...) or rip Office and Macs away from the addicts (no, even MacOSX isn't ready for integration into an infrastructure IMHO); there are still technical gripes:
Unattended package install and upgrades: it took us a while to silence some undisciplined packages which insist on being installed and asking questions such as "Change anything? [Y/n]" (lilo comes to mind); and a few days ago there was a security update of X, Debconf decided to take charge of/etc/X11/XF86Config-4 and broke it.
We'll probably come to desynchronize our mirror and test all updates, that's a lot of work.
Keeping systems up-to-date, not only for security but also which packages are installed, configuration files, and so on. Machines installed at different times tend to diverge quickly, as we adjust FAI configuration. The solution we are currently considering is to develop a special package with ad hoc dependencies and post-install scripts. Again, all this doesn't just happen by magic.
Debian-stable is indeed stable, but is aging rapidly. Not only graphics card support is problematic (we had to make a xserver-xfree86-4.3 package and install it alongside the rest of XFree-4.1), but users (and I) want KDE-3, teTeX-2, Mozilla-1.4... Sure, we can recompile packages from testing or sid (I did that a lot before Woody's release), but then dependencies kick in; and if you're not going to enjoy Debian's polished packaging, you might as well use FreeBSD or even RedHat.
Finally, you can't beat Solaris for serving NFS, which means we have to keep a Sun Enterprise server to store the users' home directories etc., and handle Samba and e-mail: at least the latter must run on the same machine which serves $HOME (think.forward,.procmailrc and so on; NFS just isn't reliable enough).
All in all, I'd recommend such a move, with Debian indeed, but it definitely isn't as easy as you make it sound...
- markus@cvs.openbsd.org 2003/09/18 08:49:45
[deattack.c misc.c session.c ssh-agent.c]
more buffer allocation fixes; from Solar Designer; CAN-2003-0682;
it would seem that in addition to the PAM patch, there are more buffer management-related fixes which didn't find their way into 3.7.1p1 but prompted Debian to make a third update to ssh. One may want to update even on OpenBSD or with PAM disabled.
Just because Shakespeare grew up in a small town and never received any formal education does not stop him from writing Hamlet.
"The usual rejoinder to someone who says 'They laughed at Columbus, they laughed at Galileo' is to say 'But they also laughed at Bozo the Clown.'"
(Carl Sagan)
For those of you who don't understand the article (myself included), it maybe because the article is just a rather crappy summary of the work.
That it is, anyway. But the comments it quotes from other scientists, especially those favorable to the crackp^H^H^H^H^H^Hyoung groundbreaker, point to him restating the obvious, at best. OK, who knows...
Further still, there is a quote at the end, from "mathematical physicist Chris Grigson": "(...) the idea was hard to understand. He is theorising in an area that most people think is settled. Most people believe there are a succession of moments and that objects in motion have determined positions."
Well, I thought it was well-settled that objects do not have determined positions or speeds, because quantum mechanics say that position and momentum are conjugate variables (delta-X * delta-P > \hbar).
And same for energy and time: you cannot measure phenomena of arbitrarily short durations because you would need to work at arbitrarily high frequencies, hence arbitrarily high energies.
As for Achilles' "paradox", it took some time for me to understand it, but now it is obvious that the mathematical model used simply cannot account for the time beyond the point where Achilles passes the tortoise. Therefore, in that model, of course he cannot pass it, and time "stops". This not being what we observe in reality, a better model is required; just like Newtonian mechanics not being compatible with electromagnetics, time dilation, etc. but simpler.
I'd have to read the actual paper, but the linked article definitely stinks and points to the guy being a crackpot. One of many...
In message <fa.n9kl75v.1nugol@ifi.uio.no>,
Linus himself admitted to releasing 2.4.0 because he "decided that enough is enough, and that things don't get better from having the same people test it over and over again." (In short, "we know it's still buggy as hell, but we hope more people will help solve that--if we just have them believe it's production-ready", right?)
I read your link and must say that I don't agree that it used solar-anything for propulsion. They made great use of gravitation to slingshot it around which was kind of a first at the time.
