[Apollo 13] — Flown Descent Engine Signal Flow Schematic. Signed and inscribed by LMP Fred Haise

Originally from the personal collection of Apollo 13 Lunar Module Pilot Fred Haise

[Apollo 13]

Flown Apollo 13 Schematic

FLOWN "Descent Engine Signal Flow" folding printed schematic from the FLOWN Apollo 13 LM Systems Data Book, P/N SKB32 100082-387, S/N 1001, 10^½ x 36^3/8 in. 

SIGNED and INSCRIBED in blue ink by Lunar Module Pilot Fred Haise: "Carried around the / Moon on Apollo 13 / Fred Haise / Apollo 13 LMP"

Accompanied by signed provenance letter from Haise on his personal letterhead.

FLOWN TO THE MOON ON APOLLO 13.

This folding schematic illustrates the LM Descent Engine signal flow and shows control panel knobs and switches including "START", "ABORT", "ABORT STAGE", and "LUNAR CONTACT" with the corresponding electrical lines. The LM Descent Engine was used on the Apollo 13 mission to put the astronauts back on a path to earth, preventing them from being stranded in space forever.

Apollo 13 LMP Fred Haise's provenance letter reads, in full:

"Accompanying this letter is a folded sheet labeled 21 DPS SIG from the Apollo 13 LM Systems Data Book carried on the flight of Apollo 13 during April 11 to 17, 1970. Our flight was scheduled to be the third manned lunar landing mission but had to be aborted after a Service Module oxygen tank explosion. 

This particular schematic illustrates the LM Descent Engine signal flow and shows control panel knobs and switches including "START", "ABORT", "ABORT STAGE", and "LUNAR CONTACT" with the corresponding electrical lines. Many of our LM systems were powered down during the period after the explosion to conserve electrical power. It was reassuring to have this and the other schematics in the Data Book as a trouble shooting tool in case of any other failures during the remainder of the flight. 

This sheet has been in my personal space collection since 1970, which is now 36 years since the launch of Apollo 13. I have inscribed and signed the schematic with: "Carried around the moon on Apollo 13! Fred Haise, Apollo 13 LMP" along the lower right-hand corner."