Project Mercury

The Mercury program was the first manned space program of the United States. It lasted from 1958 to 1963 and was aimed at a man in orbit to fly around the Earth. The early phase was planned by the National Advisory Committee for Aeronautics ( NACA ). Carried out, it was the newly founded NASA.

The Mercury program was preceded by the Manhigh program of the U.S. Air Force, in which by means of the ballooning effect of cosmic radiation has been studied on humans in the stratosphere.

• 4.1 The "Mercury Seven"

The planning

In early October 1958, decided to conduct a manned space program in the U.S.. The plans before looked to man a spacecraft with a person and to let this orbital circle around the earth. In the early phase there was talk of a manned satellite.

To run this program, different systems had to be designed and tested. Such a program has been developed for the fully controlled parachute landing in the Langley Research Center. In addition, were using the United States Air Force, which already had experience in this field, showing the missiles. As these, however, were built for military purposes, they had to be further developed. These were primarily the Atlas and Redstone rockets. On the latter, the German group to Wernher von Braun was involved.

On November 26, 1958, the name Mercury was the official project name.

The Mercury space capsule

The Mercury space capsule was in charge of NASA developed under the direction of Maxime Faget, more than twenty industrial companies worked with. The contract to build the spacecraft was awarded to McDonnell Aircraft Corporation.

The take-off mass of the capsule was 1935 kg, height 3.51 m without rescue rocket, the largest diameter of 1.89 m. With a false start, the space capsule could be separated by a rescue rocket from the rocket and brought to safety. The rescue rockets never had to be used.

The astronaut could affect the position and trajectory of the capsule with the hand control, the space capsule but was also equipped with a device which allowed the ground crew to completely control the spaceship. The space capsule was flown by an astronaut - due to the very compact dimensions it was said in jest, that the Mercury capsule is tightened and not flown.

The interior of the capsule had a volume of 1.7 cubic meters, and the astronaut has the capsule 55 switches, 30 and fuses 35 to operate the lever. An important task during re-entry of the space capsule had the heat shield. When entering acted acceleration forces of 4 g of the astronaut. After re-entry, the capsule was slowed by parachutes and splashed in the sea.

NASA ordered 20 space capsules, in addition additional, non- airworthy samples for test were built.

The first tests

With the help of test rocket Little Joe, which was already available for testing ballistic paths, the first tests were performed with the spacecraft and the rocket apparatus.

In addition, the "Big Joe" system was introduced on the basis of an Atlas rocket, with the aid of a spaceship could be transported high enough into space to test the critical re-entry into Earth's atmosphere and practice.

On 13 December 1958, the squirrel monkeys Gordo was promoted to the head of a Jupiter -C rocket to the U.S. Army in the weightlessness that he was exposed to 8.3 minutes. Gordo survived off and landing, but drowned due to mechanical failure of the parachute functions with the nose cone in the ocean.

Likewise, began at the beginning of the year the development of the heat shield for the Mercury landing capsule. Several test launches failed in the course of February and March.

The rescue system

The rescue system of the spaceship worked at the second start in April 1959 as planned and brought the landing capsule prescribed to splashdown in the Atlantic, so the spacecraft could be rescued by a helicopter.

With the help of a pig, Gentle Bess, McDonnell tested the impact stiffness of the landing capsule. The test was successful, the pig survived. Further tests with pigs refused to NASA, since pigs can not survive long in a sitting position.

The two monkeys Able and Baker were shot on May 28, 1959 using a Jupiter rocket 480 km into space. They ended 2735 km from Cape Canaveral and survived the flight.

In September was a Mercury test flight with a Big Joe Atlas successfully almost one hundred percent. Valuable insights into the re-entry angle and the temperatures occurring at the heat shield were recovered.

On 4 December 1959, started to test the functionality of the rescue mission with the Little Joe 2 the rhesus monkey Sam. Likewise, medical findings should be obtained during the flight. The test was successful, and Sam survived him. A second test Little Joe 1B with the rhesus monkey Miss Sam was on January 21, 1960 just as successful.

