The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity

OAO (Orbiting Astronomical Observatory)
A series of large NASA astronomical satellites, launched
from Cape Canaveral, of which two, OAO-2 and OAO-3,
were highly successful, and two, OAO-1 and OAO-B, were
failures. OAO-1 stopped working on April 10, 1966, two
days after launch, when its primary battery overheated. Its
replacement, known as OAO-B, was also lost, immediately
after launch on November 30, 1970, when the Centaur
nose shroud in which it was enclosed failed to open and
the spacecraft tumbled back into the atmosphere.
OAO-2 made 22,560 observations over an operational
lifetime of more than four years of objects both within the
Solar System and beyond, and discovered a hydrogen
cloud around Comet Tago-Sato-Kosaka and ultraviolet
(UV) emissions from Uranus. Its instruments included
seven UV telescopes and four large-aperture television
cameras.
OAO-3 was renamed the Copernicus Observatory
after launch in honor of the 500th anniversary of the
birth of the Polish astronomer Nicolaus Copernicus
(1473–1543). It involved a collaboration between NASA
and the Science and Engineering Research Council of the
United Kingdom. The main experiment onboard was the
Princeton University UV telescope, but Copernicus also
carried an X-ray astronomy experiment for use in the 0.5
to 10 keV range developed by the Mullard Space Science
Laboratory of University College London. It operated
until late 1980. (See table, “OAO Missions.”)
Oberth, Hermann Julius (1894–1989)
A German space pioneer, born in the Transylvanian town
of Hermannstadt. Along with Konstantin Tsiolkovsky
and Robert Goddard, he is considered to be one of the
founding fathers of modern rocketry and astronautics.
Oberth’s interest was sparked at the age of 11 by Jules
O
OAO Missions
301
Verne’s From the Earth to the Moon, a book that he later
recalled he read “at least five or six times and, finally, knew
by heart.” By the age of 14, he had already envisioned a
“recoil rocket” that could propel itself through a vacuum
by expelling exhaust gases from a liquid fuel. He realized
early on, too, that staging was the key to accelerating rockets
to high speed. In 1912, Oberth enrolled in the University
of Munich to study medicine and later served with a
medical unit in World War I. During the war years, however,
he realized that his future lay in a different direction,
and upon returning to the University of Munich, he took
up physics. In 1922, his doctoral thesis, in which he
described a liquid-propellant rocket, was rejected as being
too unorthodox. However, Oberth published it privately
the following year as a 92-page pamphlet entitled Die
Rakete zu den Planetenräumen 222 (The Rocket into Planetary
Space), which set forth the basic principles of spaceflight.
A much-expanded version, entitled Ways to Spaceflight,
appeared in 1929 to international acclaim and served to
inspire many subsequent spaceflight pioneers.
Unlike Robert Goddard, Oberth was not slow in seeking
publicity for his work. In the same year his enlarged
treatise went on sale, he became technical advisor for the
film Frau Im Mond (Woman in the Moon), and was commissioned
to build a rocket that would be sent up as a
publicity stunt. Aided by the young Werner von Braun,
Oberth managed to build and statically test a small rocket
engine—a risky laboratory exercise in which he lost
the sight in his left eye. But when it became clear that
the rocket would not be ready to launch in time for the
movie’s release, the project was abandoned, and, shortly
after, Oberth returned to teaching in Transylvania.
Following World War II, Oberth came to the United
States to work again with his former student, von Braun,
at the Army’s Ballistic Missile Agency. However, three
Spacecraft Date
Launch
Vehicle Orbit Mass (kg)
OAO-1 Apr. 8, 1966 Atlas-Agena D 783 × 793 km × 35.0° 1,774
OAO-2 Dec. 7, 1968 Atlas IIIC 749 × 758 km × 35.0° 2,012
OAO-B Nov. 30, 1970 Atlas IIIC Failed to reach orbit 2,121
OAO-3 Aug. 21, 1972 Atlas IIIC 713 × 724 km × 35.0° 2,204