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

312 Osumi
OSO (Orbiting Solar Observatory)
(continued from page 308)
extrasolar sources at ultraviolet, X-ray, and gamma-ray
wavelengths. OSO-1 was the first satellite to carry
onboard tape recorders for data storage and instruments
that could be accurately pointed. The two-section observatory
was stabilized because the lower section, the
“wheel,” spun as a gyroscope at a near constant 30 rpm.
The upper fan-shaped section, the “sail,” was joined to
the wheel by a connecting shaft and remained pointed at
the Sun during the OSO daytime. Experiments in the
wheel scanned the Sun every two seconds and those in
the sail pointed continuously at the Sun. (See table,
“OSO Missions,” on page 308.)
Osumi
The first Japanese satellite. It comprised the fourth stage
of a Lambda 4S launcher and transmitted in orbit for
about 17 hours.
Launch
Date: February 11, 1970
Vehicle: Lambda 4S
Site: Kagoshima
Mass: 24 kg
Orbit: 340 × 5,140 km × 31° orbit
overshoot boundary
The upper side of a reentry corridor, marking the region
above which the atmospheric density is so low that the
spacecraft cannot decelerate sufficiently and instead skips
back into space.
OWL (Orbiting Wide-angle Light-collectors)
A proposed space mission to study cosmic rays of the
highest energy. These particles are so rare that only a few
have ever been seen; they may have as much energy as a
fast-thrown baseball, and it is not even known whether
they are protons, heavy nuclei, or photons. OWL will
employ Earth as a particle detector by using two highaltitude
spacecraft to obtain a binocular view of the light
flashes produced by super-energetic cosmic rays interacting
with the atmosphere. It has been identified in
NASA’s Office of Space Science Strategic Plan as a potential
mission beyond 2007, but it remains in the very early
concept definition phase.
oxidizer
A substance that supports the combustion reaction of a
fuel or propellant.
OSO An engineer checks two spectrometers on OSO 8.
Hughes Aircraft
oxidizer-to-fuel ratio
The ratio between the mass of oxidizer burned per mass
of fuel burned (liquid engines only).
oxygen, regenerative
A spacecraft’s oxygen supply that is recycled for repeated
use after being cleaned of carbon dioxide. This is accomplished
by human-made chemical devices or (in theory)
by plant life onboard. The latter is suggested for interplanetary
missions, which will be of long duration.
oxygen-hydrocarbon engine
A rocket engine that operates on a propellant of liquid
oxygen as oxidizer and a hydrocarbon fuel, such as the
propellant derivatives.