Rusty Schweickart, the first Lunar Module Pilot, shows us how it’s done — with the Apollo Hand Controllers

2 responses to “Rusty Schweickart, the first Lunar Module Pilot, shows us how it’s done — with the Apollo Hand Controllers”

1. 

   jurvetson

   Dec 30, 2014 at 1:34 am

   The Thrust Translation Control Assembly (TTCA) was used by the Apollo astronauts to control translation of the Lunar Module in any axis during missions to and from the lunar surface. Two TTCAs, each made for left-handed control, provided the LM astronauts with the capability to gently guide the LM on each axis and also provided a manual throttle mode to provide varying thrusts of the descent engine. A soft stop is designed at 53 degree deflection of the throttle handle, which allowed for command of 0-53 percent thrust of the descent engine when fine control was required during landing maneuvers. Beyond the soft stop were 10 degree of handle deflection for controlling 53-100 percent of descent-engine thrust.

   In the very first moon landing, Neil Armstrong was forced to take manual control of the LM when it was headed for a boulder-strewn area. With the TTCA joystick, Armstrong was able to land the LM safely with less than 30 seconds of fuel available. So, the TTCA he is looking at is quite rare, and it’s possible that he has not touched one since his Apollo program…

   And then Rusty explained his passion for the Sentinel Mission to protect Earth (at DFJ with B612 co-founder, astronaut Ed Lu):

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2. 

   jurvetson

   Nov 2, 2022 at 12:55 am

   I had lunch with Apollo 9 LMP Rusty Schweickart today, and we spoke a bit about this new book. Rusty took the cover shot (another near-black underexposure, recovered digitally). He also told me “It was the dumbest thing we did in Apollo.” It shows McDivitt performing a docking from the Apollo 9 LM to the CM. This was a test case to cover the possibility that a CM-guided docking was not possible for some reason, and all subsequent missions used CM-guided docking.

   The problem: the LM hand controllers were programmed for the use case of landing, where the astronaut would be looking forward, through the triangular window, not up, through the docking window. The hand controls actuate thrusters that are 90° rotated from the usual line of sight. It was exceptionally difficult. Rusty asked if the software could switch the control orientation, but was told that the program code budget was tight, and it takes three months of effort to change the magnetic core memories that hold the flight program.

   He confirmed that McDivitt saw the photos of him and by him (e.g., the Ed White photo in the original post) before he died. These were just the photos; he died before the book came out in print.

   Rusty also relayed an interesting story about the docking probe that I had not heard before. After docking, the probe retraction was interrupted by a jolting stop. While they were asking mission control about a plan to retry, CMP David Scott pressed and held the Probe Retract switch for a second try, and that worked. In the simulator, it just took a quick press of the button, but the simulator was not a perfect rendition of the physics of the real system where latches needed to be held open as the Probe and Drogue mates slid past each other. As this was the first flight of the LM, this particular learning passed to all subsequent missions; the protocol became “press and hold” to retract.

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