Atlas-Agena

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Ranger block I spacecraft bus was used for the first two Rangers, and also for the first two Mariner interplanetary probes Ranger Block 1 scientific experiments.jpg
Ranger block I spacecraft bus was used for the first two Rangers, and also for the first two Mariner interplanetary probes

The Ranger spacecraft were designed to impact the Moon, returning photographs of the lunar surface until their destruction. The spacecraft was designed in three Blocks, all similar in appearance with a forward antenna and magnetometer, supported by a boom, with more sensors and two solar panels and a dish antenna mounted at the base. The first two Block I spacecraft, Ranger 1 and Ranger 2, were launched on August 23 and November 18, 1961, not to the Moon, but in intended high Earth orbits to test the Atlas-Agena and spacecraft capabilities. However, the Agena malfunctioned on both flights and left the probes trapped in a useless low Earth orbit from which they soon decayed.

The Block II missions, Ranger 3, Ranger 4, and Ranger 5, were launched away from Earth in January, April, and October 1962, but all three failed due to either malfunctions of the probe or launch vehicle difficulties. Ranger 3 missed the Moon entirely. Ranger 4's solar panels failed to deploy, and the navigation system failed, sending the probe to impact the lunar far side without returning any pictures or data. Ranger 5 suffered an unknown failure which deprived it of power, and it missed the Moon by 725 kilometers (391 nautical miles).

Ranger 6, launched January 30, 1964, successfully impacted the Moon but its cameras failed to return pictures. The last three Rangers were finally successful: Ranger 7 in July 1964, Ranger 8 in February 1965, and Ranger 9 in March 1965.

Mariner

The Mariner spacecraft were built by NASA's Jet Propulsion Laboratory. Mariner 1 and Mariner 2 were twins, launched on July 22 and August 27, 1962, to fly by the planet Venus. The first two craft used the same spacecraft bus as the Block I Rangers, each weighing 446 pounds (202 kg) and instrumented to perform radiometric temperature measurements of the planet, and to measure interplanetary magnetic fields and particles. [3] [4] Mariner 1's Atlas-Agena malfunctioned and went off course, requiring its destruction approximately 5 minutes after liftoff. Mariner 2 successfully made the 3½-month flight, becoming the first spacecraft to fly by another planet. It carried microwave and infrared radiometers, and sensors for cosmic dust, solar plasma and high-energy radiation, and magnetic fields.

Mariner 3, 4, and 5 spacecraft bus Mariner 4 1304 1964novembemariner4.jpg
Mariner 3, 4, and 5 spacecraft bus

Mariner 3 and Mariner 4 used a redesigned spacecraft bus weighing 575 pounds (261 kg), and were launched on November 5 and November 28, 1964, to fly by the planet Mars. Mariner 3 failed after a successful launch when its payload shroud failed to open. These Mariners carried cameras, and Mariner 4 successfully returned pictures of Mars as it flew by.

The 540-pound (240 kg) Mariner 5 was successfully launched to Venus on June 14, 1967, and flew by in October, probing Venus's atmosphere with radio waves, scanning its brightness in ultraviolet light, and sampling solar particles and magnetic field fluctuations above the planet.

Gemini

The Agena Target Vehicle as seen from Gemini 8 during rendezvous, March 16, 1966 The First Docking in Space - GPN-2000-001344.jpg
The Agena Target Vehicle as seen from Gemini 8 during rendezvous, March 16, 1966

The Agena rocket stage was used as the passive docking target for the Gemini crewed space program. After docking, the Agena could also be fired by the astronauts to raise the combined Gemini-Agena spacecraft into a higher orbit. The first attempt at such a docking mission was made for the Gemini 6 mission on October 25, 1965, but the Agena suffered an engine failure and did not reach orbit. [5] This forced postponement and replanning of the Gemini 6A mission, which performed rendezvous with Gemini 7 without docking. [6]

The GATV was first successfully launched for Gemini 8 on March 16, 1966, permitting the first successful docking in space. GATV-8 was later used as the secondary Agena target for Gemini 10, which also docked with its own GATV. GATV-9 failed to orbit when the Atlas suffered a control malfunction, forcing a similar reschedule of the Gemini 9A mission using a backup Augmented Target Docking Adapter atop an Atlas, but with no Agena rocket stage. Two more GATVs were successfully launched and used on Gemini 11 and Gemini 12.

