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if someone would have asked me 30 years ago where we would be now i would have guessed a lot further, the Space Program has stagnated when it comes to human travel, the robots have done a good job but lots of mars failures if you know what i mean. We have a major threat right now and that is a collision with asteroids or comets. its not if, its a matter of when and right now we are not prepared. This should be Goal #1 to many mass extinctions from impacts in our history. how many rocks just hit Jupiter?
 
Originally posted by Dont Hurt Me
if someone would have asked me 30 years ago where we would be now i would have guessed a lot further, the Space Program has stagnated when it comes to human travel, the robots have done a good job but lots of mars failures if you know what i mean. We have a major threat right now and that is a collision with asteroids or comets. its not if, its a matter of when and right now we are not prepared. This should be Goal #1 to many mass extinctions from impacts in our history. how many rocks just hit Jupiter?

Lots of problems here. First of all, at present speeds, there's nowhere for people to go in space. The fact that it takes us a year or more to see if one of our probes that we've spent zillions of dollars on can even land on Mars makes troubleshooting the next step exceedingly difficult. The troubles surrounding a manned trip to that type of distance are huge, with the chance of everyone dying on board for one of thousands of reasons very likely. Think Apollo 13, but with 5 years to get home. Robots are a less romantic, but far smarter option now and probably at any time. Asteroid collision is an extremely minor threat, but with major consequences if it happens. Again, we have no technology that could do anything to avert such a disaster.

Our dreams are in the right place, but reality is far, far behind...
 
Okay, this is a good thread, aside from all the President bashing that is going on. Can't some of you people just set aside your partisanship and add meaningful comments to the topic of a renewed US Space Program?

I think what would make for a robust US Space industry would be a lunar base or a Martian base. I would think the first ones would be scientists and engineers, followed by industry hoping to make new materials in the low gravity of the Moon.

When you start having regular resupply trips and maybe even freight/cargo trips to and from the Moon and Mars, then we would definitely be in space to stay.

Anyone know what would the ramifications be of silicon manufacturing in low gravity? Lower defect rates? Heck, maybe Intel would be on the moon first. Their Itanium and x86 chip sizes are going through the roof, and they are going to need lower defect rates first.

Mars would need to be terraformed though. Probably take years, when scientist finally agree to introduce terrestial bacteria and microbes to do the work, since they were the ones that have been so cautious about potential terrestial contamination from the lunar lander.

I think a renewed US Space Program would be great. It would definitely be a kick in the *ss for the high tech industry, and that does not include the IT bubble. High tech as in physics, biosciences, chemistry, etc.

One thing I see though is that we are probably going to need to go nuclear if we do this. So far, nuclear is about the only technology with the high energy to weight ratio.
 
Sorry, have to make a few corrections on previous posts.

"we do it on the moon & that gives us the ability to do it anywhere in the inner solar system."
Actually the only viable place for us to possibly explore in the inner solar system,besides the moon, is Mars. With an average temperature of -55 C it is the only other planet that we might be able to survive on. Trips to Veuns, with an average temp. of 454 C, and Mercury, with an average Temp of 116 C, just don't seem to be very likely.


"The fact that it takes us a year or more to see if one of our probes that we've spent zillions of dollars on can even land on Mars makes troubleshooting the next step exceedingly difficult."
The Mars Express is just a few weeks from landing. I believe it will take only 7 months. With the advances in new propulsion technologies, I wouldn't be suprised to see these times cut in the near future.


I think the revamping of the lunar missions would be much better received if there were some sort of high profile physical presence or scientific mission to the moon, rather than just another stroll around to collect rocks. I would love to see a solar powered radio telescope on the far side of the moon. This could be achieved without a manned mission. Think of a large, foldable , foil dome. Make sure it is pointing the right way, add the electronics, and there you go.
 
Originally posted by kevin49093
With the advances in new propulsion technologies, I wouldn't be suprised to see these times cut in the near future.

For the most part (if not the entire part), the newest of propulsion technologies have the ability to achieve very high speeds, but with extremely low acceleration rates, making them more useful for cutting centuries of time off of traveling to other stars, or possibly years off of going to Neptune or Pluto, but wouldn't have the time necessary to speed up a trip to Mars.

