Forty years ago today, Apollo 8 entered lunar orbit:
The SPS ignited at 69 hours, 8 minutes, and 16 seconds after launch and burned for 4 minutes and 13 seconds, placing the Apollo 8 spacecraft in orbit around the Moon. The crew described the burn as being the longest four minutes of their lives. If the burn had not lasted exactly the correct amount of time, the spacecraft could have ended up in a highly elliptical lunar orbit or even flung off into space. If it lasted too long they could have impacted the Moon. After making sure the spacecraft was working, they finally had a chance to look at the Moon, which they would orbit for the next 20 hours.
Frank Borman, James Lovell, and William Anders were the first humans to escape Earth's gravitational field and the first to look directly upon the far side of the moon.
Apollo 8 was only the second manned Apollo flight. It was the first manned flight atop the Saturn V rocket. The mission was originally planned as a low-Earth orbit test of the combined command module (CM) and lunar module (LM). Depending on whom you believe, NASA gave Apollo 8 a lunar-orbit mission either because production of the LM was behind schedule or because the Soviets were suspected of planning a manned lunar-orbit mission for late 1968.
The Soviets, of course, never made that flight. NASA repeated the lunar orbit mission five months later with Apollo 10. Two months after that, Apollo 11 landed men on the moon. That should be a big anniversary celebration next July!
Maybe then someone can explain to me why, 40 years later, we don't have a thriving lunar colony, a large orbiting colony at L5, and reasonably priced space tourism — all the stuff Heinlein envisioned back in the 50s.
