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Round Trip to Orbit: Human Spaceflight Alternatives

Description: This special report examines a wide range of potential improvements to the Space Shuttle, explores the future of space transportation for humans, and presents policy options for congressional consideration. It is one of a series of products from abroad assessment of space transportation technologies undertaken by OTA, requested by the Senate Committee on Commerce, Science, and Transportation, and the House Committee on Science, Space, and Technology.
Date: August 1989
Creator: United States. Congress. Office of Technology Assessment.
Partner: UNT Libraries Government Documents Department

Equations Representing Reactor System with Emphasis on KIB Digital Program

Description: "This report is written as a supplement to LAMS 2539. It is hoped that one will be able to read LAMS 2539, with emphasis on the fourth part (Memorandum N-4-79OU by 0. Farmer), with this memorandum to bridge the gaps and understand more about the model used and what the KIB Program can be used for. The system is defined by subsystems or subprograms: Thrust System, Heat Exchanger, Neutron Dynamics, Rod Actuator Dynamics, and Thermocouple Dynamics. The original Kiwi-B Flow System is included in the first part of LAMS 2539. This has been replaced by the newer system which includes a turbo-pump (per R, Bohl & E. Wheatley). This system will not be included here. Recommendations are made for improvement and more work in certain areas."
Date: August 29, 1961
Creator: Mohler, Ronald R.
Partner: UNT Libraries Government Documents Department

On the Possibility of Extracting Energy from Gravitational Systems by Navigating Space Vehicles

Description: This report describes a number of problems, generally involving the possibility of using reserved kinetic energy in such a way as to acquire, by suitable near collisions with one or the other of the celestial bodies discussed, much more kinetic energy that it possesses -- more by an order of magnitude than the available reserve energy would allow it to acquire by itself.
Date: 1958
Creator: Ulam, Stanislaw M.
Partner: UNT Libraries Government Documents Department

Affordable Spacecraft: Design and Launch Alternatives

Description: This background paper examines several proposals for reducing the costs of spacecraft and other payloads and describes launch systems for implementing them. It is one of a series of products of a broad assessment of space transportation technologies undertaken by OTA at the request of the Senate Committee on Commerce, Science, and Transportation, and the House Committee on Science, Space, and Technology.
Date: January 1990
Creator: United States. Congress. Office of Technology Assessment.
Partner: UNT Libraries Government Documents Department

Interplanetary space transport using inertial fusion propulsion

Description: In this paper, we indicate how the great advantages that ICF offers for interplanetary propulsion can be accomplished with the VISTA spacecraft concept. The performance of VISTA is expected to surpass that from other realistic technologies for Mars missions if the energy gain achievable for ICF targets is above several hundred. Based on the good performance expected from the U. S. National Ignition Facility (NIF), the requirements for VISTA should be well within the realm of possibility if creative target concepts such as the fast ignitor can be developed. We also indicate that a 6000-ton VISTA can visit any planet in the solar system and return to Earth in about 7 years or less without any significant physiological hazards to astronauts. In concept, VISTA provides such short-duration missions, especially to Mars, that the hazards from cosmic radiation and zero gravity can be reduced to insignificant levels. VISTA therefore represents a significant step forward for space-propulsion concepts.
Date: April 20, 1998
Creator: Orth, C.D.
Partner: UNT Libraries Government Documents Department

Radiation Effects in the Space Telecommunications Environment

Description: Trapped protons and electrons in the Earth's radiation belts and cosmic rays present significant challenges for electronics that must operate reliably in the natural space environment. Single event effects (SEE) can lead to sudden device or system failure, and total dose effects can reduce the lifetime of a telecommmiications system with significant space assets. One of the greatest sources of uncertainty in developing radiation requirements for a space system is accounting for the small but finite probability that the system will be exposed to a massive solar particle event. Once specifications are decided, standard laboratory tests are available to predict the total dose response of MOS and bipolar components in space, but SEE testing of components can be more challenging. Prospects are discussed for device modeling and for the use of standard commercial electronics in space.
Date: May 17, 1999
Creator: Fleetwood, Daniel M. & Winokur, Peter S.
Partner: UNT Libraries Government Documents Department

Mars to orbit with pumped hydrazine

Description: A propulsion point design is presented for lifting geological samples from Mars. Vehicle complexity is kept low by choosing a monopropellant single stage. Little new development is needed, as miniature pump fed hydrazine has been demonstrated. Loading the propellant just prior to operation avoids structural, thermal, and safety constraints otherwise imposed by earlier mission phases. Hardware mass and engineering effort are thereby diminished. The Mars liftoff mass is 7/8 hydrazine, <5% propulsion hardware, and >3% each for the payload and guidance.
Date: April 27, 1999
Creator: Whitehead, J C
Partner: UNT Libraries Government Documents Department