For heavy craft, like one carrying people, we still have no other choice than our 1930's era controlled explosions. Today's engines may be more efficient, but they work essentially the same.

I believe one of the craft heading to Jupiter or Mars uses an ion engine, the trust of which has been described as less force than a sheet of paper puts on your hand.

Personally, I don't think the U.S. government will send anyone to Mars in the next 50 years. There are no practice runs like we had looping around the moon and the mission failure rate, when taking into account all of the variables of what could go wrong, is waaaayyy to high for this countries' collective stomach. Now China... I could see them shooting for the moon. Technology-wise, they're relatively young and reckless, and they are dying for attention... and respect.
 
Originally posted by jayscheuerle
For the most part (if not the entire part), the newest of propulsion technologies have the ability to achieve very high speeds, but with extremely low acceleration rates, making them more useful for cutting centuries of time off of traveling to other stars, or possibly years off of going to Neptune or Pluto, but wouldn't have the time necessary to speed up a trip to Mars.

Wha? :confused:

How do you get very high speeds but extremely low acceleration rates? First year physics course... acceleration is rate of change of velocity. If your acceleration rate is low, then how do you possible get to high velocities?

If you mean rate of change of acceleration, then that is termed jerk. There is no reason why an engine cannot maintain a steady acceleration, this would actually help create an artificial gravity.

Fastest trip, barring inter-dimensional travel would be with the fastest accelerating ship. You accelerate towards your destination up until the middle of the trip, then turn the ship around and decelerate until you arrive at your destination (where you are at zero velocity).
 
Originally posted by Frohickey
Wha? :confused:

How do you get very high speeds but extremely low acceleration rates? First year physics course... acceleration is rate of change of velocity. If your acceleration rate is low, then how do you possible get to high velocities?

If you mean rate of change of acceleration, then that is termed jerk. There is no reason why an engine cannot maintain a steady acceleration, this would actually help create an artificial gravity.

Fastest trip, barring inter-dimensional travel would be with the fastest accelerating ship. You accelerate towards your destination up until the middle of the trip, then turn the ship around and decelerate until you arrive at your destination (where you are at zero velocity).

Perhaps I'm using the wrong terms, but the point is that there is very little acceleration going on here with the up and coming propulsion technologies, but it's a constant acceleration. For example, say that the ship starts out at zero mph and by the end of the day is going 100 mph. That's not very fast for a space ship, but at the end of one year, it's going 36,500 mph! The 100 mph number is deceiving because I believe the rate of acceleration won't net you an extra 100 mph every day with the technologies that are being experimented with now. Acceleration is slow, but steady.

You're right about the fastest trip part, but the problem is that we don't have any faster accelerating technologies in existence (other than in theory) right now than the old controlled explosion kind...
 
A second article has surfaced:
http://www.upi.com/view.cfm?StoryID=20031204-104042-8972r


WASHINGTON, Dec. 4 (UPI) -- Since last spring, the Bush administration has been conducting a confidential effort to establish a dramatic new goal for the nation's civil space program, perhaps rivaling President John F. Kennedy's call to place a U.S. astronaut on the moon before the end of the 1960s, sources told United Press International.

Only a few administration insiders have been involved, with Vice President Dick Cheney heading the effort, said sources, who requested anonymity.

Though some details have leaked out -- most notably reports Wednesday and Thursday that President George W. Bush will call for returning Americans to the moon -- sources insist no final decisions have been made. Instead, the president is reviewing a list of alternative goals -- some of them more practical than dramatic -- that must conform to a pair of overriding directives: Any option must be achievable within a reasonable period of time, and it must not require any major new federal spending.

Bush's decision and announcement, sources told UPI, could come as early as Dec. 17, when the president is scheduled to speak at Kitty Hawk, N.C., at a ceremony marking the 100th anniversary of the Wright Brothers' first powered flight. The matter also could be deferred until January 2004 and included in his State of the Union address to Congress.

The White House Office of Management and Budget has completed a cost review of the proposed alternatives. Reportedly, the alternatives validate the idea a new U.S. space initiative could be attempted with existing or proposed technology and hardware and could avoid the budget build-ups of previous projects, such as the

space shuttle or the International Space Station -- although such a policy change would require NASA to make tough choices regarding cuts in existing programs.

