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The laser elevator - Momentum transfer using an optical resonatorIn a conventional laser lightsail system the payload is propelled by the momentum imparted to it by the reflection of a laser beam without the use of any propellant. Because of the unfavorable relationship between energy and momentum in a light beam, these systems are very inefficient. The efficiency can be greatly improved, in principle, if the photons that impact the payload mirror are returned to the source and then redirected back toward the payload again. This system, which recirculates the laser beam, is defined as the 'laser elevator'. The gain of the laser elevator over conventional lightsails depends on the number of times the beam is recycled which is limited by the reflectance of the mirrors used, any losses in the transmission of the beam, and diffraction. Due to the increase pathlength of the folded beam, diffraction losses occur at smaller separations of the payload and the source mirror than for conventional lightsail system. The laser elevator has potential applications in launching to low earth orbit, orbital transfer, and rapid interplanetary delivery of small payloads.
Document ID
19880028776
Document Type
Conference Paper
Authors
Meyer, Thomas R. (Boulder Center for Science and Policy CO, United States)
Mckay, Christopher P. (NASA Ames Research Center Moffett Field, CA, United States)
Mckenna, Paul M. (Electro Magnetic Applications, Inc. Lakewood, CO, United States)
Date Acquired
August 13, 2013
Publication Date
October 1, 1987
Subject Category
SPACECRAFT PROPULSION AND POWER
Report/Patent Number
IAF PAPER 87-299
Distribution Limits
Public
Copyright
Other