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This Defense Intelligence Reference Document, prepared in fiscal year 2010 by the Defense Intelligence Agency's Defense Warning Office under the Advanced Aerospace Weapon System Applications (AAWSA) Program, reviews aneutronic fusion as a way to propel spacecraft. It compares chemical, ion, fission, fusion and antimatter propulsion, and it also covers radiation shielding and relativistic rocket calculations. It looks at research needs over the next 30 years for missions from low Earth orbit to Mars, Jupiter and Alpha Centauri.
From the source:Release of 2026-09-18 Incident: 11/1/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD surveys aneutronic fusion as a possible advanced space-propulsion method, focusing on fusion reactions that release most of their energy in charged particles rather than neutrons and therefore offer potential advantages over more neutron-intensive fusion concepts, especially in radiation shielding, direct energy conversion, and thrust generation. The report reviews the underlying rocket physics, compares candidate fusion fuels and ignition conditions, and gives particular attention to proton-boron and related schemes, while also discussing Bussard’s concepts and other fusion projects as representative development paths. It also makes clear that the central obstacle remains ignition and sustained net-energy fusion under practical conditions, and it notes additional problems such as x-ray energy losses from the hot plasma, extreme temperature requirements, and the gap between theoretical specific impulse and what proposed systems had demonstrated experimentally. Overall, the document presents aneutronic fusion propulsion as an attractive long-range concept for deep-space travel, but one whose practical realization still depended on major unresolved advances in fusion engineering.
“Low Earth orbit”6 pages
UNCLASSIFIED//POlt Offl@IAL WS& &NkY Germany called the Silvervogel that was intended for use in suborbital bombing of distant targets. The shuttle requires expendable rockets to attain orbit. Several efforts are underway to manufacture aircraft that can attain orbit with less cost and env ironmental damage as the current rocket technology . Wh il e the Spaceship One and Spaceship Two designed by Scaled Composites and Virgin Atlantic can carry passengers into space, they lack the energy to propel a payload into orbit at the required 17,000 miles per hour. The Boeing X-37 is designed to carry unmanned payloads into orbit, yet still requires an Atlas V rocket to launch. The DARPA/USAF Falcon is designed for hypersonic flight at Mach 6, far short of the Mach 23 or so required for orbit. Through the use of RAM jets and hybrid systems (air breathing/rocket), the goal of SSTO is achievable over the next 30 years. LEO TO MARS (34 TO 249 MILLION MILES) Chemical rockets have been used to launch probes to Mars with great success. The transit time is typically 9 months, each way. Aerobraking in the Martian atmosphere is used to slow down the vehicles, resulting in a considerable savings in fuel. For human flight to Mars, the transit time must be as short as possible to minimize rad iation exposure from cosmic sources, including the proton flux from the Sun. The specific impulse of chemical rockets is low; l sp = 421 seconds for the last two stages of the Saturn V, for example. Ion thrusters are also existing technology and can generate much higher specific impulse (3,000 seconds for xenon electrostatic drives to 30,000 seconds for VASIMR). Ion drives, however, typically generate very low thrust. A high performance Hall effect ion drive with lsp = 8,000 seconds generates only 2.5 newtons of thrust, for example, which is enough to accelerate one kilogram of mass at 0.25 g, where g = earth's gravitation acceleration. This drive requires 140 kW of electricity to operate and a supply of xenon gas as a propellant. For a probe having the mass of the International Space Station (370 metric tons), we can use equation 6.1 to calculate the time required to transit to Mars with our Hall effect ion drive. t -- ✓ 2dFm (6.1) In this equation, t is the transit time, F the thrust, d the distance, and m the mass of the object to be accelerated at a constant rate. Results show that it will take at least 4 years to make this transit . The use of multiple drives may decrease this time. For manned flights to Mars, an estimated transit time of 30 days would be considered appropriate in order to minimize radiation exposure to the crew. For this scenario, 10,000 Hall effect ion drives would be needed along with 1.36 gigawatts of electrical power, slightly more than the power generated by a single reactor at the San Onofre Nuclear Power Plant. An alternative ion drive design is the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) developed by Franklin Chang- Diaz in 1977. These systems use hydrogen, argon, or neon gas and generate 1 newton of thrust for 100 kW of power. The VX-200, a 200-kW VASIMR engine, will be tested on the International Space Station in 2011 or 2012. 21 Chemical rockets and nuclear electric propulsion can be used to reach Mars; both are based on existing technology. A third candidate is nuclear thermal propulsion. Rockets of this design were tested at the Nevada Test Site and were intended to launch payloads from the Earth's surface. With Isp = 850 seconds, the performance more than UNCLASSIFIED/fF&A &FFI&I:.l.k W&li &NkY 27
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Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 50 pages are in the text index: search them above, or from the library's search.