Sources said the White House space policy review is not connected to the ongoing investigation of the National Aeronautics and Space Administration, which was made necessary by the space shuttle disaster. On Feb. 1, shuttle Columbia broke up over several southwestern states during its reentry into the atmosphere, provoking a massive re-examination of the agency's manned space program.

Instead, the effort seems to have grown from a more fundamental motivation to reform and revitalize NASA -- something Cheney has been championing almost from the first day he and Bush took office in January 2001.

Bush ordered the policy review in late May. Since then, it has proceeded slowly and carefully, sources said, perhaps more so than any previous examination of the space program. Its progress was managed at a series of meetings involving only a few participants, headed by Cheney and including NASA administrator Sean O'Keefe.

The recommendations were developed confidentially by O'Keefe and his staff and the cost of each recommendation was analyzed by OMB and evaluated according to Bush's twin directives. Cheney -- who has gathered other input from members of both houses of Congress with an interest in the space program -- will make the final recommendation to the president.

On July 20, 1989, on the 20th anniversary of the first Apollo moon landing by astronauts Neil Armstrong and Buzz Aldrin, President George H.W. Bush proposed a return to the moon and an attempt to go to Mars. Neither of those proposals so far has borne fruit.

If Bush accepts the new recommendation for a major space objective and makes such a commitment -- and if the effort moves forward -- it would represent the first time in nearly two decades a U.S. president has proposed a new vision for the space program that yielded results. The last time such a proposal succeeded was when President Ronald Reagan announced a plan to built permanent space station in his January 1984 State of the Union speech.
 
Originally posted by jayscheuerle
Personally, I don't think the U.S. government will send anyone to Mars in the next 50 years. There are no practice runs like we had looping around the moon and the mission failure rate, when taking into account all of the variables of what could go wrong, is waaaayyy to high for this countries' collective stomach. Now China... I could see them shooting for the moon. Technology-wise, they're relatively young and reckless, and they are dying for attention... and respect.
So long as we expect moon and mars exploration to be entirely safe (both legally and public perception) I don't think we can afford a moon and mars base. The chinese won't be as limited by that as the western world, they could have a base up and running with a higher casualty rate at lower cost - if their design is quite modular then if one module loses pressure the base survives and fixes it.

I always liked Shackleton's Antarctic trip employment advert:

"MEN WANTED: FOR HAZARDOUS JOURNEY. SMALL WAGES, BITTER COLD, LONG MONTHS OF COMPLETE DARKNESS, CONSTANT DANGER, SAFE RETURN DOUBTFUL. HONOUR AND RECOGNITION IN CASE OF SUCCESS._
SIR ERNEST SHACKLETON"


Rumour has it this resulted in an overwhelming response. How would people react to an ad in that style, for Mars?

Greg
ps. If I remember correctly, 10 years or more ago NASA changed their strategy for Mars exploration - if they made their automated craft with a 50% failure rate, each craft would cost 1/10th. So they could send 10 times as many for the same price, but only half would succeed. And indeed, soon after, there were many more failures... and the public perception was very bad - yet they had met their expectations (maybe I remembered wrongly?).
 
Originally posted by jayscheuerle
Perhaps I'm using the wrong terms, but the point is that there is very little acceleration going on here with the up and coming propulsion technologies, but it's a constant acceleration. For example, say that the ship starts out at zero mph and by the end of the day is going 100 mph. That's not very fast for a space ship, but at the end of one year, it's going 36,500 mph! The 100 mph number is deceiving because I believe the rate of acceleration won't net you an extra 100 mph every day with the technologies that are being experimented with now. Acceleration is slow, but steady.

You're right about the fastest trip part, but the problem is that we don't have any faster accelerating technologies in existence (other than in theory) right now than the old controlled explosion kind...

I think you meant controlled acceleration. I think that we have come a long way with our control systems, and that we can control the rate of acceleration better.
 
