NASA Scientific and Technical Aerospace Reports

space industry toward a broader base than currently exists under traditional aerospace norms. The NASA Jet Propulsion
Laboratory here will play a key role in advancing this overall new exploration strategy. JPL Center Director Charles Elachi
heads the venerable center that, among other things developed the Cassini spacecraft, fast approaching Saturn, and the Spirit
and Opportunity rovers now on Mars outperforming original expectations. While large aerospace companies will continue to
be vital in exploration, the rover development was buttressed by smaller, dynamic, more specialized Companies (AW&ST
Mar. 8, p. 28). JPL will continue to lead all Mars robotic missions and be heavily involved in new lunar robotic missions with
the Goddard Space Flight Center. Elachi brings 33 years of experience at JPL to his leadership position of this Pasadena,
Calif.-based 5,300-employee facility. The Lebanon-born engineer did his undergraduate work in physics and engineering in
Grenoble, France, and his master’s and doctorate in electrical sciences at California Institute of Technology. The Caltech/JPL
realm became a perfect fit. As an imaging radar expert, he helped map Earth and Venus, and he still heads the Cassini Titan
imaging radar team, among many other projects. He spoke at JPL to Aviation Week & Space Technology Senior Editor Craig
Covault about the importance of a combined human/robotics exploration program. Elachi addressed the growing number of
smaller companies involved in exploration technologies and the public’s role in the new strategy. His answers are condensed
here.
Author
Manned Mars Missions; Mars Roving Vehicles; Mars Exploration; NASA Space Programs; Aerospace Engineering
20040121130 Illinois Univ. at Urbana-Champaign, Urbana, IL, USA
Effects of Gravity-Assist Timing on Outer-Planet Missions Using Solar-Electric Propulsion
Woo, Byoungsam; Coverstone, Victoria L.; Cupples, Michael; [2004]; 10 pp.; In English; Astrodynamics Specialist
Conference, 18 Aug. 2004, Rhode Island, USA; Original contains black and white illustrations; Copyright; Avail: CASI; A02,
Hardcopy
Missions to the outer planets for spacecraft with a solar-electric propulsion system (SEPS) and that utilize a single Venus
gravity assist are investigated. The trajectories maximize the delivered mass to the target planet for a range of flight times. A
comparison of the trajectory characteristics (delivered mass, launch energy and onboard propulsive energy) is made for various
Venus gravity assist opportunities. Methods to estimate the delivered mass to the outer planets are developed.
Author
Solar Electric Propulsion; Gravitational Effects; Gas Giant Planets; Gravitation
92
SOLAR PHYSICS
Includes solar activity, solar flares, solar radiation and sunspots. For related information see 93 Space Radiation.
20040111034 European Space Agency, Greenbelt, MD, USA
Nearly Eight Years of SOHO Observations: Some Highlights
Brekke, P.; Fleck, B.; 8th Spacecraft Charging Technology Conference; March 2004; 15 pp.; In English; See also
20040111031; No Copyright; Avail: CASI; A03, Hardcopy
Since its launch on 2 December 1995, the Solar and Heliospheric Observatory (SOHO) has provided an unparalleled
breadth and depth of information about the Sun, from its interior, through the hot and dynamic atmosphere, and out to the solar
wind. SOHO has continued to revolutionize our understanding of the Sun with its 24 hour per day observations of our daylight
star. The main objectives of the SOHO mission was to study the structure and dynamics of the solar interior, the heating of
the solar corona, and the acceleration of the solar wind. Five years later, science teams from around the world have made great
strides toward answering these ‘big three’ questions. At the same time, SOHO’s easily accessible, spectacular data and basic
science results have captured the imagination of the space science community and the general public alike. This presentation
will summarize some of the scientific highlights and illustrate how SOHO is monitoring the energy output from the Sun and
how it acts as s watchdog for solar storms. It will also summarize some of the space weather effects on the SOHO spacecraft
itself.
Author
Solar Observatories; Soho Mission; Image Analysis; Sun
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