ODU'S NOOR PUBLISHES ARTICLE IN AEROSPACE AMERICA MAGAZINE

Mobile atmospheric platforms that resemble hot-air balloons with gondolas could allow NASA to take close looks at Saturn's largest moon-Titan-and the planet Venus during the next quarter century, according to an article co-authored by Old Dominion University aerospace engineer Ahmed K. Noor and published in the June 2007 edition of Aerospace America magazine.

The article is titled, "Platforms for Discovery: Exploring Titan and Venus."

Noor, the William E. Lobeck Professor of Aerospace Engineering and director of ODU's Center for Advanced Engineering Environments, wrote the article together with James A. Cutts, chief technologist in the Solar Exploration Program Directorate at Jet Propulsion Laboratory, and Tibor S. Balint, senior engineer with the Planetary and Lunar Missions Concept Group at Jet Propulsion Laboratory.

Explorations of Titan and Venus were selected as two of the flagship missions in the 2006 NASA Solar System Exploration Roadmap. The authors explore the sort of probes these missions could utilize to collect surface and near-surface samples, measurements and images. The solution they favor is a mobile atmospheric platform, together with a high-orbiting data relay satellite.

For the Titan probe, the platform and relay orbiter would be packed separately and delivered over about seven years to their destination. They would travel by means of a conventional rocket and a solar electric propulsion system before the platform package is hurtled into Titan's atmosphere and the orbiter package just skims the atmosphere to settle into its orbit.

The authors propose some sensing duties for the orbiter, but, more importantly, it would serve, as its name implies, to relay data from the platform to Earth. The orbiter's much larger antenna would allow the transmission of more scientific data than would be possible from the platform alone.

For most of its lifespan-which remarkably could be decades-the platform would float thousands of feet above Titan, but close enough to not be hampered by atmospheric haze and interference. Occasionally, it would dip to the surface to take measurements and collect samples for testing. On the gondola would be 100 pounds of instruments, including cameras and spectrometers.

The balloon system, known as Montgolfiere, could operate efficiently in Titan's high air density and low temperature-about minus 300 degrees Fahenheit-with a long-lived radioisotope heat source, the authors state.

Venus, which is closer to the sun than Earth and much warmer, presents different challenges for NASA, but probes of that planet also could be handled by some sort of air mobility platform, according to the article. The authors contend that a sensor device that floats above the surface of the planet has advantages over a surface rover.

If NASA's target schedule holds, the Titan probe would be launched in 2020 and arrive at Titan about 2028 to begin a five-year mission. The Venus probe would be launched more than five years after the Titan rocket, but would need only 180 days to get to its target, and therefore would begin its mission first.

"A single atmospheric platform complemented with an orbiter proves a formidable exploration capability," the authors conclude. "In the next two decades we can expect such platforms to assume a key role in the exploration of Venus and Titan."