Astronauts search

In early 1959, the criteria were established for the selection of pilots. These were:

• Age under 40 years
• Height less than 180 cm
• Excellent physical condition
• Bachelor's degree
• Completion as a test and Jetpilot
• At least 1500 hours of flying

In February 1959 110 candidates for the Mercury program were tested. On April 9, 1959, at a press conference in Washington, DC presented the seven selected public Mercury astronauts. There were:

The "Mercury Seven"

• Lt.. Commander Alan B. Shepard, Jr. (1923-1998) Navy
• Captain Virgil I. Grissom (1926-1967) Air Force
• Lt.. Colonel John H. Glenn, Jr. ( born 1921 ) Marines
• Lieutenant Malcolm Scott Carpenter (1925-2013) Navy
• Lt.. Commander Walter M. Schirra, Jr. (1923-2007) Navy
• Captain Donald K. Slayton (1924-1993) Air Force
• Captain Leroy Gordon Cooper, Jr. (1927-2004) Air Force

All astronauts were born in small towns in the United States until some future astronauts of the second selection group were born in big cities.

The number 7, which was appended to the name of each spaceship and is also found in the logo of the mission is due to these seven astronauts. So that the good co-operation should be demonstrated and recalls for each individual mission to the team.

Each astronaut was given a special area of ​​mission preparations attributed. Nevertheless, the astronauts often exchanged views on issues of common discussed partly violent, were always some, and thus obtain several changes to the landing capsule, the booster rockets and security systems.

Mercury - Redstone and Mercury - Atlas

After mid- 1960, the first Atlas and Redstone missiles and associated spaceships had been delivered, could be started on 29 July 1960, the Mercury - Atlas 1 (MA -1) mission. But already after 59 seconds, the rocket had to be blown up due to a structural failure. The Mercury spacecraft was lost because no rescue system was available. After failing the project several months of investigation has been subjected.

During this time, the seven astronauts were prepared with a variety of medical and physical tests on their first flight. So a centrifuge to test the gravity loads has been installed and a large water tank to simulate weightlessness.

The Mercury - Redstone 1 (MR -1) mission was terminated when at the start of a course within the rescue system was activated on November 21, 1960 during launch. The replacement mission, Mercury - Redstone 1A ( MR -1A ), on the other hand was on December 19th, 1960 easily. The spacecraft reached an altitude of about 210 miles and was rescued by a helicopter from the Atlantic Ocean 15 minutes later after splashdown.

On 31 January 1961, promoted the chimpanzee Ham mission into space with the Mercury - Redstone 2 (MR -2). Minor errors meant that the spacecraft flew higher and farther than previously planned, and had been calculated. An unmanned mission, Mercury - Atlas 2 (MA -2), was on February 21, 1961 successfully.

The unmanned Mercury - Atlas 3 (MA -3) mission on April 25, 1961, however, was a failed attempt. After not go as planned turned after launch, the rocket by 70 ° in order to get to the intended flight path, the rescue system has been activated and separated the landing capsule. The Atlas rocket was blown up shortly after.

Manned flights

With the launch of Alan Shepard in the Mercury - Redstone 3 (MR -3) began the era of manned space flight for the Americans on May 5, 1961. While the first flights were only ballistically; but they could prove the reliability of the technology and that it is possible to expose a person very high acceleration during takeoff and landing. Only from Mercury - Atlas 6 orbit was achieved.

Flight Chronology

The end of the project

The smoothness of the flight of Walter Schirra about 6 earth orbits with Mercury 8 led to a premature termination of the Mercury space flights and the early start of the Gemini program. On 12 June 1963, the Mercury program was officially discontinued. As President John F. Kennedy had issued his famous convention speech on May 25, 1961, the moon landing within the current decade as the target, further space programs had to be targeted, since such ambitious plans with the Mercury program were not to be realized. This was due first and foremost to the inability to maneuver the spacecraft. But that was for docking in space indispensable prerequisite. It was followed by the Gemini program, the planning phase had started even as early as 1959.