It really depends on how much of a kick the booster has.
On both Gemini 10 and Gemini 11, the Gemini spacecraft docked with its Agena target vehicle and used the Agena's engine to change orbit. This is was the same configuration as the proposed Soyuz manuever (i.e., "eyeballs out" acceleration).
Obviously, the Agenas didn't accelerate the crews to escape velocity, but I believe that the Gemini 11 crew (Pete Conrad and Richard Gordon) held the altitude record until the Apollo 8 crew performed their trans-lunar injection burn, so the Agenas did pack something of a kick.
Slashdot Mirror
It really depends on how much of a kick the booster has.
On both Gemini 10 and Gemini 11, the Gemini spacecraft docked with its Agena target vehicle and used the Agena's engine to change orbit. This is was the same configuration as the proposed Soyuz manuever (i.e., "eyeballs out" acceleration).
Obviously, the Agenas didn't accelerate the crews to escape velocity, but I believe that the Gemini 11 crew (Pete Conrad and Richard Gordon) held the altitude record until the Apollo 8 crew performed their trans-lunar injection burn, so the Agenas did pack something of a kick.