SpaceElevatorPower

Power Beaming System

Power is needed for everything and effective delivery over 10's of thousands of kilometers is not easy. Various methods were examined and laser power beaming was selected for the baseline. This is a mature yet still rapidly evolving technology.

	Value	Details
Power input	20 - 150 MW	Can be from any conventional source. Ocean going platforms can have this amount of power available from diesel engines. Spreadsheet on energy needed for ascent File:Energy worksht.ods
Power in laser beam	2 - 15 MW	This power does not need to be in a single beam but can come from multiple beams interlaced in time (pulsed beams)
Primary Optics		Segmented adaptive optics mirror similar to those in major astronomical observatories
Primary Beam diameter	10-30 meters	This size is determined by the focusing required and to reduce the intensity to a relatively safe level.
Wavelength	TBD nm	To be matched to the type of cells and lasers available.
Tracking accuracy	TBD mrad	Determined by laser beam and receiver sizes.
Power source	Solid-state disk laser	Stacked diodes are also coming on line. See File:Ultrahigh-Average Power Solid-State Laser.pdf, File:MCDL LASE 2004 1f.pdf, File:LASE 2004 SSDL 2k final.pdf

Status

Boeing has demonstrated operation of a 25kW laser of the kind we need and claim they can build MW lasers Beaming 9+kW lasers over short distances are to be demonstrated at the Spaceward Space Elevator Games Adaptive optics have been demonstrated with long distance capabilities

Include images and videos from the SE Games Include design write-ups

Delivering power over the distance of the elevator is a challenge but quickly being addressed by current technology.

Major Design Challenges

• Climber Tracking on the Ribbon
• Overall Climber System Engineering

Additional Work Needed

Item	Notes	Completed and Ongoing Efforts
Categorize the available laser systems	Select for overall capital and operational cost, efficiency of recievers, lifetime, weather considerations, platform stability requirements,...	Laser List by User 1
Detail optics system	Size, performance, cost, ... considerations.	Optics System I by User 2 Optics System II by User 4
Weather concerns for the power beaming	Determine the potential down time due to weather	The Space Elevator by Edwards Cloudmap.jpg in file list by Edwards File:EPIC excerpts.doc report on Pacific weather studies
Safety issues with high power laser	Outline the requirements for safe operations	Safety Issues by User 3

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