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

oll
The motion of a spacecraft about its longitudinal, or
nose-tail, axis.
Romb
Subsatellites, released by Soviet Taifun spacecraft, to
enable the calibration of air and space defense radars.
Their name means “rhombus.”
Roosa, Stuart A. (1933–1994)
An American astronaut who orbited the moon as Apollo
14 Command Module (CM) pilot in 1971 while crewmates
Alan Shepard and Edgar Mitchell explored the surface.
Roosa received a B.S. in aeronautical engineering
from the University of Colorado, under the U.S. Air
Force Institute of Technology Program. He served on
active duty in the Air Force from 1953 to 1976, retiring as
a colonel. Roosa was one of 19 astronauts selected by
NASA in April 1966 and made the one spaceflight, during
which he orbited the Moon alone for 35 hours. Roosa
retired from NASA and the Air Force in 1976 and subsequently
served in managerial positions with several companies.
RORSAT (Radar Ocean Reconnaissance Satellite)
Soviet naval reconnaissance satellites often launched to
coincide with major NATO and American Navy maneuvers.
A characteristic feature of RORSATs was their large
radar antennas used to bounce signals off the ocean in
order to locate ships. The strength of the signals required
for this to work effectively, combined with the relatively
backward state of electronics technology in the Eastern
bloc, forced Soviet designers to adopt a radical solution—
the use of a small nuclear reactor to power the RORSAT
radar. Although prototype RORSATs in the mid-1960s
flew with only chemical batteries, their operational counterparts,
beginning in the 1970s, carried reactors. This
introduced a serious risk of contamination, because all
the RORSATs reentered after a few weeks or months in
orbit. To counter the problem, each RORSAT consisted
of three major components: the payload and propulsion
section, the reactor, and a disposal stage used to lift the
reactor into a higher orbit, with an altitude of 900 to
1,000 km, at the end of the mission. Thus, while the main
spacecraft decayed, the reactor continued to circle the
Earth. Unfortunately, the lifetime of an object at this altitude
is about 600 years, whereas uranium-235 and -238
have a half-life of more than one billion years. This means
there is at present, in 1,000 km ×65°orbits, about 940 kg
of highly enriched uranium and a further 15 tons of other
radioactive material including tens of thousands of
droplets, 0.6 to 2 cm in diameter, which are the remains of
the liquid sodium-potassium used to cool the RORSAT
Rosen, Milton W. 349
reactors. There have also been accidents—the worst of
them on January 24, 1978, when a RORSAT malfunctioned
and crashed within Canada’s Northwest Territory,
showering radioactive debris onto the Great Slave Lake
and surrounding region.
Size: 1.3 m (diameter) × 10 m (length)
Satellite mass
Total: 3,800 kg
Reactor +disposal stage: 1,250 kg
Reactor
Fuel: highly enriched (90%) uranium-235
Fuel mass: 31 kg
No. of elements: 7
Casing: beryllium
ROSAT (Roentgen Satellite)
German-American-British X-ray and ultraviolet astronomy
satellite, named for Wilhelm Roentgen (1845–1923),
who discovered X-rays; it operated for almost nine years.
The first six months of the mission were dedicated to an
all-sky survey in X-rays (0.1 to 2.5 keV) and ultraviolet
(62 to 206 eV) using an imaging telescope with a sensitivity
about 1,000 times greater than that achievable
with the instruments on Uhuru. During the subsequent
pointed phase of its mission, ROSAT made deep observations
of a wide variety of objects. Its operation ended
on February 12, 1999.
Launch
Date: June 1, 1990
Vehicle: Delta 6925
Site: Cape Canaveral
Orbit: 539 × 554 km × 53.0°
Mass: 2,426 kg
Rosen, Milton W. (1915–)
A key figure in the development of the Viking rocket and
Vanguard programs. Rosen trained as an electrical engineer
and joined the staff of the Naval Research Laboratory
in 1940, where he worked on guidance systems for missiles
during World War II. From 1947 to 1955, he was in
charge of Viking rocket development and subsequently
was technical director of Project Vanguard, until he joined
NASA in October 1958 as director of launch vehicles and
propulsion in the Office of Manned Space Flight. In
1963, he became senior scientist in NASA’s Office of the
Deputy Associate Administrator for Defense Affairs and
was later appointed deputy associate administrator for
space science (engineering). In 1974, Rosen retired from
NASA to become executive secretary of the National
Academy of Science’s Space Science Board. 248