Orsdxy

Manned launches have always been launched prograde to take advantage of the Earth's rotation velocity boost, and often in order to match the prograde orbit of another spacecraft for rendez-vous.

I wonder if any of the manned orbital launches to date could have reached at least a lower, short-term-stable orbit if launched in a retrograde direction, let's say with an additional 180 degrees inclination, they don't need to be zero-degrees equatorial.

I'm curious if this would have been impossible, or achievable and simply requiring the topping-off existing propellant tanks.

I have read that the launching near the equator gives the rocket more speed, but I wonder if it is at all possible to launch against the rotation.

The “westward penalty” from Canaveral would be about 800 m/s of delta-v, about 8-9% of the total delta-v requirement to orbit. Most crewed launchers to date have not had that much performance in reserve.

Atlas/Mercury and Titan/Gemini could not have managed it. The boosters were completely expended to reach orbit, and Gemini didn’t have much maneuvering capability.

The low Earth orbit Apollo missions (Apollo 7 and 9) could have reached orbit, and even carried out something like their intended missions.

Apollo 7 was a crewed CSM on a Saturn IB booster. The CSM had substantially more than 800 m/s available, and in fact the “mode IV” abort option would use the CSM as a third stage to reach orbit if the S-IVB second stage failed. Apollo 7 did a lot of orbital maneuvering to test the CSM engine, and that would have had to be cut short if it were going to spend that much fuel on ascent, but a sizable portion of the original mission plan could have been carried out in retrograde.

Apollo 9 was a CSM/LM flight to LEO on a Saturn V; if fully fueled, the third stage would have had around 3000 m/s of delta-v capability (needed for translunar flight), so a much lighter fuel load would suffice to go into retrograde orbit.

I believe any of the Apollo lunar missions could have gone from a retrograde Earth orbit ascent to a lunar flyby without hardware modification, abandoning the LM (or docking and extracting it very quickly) when the S-IVB ran out of fuel and completing the TLI on the CSM’s engine. If the LM wasn’t brought along (as on Apollo 8) and both the S-IVB and CSM were fully fueled, a lunar orbit mission might even have been possible from retrograde LEO.

The space shuttle might have had the capability if little or no payload was carried — I’ll run the numbers once I’m near a bigger computer.

I don’t think the Soyuz or Long March launchers had that sort of performance margin.