Launching atop an Atlas rocket, on February 20, 1962 astronaut John Glenn became the first American to orbit the Earth in Mercury Spacecraft Friendship 7. As the craft began the second orbit, Mission Control received a signal which indicated the critical heat shield was loose. If the heat shield were to fail during reentry, John Glenn would be lost along with the disintegrating spacecraft.
The retrorocket package which is used to slow the spacecraft so it can reenter the Earth's atmosphere would normally be jettisoned during reentry but the decision was made to leave it in place in hopes it would provide extra support to keep the potentially loose heat shield in place. Glenn described the reentry as "a real fireball outside" and "had great chunks of that retropack breaking off all the way through".
The retrorocket package which is used to slow the spacecraft so it can reenter the Earth's atmosphere would normally be jettisoned during reentry but the decision was made to leave it in place in hopes it would provide extra support to keep the potentially loose heat shield in place. Glenn described the reentry as "a real fireball outside" and "had great chunks of that retropack breaking off all the way through".