STS-2 Deorbit Burn Cue Card (Unbalanced PRPLT / Mixed XFEED Card) - Training-Used, Ex. Astronaut Sherwood Spring

This flight-ready article was prepared for the STS-2 mission and used in training at Johnson Space Center. It was obtained in the late-1980s from Astronaut Sherwood Spring (Mission Specialist, STS-61-B) during a visit to the Astronaut Office. At the time, Spring reported that the cards had been given to him by Bob Crippen sometime around 1985.
 
When originally obtained, the card came in a clear plastic bag with a “SAIL – Do Not Remove” sticker, indicating they originated in the Shuttle Avionics Integration Laboratory (SAIL)—the only place where actual orbiter hardware and flight software could be integrated and tested in a simulated flight environment.
 
Cue cards contain quick-reference abbreviations of the more detailed procedures found in the flight checklists. They list the basic functions the crew must execute during dynamics phases of flight when there is no time to refer to the full checklist procedures.
 
Printed on thick cardboard, the card features multiple hook-and-loop squares, allowing it to be attached to control panels in the cockpit for easy reference during the mission.
 
The Deorbit Burn (2 Eng / 1 Eng) cue card lists several potential failures that might occur during the Deorbit Burn (shaded portion) and provides procedures for each type of failure. It has two sides: the front of the card lists the nominal “2 Engine” condition, when both OMS engines are used to perform the Deorbit Burn (left pod feeds left OMS engine; right pod feeds right OMS engine; on the reverse side is the off-nominal “1 Engine” case, in which one of the two OMS engines has failed (or fails during the burn). In such a case, the ‘good’ OMS engine uses the failed engine’s propellant via a crossfeed, and then is reconfigured back to straight-feed during the burn to use its own propellant.
 
The deorbit burn is started with both of the engines being supplied by the ‘heavy’ pod. When the imbalance is eliminated, the engines are returned to the normal straight-feed condition to complete the burn. This method would be used if both OMS engines were operable, and a normal two engine de-orbit burn would result in a large offset during entry. If a propellant failure (tank or line) occurs in the oxidizer or fuel system of one pod, that pod’s OMS engine is considered failed. Therefore, the burn is performed with the other OMS engine, using oxidizer from one pod and fuel from the other (Mixed Crossfeed). During the burn, the propellant system can be manually reconfigured, if desired, to feed the engine from its own pod so that balanced is maintained.
 
Owing to their scarcity and direct association with mission preparations, training cue cards from the early Orbital Flight Tests are exceedingly desirable artifacts from the earliest days of the Shuttle Program.
 
This item comes with a lifetime guarantee of authenticity, as well as a Letter of Authenticity describing the item and its provenance, as well as an information sheet on the cue card and the SAIL facility.