Starships of Tomorrow
by SpaceHike.comMore articles in Shuttles
The American physicist, Robert Bussard, suggested the use of a 3,200 km wide magnetic field of hydrogen to power a nuclear fusion rocket in 1960. Others suggested using exploding nuclear bombs for sending a starship to the outer solar system; it's name was Project Orion. Project Daedalus was an updated version of Project Orion. This idea suggested the use of minibombs for sending a spacecraft 5.9 light-years from Earth to Bernard's star.
Alpha Centauri star system is Earth's closest neighbor, approximately 40 trillion km away, and if the fastest technology currently available were to head toward it, it would be about 10,000 years before it arrived. The fastest known thing in the universe is light (300,000 km/s), and it takes light more than 4 years to reach alpha Centauri. It is uncertain that even with the warp drive of the USS Enterprise, if this journey would be possible. The writers of the series Star Trek were the first to use the phrase "warp drive," which was a substitute for saying "traveling faster than light." A warp drive needs negative mass to expand behind the spacecraft. It would require an equal amount of positive mass to be in front of the spacecraft. The existence of negative mass is supported through quantum physics, but its certainty is still not completely known. Thanks to the TV series of Star Trek anti-matter engines became famous. This anti-matter releases large amounts of energy, once it collides with matter. Although this matter-anti-matter engine may someday power spacecraft, it is not believed to be able to travel faster than light.
Einstein's theory of special relativity, published in 1905, showed that traveling at the speed of light is possible, since the faster an object moves, the heavier it will become. The spacecraft that traveled at light speed would have infinite mass. The special relativity theory states that only electromagnetic radiation (no mass) can travel at light speed.
The biggest problem with interstellar space travel is finding the needed fuel and oxidants necessary for travel. Today's rocket carry their own propellants, but this would not be enough for a beginning when considering the vastness of interstellar travel. An ion engine that reaches ten times the speed of voyager 2 would need 500 propellant supertankers to arrive at alpha Centauri within a hundred years. Voyager left our solar system at the speed of almost 60,000 km/h, but even at this speed it will take Voyager 80,000 years to arrive at alpha Centauri. The universe does not contain enough mass to even consider providing enough propellant for today's rockets to reach alpha Centauri.
Other ideas have been laser drives, Alcubierre's drive, and wormholes for use in interstellar space travel. The laser, proposed by Robert Forward (American scientist), is considered a possible means for space travel. Lasers would not need a propellant. One theory is to launch a spacecraft with a laser in Earth's orbit, and the laser light would beam toward sails, which would be attached to a stellar probe. The laser light's pressure would drive the probe to about 20% of light speed. Alcubierre's warp engine would contract the front space of a starship, and then expand the space behind it. This theory suggests a warp drive spaceship would travel slower than light speed within the confines of its own space, but the action of contraction and expansion of the space itself would be moving along faster than light speed.
The idea of using wormholes was proposed by Kip Thorne, an American physicist. It is believed that the wormhole could provide a shortcut through time and space. A wormhole is described as similar to drilling a tunnel through a mountain. The problem with wormholes is the idea that they would not live long enough for safe passage through it. Should anything happen, it could close and crush anything passing through it. Negative energy, which is partnered with negative mass, could help keep wormholes open, as suggested by physicists. If it becomes possible to keep the wormhole hole open, the next problem would be the worry of the wormhole hole opening in the correct part of time and space.
Even with all the potential hazards of traveling to another galaxy, the second great problem would be a safe return home for the starship crew members. But, then again, there is the possibility that if the fuel problem were solved for interstellar space travel, it may possibly contain the answer for the return trip home.
1. Couper, Heather and Nigel Henbest. Space Encyclopedia DK Publishing, Inc.: NY 1999
2. Editors. Secrets of the Universe. International Master Publishing: US. 1999