Control isn't the problem. An ion drive under current technology provides a tiny amount of thrust but can do so for years. You could toss stuff out of the back of the space craft and get more thrust but you run out of stuff to toss out before you get where you are going. Use an energetic fuel such as hydrogen and you still run out of fuel. Both of these methods can get you up to a decent speed in terrestial terms but then you have to coast the rest of the way and save some fuel for slowing down before the end of your journey. An ion drive is dramatically different in that you have very little thrust but you have it on constantly which means that your speed continues to increase gradually rather than coast at a constant speed. This means you will be eventually be travelling very fast after a long period of time such as a year or more. This wouldn't work very well in Earth's atmosphere since friction would slow you down but in space this isn't a problem. Other possibilties for propulsion also exist of course, such as solar sails. I have just used an ion drive as an example. Gravitational effects of large bodies such as planets can also be used to adjust speed to some degree.
 
Ion drive, or other types of technologies are just fine, but no one ever proposes to set out on a space trip with propulsion system that can't take you there (and back).

In your example of ion drive vs throwing things out the back, what is the difference? In ion drive, the stuff you are throwing out is just a lot smaller, but you are still throwing things out the back. You can't cheat. The Physics police will haul you into jail if you do.

In chemical propulsion, the energy is really from the combustion of the chemicals, and there, you are not comparing mass vs mass. In ion drive, it really is the amount of mass you have to throw out the back.
 
Sorry, I was just trying to clear up confusion about rate of change in speed versus maximum speed. I only brought up the fuel supply problem in travelling great distances as a side note to this mental exercise.

There is of course no difference in physics between tossing ions or marbles or water or unruly passengers out the back in order to provide thrust in the opposite direction. I'm pleased that I was able to at least make that fairly clear. Chemical propulsion provides extra thrust beyond it's mass but still provides thrust by throwing excited matter out the back. Nitpicking over physics isn't very interesting (for me at least) so let's get back to the space program topic.

I have seen a few reports of experiments done in low and zero gravity which suggest a wide variety of possible benefits to manufacturing and biosciences. A permanent base on the far side of the moon with radio and optical telescopes also sounds very exciting to me. Imagine images from space much clearer and looking farther than an orbital telesope such as Hubble could ever hope to provide. Eventually I envision lunar bases throughout the solar system for communications, maintanence, and supply depots.

Interplanetary travel will be enormously expensive. This cost may or may not be recovered in future centuries from the extraction of mineral wealth, tourism, and scientific research. Nevertheless I believe we should grow beyond the confines of Earth no matter the cost. It is a matter of embracing the progress of an evolving human civilization as well as protecting the long term survival of the human race.
 
Originally posted by Frohickey


In your example of ion drive vs throwing things out the back, what is the difference? In ion drive, the stuff you are throwing out is just a lot smaller, but you are still throwing things out the back. You can't cheat. The Physics police will haul you into jail if you do.

you can't cheat, but you can inject energy into the things you send out back. In ion drives, the ions are magnetically accelerated through the thruster so there's energy being added to help speed up the process. The electrical energy required for the magnetic coils should be far more efficient than simple chemical reactions, which are really quite wasteful. If you stick a nuclear reactor on the thing powering the ion drive, I would think that you can get pretty far pretty fast. The nuclear fission reaction will release energy orders of magnitude more than chemical reactions and that should allow the vehicle to carry less fuel.
 
Originally posted by topicolo
you can't cheat, but you can inject energy into the things you send out back. In ion drives, the ions are magnetically accelerated through the thruster so there's energy being added to help speed up the process. The electrical energy required for the magnetic coils should be far more efficient than simple chemical reactions, which are really quite wasteful. If you stick a nuclear reactor on the thing powering the ion drive, I would think that you can get pretty far pretty fast. The nuclear fission reaction will release energy orders of magnitude more than chemical reactions and that should allow the vehicle to carry less fuel.

We are saying the same thing. Its still 'throwing stuff out the back'.

I think that there should be a lunar base. We can send the lunatics there. :p
 
But it's not mass. it's newton's 3rd law that's propelling the spacecraft. the force used to expel the ions is also enacted on the spacecraft. Therefore, acceleration of the particles is paramount in producing thrust in an ion drive. with all things equal, the energy given to the ejected particles is what makes the difference in efficiency.

Chemical reactions produce FAR less energy for the same amount of reactant than nuclear reactions, so with a nuclear powered ion drive, you would be able to put much more energy into launching the particles out back than with a chemical method with the same amount of reactant and generate greater force.
 
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