Gemini 10, John Young and Mike Collins, a standard three-day Gemini mission.  Of course none of them are standard and now only three more are left to practice the techniques to get us to the moon.  Gemini 10, a most complex mission, 72 hours packed with rendezvous and EVA (spacewalking).   On this flight, not just one rendezvous target, the jinxed Agena, but two.

Finally.  The big burn.  We’re looking out at the long cylinder of the Agena stage, this one launched perfectly, unlike what happened with Geminis 6 and 9.  We wish our rendezvous had gone as perfectly, but little miscues plotting our maneuvers to the target added up, requiring major course corrections of brute force.  We expended three times the fuel that had been budgeted.  All that’s moot at the moment.  We have all the gas we need in the form of Agena locked to our nose, it’s big engine, the PPS, the Primary Propulsion System, out in front of us.  We’re about to use it to boost us to the highest orbit ever achieved by a manned spacecraft, 475 miles up, the first step toward a second rendezvous and a step toward leaving earth orbit entirely in the Apollo flights of the future.

Three, two, one, ignition…and for half a breath…nothing.  Then — wham — the engine in front of us lights, the sky flares orange-white, the big PPS drives the spacecraft back, throwing us forward against our shoulder straps, “eyeballs out.”  It drives with the force of one gravity, he biggest one-gee we’ve ever felt, making clanging noises and shooting fireworks out its nozzle.  It keeps driving for 80 seconds.  We soar to apogee, the highest humans ever.  Alas, with that big rocket stage blocking most of our view, we can’t see much but the increasing curve of the earth out the corner of our windows.

We are the Agena kings, visiting not one but two.  After a sleep period, we fire the Agena again for 78 seconds to lower our orbit toward a second target, the Agena left behind by Gemini 8.  In space since March, batteries long dead, it is a derelict.  Which means we must find it by finesse, without its radar transponder giving us range distances.  We fly almost by feel and depend on our Agena for engine power as long as we can, then cut it loose for the final approach.  At the same time, we begin preparing for a daring spacewalk.   The space derelict appears like a dim star — right where it’s supposed to be.  And we slowly approach to station-keeping distance.  John Young keeps the Gemini close hanging at an angle overhead, ten feet away.  Lucky the dead stage is stable.  He closes the gap even more.

At dawn, we emerge, float to the back of the spacecraft to attach a nitrogen line, the fuel for our zap gun.  Returning to the open hatch, we are ready to bridge the void between ourselves and the silvery Agena hanging overhead about six feet away.   We push off, floating toward the docking cone on the stage’s end.  Reaching out a gloved hand for it.