Lightcraft

A Light Craft is a spacecraft that gets fed by ground-based pulsed laser or maser, the required drive power. The laser radiates on a parabolic reflector at the bottom of the missile. At the focal point of the reflected beam results in extremely high temperatures 10000-25000 ° C. Matter in this area expands due to the extreme heat in an explosive manner, transfers part of the momentum of the gas particles with the reflector, thus accelerating the missile. During the break between 2 pulses flowing again cool gas behind the reflector, which again accelerates the missile on the next pulse.

When flying within the earth's atmosphere, the atmospheric gas is heated, for the flight in space ( on the ground from about 11 km altitude ) has additional a supporting mass, such as Delrin, be taken, which is then placed in the focal region behind the reflector and its heating the spacecraft drives.

This drive concept is scheduled for launch of small satellites up to a few kilograms of mass. This laser is required with capacities up to 1000 kW.

Advantages over conventional drives

• Very high payload ratio due to the high temperature because of the high specific impulse
• Low cost, since no complex system for fuel production and combustion control is required
• Environmentally friendly because few, possibly toxic, combustion gases arise.

Trouble

• The required laser power can not be achieved with today's means.
• The divergence of the laser beam makes with increasing distance for a reduction of usable power for the drive.
• Complicated path control and position control for the missile.

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Model missiles, this concept will be tested in the laboratory for many years. Because of these difficulties ( particularly in the absence laser power ) is a practical application currently not yet in sight. The Air Force Research Laboratory ( AFRL ), a research facility of the United States Air Force is researching a possible small satellites, using this technology to start.