“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…
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The communications subsystem is further complicated by constellations requiring spin-
stabilized nanosats. A spinning nanosat cannot easily point an antenna toward Earth.
Therefore, a low gain omni antenna is assumed and communications must take place
near perigee, when the range is 3 to 5 Earth radii. A large ground antenna and high
data rate compression must be used to achieve reasonable data rates with minimum
power. This places an additional burden on the ground stations for both sensitive
receivers/bit synchronizers and advanced decoders. These same considerations limit
data rate for satellite-to-satellite communication.
Although the inclusion of an onboard command receiver is highly desired, it puts an
additional strain on an already challenged nanosat mass and power budget. For this
reason, the concept of a totally autonomous, receiverless nanosat design appears most
attractive. However, "receiver-on-a-chip" technology has advanced to the point where
including a receiver onboard looks feasible. The biggest disadvantage of a receiver now
becomes the ground personnel and software needed to support the ability to command
the nanosat. Command actions taken onboard will of course be limited to basic
functions such as "transmit data" because of the lack of redundancy and mechanical
functions. Although scenarios have been defined to allow nanosats to autonomously
determine when to transmit their stored data, utilizing a receiver to control the
telemetry downlink from the ground still has value. The capability of uploading flight
software changes, as well as sending a master reset if necessary, would also exist with
such an onboard command receiver.
MECHANICAL AND STRUCTURES
The nanosat mechanical system will be kept as simple as possible. The ideal nanosat
mechanical design should consist of a one-piece structure on which all other
components are mounted.
Multifunctional structures can provide thermal control, shielding and serve as substrates
for printed circuit boards. For example, diamond facesheet honeycomb panels can
serve as a structure, thermal conductor and radiator, and printed circuit board
substrates. The diamond facesheet provides ten times greater thermal conductivity
than aluminum and can dissipate heat from high power density electronics modules
with a low mass comparable to carbon fiber composites. Another example is the
structural battery system. It consists of a honeycomb panel whose core is filled with
the cells of a nickel-hydrogen battery (or other flight qualified cell technology).
Concurrent engineering and fabrication techniques will be used to create a single
computer model for the design, analysis (structural, thermal, and dynamic), and
fabrication of the nanosat and its components. Dynamic modeling capabilities to
simulate nanosat deployments will provide faster designs and a reduction in the amount
of deployment testing required. This approach will significantly lower development
costs by reducing duplication of effort, chances of errors, the number of drawings and
paperwork required.
Mass production techniques not traditionally used for spaceflight hardware will be used,
such as casting and injection molding. Options being considered for the nanosat
structure material are: cast aluminum; cast aluminum-beryllium alloy; injection molded
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