[iii] To explore the upper atmosphere man first used kites, then balloons, then aircraft. For many years balloons were the most effective means of obtaining direct measurements in the stratosphere. But they were limited in altitude, so scientists had to probe the ionosphere and other portions of the atmosphere beyond the stratosphere by indirect means.

Sounding rockets provided the first means to carry instruments to the outermost reaches of the Earth's atmosphere. They were, indeed, our first space vehicles. As Mr. Corliss relates in this history, in this day of satellites and deep space probes, sounding rockets remain as important to space science as ever, furnishing our most powerful means for obtaining vertical profiles of atmospheric properties. NASA continues to depend on sounding rockets for research in aeronomy, meteorology, ionospheric physics, exploratory astronomy, and other disciplines.

Those of us who were privileged to take part in the early upper atmosphere rocket program, who recall with considerable nostalgia watching V-2s, Vikings, and Wac Corporals carry our instruments into the sky, are pleased to see some of the record of those pioneering days preserved. Out of that early work has come the more flexible, more capable sounding rockets of today, and a facility in their use that permits a broad involvement of university, Government, and other researchers. As Mr. Corliss suggests, this most valuable feature is a major reason why sounding rocket research continues to flourish.

HOMER E. NEWELL

Associate Administrator

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