Engineering topics

Andrews, Dana G.

Publications and source records attributed to Andrews, Dana G..

5 records

NASA NTRS1992

A space transportation system for early lunar exploration

This paper presents a Lunar Transportation System (LTS) based on existing technology and liberal use of existing or planned national and international space infrastructure. The objective of the studies described herein was to define a LTS capable of delivering and servicing a manned lunar outpost shortly after the turn of the century. Alternative approaches examined used derivatives of elements from the planned National Launch System or existing international assets to reduce development and launch costs. This study incorporates many design features determined by contracted NASA efforts to reduce nonrecurring and recurring costs for a LTS.

Andrews, Dana G.↗

NASA NTRS1992

Space transfer vehicles for an affordable lunar exploration program

The paper describes a lunar transportation system (LTS) based on a minimum cost approach to the lunar exploration scenario. A three-part exercise was conducted to minimize the cost and risk of lunar exploration, and the results of these optimization studies are presented. Particular consideration is given to the proposed concepts for the translunar injection stages, the common crew module of the LTS, the lander configuration, the LTS performance, and a concept of a long-range rover ('Rover First ') for discovering and mapping lunar resources for future utilization.

Andrews, Dana G.↗

NASA NTRS1990

A Personnel Launch System for safe and efficient manned operations

Several Conceptual designs for a simple, rugged Personnel Launch System (PLS) are presented. This system could transport people to and from Low Earth Orbit (LEO) starting in the late 1990's using a new modular Advanced Launch System (ALS) developed for the Space Exploration Initiative (SEI). The PLS is designed to be one element of a new space transportation architecture including heavy-lift cargo vehicles, lunar transfer vehicles, and multiple-role spcecraft such as the current Space Shuttle. The primary role of the PLS would be to deliver crews embarking on lunar or planetary missions to the Space Station, but it would also be used for earth-orbit sortie missions, space rescue missions, and some satellite servicing missions. The PLS design takes advantage of emerging electronic and structures technologies to offer a robust vehicle with autonomous operating and quick turnaround capabilities. Key features include an intact abort capability anywhere in the operating envelope, and elimination of all toxic propellants to streamline ground operations.

Petro, Andrew J.↗

NASA NTRS1990

Use of magnetic sails for advanced exploration missions

The magnetic sail, or magsail, is a field effect device which interacts with the ambient solar wind or interstellar medium over a considerable volume of space to generate drag and lift forces. Two theories describing the method of thrust generation are analyzed and data results are presented. The techniques for maintaining superconductor temperatures in interplanetary space are analyzed and low risk options presented. Comparisons are presented showing mission performance differences between currently proposed spacecraft using chemical and electric propulsion systems, and a Magsail propelled spacecraft capable of generating an average thrust of 250 Newtons at a radius of one A.U. The magsail also provides unique capabilities for interstellar missions, in that at relativistic speeds the magnetic field would ionize and deflect the interstellar medium producing a large drag force. This would make it an ideal brake for decelerating a spacecraft from relativistic speeds and then maneuvering within the target star system.

Andrews, Dana G.↗

NASA NTRS1989

Near-term nuclear space missions

This paper summarizes the current status of proposed NASA Human Exploration Missions (MEMs) presenting detail with respect to schedule and system features. Using the Lunar exploration and Mars exploration missions as design drivers, new vehicle elements have been configured and optimized to meet proposed mission requirements. Both conventional chemical propulsion and alternative vehicle designs incorporating advanced nuclear propulsion systems are included, and the total mass required in Low Earth Orbit (LEO) is compared for each propulsion system.

Andrews, Dana G.↗