I read today that NASA is researching laser propulsion and that may change the way we send people and cargo into space. What is this researcher into laser propulsion? Two ways of doing it from what I understand. 1 Build a laser platform on the ground to shoot at the craft2 Build laser on the craft to shoot out the back of the craft I hear that NASA and some other private companies are doing researcher now into laser propulsion and so far it looks really good the research!!!Can some one explain this laser propulsion that NASA and some other private companies are working on? The pros and cons of laser propulsion. And when we may have it like 15 or 20 years from now?
Laser ablative propulsion - Very short pulses of high-intensity light are pointed at orbitting debris, vaporizing milligrams of material; The expanding gas produces a small thrust which acts to eventually push the debris out of orbit
Four types, all of which build big, heavy lasers somewhere easy to reach, like Earth's surface, and use them to power a lightweight remote craft:Laser thermal propulsion - Uses the laser to heat up an inert propellant aboard a rocket, through a transparent window, so it can emit it out of an expansion nozzle like a normal rocketLaser electric propulsion - Normal solar electric propulsion uses solar panels to gather electricity to power a small particle accelerator, an 'ion thruster'. This simply adds laser light to supplement the light from the sun, increasing generated power to weight ratio.Laser ablative propulsion - Very short pulses of high-intensity light are pointed at orbitting debris, vaporizing milligrams of material; The expanding gas produces a small thrust which acts to eventually push the debris out of orbitLaser lightsails - Like solar sails, these are big mirrors affected by photon momentum exchange, but supplemented by lasers for higher thrust to weight, this is a plausible path for far outer solar system probes.In re: mounting it on the spacecraft - there's no point in building a photon rocket out of a laser, since a small elliptical reflector around a light/heat source is nearly as effective, and neither power generation nor lasers can ever be 100% efficient. A photon rocket itself is only useful for missions millenia long; In reasonable timespans, it makes more sense to use propellant, which generates much more thrust per watt.
It would change the way we send people and cargo into space.
{snip}Lightcraft concept, by Leik Myrabo also follows the same concept
Quote from: aceshigh on 09/22/2015 07:19 pm{snip}Lightcraft concept, by Leik Myrabo also follows the same conceptTo achieve LEO the spacecraft has to get to very high and gain an enormous horizontal speed. For what amounts to a propeller gaining horizontal speed in a vacuum will be difficult.Current balloons have reached 53 km (32.9 miles). There may be customers for a product that can hover higher than that, which costs less than a sounding rocket and Virgin Galactic's suborbital craft.
Quote from: nec207 on 09/22/2015 08:58 pmIt would change the way we send people and cargo into space.no not really. Old non news
Escape Dynamics are design a LV that uses Microwave beamed power to heat hydrogen, giving a 750 ISP. This is similar to one of NASA Laser systems. Don't know how financially viable it is, requires quite a large outlay for the ground station. http://spacenews.com/startup-makes-progress-in-beamed-propulsion-for-reusable-launch-vehicles/