They
point out that while we have had the math worked out on reaching space
for a century and we've been doing it for about half as long, it is
still too great a hurdle for cheap access and large scale development.
This
is a side effect of expendable launchers, which make sense from an
engineering standpoint (they have maximum fuel efficiency and the
highest payloads) but in an economic sense...they
no sense.
The
problem here is that with the most current launch vehicles we are doing
the equivalent of flying to Japan in a 747 and then blowing up the
plane......every time. If that were the process for a transpacific
flight..I could not have afforded to go to Japan last
month.....just about no one could have.
So how do we fix the problem? Well obviously we make the damned thing reusable so you can fly it more than once!
While it may seem at first blush to be a dispatch from the department of "Duh!", that task is not as easy as it sounds...nor as impossible as some suggest.
1
Check out this:
http://selenianboondocks.blogspot.com/2007/04/myth-of-25x.html
Ubu's numbers may be correct, but they're not telling the whole story when comparing SS2 and orbital launchers.
Posted by: Pete Zaitcev at Fri Sep 5 23:06:20 2008 (/ppBw)
2
Thanks for the post, Ken. That made for some interesting reading. I've bookmarked it for future reference, as well.
If you can find a copy available, there's a book from '78 that the AIAA put together showing where the STS program was "supposed" to go. The title on it is "Space Transportation Systems: 1980-2000," and it was edited by Salkeld and Patterson. A number of Shuttle follow-ons and interim-upgrades (which we naturally never went with) are covered in great detail. It's a crying shame that none of the lessons of the Shuttle are being built into its intended successor - and almost a big a shame that we're not looking to fix much of the easier problems on the current equipment, either.
If I may, where did you find the info for the SSV? Something similar is used as a design study in the AIAA book, but that's the first I've heard of it as something studied in any kind of "official" capacity.
Posted by: Rich Anderson at Sat Sep 6 21:18:13 2008 (iGCiD)
3
If I may, where did you find the info for the SSV? Something similar
is used as a design study in the AIAA book, but that's the first I've
heard of it as something studied in any kind of "official" capacity.
I first heard about in in a Popular Mechanics article in the 80s, and it has appeared from time to time in internet searches. It is mentioned in a very brief entry at astronautix.com and in Millers
The Dream Machines which is long out of print. While researching this post I found what is the most complete overview of it I've found on the Secret Projects Board
here. note that to see the images (one of which I nicked) you need to register.
There is a very similar proposal (independently developed it seems) in Russia that is an on again off again proposition called
MAKS.
Posted by: The Brickmuppet at Sat Sep 6 23:54:19 2008 (V5zw/)
4
I've been following the attempts to develop CATS since 2001 or so (indeed he first blogs I found were space ones link Hobbyspace).
It does seem that everything it due to happen '3-4 years from now, but I'm still cautiously optamistic that it will happen.
Now that there are a number of individuals putting serious cash into it (Bezos, Musk and so on), It looks more likley than at any time since the 80's. I still recon I'll to be able to retire to the belt (though LEO would be enough)
Posted by: Andrew Janes at Sun Sep 7 15:23:12 2008 (h7yN2)
5
Thanks for the references. Another source to scour is always a good thing.
A thought occured regarding the acceleration of the gun-type launch vehicles, I'm curious why it would be a bad idea to use an electromagnetic mass driver set up in a loop, with a spur-track coming off at a tangent for the final loft. The loop would be where you could come up to speed over as much time as needed before the final few m/s of vee are added in the spur-track. Accelerations could then be anything from a few tenths of G up to multiple 10s of G. The only really difficult part would be designing the "switch" point, which is somewhat amusing - Dr. O'Neill made his fame for writing "The High Frontier," but made his career and earned his Nobel for designing that very "switch" for use with particle accelerators back in the 1950s. If Ken or Pete or anyone can point out the flaw in this reasoning, I'd be grateful.
Posted by: Rich Anderson at Sun Sep 7 16:22:55 2008 (HzN2k)
6
I'm a biology major so take this with a grain of salt.
I think that regards the "switch" you are referring to, for it to have applications for a useful payload, it would have to be vastly more problematic than manipulating magnetic fields. Rather than magnetic fields to bend the course of subatomic particles (which are pretty robust...that's why we need big apparatus to break them) this would require something akin to a train switching tracks at a high Mach number. Also, running at a high Mach number on the ground has noise issues and the potential for damage not only to the surounding area, but the device itself as the sonic boom might be reflected back on it due to the close proximity to the ground.
This doesn't get into the effect of really high powered magnetic fields on biological processes such as brain activity or movement of hemoglobin.
There may be work-arounds for this but I don't see them in the near term.
Posted by: The Brickmuppet at Sun Sep 7 19:59:10 2008 (V5zw/)
Hide Comments
| Add Comment
has picked up this bit of scuttlebut from that thar scurrvy dog Brian Wang.
all dressed up, with nowhere to go..and this pisses them off!
