Also called: Able 1 - 1st to the Moon
Spacecraft n°: 17
USA satellite n°: 13
||F00022 / 58F09|
||17 Aug 1958 - 12:18 UT|
||Thor-DM18 Able-1 (#127)|
||Lunar orbiter |
|| Able 1 |
||17 Aug 1958 ||
Pioneer 0 - Credit: NASA
First Thor-Able 1 launch.
Pioneer 0 was the world's first attempt to launch a probe out of Earth's orbit.
||Space Technology Laboratories (TRW)|
|Mass at launch
||2 glass fiber cones jointed at their base by a cylinder|
|| Length: 0.8 m - Max. diameter: 0.7 m|
||camera (oscillating mirror scanner), radiation counter, search coil magnetometer, microphone
||8 vernier rockets (seperable), TX-8 (Falcon) orbit insertion motor|
|| Spin stabilized|
- Pioneer 0 consisted of a thin cylindrical midsection with a squat truncated cone frustum
on each side. The cylinder was 74 cm in diameter and the height from
the top of one cone to the top of the opposite cone was 76 cm. Along
the axis of the spacecraft and protruding from the end of the lower
cone was an 11 kg solid propellant injection rocket and rocket case,
which formed the main structural member of the spacecraft. Eight small
low-thrust solid propellant velocity adjustment rockets were mounted on
the end of the upper cone in a ring assembly which could be jettisoned
after use. A magnetic dipole antenna also protruded from the top of the
upper cone. The shell was composed of laminated plastic and was painted
with a pattern of dark and light stripes to help regulate temperature.
- The scientific instrument package had a mass of 11.3 kg and
consisted of an image scanning infrared television system to study the
Moon's surface, a diaphragm/microphone assembly to detect
micrometeorites, a magnetometer, and temperature-variable resistors to
record spacecraft internal conditions. The spacecraft was powered by
nickel-cadmium batteries for ignition of the rockets, silver cell
batteries for the television system, and mercury batteries for the
remaining circuits. Radio transmission was at on 108.06 MHz through an
electric dipole antenna for telemetry and doppler information and a
magnetic dipole antenna for the television system. Ground commands were
received through the electric dipole antenna at 115 MHz. The spacecraft
was to be spin stabilized at 1.8 rps, the spin direction approximately
perpendicular to the geomagnetic meridian planes of the trajectory.
- Scientific Instruments:
2) micrometeoroid impact detector
3) temperature sensors
4) infrared camera
The Pioneer 0 (also known as Thor-Able 1) probe was designed to go into orbit around the Moon and carried a TV camera and other instruments as part of the first International Geophysical Year (IGY) science payload. It was the first attempt by the USA at a lunar mission, and the first attempted launch beyond Earth orbit by any country. Propelled by the U. S. 's desire to beat the Soviet Union to the moon, each of the three vehicles was designed to go into orbit around the Moon and photograph the Moon's surface. None of the vehicles accomplished its intended mission, although some useful data was returned.
- The first vehicle, Pioneer 0, was the first of two U.S. Air Force (USAF) launches to the Moon. The Able 1 spacecraft, a squat, conical, fiberglass structure, carried a crude
infrared TV scanner. This device was a simple thermal radiation device comprising a small parabolic mirror for focusing reflected light from the lunar surface onto a cell that would transmit voltage proportional to the light it received. Engineers painted a pattern of dark and light stripes on the spacecraft’s outer surface to regulate internal temperature. The
spacecraft was also disinfected with ultraviolet light prior to launch. According to the ideal mission profile, Able 1 was designed to reach the Moon 2.6 days after launch; then the TX-8-6 solid propellant motor would fire to
insert the vehicle into orbit around the Moon. Altitude would have been 29,000 kilometers with an optimal lifetime of about two weeks.
- The actual mission, however, lasted only 77 seconds after the Thor first stage exploded at 15.2 kilometers altitude. The upper stages hit the Atlantic about 123 seconds later. Investigators concluded that the accident had due to a propellant tank rupture caused by the explosion of a turbopump.
- Following this attempt, Pioneer 1 and Pioneer 2 were turned over to United States' newly formed National Aeronautics and Space Administration (NASA). Pioneer 1 was the first spacecraft launched by NASA. A programming error in the Pioneer 1 launch vehicle upper stage resulted in Pioneer 1 being given insufficient velocity to escape the Earth's gravitational field. Although lunar orbit was not achieved, it did reach an altitude of 113854 km above Earth and provided data on the extent of the Earth's radiation belts. The vehicle re-entered over the Pacific Ocean 2 days later. Pioneer 2 also suffered a launch vehicle failure and re-entered the Earth's atmosphere 6 hours and 52 minutes after launch (it did not return any significant data).
Ref.: #6, #7, #8, #14, #98, #102 - update: 14.07.08