• Quick note - the problem with Youtube videos not embedding on the forum appears to have been fixed, thanks to ZiprHead. If you do still see problems let me know.

Propulsion Technology

Larspeart

Muse
L
Joined
Feb 28, 2003
Messages
581
Okay, I am conviced that the ONLY way humankind is going to make any kind of progress in the future in regards to space is in a breakthrough in propulsion technology. Besides Ion Drives (which are still kind of primitive), we haven't developed anything of note in 30-40 years, right?

What kinds of work is being done on this right now, and what do you all forsee as the solution? Or, should we even bother to explore/colonize space?
 
Still bound by action-reaction for the time being. I don't think any of the reactionless propulsion systems that NASA checked out have gone anywhere (:D ).
 
Our part of the galaxy is sparlesly populated and as such there are vast distances to be overcome in order to explore even the nearby stars.

Even if one could make a drive that could propel a ship to a bit less than the speed of light (the speed limit for anything with mass), then it would still take years to travel from one star to another. So unless there is a away to travel much faster than the speed of light, it looks like we are pretty much stuck here.
 
That is pretty much what I thought as well. Kind of depressing, but hey, it is what it is, right? :)

Forget colonizing other star systems (unlikely, unless we are talking, 'the Earth is about to die, and we ALL have to leave and go elsewhere as there won't BE an Earth' type scenario), and lets just focus on 'Our Neighborhood', i.e. the Solar System. Mars is the 1st, obvious, and frankly only immediate place to go, with the moon possibly having some uses as well. We don't need to advance 'too' much in terms of propulsion to reach them in efficient time frames. To go beyond them, say to Europa, Titan, Or any of the outer planets and their moons, we would need something faster to make the trip doable in reasonable time frames (days/weeks instead of months/years)

Or, are we locked not only out of the rest of the galaxy, but in fact destined to spend out time on this particular rock?
 
The latest issue of Discover magazine (Augsut 2003?) has an article on propulsion systems with interstellar potential; things like fission, fusion, hydrogen ramjet. None of them look too affordable or near-term feasible.
 
It is hard to say if we are really stuck here or not.

After all, there have been some great changes in science just when people have thought that everything was pretty well set. I think the year was 1872 when the person in charge of the US Patent Office suggested closing it down since everything worthwhile had already been invented.

And the next year, X-Rays were discovered which in turn lead to Atomic Studies and a whole new way of looking at the world that was so unexpected that not even fiction writers touched upon the subject.

So who knows if we are really stuck here or not for all time?
 
Got a link to that issue of Discover? I'd be interested in seeing that.

As far as leaps and bounds in advancements, I am a big believer in them. Going faster then light though seems tricky (to say the least). I have heard that we have actually seen evidence that things can move faster then light (strictly sub-atomic level so far) but that is aa far as I have seen/heard on it.

Of course, there is always the old 'Wrinkle in Time' cliche; Instead of going to two points in space, bring the 2 points together. . .



:roll:
 
Crossbow said:
I think the year was 1872 when the person in charge of the US Patent Office suggested closing it down since everything worthwhile had already been invented.
Click to expand...
You might want to check that one out on Snopes or elesewhere.



Larspeart said:
Got a link to that issue of Discover? I'd be interested in seeing that.
Click to expand...
No, I get my copy in the mail well before they roll over their web site. (For which I am grateful). If I remember in a week or two I'll come back and give a link.
 
Crossbow said:
Our part of the galaxy is sparlesly populated and as such there are vast distances to be overcome in order to explore even the nearby stars.

Even if one could make a drive that could propel a ship to a bit less than the speed of light (the speed limit for anything with mass), then it would still take years to travel from one star to another. So unless there is a away to travel much faster than the speed of light, it looks like we are pretty much stuck here.
Click to expand...

Also note that there is a limit to the amount of acceleration the human body can survive. I think we will end up being very practical and stick with an acceleration of 10 meters/sec or there abouts. This acceleration will simulate earth gravity nicely. It will only take a year or so to get near the speed of light.
 
Keep in mind that as far as space exploration goes, even if it takes a near luminal ship several decades to reach another star, this is only as measured in the earth's frame of reference. In the ship's frame of reference (and therefore the crew's frame of reference) it will take less time.
 
Jethro said:
Keep in mind that as far as space exploration goes, even if it takes a near luminal ship several decades to reach another star, this is only as measured in the earth's frame of reference. In the ship's frame of reference (and therefore the crew's frame of reference) it will take less time.
Click to expand...

At first this seems an insuperable obstacle. Who would accept the condition that you would be forever separated in time from Earth? But if we look at it closer, that's inevitable anyway. Communications would take many years each way. Civilizations on other stars will, of necessity, be completely independent of Earth and of each other, their only word of the mother planet coming from decades-old transmissions.

