“BEAMS”49 pages
- p. 3 …Free-Electron Laser Electron Beam Phase-Space Evolution ....................... 59
Figure 31. Recirculating-Beam FEL System ........................................................... 60…
- p. 4 …HEL Beam Pointer/Tracker ................................................................... 65
Figure 35. Basic Shared Aperture Beam Control System ......................................... 66
Figure 36…
- p. 7 …This can only be achieved via laser propulsion in
which the laser beam energy that is…
- p. 15 …By launching
spacecraft on a beam of electromagnetic radiation, researchers will have developed the
first new…
- p. 16 …The laser beam's pulse
interacts with the mirror, spreading out and focusing into an annular…
- p. 17 …1) power supply; 2) high-power (megawatt-class)
laser beam generator/transmitter using novel beam optics…
- p. 20 …is to the right and the laser beam strikes the stretched-out parabolic
mirror/propulsion section…
- p. 21 …It
requires a beam power of 0.1 to 1 MW per kg of vehicle mass…
- p. 22 …The ground-based
megawatt-class laser beam generator is state-of-the-art technology. The cost…
- p. 25 …Figure 8 illustrates the adverse beam
propagation geometry associated with ETO laser propulsion by means of…
- p. 26 …Attenuation Effects on Captured Laser Beam Power 261.
0.4
0.J
0.2
0.1…
- p. 27 …Unfortunately the demonstrated laser beam power levels for the attractive 1.62 μm
wavelength, which suffered…
- p. 28 …Beam combining
of several 1 MW (or higher) FELs can achieve a total combined beam output…
- p. 31 …Appropriate rotation of a high-energy laser beam,
emanating from a ground/sea-based laser, guides…
- p. 32 …Appropriate rotation and translation of a high-energy laser
beam, emanating from a moving aircraft, guides…
- p. 33 …But
multiple target interception within allowable time is limited by relatively long beam-
riding time needed…
- p. 37 …In this case, it is envisioned that the high-
pulsed power within high-energy laser beams…
- p. 39 …In this case, airborne laser beams at 12 km altitude will not suffer the
significant propagation…
- p. 41 …sidelobes, creates multiple beams, and steers the ensemble of the
individual beams anywhere on Earth. The…
- p. 42 …Each picosat is gravity-
gradient stable, has a dipole array facing Earth, and a broader beam…
- p. 43 …Commands for beam sweep delays are superimposed on the time delays of each
nanosat. Each nanosat…
- p. 44 …piezoelectric membrane kept flat by an electron beam in response to an optical figure
sensor. MEMS…
- p. 46 …technical issues include large wavelength and
atmospheric absorption of the laser beam.
• Carbon Monoxide (CO) Laser…
- p. 47 …125 Hz@ 20μs.
• Laser power, P = 2.5 MW/beam x 4 beams = 10 MW.
• Laser…
- p. 50 …Each power oscillator optics module transmitting a 2.5 MW beam of
10.6 μm wavelength…
- p. 52 …Adding an eight amplifier chain that the system was designed for will
increase the beam power…
- p. 53 …However,
BSSSL beam power can be scaled up further by improving presently known gain media
and…
- p. 54 …scalable
to 1 MW beam power within 2 years.
Typical solid-state lasers have the following…
- p. 55 …A new technology that enables the scaling-up of BSSSL beam power is a recently
developed…
- p. 56 …at the same time increasing the average
beam power.
Figure 21. Phase Change Materials Allow Storage…
- p. 57 …This exponential growth in beam output power is the result of many factors,
including the parallel…
- p. 58 …Microlens -O _
,:1
Incoherent Beam Combining 'Ind1vidually Incoherent Gaussian Beams i=L
Controlled
/_/Steering • ... o~bined…
- p. 59 …Neodymium
Thulium (Tm 3+), Holmium
- Range of beam wavelengths(),) produced: 0.48 μm to 2.9…
- p. 61 …Multlmode Fiber Lasers
50kW Multimode
Output beam quality BPP-1 o
M"2-33
DC EDE…
- p. 62 …The resulting laser beam photon energy depends on the
electron energy, the undulator period, and (weakly…
- p. 63 UNCLASSIFIED/ /F8~ 8FFl&I.«1k WliEii a,.klf
electron beam
( \ I,:--- ■■>ti■--
undulator
)
resonator mirror
0…
- p. 64 …The superconducting accelerator gives good
efficiency and gradient while recirculation of the electron beam recovers beam…
- p. 65 UNCLASSIFIED/ /F&~ 8FFHiil.«1k 1!181! &••kY
- K"' 1.5.t
• Electron Beam:
- Photocathode injector creates…
- p. 66 …HIGH ENERGY LASER BEAM CONTROL
··costs could be reduced to as low as $20 per kg…
- p. 67 …The typical HEL beam control system includes:++ 1) a gimbaled
beam director, 2) tracking and pointing…
- p. 68 UNCLASSIFIED//F&II. &FFiii,111!! l!llili &HI!¥
A novel new HEL beam control architecture being…
- p. 69 …HEL Beam Pointer/Tracker (courtesy of the Directed Energy Professional
Society).
