A Solar Electrical Propulsion Lunar Exploration Architecture Evaluation

Paper number

IAC-06-C4.4.02

Author

Mr. William Kosmann, Orbital Sciences Corporation, United States

Year

2006

Abstract

From 2004 September 1 until 2005 August 31, Orbital Sciences conducted a NASA-funded Concept Exploration and Refinement (CER) study, designed to make recommendations to NASA on how to return men (and women) to the Moon, then onto Mars.  Once that study was completed, an un-funded in-house study was performed to evaluate the effect of substituting an in-space Solar Electric Propulsion (SEP) system for a chemical in-space propulsion system.

A Space Transportation System (STS)-based all chemical Lunar Transportation System was designed. The launch vehicle used 2 five segment SRBs, and 4 SSMEs using Hydrogen and Oxygen as propellents.  The SEM used three MB60 LOX/Hydrogen rocket engines.  The Lunar Landers used four new RD160 LOX/Methane rocket engines.  The optimized transportation system could deliver 140 MT to Low Earth Orbit (100 n.mi. altitude, 28.5 degree inclination), 85,000 lbm. of payload to Low Lunar Orbit, and 35,000 lbm. of payload to the Lunar Surface, using only 1 launch.

It was recommended to NASA that the fundamental objective of the Lunar Surface Activity should be to construct and operate a Lunar Base with Permanently Manned Capability (PMC).  A time ordered functionality analysis was completed, to determine what functionality was needed, and in what order, to construct and operate the Lunar Base.  Each functionality was translated into design requirements.  Then a design was created, complete with mass and volume estimates.  The collection of such designs, along with needed propellents, human consumables and spares for base operation were manifested onto a series of launches, from 2015 to 2025.

Once the NASA-funded study was completed, an architectural level trade study was conducted, to determine the effect of changing the SEM Liquid Oxygen/Liquid Hydrogen propulsion system to a SEP SEM.  Mission level requirements such as 5 round trip lifetime were formulated.  A conceptual design approach, consisting of using four 150 Kwe Hall Effect thrusters for propulsion, Xenon as the propellent, and a refractive solar collecting Stretched Lens Array (SLA) as the electric power source was defined.  The conceptual design of a SEP SEM was completed.  The performance of the SEP SEM, in terms of mass delivered to LLO, was determined, and the cost of both developing the new technology and manufacturing SEP SEMs was estimated.  The same set of designs, propellents, consumables, and spares were manifested on the SEP SEMs.  Finally, the cost of the all chemical approach versus the SEP SEM approach was estimated, and the architectural advantages/disadvantages quantified.

Abstract document

IAC-06-C4.4.02.pdf

Manuscript document

IAC-06-C4.4.02.pdf (🔒 authorized access only).

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