“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/,, OK 01 I ICIAE 652 one I
These array functions can be made coherent over very great distances. RF antennas
with sizes of hundreds of kilometers and optical telescopes of hundreds of meters
diameter can be formed. These systems can enable new capabilities not possible with
single spacecraft either acting alone, as a proliferated but non-coherent constellation,
or as relays for each other. Formed of nanosats and picosats, such swarms will contain
so many spacecraft that the economics of true mass production will come into play in
space for the first time, greatly reducing the cost of producing the system. In addition,
these systems feature the advantages of truly distributed satellite systems, including
fault tolerance, robustness, survivability, reconfigurability by software, and the ability
to be incrementally emplaced and upgraded as budgets are available.
These swarms can be implemented in a cost effective manner using laser propulsion for
both launch and orbital insertion. However, the system designs described in the
following sections are flexible enough to allow for the use of alternative conventional
launch vehicle technologies. The technologies to produce these swarms and their
constituent nanosats or picosats probably can be demonstrated by 2015 and deployed
in space by 2020.
The following concepts were provided via the voluminous research notes, lectures, and
briefings provided courtesy of I. Bekey.
ROTATING PICOSAT SWARM ARRAY RADIO FREQUENCY COLLECTOR
An unconventional, large sparse antenna array RF collector spacecraft with a small
surface footprint even when deployed in geosynchronous Earth orbit (GEO) separates
different sources in proximity and also detects weak signals. Its implementation would
result in a highly desirable, long dwell RF emitter detection capability.
At the heart of this system is a large antenna that is formed by a swarm of tiny
elements that make up the lens of a space-fed array with no structure. The antenna is
a sparse, self-cohering array formed from a large number of picosats rotating (in
relative coordinates) in a plane around a central orbital point in GEO. The picosats are
self-contained repeater spacecraft. Each one receives the ground signal, delays it, and
retransmits the signal so that it arrives at the feeds at the same time as a direct ray
through the center of the array. The time delay of each picosat is self computed based
on its location in the swarm, as measured by a local differential global positioning
system (DGPS)-like navigation signal, to compensate for its deviation from its assigned
ideal location. Each picosat digitizes, delays, frequency shifts, and retransmits its
received signals independently, causing an in-phase composite signal from the ground
to be received at the feeds.
The relative positions of these picosat elements change slowly, and only small and
infrequent propulsive maneuvers are needed for constellation maintenance. A tether
along the local vertical at the central point holds the receivers and DGPS-like reference
at the focus against a counterweight. A pseudorandom distribution of the picosats
suppresses the antenna grating lobes, and intensive computation greatly reduces much
of the remaining sidelobes, creates multiple beams, and steers the ensemble of the
individual beams anywhere on Earth. The antenna system will function with far fewer
elements as a more sparse array, though with limited sensitivity. This system can be
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