SNAP 10A Structural Analysis

Description: Abstract: this report discusses and summarizes all stress analysis done on the SNAP 10A system; it also mentions many of the structural tests which were accomplished.
Date: July 15, 1964
Creator: Boulanger, J. R.
Partner: UNT Libraries Government Documents Department

Application of Nuclear Power Plants (SNAP Units) to the Manned Orbiting Research Laboratory (MORL)

Description: Abstract: This report describes in detail two designs of a nominal 6-kwe Nuclear Power Plant (NPP), one using thermoelectrics for power conversion and the other using the Mercury-Rankine cycle NPP.
Date: February 1, 1965
Creator: Botts, W. V.; Marko, M.; McCourt, P. E.; Keshishian, V.; Piccot, A. R. & Budney, G. S.
Partner: UNT Libraries Government Documents Department

MARS Flight Engineering Status

Description: The Multi-sensor Airborne Radiation Survey Flight Engineering project (MARS FE) has designed a high purity germanium (HPGe) crystal array for conducting a wide range of field measurements. In addition to the HPGe detector system, a platform-specific shock and vibration isolation system and environmental housing have been designed to support demonstration activities in a maritime environment on an Unmanned Surface Vehicle (USV). This report describes the status of the equipment as of the end of FY09.
Date: April 6, 2010
Creator: Fast, James E.; Dorow, Kevin E.; Morris, Scott J.; Thompson, Robert C. & Willett, Jesse A.
Partner: UNT Libraries Government Documents Department

Preliminary Studies on Electrical Propulsion Systems for Space Travel

Description: Report discussing low and high acceleration flight mechanics for interplanetary missions, as well as the energy limitation for electric propulsion systems powered by a nuclear energy source. From abstract: "An optimization procedure for low acceleration systems is given which leads to a simple relationship between mission requirements, payload fraction, power plant specific power, and exhaust velocity."
Date: unknown
Creator: Fox, Robert H.
Partner: UNT Libraries Government Documents Department

The application of quaternions and other spatial representations to the reconstruction of re-entry vehicle motion.

Description: The analysis of spacecraft kinematics and dynamics requires an efficient scheme for spatial representation. While the representation of displacement in three dimensional Euclidean space is straightforward, orientation in three dimensions poses particular challenges. The unit quaternion provides an approach that mitigates many of the problems intrinsic in other representation approaches, including the ill-conditioning that arises from computing many successive rotations. This report focuses on the computational utility of unit quaternions and their application to the reconstruction of re-entry vehicle (RV) motion history from sensor data. To this end they will be used in conjunction with other kinematic and data processing techniques. We will present a numerical implementation for the reconstruction of RV motion solely from gyroscope and accelerometer data. This will make use of unit quaternions due to their numerical efficacy in dealing with the composition of many incremental rotations over a time series. In addition to signal processing and data conditioning procedures, algorithms for numerical quaternion-based integration of gyroscope data will be addressed, as well as accelerometer triangulation and integration to yield RV trajectory. Actual processed flight data will be presented to demonstrate the implementation of these methods.
Date: September 1, 2010
Creator: De Sapio, Vincent
Partner: UNT Libraries Government Documents Department

Control of a high beta maneuvering reentry vehicle using dynamic inversion.

Description: The design of flight control systems for high performance maneuvering reentry vehicles presents a significant challenge to the control systems designer. These vehicles typically have a much higher ballistic coefficient than crewed vehicles like as the Space Shuttle or proposed crew return vehicles such as the X-38. Moreover, the missions of high performance vehicles usually require a steeper reentry flight path angle, followed by a pull-out into level flight. These vehicles then must transit the entire atmosphere and robustly perform the maneuvers required for the mission. The vehicles must also be flown with small static margins in order to perform the required maneuvers, which can result in highly nonlinear aerodynamic characteristics that frequently transition from being aerodynamically stable to unstable as angle of attack increases. The control system design technique of dynamic inversion has been applied successfully to both high performance aircraft and low beta reentry vehicles. The objective of this study was to explore the application of this technique to high performance maneuvering reentry vehicles, including the basic derivation of the dynamic inversion technique, followed by the extension of that technique to the use of tabular trim aerodynamic models in the controller. The dynamic inversion equations are developed for high performance vehicles and augmented to allow the selection of a desired response for the control system. A six degree of freedom simulation is used to evaluate the performance of the dynamic inversion approach, and results for both nominal and off nominal aerodynamic characteristics are presented.
Date: May 1, 2005
Creator: Watts, Alfred Chapman
Partner: UNT Libraries Government Documents Department