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Pioneer 1

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This article is about the spacecraft. For the TV series, seePioneer One.For the land speed racer, seePioneer 1 (land speed racer).
Pioneer 1
Mission typeLunarorbiter
OperatorNASA
Harvard designation1958 Eta 1[1]
COSPAR ID1958-007AEdit this at Wikidata
SATCATno.110[1]
Mission duration2 days (43 hours)[2]
Apogee113,800 kilometers (70,700 mi)
Spacecraft properties
ManufacturerSpace Technology Laboratories
Launch mass34.2 kilograms (75 lb)[1][3]
Start of mission
Launch date11 October 1958, 08:42:00(1958-10-11UTC08:42Z)GMT[2]
RocketThor DM-18 Able I
Launch siteCape Canaveral,LC-17A
End of mission
Decay date13 October 1958, 03:46(1958-10-13UTC03:47Z)GMT

Pioneer 1(also known asAble 2)[4]was an Americanspace probe,the first under the auspices ofNASA,which was launched by aThor-Ablerocket on 11 October 1958. It was intended toorbit the Moonand make scientific measurements, but due to a guidance error failed to achieve lunar orbit and was ultimately destroyed upon reentering Earth's atmosphere. The flight, which lasted 43 hours and reached an apogee of 113,800 km (70,700 miles), was the second and most successful of the three Thor-Able space probes.[5]

Spacecraft design[edit]

The Pioneer 1 atop its launcher.

Pioneer 1 was fabricated by Space Technology Laboratories, a division of Ramo-Wooldridge Corp (laterTRW Inc.),[6]and consisted of a thin cylindrical midsection with a squat truncated cone on each side. The cylinder was 74 cm (29 in) in diameter and the height from the top of one cone to the top of the opposite cone was 76 cm (30 in). Along the axis of the spacecraft and protruding from the end of the lower cone was an 11 kg (24 lb) solid propellant injection rocket and rocket case, which formed the main structural member of the spacecraft. Eight small low-thrustsolid propellantvelocity adjustment rockets were mounted on the end of the upper cone in a ring assembly which could be jettisoned after use. A magneticdipole antennaalso 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 (75 lb), after injection rocket firing it would have been 23.2 kg (51 lb).

The three-stage Thor-Able vehicle consisted of a modified Air Force Thor IRBM (liquid propellant, thrust about 69,400 kg (153,000 lb)) as the first stage. Aliquid-propellant rocketengine powered the second stage (modified Vanguard second stage, thrust about 3,402 kg (7,500 lb)). The third stage was a solid-propellant unit based on Vanguard design, rated at 116,500 lb (52,844 kg)-sec totalimpulse.[7]

The scientific instrument package had a mass of 17.8 kg (39 lb) and consisted of an image scanning infrared television system to study theMoon's surface to a resolution of 0.5°, anionization chamberto measure radiation in space, a diaphragm/microphone assembly to detectmicrometeorites,a spin-coilmagnetometerto measure magnetic fields to 5 microgauss, and temperature-variableresistorsto record the spacecraft's internal conditions. The spacecraft was powered bynickel-cadmium batteriesfor ignition of the rockets,silver cell batteriesfor the television system, andmercury batteriesfor the remaining circuits. The radio transmission was 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 wasspin-stabilizedat 1.8 rps, the spin direction was approximately perpendicular to the geomagnetic meridian planes of the trajectory.

Mission[edit]

Reconstructed replica of Pioneer 1

Two days after the failure of Pioneer 0 on 17 August 1958, Thor 129, the backup vehicle, was erected on LC-17B in preparation for a September attempt. The postflight investigation of Pioneer 0 pointed to aturbopumpfailure, which had also caused the loss of Thor-Able 116 in April.[citation needed]This was followed by the failure of an Atlas launch on 18 September, so the Air Force moved to replace the turbopumps in their inventory of Thor and Atlas missiles.[citation needed]Thor 129 was pulled from the pad for modifications and replaced with Thor 130.

On 11 October 1958, Pioneer 1 lifted off smoothly, but the guidance system steered the Thor slightly too high and fast, causing the second stage to be lofted 3° higher than intended. As a result, it shut off 10 seconds earlier than planned, and also bumped the third stage during separation. The third stage was left pitched up about 15° and suffering a velocity shortfall of about 500 feet per second. Thevernier engineson the third stage were fired to make up for the thrust deficit, but added only 150 feet per second of velocity, insufficient to escape Earth orbit. As a last resort, ground controllers decided that if they could not get Pioneer 1 to the Moon, they would place it in a high Earth orbit by firing the attached solid rocket motor. The inaccurate launch trajectory, however, had placed the probe on an orbital track that resulted in thermal heating and cooling beyond what the primitive temperature control system could handle. The probe's internals fell to near-freezing temperatures, rendering the solid motor igniter inoperable. Pioneer 1 reached a total distance of 113,800 km (70,712 mi) before beginning its descent back to Earth.[8]

The spacecraft was launched fromLC-17Aat Cape Canaveral at 08:42:00 GMT 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°). This resulted in a ballistic trajectory with a peak altitude of 113,800 km (70,712 mi) around 13:00 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. The spacecraft ended transmission when it reentered the Earth's atmosphere after 43 hours of flight on 13 October 1958 at 03:46 GMT over the SouthPacific 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 themagnetic field,and taking the first measurements of the density of micrometeorites and theinterplanetary magnetic field.[citation needed]

See also[edit]

References[edit]

  1. ^abc"NASA - NSSDCA - Spacecraft - Details".
  2. ^ab"NASA - NSSDCA - Spacecraft - Telemetry Details".nssdc.gsfc.nasa.gov.Retrieved18 August2023.
  3. ^1958 NASA/USAF Space Probe (ABLE-1) Final Report: Volume 2. Payload and Experiments(Report). Space Technology Laboratories. February 18, 1959.Archivedfrom the original on April 12, 2022.RetrievedFebruary 17,2009.
  4. ^"In Depth | Pioneer 1".NASA.Retrieved20 Feb2021.
  5. ^"Pioneer 1 - NSSDC ID: 1958-007A".NASA NSSDC.
  6. ^"Pioneering Space”
  7. ^Rosenthal, Alfred (January 1982)."A record of NASA space missions since 1958".NASA.NASA Technical Reports Server.hdl:2060/19940003358.Retrieved24 September2011.
  8. ^"Moon Rocket Falls, Burns Up; Plunges Back Into Atmosphere".Pittsburgh Post-Gazette.Associated Press.October 13, 1958. p. 1.RetrievedMarch 7,2011.

External links[edit]

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