The good news is, a galactic empire is impossible. No empire can exist without communications. If mankind makes it to the stars, it will be as many completely independent societies that will even one day be different races because of lack of contact with each other.
 
I believe the same thing Sundog does. While it seems unlikely, or abhorrent, to think of 'leaving everything' it is really the only way LONG range travel/colonization can take place (as we understand physics and the universe today).

In terms of propulsion, if we look at the ion drive (viable for inter-solar system jaunts), it works on the principal of slow, but steady and consistent acceleration, right? What if it was to slowly, but CONSTANTLY accelerate? Give it a HUGE fuel supply, and in essense, let it burn. You get it into orbit, at orbital speed. If it takes one week to double that speed (or 4 weeks for that matter) so be it. After 3 months, it is going to be clipping along pretty darn fast, right? Lets say it doubles in speed every week, starting at orbital speed (forgive me, as that number illudes me at the moment). How long would it take to reach near-light speed? In this case, it isn't a matter of new propulsion, but almost strickly fuel concerns.

DEEP had a fairly small fuel tank compared to solid or liquid fuel systems, so it seems it is far more efficient, right?
 
Sundog said:

At first this seems an insuperable obstacle. Who would accept the condition that you would be forever separated in time from Earth?
Click to expand...
Anyone coming off a really bad relationship.

I see a movie about this, starring Bruce Willis.
 
Travelling at these enormous speeds presents more barriers than just propulsion. The faster you go, the more you have to worry about unavoidable small objects in your path. At .5c, you are looking at complete anihilation from contact with a stray pebble.

The only way to go is slow (currently, and forseeably). Multigenerational, fully self-sufficient ships are the only chance for success. Of course, we need to build fully self-sufficient habitats in orbit of Earth, or the Sun, first. Propulsion is not the biggest problem.
 
True, but haven't studies been done on the likelyhood of hitting anything in space (being that is is so, well, BIG and empty) are darn near nil?

You plot a course to get you outside of the solar system, and from there until your destination system, you (should) not run into much of anything, right? Between star systems (where most matter in the universe is located) there really isn't much to hit.
 
Wile E. Coyote said:
Travelling at these enormous speeds presents more barriers than just propulsion. The faster you go, the more you have to worry about unavoidable small objects in your path. At .5c, you are looking at complete anihilation from contact with a stray pebble.

The only way to go is slow (currently, and forseeably). Multigenerational, fully self-sufficient ships are the only chance for success. Of course, we need to build fully self-sufficient habitats in orbit of Earth, or the Sun, first. Propulsion is not the biggest problem.
Click to expand...

Excellent point, barring some magical device to shove them aside.

In which case, ironically, to master space travel it is essential that we become expert in managing ecosystems on the hundreds- or thousands-of-years scale... and how better to learn than by rescuing our own Earth and learning how to live sustainably on it?

In other words, Earth is a test case. If we can't make THAT spaceship work, we have no chance of making the other ones work.

Success in space travel for mankind = success in rescuing the Earth from ecological disaster.
 
Larspeart said:
True, but haven't studies been done on the likelyhood of hitting anything in space (being that is is so, well, BIG and empty) are darn near nil?

You plot a course to get you outside of the solar system, and from there until your destination system, you (should) not run into much of anything, right? Between star systems (where most matter in the universe is located) there really isn't much to hit.
Click to expand...

Although the distribution of matter is sparse, there are pockets of dust and random bits of debris floating about. It would be an awful waste to send a bunch of people on a long journey only to lose them to the "unlikely" space rock.

I also wonder about radiation effects from light being noticeably shifted to shorter wavelengths as the craft moves faster. I have not done the math, so I cannot say, but it seems like this might also offer some difficulties.
 
Wile E. Coyote said:


Although the distribution of matter is sparse, there are pockets of dust and random bits of debris floating about. It would be an awful waste to send a bunch of people on a long journey only to lose them to the "unlikely" space rock.

I also wonder about radiation effects from light being noticeably shifted to shorter wavelengths as the craft moves faster. I have not done the math, so I cannot say, but it seems like this might also offer some difficulties.
Click to expand...

The matter is quite bad enough. Most sources I've found estimate the density at about one atom per ccm in interstellar space. I have no trouble believing that this alone would tear a ship to pieces that was traveling at any appreciable fraction of the speed of light.

We have people here who can actually perform calculations of this kind, hint, hint. ;)
 
The only time I ever object to ideas of space colonization is when it is clear that they are being voiced as answers to our problems here on Earth. As in, "Yes, Earth is overpopulated, but when we have cheap space travel all those problems will go away."

As I pointed out the other day, this is a pipe dream. Yes, we should colonize space. But no, it won't have the slightest effect on our home planet, except as an additional drain on resources.
 
You must log in or register to reply here.

Back
Top Bottom