SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 44, ISSUE 10 - MAY 19, 2006

12 ASTRONAUTICS (GENERAL)
Includes general research topics related to space flight and manned and unmanned space vehicles, platforms or objects launched into, or assembled in, outer space; and related components and equipment.

Also includes manufacturing and maintenance of such vehicles or platforms.

For specific topics in astronautics see categories 13 through 20.

For extraterrestrial exploration see 91 Lunar and Planetary Science and Exploration.

20060012174 NASA Glenn Research Center, Cleveland, OH, USA

Solar Electric Propulsion for Primitive Body Science Missions

Witzberger, Kevin E.; March 2006; 28 pp.; In English; 53rd Propulsion Meeting (JANNAF Space Propulsion Meeting), 5-8 Dec. 2005, Monterey, CA, USA; Original contains color and black and white illustrations Contract(s)/Grant(s): WBS 620-02-01-1-03-02 Report No.(s): NASA/TM-2006-214236; E-15482; No Copyright; Avail.: CASI: A03, Hardcopy

This paper describes work that assesses the performance of solar electric propulsion (SEP) for three different primitive body science missions: 1) Comet Rendezvous 2) Comet Surface Sample Return (CSSR), and 3) a Trojan asteroid/Centaur object Reconnaissance Flyby. Each of these missions launches from Earth between 2010 and 2016. Beginning-of-life (BOL) solar array power (referenced at 1 A.U.) varies from 10 to 18 kW. Launch vehicle selections range from a Delta II to a Delta IV medium-class. The primary figure of merit (FOM) is net delivered mass (NDM). This analysis considers the effects of imposing various mission constraints on the Comet Rendezvous and CSSR missions. Specifically, the Comet Rendezvous mission analysis examines an arrival date constraint with a launch year variation, whereas the CSSR mission analysis investigates an Earth entry velocity constraint commensurate with past and current missions. Additionally, the CSSR mission analysis establishes NASA's New Frontiers (NF) Design Reference Mission (DRM) in order to evaluate current and future SEP technologies. The results show that transfer times range from 5 to 9 years (depending on the mission). More importantly, the spacecraft's primary propulsion system performs an average 5-degree plane change on the return leg of the CSSR mission to meet the previously mentioned Earth entry velocity constraint. Consequently, these analyses show that SEP technologies that have higher thrust-to-power ratios can: 1) reduce flight time, and 2) change planes more efficiently. Author

Solar Electric Propulsion; Flyby Missions; Sample Return Missions; Atmospheric Entry; Launch Vehicles; Centaur Launch Vehicle; Flight Time

Source: NASA