We're going back to the moon!

[BornAgainPagan]

EagleRJ,

First of all, I'm not, by a long shot, an authority on the subject. Just a little cursory knowledge from reading and discussions with knowledgeable friends.

In a nutshell, the "burn" required to get a vehicle to the moon is much longer (pulling almost directly away from the Earth to the moon) compared to the burn required to put a Mars bound vehicle on the required expanding "circle" (if you will) to join the orbital plain of Mars. This site might help.

http://www.strout.net/info/science/delta-v/intro.html

I'll just let the political part of this go. I believe what I believe as do you.

However, I do not agree that a lunar base is nearly as important as exploring Mars, Europa, and deep space. Not all in the field agree that lunar fueling is necessarily cost/effort effective for planetary and space exploration.

We've needed a new goal for the manned space program for decades, so we can maintain our lead, and I'm glad this Administration is apparently going to set that goal.

I personally don't think that we should fabricate goals to fit an agenda or method. Reference the Int'l Space Station, more glitz than anything. The agenda should be made to reach the goal, that being the fundamental drive to explore and expand human knowedge. All else is just fluff. I do acknowledge the importance of maintaing public interest, however, this is simply a logistical part of the main goal.

 

[A Squared]

For all of the "budget buster" naysayers; For every dollar the US spends in space exploration, $7.00 revenue is returned.

That is certainly an extrordinary claim. How exactly do you arrive at that conclusion? How much money had the US spent on space exploration. How much has been "returned?" To whom does it return? How did you measure "return?" Do you have someting, anything which supports that claim?

Space exploration yielded that laptop you are using right now.

I think that's a bit of a stretch. It seems tempting to many to characterize the space program as a swirling tornado of technology, spitting out useful household products, without which we would still be mired helplessly in the mid 20'th century wth dial telephones, grainy black and white tv's and an Edsel in every garage.
No doubt the space program has accelerated research in many areas, but to beleive that the technology wouldn't have advanced is simplistic.

The Laptop of which you speak isn't a "product of the space program" It is a product, in part, of low power semiconductor logic technology, improving drycell battery technology, and Liquid Crystal Display technology. Were these technologies advanced by the space program? No doubt. Do they exist solely as a result out space program? Not even close.
Liquid Crystal behavior, for example has been studied since the late 1800's. research was active up until about WWII, then stopped. it was revived, in part by Russian researchers. Perhaps of the biggest advances toward practical LCD's, the discovery of a substance which exibits nematic properties at room temperature, was made at the University of Hull in the UK. Kinda hard to say that the russians and brits were part of the US space program. The most astounding advances in LCD technology have been made in the last 2 decades, a time when NASA has been having budget cuts and wasn't participating in a lot of gee-whiz research. The development was driven predominantly by incredible consumer demand for better Liquid Crystal displays. The companies spending millions and millions of thier own money on LCD research are not doing it so that they can sell a few units to NASA, they are doing it so thay can sell millions and millions of laptops, flat screen TV's and cell phone displays to the public

Semi-conductor and battery technology similarly existed long before the space program, and while perhaps receiving a shot in the arm, developed mostly independently of the program, driven by increasing commercial demand.

To suggest that laptops exist because of the space program, and wouldn't have developed without it is simplistic to the point of falsehood and displays a total lack of understanding of the nature of technology and how it develops.

All these claims you hear about what wonderful things we get from space travel, guess what, folks, it's propaganda, propaganda from the space biz folks, propaganda designed to keep the funding coming at all costs, propaganda designed to provide a pat, simplistic answer to the question, "Why are we spending billions and billions to send a tv camera to mars?"

 

[EagleRJ]

I have a bit of experience in the field, and if you take my word for it, a manned Mars mission will definitely take more fuel than a mission to the Moon.

The procedure for getting to the moon is only a little longer than that required for Earth orbit. Once the vehicle has achieved enough velocity to remain in Earth orbit (approximately 14,500 MPH), another burn is made to escape Earth orbit and enter a paraboloid orbit around the moon. Engineers for the Apollo program called this the Trans-Lunar Injection burn. Once nearing the desired orbital altitude, another burn is made to circularize the orbit and remain in lunar orbit. The vehicle or a seperate lander can then decellerate further and decend to the surface.

The easiest, least-fuel way to get to Mars is impractical for manned missions because it takes so long. After the probe enters Earth orbit, a series of short burns are made to make the orbit more and more elliptical. The probe's velocity at the perigee (lowest altitude) of each orbit gets higher and higher, until it has enough energy to leave Earth orbit and enter a paraboloid orbit that will intersect Mars' gravity well. If it is planned right, the probe will be captured by Mars gravity and will enter Mars orbit with no further engine burns. A variation is to use a higher-energy transfer that will get you there faster, but then you have to use aerobraking (dipping into the upper atmosphere) or another engine burn to slow down. That's a great system, and it works well to get robotic probes to Mars with minimal cost, but we don't have the technology to keep a crew on a ship for almost a year for the flight there.

One of the concepts NASA is working on for manned missions is to accellerate continuously out of Earth orbit until the midpoint, then turn the ship 180 degrees and brake continuously until reaching Mars. Obviously, chemical rockets wouldn't be able to do that, so we need to develop new technology. The ion thrusters used on some satellites are one promising possibility. They use an electric field to accellerate xenon gas to extremely high velocities. That means they have very high specific impulses (good gas mileage), but their thrust level is very low. Right now, they're only used for stationkeeping, but if we could develop larger versions, powered by a nuclear reactor, it might open up the solar system for manned exploration.

Building the space station has turned out to be much more difficult than it had to be. Making it an international project for the sake of unifying people was a bad idea, and I've said from the beginning that it was a mistake to include the Russians in the project. Right now, the combination of the Shuttle problems and Russian financial problems mean all we can do right now is keep it in orbit, not continue construction or do any science. We do need a space station, both for orbital research and as a place to assemble future vehicles. Hopefully we'll work out the kinks before people start calling for it to be scrapped.

Thanks for the interest.