Obituary: Karl Henize

Karl G. Henize, astrophysicist, astronaut: born Cincinnati 17 October 1926; Professor of Astronomy, Northwestern University, Illinois 1959-67; scientist- astronaut, National Aeronautics and Space Administration 1967-86, Senior Scientist, Space Sciences Branch, Johnson Space Center, Houston 1986- 93; married; died Mount Everest 5 October 1993.

KARL HENIZE, the astronaut and Nasa scientist, dedicated his life to the exploration of the universe. By the time he joined Nasa as a scientist-astronaut in 1967, he was already a well-respected figure in the field of astrophysics.

His career began in 1948 at the University of Michigan Observatory. While stationed in Bloemfontein, South Africa, he conducted a survey of the southern sky, during which he discovered a rare exploding star or nova in a neighbouring galaxy. On gaining his doctorate in astronomy in 1954, he moved to Mount Wilson Observatory in California, and then to the Smithsonian Astrophysical Observatory where he was responsible for setting up a network of global photographic stations for tracking the first satellites.

From 1959 until his selection by Nasa, Henize continued his research on stars and planetary nebulae as Professor of Astronomy at Northwestern University, in Illinois. Keen to take advantage of the viewing opportunities offered by carrying instruments above the atmosphere, he became principal investigator for an ultraviolet experiment on the final manned Gemini flights.

At the age of 40, he joined Nasa as a scientist-astronaut. After training as a jet pilot, he served on the support crews for Apollo 15 and the three Skylab missions. Throughout the 1970s he was closely involved in studies of how to fly ultraviolet telescopes on manned spacecraft.

His opportunity to fly in space finally came with the Spacelab-2 mission in 1985. Now 58 years old, he was the oldest astronaut to have travelled in space up to that time. His ambition to operate an orbital observatory was almost frustrated as the first launch attempt was aborted just three seconds before lift-off. Then, on 29 July, one of Challenger's main engines shut down prematurely and a second threatened to follow. The shuttle struggled into orbit 70 miles lower than planned.

Henize's main role was to operate a new instrument-pointing system designed to aim four telescopes at their targets with great accuracy. Unfortunately, the equipment proved a big headache, causing Henize and his colleagues to waste a long time on remedial action before it eventually operated properly and returned 'sensational results'. Challenger returned to California after 188 hours in space.

Six months later Challenger exploded during launch and, aware that the programme would be grounded for several years, Henize resigned from the astronaut office. As Senior Scientist in the Space Physics Branch at Johnson Space Center in Houston, he concentrated on the problem of space debris alongside his beloved stellar research.

An experienced mountaineer, Henize climbed Mount Rainier in 1991. At the time of his death he had taken leave from Nasa to participate in an expedition to Mount Everest with a British research group sponsored by the Guinness Foundation. He was hoping to test a Nasa device for measuring radiation, but he was taken ill with respiratory problems and died at the base camp. He was buried on the mountain.

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