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

316 parking orbit
rifled barrel with a 6-m-long smoothbore extension. After
65 shells had been fired, each of progressively larger caliber
to allow for wear, the barrel was rebored to a caliber
of 240-mm. The German goal of their great cannon was
not to destroy the French capital—it was far too inaccurate
a device for that (although it killed 256)—but to erode
the morale of the Parisians. A similar giant gun with the
same objective, the V-3, was built during World War II.
Technologically, the Paris Gun can be seen as the first
serious attempt to build a launch system with the capability
of a space cannon.
parking orbit
An intermediate, waiting orbit adopted by a spacecraft
between two phases of a mission.
Parus
A network of military satellites that, for a quarter of a
century, has provided navigational information and
store-dump radio communications for Russian/Soviet
naval forces and ballistic missile submarines. Being the
operational successor to Tsyklon, Parus is also known as
Tsyklon-B. Flight trials of the new satellites began in
1974, and the system was accepted into military service in
1976. From 1974 to the present, there have been about 90
launches in the series, all by Cosmos-3M rockets from
Plesetsk, into roughly circular orbits with an altitude of
about 1,000 km and an inclination of 83°.
passive satellite
A satellite that simply reflects light or radio waves transmitted
from one ground terminal to another without
amplification or retransmission. An example is the Echo
series of orbiting balloons.
Pathfinder
See Mars Pathfinder.
Patrick Air Force Base
A U.S. Air Force base located at the south end of Cape
Canaveral, 19 km southeast of Cocoa, which is home to
the 45th Space Wing of the Air Force Space Command.
Patrick AFB operates the Cape Canaveral Air Force Station,
from which many military and nonmilitary launches
take place. The base is named after Major General Mason
M. Patrick, chief of the Army Air Service (1921–1926) and
chief of the Army Air Corps (1926–1927), and was established
following the transfer of control of the Banana
River Air Station, set up in 1940 to support Atlantic coastline
defense, from the Navy to the Air Force.
Paulet, Pedro E.
A Peruvian chemical engineer reputed to have conducted
experiments in Paris, beginning in 1895, on a rocket
engine made of vanadium steel that burned a combination
of nitrogen peroxide and gasoline. If true, this
would credit Paulet as the designer of the first liquidfueled
rocket. The engine was described as weighing
about 5 lb and using spark gap ignition of the fuels
within a combustion chamber. It was said to have been
capable of producing a 200-lb thrust at 300 sparks per
minute. Paulet claimed that his rocket engine could burn
continuously for as much as one hour without suffering
any ill effects. However, news of what may have been a
groundbreaking advance in rocketry did not surface until
October 27, 1927, when a letter from Paulet appeared in
an issue of the Peruvian publication El Comercio, in
which he claimed legal ownership of his earlier rocket
engine design. Recognizing that rocketry was beginning
to boom in Europe, Paulet sought witnesses to help verify
the work he said he had done years earlier. The letter
was circulated across the world by a Russian named
Alexander Scherschevsky in summary form. Had Paulet’s
work been authenticated, he would today be considered
the undisputed father of liquid propellant rocketry. As it
is, that title is more commonly attributed to Robert
Goddard.
PAW ascent
“Powered all the way” ascent: one that follows the shortest
distance between Earth and a point in Earth orbit.
PAW ascents consume the most fuel and are not considered
feasible for orbits higher than 230 km.
payload
The load carried by an aircraft or rocket over and above
what is necessary for the operation of the vehicle during
its flight.
Payload Assist Module (PAM)
A solid motor developed for the Space Shuttle program.
Its purpose is to lift a satellite from the parking orbit into
which it is placed by the Shuttle to a higher, designated
orbit from which the spacecraft will actually operate. A
special PAM, known as PAM-D, was adapted for use with
Delta launch vehicles.
payload integration
The process of bringing together individual experiments,
support equipment, and software into a single payload in
which all interfaces are compatible and whose operation
has been fully checked out.
payload ratio
The ratio of the mass of useful payload of a rocketpropelled
vehicle to the total launch mass of the vehicle.
See rocket equation.