Each of the Mercury missions had a name followed by the number 7. Alan Shepard flew Freedom 7, Gus Grissom in Liberty Bell 7, John Glenn aboard Friendship 7 (pictured), Scott Carpenter in Aurora 7, Wally Schirra flew Sigma 7, and Gordon Cooper aboard Faith 7. Deke Slayton never flew because of a heart condition, but had he flown his mission would have been Delta 7.
So, what’s with all the ‘7’s?
When NASA was preparing to send men into orbit, it had a series of suborbital and orbital test flight planned to make sure the hardware was man rated. For these tests, it needed capsule. Prime contractor McDonnell Douglas built 20 Mercury capsules, some were upgraded but they were all the same basic machine. (Right, Langley technicians build the Little Joe versions of the Mercury capsules in-house in Langley’s shops. At this point, the rocket was a testing workhorse.)
The first capsule was used on May 9, 1960 for a one minute and sixteen second beach abort test. The second launched on a Redstone rocket for an unmanned test of the control system on December 19, 1960. On March 18, 1961, the third capsule was lost during launch when an abort command failed to separate it from its Little Joe rocket. The fourth capsule was the first launched on an Atlas rocket on July 29, 1960. The capsule was lost during launch, and so never made it to its planned orbital altitude. The fifth capsule was launched January 31, 1961, on a ballistic flight. Luckily for its passenger, Ham the chimp, this one was successful. The sixth capsule was another unmanned ballistic launch on February 21, 1961, this time on an Atlas. (Left, all that remained of the fourth capsule after the Atlas exploded during launch. 1960.)
Then the seventh capsule carried Al Shepard in Freedom 7 on May 5, 1961. Shepard chose the name Freedom because it was patriotic. He added the ‘7’ not to commemorate the seven astronauts but because his was the seventh capsule off the production line. It was an internal designation. But it seemed like a good idea for the program to pay tribute to the seven brave men that were putting their hides on the line to ride rockets into space. It was great PR, and the public loved it. So when Gus Grissom followed in Al Shepard’s suborbital footprints, he chose Liberty Bell for his capsule’s name and also added the ‘7’. (Right, Shepard walks towards his Freedom 7 capsule on launch day. 1961.)
In the interest of a complete history, here’s a brief recap of what happened to the rest of the capsules.
The eighth went into orbit twice, once on April 23 and again on September 13, in 1961. Capsule nine launched on November 29, 1961 with the chimp Enos on board. The eleventh capsule carried Gus Grissom on his suborbital flight on July 21, 1961. The thirteenth carried John Glenn into orbit on February 20, 1962. The fourteenth was launched on a Little Joe rocket on April 28, 1961 as a test of the abort system and parachutes. The sixteenth carried Wally Schirra into orbit on October 3, 1962. The eighteenth carried Scott Carpenter around the globe on May 24, 1962. Finally, the twentieth capsule took Gordon Cooper into space on May 15, 1963. (Left, Grissom and Liberty Bell 7. 1961)
The tenth, twelfth, fifteenth, seventeenth, and nineteenth were never flown. Number ten was a test capsule, twelve backed up John Glenn’s mission, fifteen and seventeen were on hand to back up any manned orbital mission, and nineteen backed up Wally Schirra’s flight.