- Alcubierre Drive
Einstein field equations state that energy and matter can curve the spacetime mesh of reality. Speculatively, stretching the fabric of space behind a ship and getting the space ahead of it, it’s possible to achieve apparent FTL (faster-than-light) travel. Of course, it would be the pace moving and not the ship, like a scrolling game, so no relativistic law would be broken. Riding on a warp bubble of spacetime waves, our ship may reach velocities many orders of magnitude greater than that of light. We could even travel to Mars in less than a second, but I think deceleration would be a problem!
- Stellar Windjammer
Sun, like any other star, constantly spouts charged particles—a true gale of high-speed protons and electrons. Such radiation pressure can push against a magnetic field and generate thrust.
After a decade of space wander, a sunjammer spacecraft would be able to cross the far borders of our solar system without wasting any fuel, maneuvering in exoplanetary magnetic and gravitational fields to calibrate its trajectory. The direction of thrust could be adjusted by changing the sail according to the solar wind.
Since the propulsive force would depend on the magnetic field’s size, a solar sail would need hundreds of meters and kilometers of superconductor material to produce its magnetic field, resembling cyclopean loops of wire instead of the Navigation Age’s wind-catching canvases.
- Coilgun Space Launcher
Science Fiction writers, such as Arthur C. Clarke and Robert Heinlein, have reckoned on electromagnetic catapults as plot devices for decades. Even today, magnetically accelerate a payload hundreds of miles above Earth may seem pure Sci-Fi, and yet scientists like Dr. James Powell and Dr. Gordon Danby think it will be part of the space travel’s future. Powell and Danby co-invented superconducting maglev (magnetic suspension), permitting the current EM trains to be developed, and now they want to apply the technology in space travel through their Startram Project.
In Powell and Danby’s vision, coils would produce a strong magnetic field to thrust a spacecraft or payload at high-speed across miles of railroad, similarly to what happens to a coilgun’s project. To achieve enough momentum, the track will have several miles of length and cost tens of billions of dollars, but—according to its inventors—it’s a small price to pay for the future.
- Photonic Laser Thruster
Young K. Bae is a Ph.D. Dr. physicist founder of the Y. K. Bae Corp—an endeavor dedicated to research “green” technologies in the fields of energy and space travel. Bae’s patents include photonic railways, a new molecular class, and the Photonic Laser Thruster (PLT). Bae studied the PLT with NASA funding and was able to design a concept of space driver that wouldn’t need to carry fuel tanks. Instead, the PLT will receive its thrust from lasers fired at the spaceship. Since the vacuum is frictionless, a PLT-driven craft would steadily gain momentum to go the distance to Mars in a matter of days.
Developments in Directed Energy technology will be crucial to delivering multi-megawatts laser beams capable of thrusting a spacecraft through outer space, enabling an architecture free of heavyweight components, such as fuel and main power supplies.
Rockets expel propellant (action) to get thrust (reaction) in accordance with Newton’s third law, but what if a driver could break this basic rule of nature? Roger Shawyer, a British aerospace engineer, believed that it was perfectly possible when in 1999 he proposed a reactionless engine called radio frequency resonant cavity thruster or just EmDrive (Electromagnetic Drive). An EmDrive would bounce microwaves inside a cone to produce thrust toward the narrow end. The experiment created controversy in the scientific community even after Chinese, German and NASA researchers have reproduced Shawyer’s procedures with positive results.
How EmDrives work exactly remains on the edge of physics. The theory of quantum fluctuation says that vacuum fizzes with energetic particles popping in and out of reality. Interacting with these particles through microwaves, it would be possible to a ship get thrust.
The EmDrive created a whole new concept of rocket engines known as quantum vacuum thrusters (Q-thrusters).