It's near the bottom, "Two firsts" (grrr, again the "solar wind" mistake):
(...) first spacecraft to use the gravitational pull of one planet to help it reach another planet. This craft was also the first to use the solar wind as a means of locomotion; when the probe's thruster fuel ran low, scientists used the solar panels as sails to make course corrections.
No (human) spacecraft to date has used the solar wind for propulsion
Mariner 10 did in 1974, although not as a primary means of propulsion. (I assume that by "solar wind" you mean radiation pressure, not actual solar wind?)
Slashdot Mirror
I can't disagree, but some of those numbers are the ones the US Congress has to use to decide whether or not to fund the program... <g>
According to the reference cited in Wikipedia, the $1.3 billion figure includes development costs. The operations costs are more difficult to estimate, but the same article has a table of five-year averages which yields per-flight costs ranging around $500-800 billion.
This indicates that the costs are largely fixed, they don't depend much on the number of flights per year. If you look at the annual budget, it remains around $3-5 billion a year for the last decade. The Transterrestrial article cites yearly operation costs of $3 billion for the CEV alone. Therefore it should cost about the same, maybe a little less, barring any budget overruns...
Cheaper than buying a bunch of light/medium boosters and developing a space tug? See my other post on launch rate.
Not necessarily, as stated above.
I'd think that many light boosters would be even more versatile. And why couldn't Apollo be reconfigured for other missions? It did launch Skylab, after all.
The Delta 2 and the Ariane 4 were not man-rated either. The Shuttle and Ariane 5 are/were supposed to be. Given their failure rates, which would you rather be on? With an escape tower-equipped capsule?
More cynically, when a company designs a rocket, are they going to take more precautions to safeguard a billion-dollar satellite, or a few astronauts (with no shortage of volunteers)?
Earlier in the article, the cost for a full lunar mission is estimated to be 3-4 billion dollars. I suspect that the "half of the Apollo program" part means that, as with the Shuttle, up-front development costs are minimized at the expense of operation costs...
But how is this more scalable, more "the right way" than Apollo, which was scrapped after a few flights? Why wouldn't the same thing happen in, say, 2020?
Actually, I've heard about studies stating that the main driver for launch cost is neither the total payload nor the technology but the launch rate. That is, for the same payload weight, a light booster that flies a hundred times a year will probably be cheaper than a heavy lifter that flies only a few times a year. It doesn't really matter if they are expendable, reusable, cryogenic or whatever.
See for example this 1994 study ("This indicates a potential paradox in the commercial space transportation market. High flight rates appear to be necessary to reduce the price per flight. However, reduced prices per flight reduces the revenue per flight, and consequently the cash flow available for investment payback.") or A Rocket a Day Keeps the High Costs Away.
Sure, a lower payload capacity means more orbital assembly required, more modular systems, which will make them heavier. But they will be more versatile, possibly cheaper, and the lower launch cost will offset the added weight.
OTOH, developing a heavy lifter starts from the opposite premise: a launch has to be expensive, so their number has to be minimized, with more payload per launch. This makes low flight rate a self-fulfilling prophecy and almost calls for a high cost.
The funny thing is that NASA arbitrarily set the CEV weight at 25 tonnes, just above the LEO capability of the heaviest rocket currently available (Delta 4 Heavy). Almost as if they wanted to need a new launcher, which then could be developed from Shuttle parts, keeping the existing workforce with a job, maybe even the very same job...
Any comments on the following analyses? Transterrestrial Musings
Space Access Update #112
History books for sure, but you must be forgetting asteroid Eros, landed on by NEAR in 2001; and (depending on your definition of "land") Jupiter, whose atmosphere was visited by Galileo.
One might add the "bombing" of Tempel 1 in a few months by Deep Impact
That would be right, but I did read "compacted the Earth" and "a shift of mass toward the Earth's center"...
Now, it is quite possible that the land was raised in one place, sunk in others, and that the net result was a reduction in the moment of inertia.
