In 1958, NASA launched a spacecraft Able 2 for the first time to the Moon but the mission failed after a small error and the probe reentered Earth's atmosphere about 43 hours after launch

In 1958, NASA launched Able 2, later named Pioneer 1, as part of an early attempt by the United States to send a spacecraft toward the Moon. The mission was launched on October 11, 1958, from Cape Canaveral Air Force Station in Florida. The spacecraft was designed to study the Moon and gather information about the environment around Earth. It carried instruments to measure magnetic fields, radiation, micrometeoroid impacts and temperature. It also carried a television camera that was intended to help obtain an image of the lunar surface. The mission did not reach the Moon. A problem during the launch caused the second stage of the Thor rocket to shut down 10 seconds earlier than planned. The spacecraft therefore did not receive enough speed to escape Earth’s gravity.

Although the mission failed in its main objective, Pioneer 1 still returned scientific information. It reached an altitude of 71,303 miles, or about 114,750 kilometers, above Earth. The spacecraft also helped confirm the existence of the Van Allen Belts and provided information about the boundary of Earth’s geomagnetic cavity.

What was Able 2, later known as Pioneer 1?

Able 2 was a lunar spacecraft developed for an American mission to study the Moon. It was later known as Pioneer 1. The spacecraft was the first spacecraft launched by NASA. There is an important detail about its management. The United States Air Force conducted the mission, but it was the first US space mission technically under the responsibility of the recently formed National Aeronautics and Space Administration.

NASA had been created in 1958 as the United States began organizing its civilian space activities. The Pioneer 1 mission therefore became part of the early history of NASA. The spacecraft was similar to the earlier Able 1 probe. Both spacecraft were built by Space Technology Laboratories, or STL. Able 2 had a mass of 84 pounds, or 38.3 kilograms. Its main objective was to study the Moon and gather scientific information during its journey away from Earth.

In 1958, NASA launched Able 2 for a Moon mission

The launch took place on October 11, 1958, at 08:42:13 Universal Time. The spacecraft was launched from Launch Complex 17A at Cape Canaveral Air Force Station in Florida. The launch vehicle was a Thor-Able I. The specific rocket was identified as Thor-Able I No. 1, Thor No. 130 and DM-1812-6. The spacecraft carried several scientific instruments.

These included:

• An ion chamber to measure radiation.
• A magnetometer to measure magnetic fields.
• A micrometeoroid detector to record impacts from small particles.
• A television camera intended to obtain an image of the Moon.
• Two temperature sensors to record temperatures during the mission.

The mission was planned to place the spacecraft on a path toward the Moon. The objective was to gather information about the lunar environment and the space environment between Earth and the Moon. However, the launch did not proceed as planned.

What caused the Able 2 mission to fail?

The main problem happened during the operation of the Thor rocket’s second stage. The second stage shut down 10 seconds earlier than it was supposed to. The shutdown happened because an accelerometer provided incorrect information.

An accelerometer is used to measure changes in velocity. Information from the instrument was used by the rocket’s control system during the flight. In the case of Able 2, incorrect information from the accelerometer caused the second stage to stop too soon. This meant the launch vehicle did not provide enough velocity to allow the spacecraft to escape Earth’s gravity.

The spacecraft was therefore unable to continue on the planned path toward the Moon. Investigators later concluded that an incorrect valve setting had caused the accelerometer to mistakenly cut off the Able stage. This was the small error that had a direct effect on the mission.

Why could the spacecraft not enter high Earth orbit?

After the second-stage shutdown, mission teams attempted to use the spacecraft’s own retro motor. The plan was to place the spacecraft into a high Earth orbit. The planned orbit would have had an altitude range of about 79,970 by 20,000 miles, or 128,700 by 32,200 kilometers. The attempt did not work.

The retro motor had been built by Thiokol. However, its internal temperature had fallen too low. Because of the low temperature, the batteries could not provide enough power to operate the motor as needed. The spacecraft therefore could not achieve the planned high Earth orbit. The failure meant that Able 2 could not continue toward its lunar objective.

How far did Pioneer 1 travel?

Even though the spacecraft did not reach the Moon, it continued to travel away from Earth for some time. According to NASA information from February 1959, the probe reached an altitude of 71,303 miles, or 114,750 kilometers, by 11:42 Universal Time on the day of launch.

This made the mission useful for studying conditions beyond the immediate region around Earth. The spacecraft also collected scientific information that helped researchers understand the space environment. Its data became one of the useful results of a mission that had failed to reach its main target.

What did Able 2 discover?

One of the key results from the mission was the verification of the Van Allen Belts. The Van Allen Belts are regions around Earth where charged particles are trapped by Earth’s magnetic field. The spacecraft also returned information about the boundary of the geomagnetic cavity.

The geomagnetic cavity is the region around Earth that is influenced by the planet’s magnetic field and interacts with the surrounding space environment. These observations gave scientists information even though the spacecraft did not reach the Moon. The mission therefore had a scientific result beyond its original lunar objective.

When did the spacecraft return to Earth?

Able 2 reentered Earth’s atmosphere about 43 hours after launch. The launch took place on October 11, 1958. The spacecraft reentered on October 13, 1958.

The key mission dates were:

• October 11, 1958 — Able 2 was launched.
• October 13, 1958 — The spacecraft reentered Earth’s atmosphere.

The spacecraft’s short mission was therefore shaped by the launch-stage problem and the failure of the later attempt to place it into high Earth orbit.

How did Able 2 get the name Pioneer 1?

The spacecraft was officially given the name Pioneer soon after launch. The US Department of Defense announced the name in a press release. The spacecraft has also often been called Pioneer 1 in later references. The name was apparently not proposed by a NASA official.

It was suggested by Stephen A. Saliga, an official responsible for Air Force exhibits at Wright-Patterson Air Force Base in Dayton, Ohio. Saliga had designed a display connected with the launch. The name Pioneer was apparently associated with that display and was then used for the spacecraft. Because of this history, Able 2 is now commonly identified as Pioneer 1.

Why is Pioneer 1 important in NASA history?

Pioneer 1 is important because it was the first spacecraft launched by NASA. The mission also came at a point when the United States was beginning its early space program. The US Air Force conducted the mission, but NASA had responsibility for the mission as the newly formed civilian space agency.

The spacecraft did not achieve its planned lunar objective. However, its journey demonstrated that an early space mission could still produce scientific information after a launch problem. The spacecraft confirmed the Van Allen Belts and returned data about Earth’s magnetic environment. The mission also showed how a small error in launch-system information could affect an entire space mission.

The accelerometer problem caused the second stage to shut down early. The resulting loss of velocity prevented the spacecraft from escaping Earth’s gravity. The later attempt to use the retro motor also failed because low internal temperatures left the batteries without enough power. Pioneer 1 therefore became part of the early history of lunar exploration and NASA’s first spacecraft missions.