| Daedalus craft and Saturn V Credit/Copyright: Adrian Mann (A very special thanks to Adrian Mann for allowing me use of the photo. For more of his incredible work, check out:http://www.bisbos.com/index.html) |
Manned Interstellar travel is currently impossible. The distance to the closest star, Proxima Centauri is over 4 light years, which translates to 5.87 E 12 miles. In contrast, the moon is 225,622 miles from Earth. Given this, it would take (given the fastest propulsion system, for instance nuclear) at least 87 years to actually get there. It would take even a relatively small craft, like Voyager 1, which is outside the Heliosphere, 80,000 years. Of course nobody has the time to actually, well, live through it. The kinetic energy to achieve reach a close star is beyond the capabilities of many modern spacecraft. Further, the dangers of outer space are well known. Whatever may fill the interstellar medium could damage the spacecraft. You would have to remain on the craft for a long time, without the ability to go outside, and to interact with the same crewmates, These problems prevent a Star-Trek esque future of interstellar travel in the near future. (Then again, that show is set in the 22nd century, so it's hardly the "near-future"). However, unmanned probes could hold potential. After all, the crafts don't have to account for the human side, just the technological side. Whilst the time and distance problems still remains (as seen in the Voyager example above), one can make the argument for an unmanned interstellar mission. One such group acting on this was the British Interplanetary Society, and in the 70's, they made their case.
The British Interplanetary Society was founded by Phillip Cleator in 1933. It was founded during a boom in rocket societies in developed countries, such as the US, Germany, and the Soviet Union (many members of these societies would become key figures during the Space Race). At first, the Liverpool based organization was based solely off rocketry experimentation, but the Explosives Act of 1875 (which banned liquid fueled rockets) put an end to that. After a move to London in 1937, the membership boomed, with notable members including famed science-fiction author Arthur C Clarke and Val Cleaver, designer of the British Blue Streak Missile in the 50's. They become known for their extrapolations speculating on the possibilities of manned and unmanned space travel. They did a notable study of a moon mission in 1930's, with notable similarities to the Apollo Missions. Even after the space race concluded unceremoniously, the BIS continued to speculate, this time going to more distant locales....
On January 10th, 1973, thirteen members of the BIS embarked on Project Daedalus, named for the mythical creator of the Labyrinth, a theoretical study dealing with the possibility of unmanned interstellar travel. This was first proposed by member and former Rolls-Royce engineer Alan Bond in 1972. The project was lead by Bond, Tony Martin, and Robert Parkinson. It was, in part a response to the Fermi Paradox, a supposition by famed physicist Enrico Fermi that contrasted the theoretical abundance of intelligent extraterrestrial life, with its absence. One possibility is that interstellar travel hasn't been developed sufficiently by extraterrestrial civilizations sufficiently. The project was in part made to debunk that interstellar travel was hypothetically impossible, at least for unmanned crafts. The final project was published in the BIS Journal in 1978. The conceived product was a 54,000 ton craft (larger than the Saturn V), equipped with scientific instrumentation such as robotic sub-probes, telescopes, and cameras, whose destination was the distant Bernard's star, over 5.9 light years away. To mitigate the impact of slow moving particles, a beryllium shield was added, due to the high latent heat and lightweight nature of Beryllium. The giant ship would have to be constructed in orbit, due to its sheer size. The journey was to take 50 years.
The mission had three stated goals:
- (1) The spacecraft must use current or near-future technology
- (2) The spacecraft must reach its destination within a working human lifetime
- (3)The spacecraft must be designed to allow for a variety of target stars
The thirteen member group had a serious task ahead of them. They needed to find a way to achieve astronomically (pun unintended) high speeds, and weather potential threats to the craft. Whilst full on nuclear propulsion (as in the cancelled Project Orion) was possible, the 1967 Outer Space Treaty prevented this. They were able to solve this, by deploying an interesting method. The engine was two stage, with pellets of deuterium and helium-3 (extracted from Jupiter or the Moon, depending on the year) being bombarded by high energy electron beams. This would induce fission, and hence energy for thrust, much like a chemical rocket. There would be 250 of these detonations per minute. The first stage would be a boost stage, which would consume 46,000 tons of fuel, achieving a speed of 75 million miles per hour. After 3.8 years, the second cruising stage would apply, where the craft would travel at 12% the speed of light, which would be 22,000 miles per hour. This would last 46 years, until reaching Bernard's Star. The ship would be inactive during the first part of this journey. However, halfway through, the probe would turn its two 5 meter optical telescopes and 20 meter radio telescopes towards the star, and take photographs, as well as analyze spectrographs, photometers, etc of the star and any accompanying planets. Eventually, its legion of robotic probes are awaken, and given coordinations. The eighteen probes will be released 1-7.2 years before the craft actually arrives to Bernards Star, and then descend upon the solar system, each equipped with spectrometers, photometers, cameras, and other scientific equipment to find more about the planets, and maybe the life on them. These will return data to the ship, and transmit it back to Earth. Robots would also be responsible for the care of the ship.
No cost was placed on this project, though estimations would put it at a whooping 100 trillion dollars. This is no surprise, given the scale of the project, and the fact the ship would be larger than several famed buildings. Also, the BIS acknowledged that a large degree of international cooperation would be needed to actually build the craft. None the less, this has influenced thinking on unmanned interstellar travel amongst major space agencies, including NASA.Despite the discovery that Bernard's star didn't actually have planets, the model can easily applied to any star. So, will it be used? Maybe, but not in its original form. Elements may survive, but the mission to a distant star system would likely be smaller in scale. After all, this was merely a speculative study, not an ironclad blueprint. Variations have appeared, including self-replicating robots, and a magnetic sail in place of nuclear engines. It was, and in a way, still is an ambitious project, one which pushes the boundary of what truly is "possible." To quote a former BIS president: "The only way of discovering the limits of the possible is to venture a little way past them into the impossible."
Sources
Project Daedalus – Interstellar Mission- The British Interplanetary Society:
Daedalus-Brisbo.com:
The Daedalus Starship- Damn Interesting:
Project Daedalus- Origins:
Project Daedalus- Wikipedia, the Free Encyclopedia:
Project Daedalus- The World of David Darling
The Cost of Interstellar probes- Centauri Dreams:
Interstellar Travel- Wikipedia, the Free Encyclopedia:
List of nearest stars and brown dwarfs- Wikipedia, the Free encyclopeida
