Glenn and Friendship 7: the course of three orbits

Project Mercury had already flown crewed suborbital missions. Friendship 7 used an Atlas rocket to send John Glenn and his Mercury spacecraft into sustained Earth orbit. He trained in systems operation, weightlessness and emergency procedures.

The rocket launched from Cape Canaveral on February 20, 1962. After reaching orbital velocity, the spacecraft separated, making Glenn the first American in Earth orbit.

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Friendship 7 completed three orbits. Glenn observed Earth, clouds, sunrises and sunsets, reporting his condition through a chain of ground tracking stations. Telemetry carried information about life support and equipment alongside the voice communications.

An attitude-control problem required him to use manual control. His actions and the automatic systems maintained the mission and supplied data for the subsequent technical review.

References: [1]

Ground controllers received a signal suggesting a possible heat-shield release. Because the shield protected the capsule during re-entry, they asked Glenn to retain the retrorocket pack after firing, so its straps might help keep the shield in place.

Burning fragments passed the window during re-entry. The capsule slowed and descended by parachute. Post-flight inspection traced the warning to a faulty switch; the shield had remained secure.

References: [1]

The flight lasted 4 hours, 55 minutes and 23 seconds. Friendship 7 splashed down in the Atlantic and was recovered by USS Noa, with Glenn still inside as the capsule was lifted aboard. He then exited for examination.

The 1962 results report brought together spacecraft performance, tracking, communications, observations and medical data, supporting subsequent Mercury missions with more orbits and longer durations.

References: [1]