> Gregg Maryniak is promoting the High Frontier viewpoint on Economist.com in regard to the usefulness of the moon:
http://www.economist.com/debate/days/view/358
I wonder how he derived that figure.
We might consider the facts that Earth's spin provides up to 465 m/s of initial boost to the entirety of any given rocket stack, has atmosphere for workers, equipment cooling and ease of space-vehicle re-entry, has oceans for transportation and launch-staging, has sufficient gravity for speedy industrial activity, and has established diversified industry. The moon has none of that.
The High Frontier viewpoint on the usefulness of the moon is positively bizarre, given the thousands of near-Earth objects (6330 to date) that have been discovered since The High Frontier was written.
http://neo.jpl.nasa.gov/stats
> He wrote: "It is more than 22 times easier to escape the moon's gravity than to escape that of the Earth."
>
> I wonder how he derived that figure.
> has sufficient gravity for speedy industrial activity
What does this mean, exactly?
> The High Frontier viewpoint on the usefulness of the moon is positively bizarre,
> given the thousands of near-Earth objects (6330 to date) that have been
> discovered since The High Frontier was written.
We may all define "the High Frontier viewpoint" differently, but I would define it to include use of NEO materials as well as lunar.
Either alternative has its advantages. Most of the moon's advantages relate to its closeness and short travel times. I'm sure that both sources of raw materials will be used.
Regards,
Mike Combs
Until people learn to use math, they're always going to be confused by these numbers, not realizing that K.E.=1/2mv^2 says that for every doubling of velocity required to reach escape velocity, the energy required to attain that quadruples. Thus, though lunar escape Velocity is 2.38 km/sec vs earths escape velocity of 11.186 km/sec and the ratio between those is 4.7, the energy required is the square of that figure or 22.09. It's an easy calculation, if you know what you're doing,,,I might note that, while Space Ship one was a marvelous accomplishment, it only reached 3518 km/hr, while roughly 32,000 km/hr was required for orbit. with a Delta v ratio of 9.1,squaring this gives a requirement for 81 times more energy,,,. Burt has a long way to go to get to orbit,,,
> I
> might note that, while Space Ship one was a marvelous accomplishment, it
> only reached 3518 km/hr, while roughly 32,000 km/hr was required for
> orbit. with a Delta v ratio of 9.1,squaring this gives a requirement for
> 81 times more energy,,,. Burt has a long way to go to get to orbit,,,
Best,
- Joe
,,,or a mass driver, or space elevator or laser launcher,,,all of these are potential solutions but none of them are being built. So, for now, we're stuck with chemical rockets,,,(come on Bussard. Make it work,,,)
> So, for now, we're stuck with chemical rockets,,, Take heart. A lot of space thinkers are saying that costs/kg relate less to the technology and more to the flight rates. And further, that if flight rates could only be brought high enough, we could get to the costs/kg we want well within the performance boundaries of chemically-fueled rockets.
Mike Combs
I've been seeing a lot of such analyses recently. I guess then we just need a massive enough project to require such large numbers of launches. Gee, I wonder what kind of project that could be?This whole discussion revolves around a chicken/egg argument, as in"Oh, if launch costs were just low enough,,," and " If we just had enough customers,,,". I recall no one had any great desire for an interstate transit system in the 1940s, until the government decided it was necessary as a rapid transport system for the armed forces. AS I recall, that system cost as much in those dollars as a massive space launch infrastructure would cost today. We just need a really salable excuse.GAry 7
> So, for now, we're stuck with chemical rockets,,, Take heart. A lot of space thinkers are saying that costs/kg relate less to the technology and more to the flight rates. And further, that if flight rates could only be brought high enough, we could get to the costs/kg we want well within the performance boundaries of chemically-fueled rockets.
Regards,
Mike Combs
I think that setting up a system similar to what Truax had in mind for
the Sea Dragon would be a good way of keeping the infrastructure costs down.
Although it might be better to power it completely by liquid hydrogen
rather than RP-1 that way you could set up an ocean thermal energy
conversion ship
near the launch location to provide the fuel needed and use that as a
way to assuage potential environmental concerns.
B
So quickly people forget there have been quite a large number of proposals for a launch infrastructure that would be universally usable to anyone. I've always liked Mike Combs Balloon supported mag lev launcher. Then there is Launch Point Technologies proposal, which is really only good for non-organic, extremely high G tolerant payloads, like, say, explosive(for the military) or solar cells, fuel, water, or other inert materials(for SPS). Leik Myrabos Laser launch system requires significant technological advances in laser tech, but it could be a viable system for a highway to space and of course, we have the space elevator, which still requires that we be in space in a big way before we can build the darn thing. Of all these proposals, those that are scalable,ie, can start off with small payloads and, as tech catches up, expand to large payloads, seem the most likely to attract funding. Mike Combs system is go for broke, wherein someone has to be
convinced to expend a lot of money up front before a single load can be launched. Launch Points system is scalable as well as the laser launch system, ie, we could start with micro payloads and move on to larger loads as the tech matures. Lower up front costs are attractive to investors.
OK. How to convince a politician,,,lessons learned from the interstate transport system.
1) Our military is required to protect this country from threats domestic and foreign. China, India and possibly Russia have the tech capability to go to the moon. This makes them potential threats, who could drop rocks(or tungsten rods) on our little pointy heads. Luna for the Air Force,,,
2) Asteroids that might be harmful to our health. Again, Luna for the Air Force.
3) SPS(the obvious choice for me, Dr. O'Neille and myriad others), ie, energy for our electric toothbrushes,(OK, really, it's for everything that makes our techno civilization go and requires a PERMANENT Lunar industrial base, as do the afore mentioned).
4),,,and of course, other resources this society needs to survive(go Luna)
5) Mr Politician, parts of this infrastructure can be built in YOUR state(very, VERY important consideration).
OK. That's all I can come up with, so far. Anything significant that can be added to that list just makes it a stronger argument. Go for it, Y'All.
GAry 7
> 5) Mr Politician, parts of this infrastructure can
> be built in YOUR state(very, VERY important
> consideration).
One problem farmers have is that they produce more food
than can be consumed. I'd love to see more of that
food given away to people who are malnourished, some to
the point of starvation. And indeed some of it is, but
for various reasons a lot of it is not. So a lot just
sits and rots, and some is deliberately destroyed.
Is there an agricultural product that could replace the
kerosene some rockets are so thirsty for? Corn oil?
Walnut oil? What happens if you take butter and remove
all of the water and solids?
If Kansas and Nebraska and Oklahoma could become big
space states, because they are making the rocket fuel,
this could be a very good thing. Wouldn't it be great
to see a Million Farmers March on Washington, carrying
signs that read "WE DEMAND A MOON BASE!!"