The maneuver evened out the heating around the spacecraft. It was normally performed by the reaction control system in the service module. The explosion onboard Apollo 13 disabled the service module. The crew famously used the lunar module to perform maneuvers which helped them get home. Was the lunar module also used to perform a barbecue roll?

Flying long before the Shuttle, the Apollo launch profile has been described in a very similar way - a roll to orient the vehicle so that a pitch maneuver puts it onto trajectory. My question is this: With no large-scale external features to break the vehicle's apparent radial symmetry, why was it necessary/preferred for Apollo to roll first ...

Jun 18, 2017 · [The PTC maneuver requires the spacecraft to be rotated around the X, or longitudinal axis, in a slow roll of 0.35° per second. A complete roll of 360° should take about 17 minutes at that speed.] [The X-axis of the CSM is an imaginary line which runs from the centre of the SPS engine bell, through the centre of the SM and out through the ...

Jan 7, 2020 · The nozzle of the SM engine and the bottom of the SM should not pass between antennas and ground station during PTC roll to ensure continous radio link with mission control. Moon landings were done during a waxing half moon. During that phase the roll axis could be oriented towards Earth as well as perpendicular to the sunrays.

Jan 31, 2020 · Pitch is given relative to the once-transformed y axis (the transformation being roll). Yaw is given relative to the twice-transformed z axis (the transformations being roll followed by pitch). This means the roll, pitch, and yaw axes always point in the same directions relative to the spacecraft. If you roll a little, the pitch and yaw axes ...

Dec 18, 2024 · $\begingroup$ I see the comment about bbq roll of apollo. I worked on that in the early 60s. That solution was laid out because thermal analysis of the service module propulsion system showed that as a solution to potential propellant freezing in the SM main engine valve.

Aug 30, 2020 · I couldn't see a roll maneuver early in the launch of the demo-2 mission, and this left me wondering if SpaceX skipped the maneuver.

Sep 16, 2015 · Attitude control during first stage was achieved by SRB thrust vector control.The large distance between the nozzles and the high thrust levels meant that the SRB TVC had enormous control authority.

Sep 10, 2017 · The S-IVB and spacecraft then go their separate ways and the docked CSM/LM coasts to the moon, over a flight of about 3 days. During the flight to and from the moon, the spacecraft would be rotating about its long axis to maintain even heating from sunlight (this is the PTC, "passive thermal control" mode, sometimes known as the "barbecue roll.").

Jun 13, 2019 · The Single Axis Rotation (SAR) maneuver started when the computed relative velocity of the stack exceeded the value stored in a reconfigurable flight software variable called PPOLY(2). The nominal value of PPOLY(2) was 118.45 ft/sec. This was nominally achieved at ~ T + 8 seconds and an altitude of ~376 feet.