Goddard Space Flight Center, Greenbelt, Maryland 20771
ENGINEERING COLLOQUIUM
Monday, September 29, 2008 / 3:30 PM, Building 3 Auditorium
Ralph Lorenz
"Titan Unveiled"
ABSTRACT -- The Huygens probe (the landed element of the NASA-ESA-ASICassini-Huygens mission to Saturn and Titan) faced many challenges, not least being the large uncertainties in the characteristics of its target body when the mission was designed circa 1990 - before the World Wide Web! The probe would need to operate, some 7 years after launch (on a trajectory taking it past Venus!), for over 2 hours in an environment down to -200 deg C (70K). Heat shields, parachutes and instruments would all need to function. The mission marked an ambitious debut for Europe in planetary exploration.
As always, a mission to the unknown brings surprises. The images from the probe revealed a strikingly Earth-like landscape, with river channels and sand dunes. The penetrometer revealed a solid, but forgiving, surface texture (initially interpreted as crème brûlée!) and other data measured Titan's winds and gas composition. Although some aspects of the mission performance were anomalous (such as the unexpected spin behavior of the probe under its parachute, and the loss of one radio channel) some engineering data gave unanticipated insights, such as the reflection of the Huygens radio signal from the surface after landing.
This talk will describe how the Huygens probe was designed and constructed, how it got to Titan, what worked and what didn't, and some of what the probe found when it arrived.
SPEAKER -- Dr. Ralph Lorenz has been aiming at Saturn's moon Titan for nearly two decades. His Ph.D. dissertation topic (November, 1994) was Exploring the Surface of Titan, part of which involved designing and building a penetrometer instrument for the Huygens probe. Prior to that he gained a B.Eng. in Aerospace Systems Engineering and then worked 1990-1991 for the European Space Agency on the Huygens project team.
He spent 12 years at the Lunar and Planetary Laboratory at theUniversity of Arizona, analyzing Hubble images of Titan and modeling Titan surface and climate evolution as well as planning Cassini radar mapping. He also served on the science teams of the New Millenium DS-2 Mars Microprobe and Mars Polar Lander missions in 1998-1999.
Since 2006 he has been at the Johns Hopkins University Applied PhysicsLab in Laurel MD, continuing his Cassini work as well as leading the 2007 NASA Titan Flagship Mission Study, and more recently has been working with GSFC as Deputy PI on a Venus New Frontiers mission proposal.
He flies instrumented Frisbees, both to study their aerodynamics and to practice instrumentation of small devices. His results are found in the book Spinning Flight: Dynamics of Frisbees, Boomerangs, Samaras and Skipping Stones. Other books he has written or co-written include Space Systems Failures, Planetary Landers and Atmospheric Entry Probes, Lifing Titan's Veil, and Titan Unveiled.