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Defense Intelligence Reference Document Laser Lightcraft Nanosatellites

Defense Intelligence Agency · 77 pages · text from the file's own layer

This Defense Intelligence Reference Document from the Defense Intelligence Agency, dated 1 November 2010, was produced under the Advanced Aerospace Weapon System Applications (AAWSA) Program. It describes nanosatellite technologies and proposes launching nanosats into orbit with laser Lightcraft propulsion. It also covers a weapon mission selection study and multi-megawatt laser options. The author recommends that the Department of Defense and NASA bring Lightcraft R&D back to the United States and restart the X-50LR flight demonstration program.

  • p. 4 …Influence of Target Velocity and Intercept Angle on Impact Energy and Required Mass .................................................................................................. 33 Table 5…
  • p. 5 …The term "minisatellite" refers to a spacecraft with a wet mass (including onboard propellant) of 100…
  • p. 7 …Nanosatellite Technologies OVERVIEW Nanosats require technologies that radically reduce the mass and power of components without…
  • p. 8 …nanosat presents some unique challenges, with low mass (0.25 kg) and low power (0.5…
  • p. 9 …In order to develop a low mass C&DH, a lightweight and low power electronics packaging…
  • p. 11 …RF COMMUNICATIONS The onboard RF subsystem must be small, low mass, and low power. The system…
  • p. 12 …additional strain on an already challenged nanosat mass and power budget. For this reason, the concept…
  • p. 13 …The material will be selected based on mass, cost, manufacturability, ease of assembly and integration, and…
  • p. 15 …for the spacecraft because a large propellant mass and heavy energy source are not carried onboard…
  • p. 17 …Current Lightcraft designs are limited to about 60 g mass and 15 cm in diameter by…
  • p. 21 …It requires a beam power of 0.1 to 1 MW per kg of vehicle mass…
  • p. 22 …The majority of the system mass required to launch a payload to orbit is left on…
  • p. 24 …Therefore, this would allow approximately 4 kg of mass to be placed into orbit with the…
  • p. 25 …same ply-thickness) to meet Lightcraft airframe mass requirements. Another important finding in the study was…
  • p. 31 …Additional estimated mass for performing the Lightsat function is no more than about 1 kg, if…
  • p. 32 …Lightcraft takeoff masses no more than about 20 kg can be accelerated to orbital velocities by…
  • p. 33 …for missile and maneuvering aircraft interception. • Additional mass along Lightcraft centerline for hardened target penetration. LIGHTCRAFT…
  • p. 34 …Lightcraft sizing assumed a propellant mass fraction of 0.5 and 1.0 MW of laser…
  • p. 35 …Hybrid Rocket Expendible Launch Vehicle - Assumed Perfonnance and Estimated Weights Payload Mass (kg) 1.00 5…
  • p. 37 …It is therefore estimated that the air-to-space Lightcraft dry mass would be about the…
  • p. 38 …Influence of Target Velocity and Intercept Angle on Impact Energy and Required Mass 2 61. Lightcraft…
  • p. 39 …Influence of Lightcraft and Target Velocity on Impact Energy and Required Mass 261. Lightcraft Lightcraft Impact…
  • p. 40 …The lower mass also saves launch costs, so the total system costs less for the same…
  • p. 41 …many spacecraft that the economics of true mass production will come into play in space for…
  • p. 44 …the local vertical, with its center of mass in GEO. The Fresnel zone plate has a…
  • p. 46 …wall plug and optical efficiencies, cost, complexity, mass, and size. Free-electron lasers are another class…
  • p. 47 …P = 2000 Pa (or 0.02 atmospheres). • Mass flow rate, Q = 60 kg/sec per module…
  • p. 48 UNCLASSIFIED//509 AEEJCJOP 11£5 O.-blf + Total mass flow rate, Qtota1 = 240 kg/sec for…
  • p. 50 …sec, and 15 kg/sec of CD2 mass flow represents 2.053 x 1026 molecules/sec…
  • p. 51 …The 60 kg/sec mass flow requirement of the 3: 1 N2/C02 lasing gases means…
  • p. 53 …mass (not including the prime power and cooling systems) to achieve the low specific mass (5…
  • p. 65 …is the undulator period, mis the electron mass, and c is the speed of light. 'MeV…
  • p. 72 …The Lightcraft specific impulse is essentially infinite (several thousand seconds in rocket mode), while payload mass…
UNCLASSIFIED//P8"1 81"1"1!111it 1!191!! SHLY
Figure 1. Air Force X-25LR Laser Lightcraft (courtesy of F. Mead, AFRL/PRSP, Edwards AFB,
CA).
In the two-mode propulsion concept, a forebody aeroshell acts as an external
compression surface for the airbreathing engine inlet. Affixed to the bottom of the craft
is a parabolic-shaped afterbody mirror, which serves as a primary receptive optic for
the laser beam and as an external plug nozzle expansion surface. The primary thrust
structure is the centrally located annular shroud, which provides air through the inlet
and also acts as a ring-shaped energy "absorption/propulsion" chamber for plasma
formation. The air inlet is closed when the Ughtcraft operates in the rocket mode.
The Lightcraft is very lightweight and uses its shape to facilitate vertical flight. The
craft has the appearance of a fat acorn when viewed from the side. The lower portion
of the craft is a very highly polished metal mirror, whereby the lower point of the
acorn-shape is the midpoint of a stretched-out parabolic mirror (see Figure 2). The
Lightcraft receives kilojoule pulses from a ground-based infrared laser at a rate of 25
times per second. The axisymmetric, off-axis parabolic collection mirror facilitates flight
by concentrating the pulsed laser light into an annular focus. The laser beam's pulse
interacts with the mirror, spreading out and focusing into an annular area inside the
circumference of the craft. The intensity of the 18 microsecond pulsed laser is
sufficiently high that atmospheric breakdown occurs in the annular area causing inlet air
to momentarily burst into a highly luminous plasma (10,000 - 30,000 K), thereby
producing a superheated plasma shock wave (with instantaneous pressures reaching
tens of atmospheres) that generates thrust in the direction of the laser beam. A lip
around the craft's circumference, akin to a plug nozzle, directs the expansion of the
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UNCLASSIFIED/ /F81it 8FFIIIAI!: 1!181! &••1::Y

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Report, from the dia collection. The PDF is mirrored here; the original link is under it. 77 pages are in the text index: search them above, or from the library's search.