In summary, this new architecture…
- p. 70 …The BILL is a solid-state, kilowatt-class laser
that measures atmospheric conditions, allowing the beam…
- p. 71 …All of these HEL beam control innovations can be quickly adapted to laser propulsion
applications with…
- p. 72 …The entire Lightcraft launch
system is comprised of a ground, sea, or airborne laser beam generator…
- p. 73 …New beam
control devices and high-power optical train combinations have a resulting beam line
that…
- p. 75 …N. (1983), "Advanced Beamed-Energy and Field Propulsion Concepts,"
BDM/W-83-225-TR, BDM Corp…
- p. 76 …N. (2001), "World Record Flights of Beam-Riding Rocket Lightcraft:
Demonstration of 'Disruptive' Propulsion Technology," AIAA…
- p. 77 …of the 6 th Int'! Symposium on Beamed Energy
Propulsion, edited by C. R. Phipps, AIP…
UNCLASSIFIED//F&~ 8FFI8IAL H!H!! 8HLY
Chapter 5: Conclusion
To reduce mission costs, advanced technology components and a novel laser propulsion
system can make nanosats (and picosats) compact, lightweight, low power, and low
cost. By producing a large quantity of nanosats for a given mission, the per-unit cost
will be reduced to a small fraction of satellite procurements for traditional missions.
Mission operation costs will be minimized by the incorporation of both onboard and
ground autonomy, use of heuristic systems, and use of a novel laser propulsion system
to launch the nanosats into LEO. Laser propulsion is an enabling technology in which a
laser-propelled vehicle, called "Lightcraft," harnesses the energy of a high-energy laser
beam and converts it into propulsive thrust.
The laser-propelled Lightcraft is an ETO transportation system that develops quasi-
steady (airbreathing) thrust by pulsing at a variable rate along the flight trajectory to
orbit, and then when it climbs above the atmosphere it begins to operate in the thermal
rocket mode using onboard propellant to convert and expand the laser energy for
propulsion. The Lightcraft is spin-stabilized and can be launched vertically upward or
on a slant upward trajectory, hover in mid-air, and undergo powered descent and
landing. The system is single-stage-to-orbit and completely reusable with no onboard
propellant required (the reaction mass is free air), except for the small internal amount
of propellant needed for final ascent to orbit and orbital maneuvering. MEMS FEEP
thrusters could provide onboard attitude and stationkeeping propulsion. The Lightcraft
specific impulse is essentially infinite (several thousand seconds in rocket mode), while
payload mass fractions are 50% to 95%.
Laser-propelled Lightcraft systems are simple, reliable, safe, environmentally clean, and
could have a very high all azimuth on-demand launch rate. This novel propulsion
system reduces space launch costs by two to three orders of magnitude below today's
levels, with estimated launch costs of $20 per kg to $600 per kg of payload, not
including life-cycle and recurring launch operations costs. The entire Lightcraft launch
system is comprised of a ground, sea, or airborne laser beam generator consisting of a
power supply, a high-power (megawatt-class) laser beam generator/transmitter using
novel beam optics, and automated tracking, hand-off and safety systems.
The most promising military mission for laser-propelled Lightcraft is the placement of
Earth and space observing nano-/pico-satellites of up to 3 kg mass into LEO. Such
Lightcraft could also serve as a "Lightsat," because it would use the Lightcraft's laser
propulsion optics as a telescope for observing military targets on Earth and in space.
Such a Lightcraft system appears capable of reaching LEO at 1/Sth to 1/lOth the cost
required for placing a similar Lightsat system into LEO using multistage chemical rocket
systems. Other potential missions include using laser-propelled Lightcraft as
ground/sea- or airborne-launched kinetic kill weapons to shoot down enemy ballistic
missiles. Very innovative near-term missions could also include deploying Lightcraft
nano-/pico-satellites to form swarms of small spacecraft which cooperate coherently to
form a real distributed system in which the whole is more than the sum of the parts.
This would be a constellation of small spacecraft each performing its separate function,
but these functions combine to create at a central location a much larger virtual
spacecraft, or sensor aperture, that exists solely because of the cooperation of the
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UNCLASSIFIED/ /1"91t 91"1"1!111it 1!191!! 9HLY