Lunar Orbiter

Lunar Orbiter Lunar Orbiter Engineering Mock-up.jpg
Lunar Orbiter

A series of five Lunar Orbiter spacecraft were launched from August 1966 through August 1967, to help select landing sites for the Apollo lunar landing program by mapping the Moon's surface. [7] Each spacecraft weighed 850 pounds (390 kg) and was 4.9 feet (1.5 m) in diameter, minus the four extended solar panels. All launches were successful, and a total of 99 percent of the surface of the Moon (near and far side) was mapped with resolution as high as 3 ft 3 in (1 meter). Altogether the Orbiters returned 2180 high resolution and 882 medium resolution frames. The spacecraft also carried micrometeoroid sensors, which showed the average micro-meteoroid flux near the Moon to be two orders of magnitude greater than in interplanetary space, but slightly less than the near-Earth environment.

OAO

Orbiting Astronomical Observatory was a series of NASA satellites flown between 1966 and 1972 for astronomy studies. The first OAO (launched April 8, 1966) used a one-off Atlas variant, mating an Agena D to the LV-3C variant of the Atlas and encased in a Centaur-type payload shroud. The remaining three launches used actual Atlas-Centaur vehicles.

ATS

Applications Technology Satellite was a series of NASA satellites flown in 1967–69 to perform various technology tests. Only the first ATS was launched on an Atlas-Agena, the remainder using Atlas-Centaurs. ATS-1 was a partial failure when the Agena failed to restart, leaving it in LEO.

OGO

Orbiting Geophysical Observatory was a series of NASA satellites flown between 1964 and 1969 for magnetosphere studies. These satellites used several different booster types, including Thor-Agenas. Five of them used Atlas-Agenas, and OGO 5 (launched March 4, 1968) was the sole civilian use of the Atlas SLV-3A Agena.

Midas

Missile Defense Alarm System was a series of Air Force satellites flown between 1960 and 1966 for infrared detection of ballistic missile exhaust plumes on Atlas-Agena A, B, and D. There were several failures and overall program performance was poor, but it would give way to the more successful DSP satellites.

Samos

Samos was a series of Air Force satellites flown between 1960 and 1962 for photoreconnaissance on Atlas-Agena A and B. There were several failures, including an on-pad explosion of an Atlas, and the program was cancelled at the end of 1962 without ever demonstrating any operational capability.

Gambit

KH-7 Gambit was a series of Air Force satellites flown between 1963 and 1966 for photoreconnaissance on Atlas-Agena D. Although there were a number of mission failures, Gambit overall was highly successful in comparison with the bungled Samos program and it returned high-value area reconnaissance of the USSR and China before giving way to KH-8 Gambit in 1967.

Rhyolite/Canyon

Rhyolite/Canyon was a series of Air Force satellites flown between 1968 and 1978 for SIGNIT intelligence on Atlas SLV-3A Agena. One Canyon mission failed when its Atlas went off course and had to be destroyed. These were the final launches of Atlas-Agena vehicles aside from the one-off Atlas F/Agena used to launch Seasat.

Vela

Vela consisted of two sets of Air Force satellites flown in 1964–65 to monitor Soviet compliance with the Nuclear Test Ban Treaty on Atlas-Agena Ds.

Snapshot

Snapshot was a one-off Air Force test of a nuclear satellite flown in 1965 on an Atlas-Agena D.

References

  1. Wade (2008-08-14). "Atlas". Encyclopedia Astronautica. Archived from the original on 2008-08-14. Retrieved 2024-09-19.
  2. Krebs. "Atlas Agena". Gunter's Space Page. Retrieved 2024-09-19.
  3. TRACKING INFORMATION MEMORANDUM NO. 332-15 MARINER R 1 AND 2 (PDF). JET PROPULSION LABORATORY. 1962. Archived from the original (PDF) on 2010-05-25.
  4. MARINER R SPACECRAFT FOR MISSION P-37/P-38 (PDF). JET PROPULSION LABORATORY. 1961. Archived from the original (PDF) on 2010-02-14.
  5. "Gemini 6 Target - NSSDC ID: GEM6T". NASA GSFC.
  6. Barton C. Hacker and James M. Grimwood (1977). "On The Shoulders of Titans: A History of Project Gemini - The Visitors". NASA. Archived from the original on 2020-04-03. Retrieved 2009-02-01.
  7. Bowker; Hughes (1971). Lunar Orbiter Photographic Atlas of the Moon, NASA SP-206 (PDF). NASA.
Atlas-Agena
Atlas Agena launching Lunar Orbiter 4.jpg
An Atlas-Agena launching Lunar Orbiter 4
Function Expendable launch system
Manufacturer Convair
General Dynamics
Country of originUnited States
Size
Height118.0 feet (36.0 m)
Diameter10.0 feet (3.0 m)
Width16.0 feet (4.9 m)
Mass341,000 pounds (155,000 kg)
Stages
Capacity
Payload to LEO
Mass2,200 pounds (1,000 kg)