posted 04-25-2020 04:41 AM            

The Mercury capsule used a landing bag to absorb some of the impact load of landing in the water and this of course made for a softer landing. No such provisions were made for the Gemini capsule and of course, the astronauts had the unusual difference of landing seated upright.

posted 04-25-2020 10:40 AM               

Combined with an ocean swell height, where the spacecraft could touch down at the peak or trough of a wave, but could also impact the wave as it was going down or coming up to meet the descending spacecraft.

For these reasons there is no answer to your question, because each landing occurred under different conditions.

posted 04-25-2020 11:58 PM               

quote:

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Originally posted by Explorer1:
Also, what were the landing speeds for the Mercury and Gemini spacecraft?

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Landing at a rate of 30 fps with the landing bag down is a good solid jolt, but certainly tolerable. In fact, one does not really have to be in an ideal position and braced tightly to be able to take this momentary shock in good shape.

Even with the huge chute, I was dropping at 32 feet per second, or approximately 22 miles per hour. Upon impact with the ocean, the force of the spacecraft drove it a good 10 to 12 feet underwater before it popped back up to the surface.

Impact was very, very soft. We just hit. We hit very easy. We didn't go underwater at all. We didn't change attitude one bit from the time we hit the water. We went bloop.

posted 04-26-2020 02:32 AM               

Later in the report "The landing bag performed satisfactorily and, although there was no instrumentation provided to record landing accelerations, the pilot reported that the landing impact was moderate. He compared the acceleration to that of an aircraft catapult launch."

Shepard reported during descent, "Main chute is good, rate of descent is reading about 35 ft/sec."

In the MR-4 Post Launch Report, Gus Grissom described his Mercury landing.

The spacecraft landing in the water was a mild jolt; not hard enough to cause discomfort or disorientation. The spacecraft recovery section went under the water and I had the feeling that I was on my left side and slightly head down. The window was covered completely with water and there was a disconcerting gurgling noise. A quick check showed no water was entering the spacecraft. The spacecraft started to slowly right itself; as soon as I was sure the recovery section was out of the water; I ejected the reserve parachute by actuating the recovery aid switch. The spacecraft then righted itself rapidly.

The landing bag arrangement adequately attenuated the landing deceleration loads to approximately 15g.

Mercury and Gemini: These manned spacecraft were omnilanders with preferred orientation, designed for injection into Earth orbit, followed by entry and landing. Each spacecraft was designed primarily for water landing, with a reduced-performance capability for land landings. The Mercury and Gemini spacecraft carried one and two men, respectively; their respective nominal vertical velocities before impact were 28 fps (8.5 m/sec) and 30 fps (9.1 m/sec).

posted 04-26-2020 08:08 AM               

quote:

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Originally posted by Explorer1:
...the astronauts had the unusual difference of landing seated upright.

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