Author Topic: Gemini-Titan-II Launch - Astronauts heads up/down/sideways ?  (Read 1814 times)

Offline IvanS

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I've been studying launch footage of several Gemini missions.  It's not clear to me how the spacecraft was oriented during launch.  The roll program lasted some 11 seconds.  If I watch the footage, the launch vehicle seems to roll slightly clockwise. 

Launch complex 19 was slightly off the norht/south axis.  Didn't measure, but let's say about 170 degrees from north, so the astronauts heads would be nearly due south.  So, that slight CW rotation would more or less mean their heads would turn due south, but then the launch vehicle 'pitch program' of the launch vehicle would be a 'yaw' for the spacecraft, and the Pilot would be on the 'Earth' side and the Command Pilot on the 'space' side. In other words 'laying' on their right side towards earth.  Video footage seems to support that, since the two engines (left-right in relation to the spacecraft) appear vertical in the videos.

Heads down would make more sense so the horizon would give a visual clue.  Puzzled, and I don't find sources which mention this. 

Offline eric z

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 Gemini, oh God, those were the days! 8)

Offline Jim

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the crew did fly sideways to orbit

Offline ppb

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Best orientation for the ejection seats?

Offline IvanS

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Thanks Jim, for confirming. 

That's what it looks like in the videos. The 11 second roll also collaborates that, it's hardly noticable in the videos.  For a heads up or down, the roll rate otherwise should have been about one revolution per 40 seconds.   


I've searched numerous Gemini docs, but could not find any details on the launch roll program.

As to the ejection seats, I believe 'heads up' would be the least optimal choice, working against gravity.

Offline goretexguy

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The nylon parachutes used had to be safely away from the fireball of an exploding rocket. I believe this was calculated to be 800 feet.
On the pad, you want your seats to point away from the tower and any other structures.
In flight, ejecting up or down puts the astronauts in the path of a fireball or falling debris. Sideways ejection has the best chance of getting astronauts clear of an explosion. Finally, the seats in the capsule were mounted at an angle relative to each other, so that in the event of ejection their paths would be divergent. (There may have been additional reasons to so arrange the seats within the capsule.)

Update: Found a supporting doc, "NASA Technical Note - Development and Qualification of Gemini Escape System"
https://ntrs.nasa.gov/api/citations/19670019706/downloads/19670019706.pdf

This doc doesn't describe the roll program or astronaut orientation, but is still interesting nonetheless.
« Last Edit: 09/15/2023 03:15 pm by goretexguy »

Offline IvanS

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Gonna look up launch vehicle data. Maybe that shows the pitch axis defined differently from the s/c.

Offline Jim

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Gonna look up launch vehicle data. Maybe that shows the pitch axis defined differently from the s/c.

they typically are different.

Offline Jim

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(There may have been additional reasons to so arrange the seats within the capsule.)


the only way they could fit

Offline IvanS

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I found everything I need to back this up...

The launch photos clearly show the stage I engines were oriented on the left-right in releation to the Gemini spacecraft being the pitch axis.

AEROSPACE REPORT NO. TOR-t001 (212680)3
GEMINI PROGRAM  LAUNCH SYSTEMS FINAL REPORT
page 105 (II C3) (see attached) shows that axis as the Launch Vehicle yaw axis.  So only a few degrees of roll to put the LV in the proper azimuth, with the crew launching 'laying' on their right side (Pilot towards earth, Command Pilot towards sky/space)

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