The Space Vault Exhibition. Pages 17-18 of the Lunar Module Contingency Checklist showing readups of the revised docked DPS+2 burn procedure. From the collection of Charlie Duke, Capsule Communicator for the Apollo 13 mission and LMP for the Apollo 16 mission to the Moon Lets work the problem people. Lets not make things worse by guessing is Dukes instruction to the crew that [if] no, START Push Button push; [if] still no ignition, [press] DESCENT ENGINE COMMAND OVERRIDE, ON. As Lovell describes in his book Apollo 13, if the computer did not fire the engine, NASA was instructing him to take over that function too using two bright-red, silver-dollar-sized buttons with the words Start and Stop stencilled beneath them. Incredibly, this actual exchange with the crew can be heard live in the moment in NASA audio archive recordings scan the QR code (right) with your smartphone and jump to minute 23. Tortoise and the hare In late 1968, three years before the flight of Apollo 13, NASA authorised the planned Apollo 8 mission to be swapped with Apollo 9, so sending a crewed spacecraft into lunar orbit for the first time. The flight did not include a lunar lander. The Grumman Corporations lunar module construction programme was behind schedule, and, to compound NASAs frustration, the Soviet Unions Zond 5 mission had just flown terrestrial organisms two tortoises around the Moon and back to Earth, alive. The earlier-than-planned Apollo 8 flight was a great success, catapulting humankind into a new era as an interplanetary species (allowing here for a little poetic licence around the definition of a planet). The delayed The Space Vault Exhibition S PAC E Evidence of how Mission Control directed the safe return of astronauts Jim Lovell, Jack Swigert and Fred Haise is well recorded, and two of these historic, mission-critical documents are currently on display at The Space Vault Exhibition in South Oxfordshire. They are the Apollo 13 Lunar Module Contingency Checklist, used by Charlie Duke while seated in Mission Control as Capsule Communicator (CapCom), and the Apollo 9 Lunar Module Systems Evaluation Checklist, which was extensively annotated by CDR Jim McDivitt and Lunar Module Pilot (LMP) Rusty Schweickart while in Earth orbit. The Apollo 13 Lunar Module Contingency Checklist is a truly fascinating historic record of the rescue. The document is original, completely intact, and contains numerous hastily improvised handwritten procedures. These annotations were generated by the work of the backup crew in simulators, as they urgently revised the existing contingency checklist to pass up to the astronauts procedures for an accelerated power-up of the lunar module (for use as a lifeboat); a free return, sling-shot trajectory around the Moon and critical burn of the lunar module descent engine; and a creative Earth-in-thewindow manual burn without aid of the computer (the latter to prevent the crew skipping off the Earths atmosphere into an endless solar orbit). An extract from this checklist is in the image below, showing handwritten modifications to the emergency procedure for a docked DPS+2 burn. This procedure facilitated the firing of the lunar module descent engine system (DPS) while docked to the damaged command and service module, and would take place at two hours past Pericynthion the closest distance of the craft to the Moon. A citation from the Apollo 13 air-to-ground transcript records Duke in Mission Control reading up this DPS+2 procedure to Lovell (CDR) and Haise (LMP) aboard the lunar module Aquarius. Notable 32 THE LOG Spring 25 pp30-35 Apollo 13 V2.indd 32 17/03/2025 15:49