SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 43, ISSUE 25 - DECEMBER 16, 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.

20050243130 Spectral Sciences, Inc., Burlington, MA USA

Predictions of Observations of Shuttle Engine Firings

Braunstein, M.; Bernstein, L.; Venner, M.; Dressler, R.; Aug. 22, 2005; 19 pp.; In English Contract(s)/Grant(s): F04611-03-C-0015; Proj-BMSB Report No.(s): AD-A439623; No Copyright; Avail.: CASI: A03, Hardcopy

This viewgraphs report on the following: 1) Chemical Mechanisms; 2) Source and Apparent Signals; 3) Instrumentation; 4) Conclusions and Future Work. DTIC

Chemical Reactions; Space Shuttles

20050243160 Naval Postgraduate School, Monterey, CA USA

Army Space and Transformation

Scherer, Clay S.; Sep. 1, 2005; 145 pp.; In English; Original contains color illustrations Report No.(s): AD-A439668; No Copyright; Avail.: Defense Technical Information Center (DTIC)

The Army is undergoing a Transformation process, the outcome of which will be an enhanced warfighting capability via the Objective Force. Space is a key enabler for the Army's Objective Force capabilities and Joint combat operations. The Army has a long history of success in the space mission area that stretches back to the 1940s. The Army established doctrine for conducting space operations in support of the Objective Force. This thesis explains why the Army is involved in space from historical, doctrinal and policy perspectives. The Army created force structure for Space Support Elements (SSE) at the tactical level and organic to Division headquarters, and has planned and proposed additional space elements at the Brigade, Corps and Army organizational levels. The FA40, (Space Operations), Career Field is a relatively new personnel category that brings space products and services to the warfighter. Proper distribution of the FA40 personnel pool is a critical part of assuring the success of the FA40 Career Field. This thesis presents recommendations on how the Army can better organize its space force structure, allocate personnel and develop future space capabilities requirements documents to ensure relevancy in a transformed Army. DTIC

Combat; Military Operations; Space Missions

20050243187 Army Research Lab., Adelphi, MD USA

Reliable Multicasting Based on Air Caching for Flat Hierarchy Networks

Manousakis, Kyriakos; Jan. 1, 2002; 219 pp.; In English Report No.(s): AD-A439717; CSHCN-MS-2002-2; No Copyright; Avail.: CASI: A10, Hardcopy

The evolution of satellite networks in the commercial and military world has pushed the research community towards the solution of important problems related to this kind of networks, which are characterized from the lack of physical hierarchy. One of those important problems is how to design an efficient reliable multicasting protocol for one-hop (flat) networks where the link may present characteristics like high propagation delay and high BER. The existing reliable multicasting protocols are inefficient when applied to flat networks, since those are based on intermediate receivers and local recovery techniques. We introduce the Air Cache, which serves as a fast access memory that is realized on the air and contains packets for the recovery of corrupted or erroneous data packets at the receivers. In this thesis we present two classes of reliable multicasting protocols, which are based on the combination of FEC and ARQ with air caching. The non-adaptive class of protocols (UDPAC, RDPAC, PPAC) is characterized by the static nature of the Air Cache in term of size and content and the second class of protocols (ACDAC, ASPAC, HADAC) is characterized by the dynamic nature of the Air Cache. DTIC

Hierarchies; Protocol (Computers); Satellite Networks

20050243194 Army Research Lab., Adelphi, MD USA

Resource Allocation in Ka-band Satellite Systems

Feng, Youyu; Jan. 1, 2001; 99 pp.; In English; Original contains color illustrations Report No.(s): AD-A439725; CSHCN-MS-2001-1; No Copyright; Avail.: CASI: A05, Hardcopy

The Ka-band satellite system is of increasing interest around the world due to its huge bandwidth. Rain fading is one of the primary factors affecting performance and availability of the Ka-band system. Extra power on the satellite can provide compensation for rain attenuation. In this thesis, we study the rain fade compensation problem for downlink transmission in the Ka-band satellite by dynamic resource allocation. The resources we consider include power and antennas onboard the satellite. The goal is to maximize the aggregate priority of packets arriving at all downlink spots as well as maintain fairness among downlinks. We formulate the problem mathematically in the framework of Knapsack Problems (KP). In particular, we show the resource allocation problem is equivalent to a Multi-choice Multiple Knapsack Problem (MCMKP), which, in general, is very hard to solve in a reasonable time. By introducing the seeding theory into the antenna scheduling, we decompose the original MCMCP into a sequence of Multiple-choice Knapsack Problems (MCKP), which are easier to solve. The effectiveness of our approach is demonstrated through simulations in OPNET. Comparison with the Multiple Knapsack Problem (MKP) approach proposed by Birmani is also provided. DTIC

Artificial Satellites; Extremely High Frequencies; Resource Allocation; Resources Management

20050243203 Maryland Univ., College Park, MD USA

Resource Allocation for KA-Band Broadband Satellite Systems

Birmani, Vineet; Jan. 1, 1999; 92 pp.; In English; Original contains color illustrations Report No.(s): AD-A439738; No Copyright; Avail.: CASI: A05, Hardcopy

Forthcoming high data rate geostationary satellite systems, which are planned to work in rain affected Ka-band, would need effective resource management from a network management perspective. In this thesis we have looked at satellite power and bursting time-slots needed for the downlink channel, as satellite resources that need to be managed. Some solutions are proposed in order to tackle the above-mentioned problem. DTIC

Allocations; Artificial Satellites; Broadband; Extremely High Frequencies; Resource Allocation

20050243216 Spectral Sciences, Inc., Burlington, MA USA

Predictions of AMOS Observations of Space Shuttle Engine Firings

Draft. Braunstein, Matthew; Bernstein, Larry; Dressler, Rainer; Venner, Marty; Aug. 2, 2005; 15 pp.; In English Contract(s)/Grant(s): F04611-03-C-0015; F19628-00-C-0006; Proj-5503 Report No.(s): AD-A439770; No Copyright; Avail.: Defense Technical Information Center (DTIC)

Engine firings of the Space Shuttle primary control system (PRCS) thrusters can give rise to radiation observable from ground-based telescopes such as AMOS. Such observations would yield valuable information on the environment near the spacecraft during engine operation. The radiation and the mechanisms that produce it are also important to characterize because such radiation can be a significant background noise source for telescopes mounted on spacecraft in low-Earth-orbit or LEO in general. Furthermore, observations of radiation associated with engine firings can give valuable information on fundamental chemical reactions that can be studied over the very large length scales, high energies, and rarefied conditions that are achievable in space but are especially difficult to reproduce in ground-based laboratories. DTIC

Engines; Space Shuttles; Supercomputers; Telescopes

Source: NASA.