6 thoughts on “The Hippy MIT Geek”

  1. Geoff Landis’ writeup matches my memory of the situation almost exactly. I’ve got serious doubts about the original story.

  2. A direct abort was the primary abort option for an abort at that phase (earth-moon leg) but, it required the CSM’s main engine, which was the only engine with sufficient Delta-V. Though a direct abort (changing course radically and entering a direct return trajectory) was the primary abort option, it was not the only one.

    All prior manned moon shots had been on “Free return” trajectories; if the lunar insertion burn did not occur, the vehicle would loop behind the moon and be on a path for splashdown. Apollo 13 was not on such a trajectory, due to the lunar latitude of the Fra Muro landing zone. However, it took only a small burn (done shortly after the accident, and with the LEM decent engine in this case) to put them back on a free return trajectory.

    Attaining a free return trajectory with a small burn was absolutely one of the abort options, just not the standard primary abort option. There were other circumstances where it was the preferred abort option, one of them being an untrustworthy CSM engine. The reason there was that if you tried a direct abort with the CSM and it cut out at almost any point during about 80% of the burn, the vehicle would be on a lunar-impact trajectory. So, lacking full faith in the CSM engine, a burn to get on a free return trajectory, not a direct abort, would have been the preferred abort option.

    Also, without a CSM direct-abort burn (and only the CSM engine had the delta/V for a direct abort) you were slingshoting around the moon no matter what. The only difference being that without a free-return trajectory, you’d miss the planet by about 20,000 miles and end up in a highly eccentric high orbit.

    I’m far more than skeptical that NASA didn’t think of the free-return trajectory THAT WAS ALREADY IN THEIR ABORT MANUAL, and one of the reasons I’m so skeptical is that it was the preferred abort option at that phase of flight if you had doubts on the CSM main engine.

    I’m thinking that the guy who made the statement might be conflating a memory or two, or he heard is second hand, etc, because as stated, it makes zero sense.

    1. Could he be confusing Apollo 13’s abort story with the MIT programmer who had to very rapidly come up with a way to program in a fix for the Apollo 14 lunar module’s glitching abort button?

  3. I’m also skeptical, because a slingshot around the moon was one of the first and easiest ways to show progress toward a landing, and the Soviets were already successfully flying that trajectory with Zond 5, 6, and 7

    On Apollo 8, if the engine didn’t fire for the 4 minute burn to put them into lunar orbit, Lovell was supposed to use the free gravity assist for the slingshot ride home. So the slingshot already had to be part of mission planning for an aborted LOI burn.

Comments are closed.