You seem to have answered your own question: yes, the angular momentum (= angular velocity times moment of inertia) has to be unchanged short of external action; the moment of inertia has been reduced (same mass but rearranged to be closer to the spin axis); therefore the angular velocity (i.e. rotation speed) has increased.
Oops... Mistook microseconds for milliseconds, it seems. Forget that.
No more than usual perturbations, I suppose: geostationary satellites already tend to drift a little and need stationkeeping.
None. The second is defined relative to quantum levels in the caesium atom, that won't change. As for keeping up with the calendar, the Earth's rotation already has small variations; since 3 microseconds is roughly 1/300 second, we might have to subtract a leap second next July or December. (E.g. straight from 2005-12-31/23:59:58 to 2006-01-01/0:00:00 UTC.)
Don't know, but don't think the resolution is that precise.
Nope. No air on the Moon, the dust did not billow, and did not race farther away than a few meters.
How about each ballot being a half-grid where people write down their preferences, instead of 0/1 on your site? For instance, with 4 candidates A, B, C, D, expressing B/{A,B,C}; A/C; D/A and C vs D undecided would yield:
The half-matrix, of course, grows as the square of the number of candidates. But I would assume that with many candidates, people would just pick a few favorites (fill the corresponding line and column with the right letter) and--what's the word?--"antagonizers" (fill the line and column with the opponent's letter), and leave the rest undecided.
It does seems a little simpler. Would it be simple enough?
... nobody knows you're a Martian.
Or Deutschland into Germany? Or España into Spain? And what about la Suisse, I mean Schweiz, I mean Svizzera...
And don't worry, to people in Bordeaux, the capital of l'Angleterre is Londres, not London. <g>
Yes.
Isn't it the point of this design, that the radionucleides will have decayed by that time, so their burning up in the atmosphere will be harmless? Not all radioactive materials have millions of years of half-life (and radioactivity from those would be less intense, I'd guess...)
All IMHO, of course.
Seconded, with reservations. We have recently transitioned from a jumbled mess of Windows, Macs, Suns, Redhat to something more manageable; that includes Debian Woody PCs, installed by FAI. No apt-proxy but we already maintain a local mirror.
The process is not complete. We are just beginning to deploy cron-apt. And apart from the difficulty of making some "historical" sysadmins to think in terms of an infrastructure instead of installing machines every which way; and the fact that we can't transition all software away from Windows (CAD tools, electromagnetic simulators...) or rip Office and Macs away from the addicts (no, even MacOSX isn't ready for integration into an infrastructure IMHO); there are still technical gripes:
All in all, I'd recommend such a move, with Debian indeed, but it definitely isn't as easy as you make it sound...
"The usual rejoinder to someone who says 'They laughed at Columbus, they laughed at Galileo' is to say 'But they also laughed at Bozo the Clown.'" (Carl Sagan)
That it is, anyway. But the comments it quotes from other scientists, especially those favorable to the crackp^H^H^H^H^H^Hyoung groundbreaker, point to him restating the obvious, at best. OK, who knows...
As for Achilles' "paradox", it took some time for me to understand it, but now it is obvious that the mathematical model used simply cannot account for the time beyond the point where Achilles passes the tortoise. Therefore, in that model, of course he cannot pass it, and time "stops". This not being what we observe in reality, a better model is required; just like Newtonian mechanics not being compatible with electromagnetics, time dilation, etc. but simpler.
I'd have to read the actual paper, but the linked article definitely stinks and points to the guy being a crackpot. One of many...
In message <fa.n9kl75v.1nugol@ifi.uio.no> , Linus himself admitted to releasing 2.4.0 because he "decided that enough is enough, and that things don't get better from having the same people test it over and over again." (In short, "we know it's still buggy as hell, but we hope more people will help solve that--if we just have them believe it's production-ready", right?)
It's near the bottom, "Two firsts" (grrr, again the "solar wind" mistake):
Mariner 10 did in 1974, although not as a primary means of propulsion. (I assume that by "solar wind" you mean radiation pressure, not actual solar wind?)
No new information in a history of something? How surprising!