On this day in engineering history, the U.S. Air Force
launched its first Aerobee-Hi sounding rocket (AF-55) from Holloman Air Force
Base near Alamogordo, New Mexico. Developed by the Aerojet
Engineering Corporation of Sacramento,
California, the suborbital vehicle
attained a height of 123 miles and carried a payload of 196 pounds. Between
1947 and 1985, the U.S.
military and the National Aeronautics and Space Administration (NASA) launched
more than 800 Aerobees. As America's
first high-altitude sounding rocket, the original Aerobee and its successors provided
low-cost access to space for short-duration experiments. They also helped
scientists study the near-earth environment and test both spacecraft components
and re-entry vehicles.
The Aerojet Engineering Corporation won the original
contract for a general-purpose, high-altitude rocket on May 17, 1946. Although
the United States
had used been using captured V-2s for military and scientific experiments,
these Nazi rockets were large and cumbersome. Originally, the Aerobee rocket
was patterned after the WAC Corporal, an Army research vehicle developed in
junction with the California Institute of Technology (CIT). The Aerobee rocket
used a solid-propellant rocket motor as a booster, but was also liquid-fueled
and spin-stabilized. Because initial acceleration was slow, the vehicles were
launched from high launch towers which could guide a rocket until the finds
took effect. The booster was jettisoned approximately 2.5 seconds into the
flight, but the nose cone with a telemetry transmitter and payload returned to
Earth via parachute.
On April 21, 1955, the U.S. Air Force launched the first of
its next generation Aerobee rockets. The Aerobee-Hi featured a longer
propellant tank, a more efficient rocket engine, and larger fins for improved
stability. Like its predecessor, however, the Aerobee-Hi required both a
liquid-fueled sustainer engine and a tall launch tower. Consequently, these
newest rockets were poorly suited for mass firings, the launch of many rockets
from a single location within a relatively short period of time. The Aerobee-Hi
was also unsuitable for launches in remote locations without towers, or from
aboard ships at sea. Nevertheless, the launch of the first Aerobee-Hi from
Holloman AFB marked another milestone in America's space and military
programs.
Resources:
http://history.nasa.gov/Timeline/1955-57.html
http://www.friends-partners.org/oldfriends/mwade/lvfam/souckets.htm
http://www.designation-systems.net/dusrm/n-2.html
http://en.wikipedia.org/wiki/Aerojet
Image Credit:
White Sands Missile Range Museum
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