Interstellar Flight?

Question

Given our limited technology of space travel and our lack of funding for this. How long do you think it will be before we can achieve this milestone in Humanity?

Answer 1

Unfortunately, it will probably never happen.

The prior posters are correct that there are several possible methods of interstellar travel (ark ships, ramjets, etc.) that are technically feasible, but the fact is that it will never be economically or politically feasible - it's simply too far away to ever be able to launch a mission that would return in our lifetimes and show either monetary, political, or psychological results to the people initiating it.

We went to the Moon and will likely go to all the planets at some point in the next 200 years (and likely establish colonies at some point in the next 500 years), since we can benefit from the technology gained, the raw materials we may be able to mine, the real estate on other planets we may use, and we will see the results of the work within a few years at most.

Governments can justify exploration for its own sake given these factors, but when you look at something costing (probably) dozens or hundreds of times as much and taking hundreds of times longer to show results, added to the fact that it's unlikely that any trip to a nearly star would allow us to see anything other than a planetary system pretty similar to the one we've got (and no way to get there or get materials back easily), it's not likely to EVER happen.

Answer 2

Nash knows what he is talking about.

Even getting to the nearest star would require more time than the average human lifespan... and thats only one way. To get there and back would require a generation ship which would include a community of several hundred which will live and reproduce on board. It would seem a waste to send hundreds of humans who give birth to thousands more just to look at a star system with our own eyes. The only real use of a generation ship would be colonization and we wouldn't know if there was a colonizable planet in the system unless we sent probes first which would take almost as long to get there as the generation ship itself. So, a hundred years to develope the technology, another hundred to build the ship, a nother hundred to get there. At least 300 years would be your answer, but it would probably be much longer.

Quicker ships might be possible. Faster than light travel will never be an option, but there is no physical law saying we can't develop ship capable of getting there with near to the speed of light travel. If what we know know is and will always be our ceiling on technological developement than antimatter annihilation will be the most energy one can attain from matter.

This is how I see it. A large machine in our solar system accelerates a ship powered by anitmatter to near relatavistic speed to save the ship from requiring the fuel to accelerate itself. Time slows down for the crew so they get there in one their life time. They use their fuel to slow down and they study the solar system. They use their own fuel to come back and the machine that sent them slows them down.... now this example tests the limits of technology and if its possible will probably not be achieved for over a thousand years.

Besides that we would need to discover some loophole in the laws of physics to travel faster than light... but don't count on it.

Answer 3

Possible never . Our technology is not that good , to travel 50 years or more ,it would fall apart.

Answer 4

We already have three craft heading out of the solar system. They haven't been designed to reach other stars, and still be functional.

We need steps.  One idea is to put a spacecraft at about 1500 AU (i might be wrong on the distance). The idea is to use the Sun as an objective lens of a very long focal length telescope.  The Sun focuses light with it's gravity.  Anyway, the mission has a use, and gets us part way to the nearest stars.  We might want to build such a thing if we discover a more Earth like planet around some other star, to get a better look.

We'll probably send probes to nearby stars.

We'll probably wait for a star to come closer before we send humans.  There are some good candidates coming up in the next 20 million years.

Answer 5

Almost there.

Answer 6

Its likely to never happen unless:

1.) we build multigenerational ships or sleeper ships

2.) we have a break thru that dramatically alters what we currently think we know about physics

3.) Aliens come down and decide to share some technology with us.

4.) all of the above

Pick one....

Answer 7

Scientists and authors have postulated a number of ways by which it might be possible to surpass the speed of light. Even the most serious-minded of these are speculative.  Barring a major breakthrough, probably at least 100 years.

"If you take in to consideration the rapid pace of technological advancement, things look brighter. The Wright brothers’ first feeble flights advanced to a man on the moon in just 50 years. In less than 100 years, we can travel 1,000 times faster. If this rule holds true for the next hundred years, we will be able to travel to the nearest stars with relative ease.

The nearest known star to the Sun is Proxima Centauri, which is 4.23 light-years away. The fastest outward-bound spacecraft yet sent, Voyager 1, has covered 1/600th of a light-year in 30 years and is currently moving at 1/18000 the speed of light. At this rate, a journey to Proxima Centauri would take 72,000 years. Of course, this mission was not specifically intended to travel fast to the stars, and current technology could do much better. The travel time could be reduced to a few millennia using lightsails, or to a century or less using nuclear pulse propulsion (Orion).

If a spaceship could average 10 percent of light speed, this would be enough to reach Proxima Centauri in forty years. Several propulsion systems are able to achieve this, but none of them is reasonably affordable.

Proposed interstellar spacecraft using nuclear pulse propulsion include Project Orion and Project Longshot. Using miniature nuclear bombs as fuel, Orion would be able to reach a velocity of 3% of the speed of light. It is one of very few known interstellar spacecraft proposals that could be constructed entirely with today's technology.

