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Goddard Space Flight Center, Greenbelt, Maryland 20771

ENGINEERING COLLOQUIUM with Goddard Safety Week

Monday, April 6, 2009 /
Building 3 Auditorium

photo of damaged NOAA N-Prime satellite

Ralph Lorenz

"Space Systems Failures"

ABSTRACT -- Space projects provide fascinating engineering challenges, but are terribly unforgiving. One small mistake or unanticipated effect can ruin a project worth hundreds of millions of dollars.

The mechanisms of spacecraft and launcher failures vary from the subtle to the absurd. Esoteric materials effects and the space environment have caused surprises, and the ever-growing complexity of software introduces a myriad of system states whose interaction with the real world becomes impossible to test. On the other hand, satellites have been damaged by such mundane hazards as water sprinklers, technicians who tripped on their lab coats, and missing bolts on ground handling fixtures.

Perversely, even measures to improve reliability can introduce new failure modes - 'heritage' has led to disaster when carelessly applied, and improper testing has broken satellite structures.

This talk will survey the hard-won lessons from a range of spacecraft failures

SPEAKER -- Ralph Lorenz is a co-author of the book Space Systems Failures, a compilation of many of the interesting, instructive and in some cases astounding problems that have occurred on spacecraft.

Lorenz has a B.Eng. in Aerospace Systems Engineering from the University of Southampton in the UK and a Ph.D. in Physics in 1994 from the University of Kent at Canterbury. He flew his first space hardware in 1990 on UoSAT-E (which failed) and he served on the science teams of the NASA New Millenium DS-2 Mars Microprobes and Mars Polar Lander missions (which all failed). He had better luck with the ESA Huygens probe to Titan, on which he worked at the European Space Agency (1990-1991), University of Kent, and the University of Arizona (1994-2006). He is now on the Senior Professional Staff at the Johns Hopkins University Applied Physics Laboratory in Laurel, MD, where he works on Titan, Venus, planetary climate, nonequilibrium thermodynamics, aerospace vehicles and radar. He is the recipient of three NASA Group Achievement awards and his other books include Spinning Flight, Planetary Landers and Entry Probes, and Titan Unveiled, and he has authored well as over 150 publications in refereed journals.




Engineering Colloquium home page: https://ecolloq.gsfc.nasa.gov