SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 44, ISSUE 7 - April 07, 2006

15 LAUNCH VEHICLES AND LAUNCH OPERATIONS
Includes all classes of launch vehicles, launch/space vehicle systems, and boosters; and launch operations.

For related information see also 18 Spacecraft Design, Testing and Performance; and 20 Spacecraft Propulsion and Power.

20060009006 NASA Marshall Space Flight Center, Huntsville, AL, USA

Axisymmetric Throttleable Non-gimballed Rocket Engine

Sackheim, Robert L., Inventor; Hutt, John J., Inventor; Anderson, William E., Inventor; Dressler, Gordon A., Inventor; November 15, 2005; 9 pp.; In English Patent Info.: Filed 11 Mar. 2003; US-Patent-6,964,154; US-Patent-Appl-390253; NASA-Case-MSF-31689; No Copyright; Avail.: CASI: A02, Hardcopy

A rocket engine assembly is provided for a vertically launched rocket vehicle. A rocket engine housing of the assembly includes two or more combustion chambers each including an outlet end defining a sonic throat area. A propellant supply for the combustion chambers includes a throttling injector, associated with each of the combustion chambers and located opposite to sonic throat area, which injects the propellant into the associated combustion chamber. A modulator, which may form part of the injector, and which is controlled by a controller, modulates the flow rate of the propellant to the combustion chambers so that the chambers provide a vectorable net thrust. An expansion nozzle or body located downstream of the throat area provides expansion of the combustion gases produced by the combustion chambers so as to increase the net thrust. Official Gazette of the U.S. Patent and Trademark Office

Rocket Engines; Throttling; Symmetry

20060009921 Government Accountability Office, Washington, DC, USA

Unmanned Aircraft Systems: New DOD Programs Can Learn from Past Efforts to Craft Better and Less Risky Acquisition Strategies

Mar. 2006; 46 pp.; In English Report No.(s): PB2006-107509; GAO-06-447; No Copyright; Avail.: CASI: A03, Hardcopy

Through 2011, the Department of Defense (DOD) plans to spend $20 billion to significantly increase its inventory of unmanned aircraft systems, which are providing new intelligence, surveillance, reconnaissance, and strike capabilities to U.S. combat forces--including those in Iraq and Afghanistan. Despite their success on the battlefield, DOD's unmanned aircraft programs have experienced cost and schedule overruns and performance shortfalls. Given the sizable planned investment in these systems, GAO was asked to review DOD's three largest unmanned aircraft programs in terms of cost. Specifically, GAO assessed the Global Hawk and Predator programs' acquisition strategies and identified lessons from these two programs that can be applied to the Joint Unmanned Combat Air Systems (J-UCAS) program, the next generation of unmanned aircraft. NTIS

Pilotless Aircraft; Unmanned Spacecraft

Source: NASA