Interstellar ramjets

In 1960 Robert W. Bussard proposed the Bussard ramjet, a fusion rocket in which a huge scoop would collect the diffuse hydrogen in interstellar space, "burn" it on the fly using a proton-proton fusion reaction, and expel it out of the back. Though later calculations with more accurate estimates suggest that the thrust generated would be less than the drag caused by any conceivable scoop design, the idea is attractive because, as the fuel would be collected en route, the craft could theoretically accelerate to near the speed of light.

A Bussard ramjet could conceivably achieve a constant 1g acceleration that would allow the pilot to make very long journeys. To an Earthbound observer, such a ship would take hundreds of thousands of years to reach the center of the galaxy. But because of relativistic time dilation, only 20 years would pass for the crew on the ship. Imagine – just 20 years to the center of the galaxy! Of course, technical problems remain such as force field drag, shielding the crew from interstellar radiation and the ability to control fusion reactions."

However, in my opinion, no one would want to leave the world they know and everyone they love, use up the bulk of their life to make a pointless trip to the center of the Galaxy, when Earth's technology will have advanced so much in hundreds of thousands of years that humans will be all over the Galaxy long before they arrive there.

"Antimatter rockets

An antimatter rocket would have a far higher energy density and specific impulse than any other proposed class of rocket. Assuming that energy resources and efficient production methods are found to make antimatter in the quantities required, theoretically it would be possible to reach speeds near that of light, where time dilation would shorten perceived trip times for the travelers considerably.

Interstellar travel via transmission

Main article: Teleportation

If physical entities could be transmitted as information and reconstructed at a destination, travel precisely at the speed of light would be possible. Note that, under General Relativity, information cannot travel faster than light. The speed increase when compared to near-light-speed travel would therefore be minimal for outside observers, but for the travelers the journey would become instantaneous.

Encoding, sending and then reconstructing an atom by atom description of (say) a human body is a daunting prospect, but it may be sufficient to send software that in all practical purposes duplicates the neural function of a person.  Presumably, the receiver/reconstructor for such transmissions would have to be sent to the destination by more conventional means.  To me, that kind of makes the transmission method pointless, since the receiver/constructor would have to be there before the transmission would be of any use.

General relativity may permit the travel of an object faster than light in curved spacetime.  One could imagine exploiting the curvature to take a "shortcut" from one point to another. This is one form of the Warp Drive concept.

Geoffery A. Landis, of NASA's Glenn Research Center, says that a laser-powered interstellar sail ship could possibly be launched within 50 years, utilizing new methods of space travel. "I think that ultimately we're going to do it, it's just a question of when and who," Landis said in an interview. Rockets are too slow to send humans on interstellar missions. Instead, he envisions interstellar craft with gigantic sails, propelled by laser light to about one tenth the speed of light. It would take such a ship about 43 years to reach Alpha Centauri, if it passed through the system. Slowing down to stop at Alpha Centauri could increase the trip to 100 years.

Wormholes are conjectural distortions in space-time that theorists postulate could connect two arbitrary points in the universe, across an Einstein-Rosen Bridge. It is not known whether or not wormholes are possible in practice. Although there are solutions to the Einstein equation of general relativity which allow for wormholes, all of the currently known solutions involve some assumption, for example the existence of negative mass, which may be unphysical.

However, Cramer et al. argue that such wormholes might have been created in the early universe, stabilized by cosmic string. The general theory of wormholes is discussed by Visser in the book Lorentzian Wormholes.

A generation ship is a type of interstellar ark in which the travellers live normally (not in suspended animation) and the crew who arrive at the destination are descendants of those who started the journey.

Generation ships are not currently feasible, both because of the enormous scale of such a ship and because such a sealed, self-sustaining habitat would be difficult to construct. Artificial closed ecosystems, including Biosphere 2, have been built in an attempt to work out the engineering difficulties in such a system, with mixed results.

Generation ships would also have to solve major biological and social problems.  Estimates of the minimum viable population vary - 180 is about the lowest, but such a small population would be vulnerable to genetic drift, which might reduce the gene pool below a safe level. A generation ship in fiction typically takes thousands of years to reach its destination, i.e. longer than most human civilizations have lasted. Hence there is a risk that the culture which arrives at the destination may be incapable of doing what is needed - in the worst case it may have fallen into barbarism.

Scientists and writers have postulated various techniques for suspended animation. These include human hibernation and cryonic preservation. While neither is currently practical, they offer the possibility of sleeper ships in which the passengers lie inert for the long years of the voyage. However, even assuming all relevant space-faring and suspended animation technologies could be developed, an automated means of guiding the ship to its destination with little or no human influence would be required."