Space Simulator

General Category => General Discussion => Topic started by: ApolloGirl on December 17, 2017, 07:00:23 PM

Title: barbecue roll
Post by: ApolloGirl on December 17, 2017, 07:00:23 PM
The Passive Thermal Control maneuver, aka the barbecue roll, is a maneuver used by the Apollo spacecraft on its coast to the Moon. The CSM rotates along its x-axis (along the length of the body) of about one revolution per 10 minutes or slower. The in order to disperse heat from the Sun and heat up the spacecraft evenly.  

(https://s19.postimg.org/5x72ns15v/CSM-axes.png)


Active torquing was required to maintain the desired attitude because the moment of inertia principal axes were not precisely aligned with the spacecraft axes. This was accomplished by using the rotational hand controller to create a pure torque about the roll axis, instead of using the active attitude control mode.

This maneuver was first successfully tested in Apollo 7.
In Apollo 13, the crew performed a barbecue roll before powering down the spacecraft to avoid further thermal damage to the ship.