#interstellar
3 posts
Solar Sails and Lightsails: Sailing to the Stars on Photons
Light carries momentum. When photons bounce off a reflective surface, they push it — imperceptibly at first, but in the vacuum of space with no air resistance, that gentle push accumulates for years and years. Solar sails use sunlight to accelerate spacecraft without carrying any fuel at all. Laser-driven lightsails could push them to a fraction of the speed of light.
Nuclear Pulse Propulsion and Project Orion: A Star Drive That Almost Was
In the late 1950s and early 1960s, a group of physicists at General Atomics designed what remains the most powerful spacecraft propulsion system ever seriously considered: a ship that would ride a series of nuclear explosions to velocities capable of reaching other stars within a human lifetime. Project Orion was cancelled in 1963. Its physics still works.
Breakthrough Starshot and Laser-Pushed Lightsails to Alpha Centauri
In 2016, a coalition of scientists and billionaires announced a project to send a thumbnail-sized spacecraft to Alpha Centauri within a generation. The plan: accelerate a tiny sail to 20% the speed of light using a ground-based laser array. The physics works. The engineering is the challenge.