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

216 Joule
Joule
An X-ray observatory that would obtain detailed energy
spectra from extreme environments in the universe ranging
from the million-degree coronas of nearby stars to the
supermassive black holes at the cores of distant galaxies.
Joule was selected by NASA for study as an SMEX
(Small Explorer) mission and remains in the early design
stage.
JPL (Jet Propulsion Laboratory)
An establishment in Pasadena, California, operated for
NASA by the California Institute of Technology. It
plays a major role in the development, operation, and
tracking of American interplanetary space probes. JPL
is responsible for the Deep Space Network and has
managed the Viking, Voyager, Magellan, Galileo, Ulysses,
and Mars Pathfinder missions. JPL was founded by
Theodore von Karman and Frank Malina in 1944 and
was a focal point of American rocket development in
World War II. In 1958, it became part of NASA and
provided America’s first successful Earth satellite,
170, 315
Explorer 1.
JPL (Jet Propulsion Laboratory) At Guggenheim Aeronautical
Laboratory, Caltech (CALCIT) students and coworkers fired
their first liquid-propellant rocket on October 31, 1936.
NASA/JPL
Jumpseat
American military intelligence satellites launched in the
1970s and early 1980s into Molniya-type orbits. These
orbits are very similar to those of SDS (Satellite Data System)
classified communications satellites, and identification
of a launch in either series as SDS or Jumpseat may
differ.
Juno
One of the most significant launch vehicles in the history
of spaceflight. Juno formed a crucial link between American
Cold War military missiles and the rockets that first
launched human beings toward another world.
Juno I
A modified Redstone missile specifically designed to
carry lightweight payloads into LEO (low Earth orbit).
Otherwise identical to the three-stage Jupiter C, it had a
fourth stage that remained attached to the satellite in
orbit. To reflect its nonmilitary role, its name was officially
changed from Jupiter to Juno at the request of JPL
(Jet Propulsion Laboratory) chief William Pickering on
November 18, 1957. It later became Juno I to distinguish
it from the Juno II. A Juno I successfully launched
Explorer 1, the first American satellite, on January 31,
1958, and in the same year two more placed Explorer 3
and Explorer 4 into orbit.
Juno II
A marriage of a Jupiter first stage and Juno I upper stages
capable of delivering a 45-kg payload into LEO. The
Juno name was also applied to the next generation of
space launch vehicles designed by the Army Ballistic
Missile Agency (ABMA), including a proposed Juno V
super-booster. Eventually, the Juno program was transferred
to NASA and renamed Saturn. Thus, the pioneering
work of the ABMA, culminating in the successful
use of Juno I and Juno II, led directly to the development
of the rockets that would carry astronauts to the
Moon.
Jupiter
See article, pages 117–118.