Pioneer 1

Launch data:   Designation 00110 / 1958 Eta 1 / 58007A Launch date 11 Oct 1958 - 8:42:13 UT Launch site CC, LC17A Launch vehicle Thor-DM18 Able-1 (#130/DM-1812-6) Mission Lunar orbiter Maximum distance from Earth 113854 km All-burnt velocity 10.5 km/sec

• Before the launch of the second probe, the whole program was transferred to NASA, with the USAF and the Army acting as simple consultants. NASA gave the probes the name Pioneer. On October 11, 1958, just ten days after NASAs foundation, the second probe Pioneer-1 (or Able-2) was launched. The second stage was shut down too early, leaving Pioneer 1 with a lack of speed to fulfill its mission. It was hoped, that firing the Falcon motor would put the probe into a earth orbit, but the ignition failed due to too low temperatures of the batteries. Pioneer-1 flew up to a height of 113854 km, less than a third of the distance of the Moon and fell back, disintegrating in the atmosphere after a 43 hours, 17 seconds flight. The mission was a failure, but the probe transmitted interesting data on the Van Allen belts, measuring their extension, on micrometeorites registering only 0.0052 impacts per second per square meter of sensor.

Spacecraft data: Prime contractor  TRW Operator  USAF, NASA Mass at launch 38,3 kg Dry Mass   kg Configaration 2 glass fiber cones jointed at their base by a cylinder Dimension 0.74 dia - 0.76 long Equipment camera (oscillating mirror scanner), radiation counter, search coil magnetometer, microphone micrometeorite detector Propulsion 8 vernier rockets (seperable), TX-8 (Falcon) orbit insertion motor

Decay: Descent date: 13 Oct 1958 Lifetime:  43.3 hours

Description:

• Pioneer 1 consisted of a thin cylindrical midsection with a squat truncated cone 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. The total mass of the spacecraft after vernier separation was 34.2 kg, after injection rocket firing it would have been 23.2 kg.

• The scientific instrument package had a mass of 17.8 kg and consisted of an image scanning infrared television system to study the Moon's surface to a resolution of 1 milliradian, an ionization chamber to measure radiation in space, a diaphragm/microphone assembly to detect micrometeorites, a spin-coil magnetometer to measure magnetic fields to 5 microgauss, 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 at 300 mW and a magnetic dipole antenna for the television system at 50 W. Ground commands were received through the electric dipole antenna at 115 MHz. The spacecraft was spin stabilized at 1.8 rps, the spin direction was approximately perpendicular to the geomagnetic meridian planes of the trajectory.

• 1) ionization chamber
• 2) magnetometer
• 3) micrometeoroid detector
• 4) NOTS infrared imaging system
• 5) temperature sensor

Mission details:

• Due to a launch vehicle malfunction, the spacecraft attained only a ballistic trajectory and never reached the Moon. However, it did return data on the near-Earth space environment.
• The spacecraft was launched on October 11, 1958 but it did not reach the Moon as planned due to a programming error in the upper stage causing a slight error in burnout velocity and angle (3.5 deg.). This resulted in a ballistic trajectory with a peak altitude of 113,800 km around 1300 local time. The real-time transmission was obtained for about 75% of the flight, but the percentage of data recorded for each experiment was variable. Except for the first hour of flight, the signal to noise ratio was good. It did return data on the near-Earth space environment. The spacecraft ended transmission when it reentered the Earth's atmosphere after 43 hours of flight on October 13, 1958 at 03:46 UT over the South Pacific Ocean. A small quantity of useful scientific information was returned, showing the radiation surrounding Earth was in the form of bands and measuring the extent of the bands, mapping the total ionizing flux, making the first observations of hydromagnetic oscillations of the magnetic field, and taking the first measurements of the density of micrometeorites and the interplanetary magnetic field.
• Moon shot. First and second stages worked well, but a programming error in the solid fuel third stage burned for 8 seconds, resulting in insufficient velocity to escape the Earth's gravitational field.
• Failed to reach Earth escape velocity; 
• Set distance record; attained 113854 km during 43 h 17 m flight.
• Pioneer 1 returned data on the Van Allen Belt and micrometeorite impacts before re-entering Earth's atmosphere on Oct. 12, 1958.