Spider flies free

This is it, the big day, fifty years ago, Apollo 9’s fifth flight day, the lunar module flies free for the first time, risking our lives in a machine with no heatshield, no way to return to earth.  We must make rendezvous with the command ship — or die.  So, as always, the day proceeds in small steps.

Into the lander again, powering it up.  We’re standing before the two triangular windows, as the LM, to save weight has no seats, just straps to hold us in place.  Ready to undock.  And things don’t go good at the start.  The docking mechanism, the three nose latches, hang up for a bit.  Dave Scott, riding the Command Module alone, hits the retract button again, holding it down, and we’re free.   Dave moves back 50 feet for a short period of station keeping in which we put our lander, “Spider,” into a pirouette so that he can inspect and photograph it.  Then he fires his thrusters to put the command ship in a different but nearby orbit, so that we can test our guidance systems and rendezvous radar.

Everything OK, we fire our Descent Engine at the bottom of the box-like landing stage.  The engine is can be throttled between 1,050 pounds and 6,300 pounds of thrust, and we fire it for 19 seconds, throttling from ten to forty percent thrust.  At twenty percent, our commander, Jim McDivitt, reports “It got a little rough and shaky as I throttled up.”  But then it smooths out.  The burn places us in a slightly higher orbit that will move us out 50 miles from the command ship, “Gumdrop.”  Imagine the course in relation to the command ship as shaped like the outline of a football that will loop us back.  We follow our football course for just over an orbit, for nearly two hours.  Back within distant sight of Gumdrop, we fire the Descent Engine for 22 seconds.  This moves us about 100 miles away, out of sight of Gumdrop.  We are alone.  We separate from the descent stage with its landing legs, which on landing missions will be left on the moon.  “The staging went OK.”   We briefly fire the Ascent Engine which actually protrudes into the cabin, it’s can-like housing just behind it.  It produces 3,500 pounds of thrust.  We are amazed that it makes no noise.

And so we loop back to Gumdrop.  Scott has trouble seeing us, as our big rendezvous light went out at staging.   Then we close, come into view.  “You’re the biggest, friendliest, funniest Spider I’ve ever seen.”  But you’re upside down, he adds

“One of us is.”

Then at close approach, we are the ones having trouble seeing.  Sunlight glaring off the command ship blinds us.  We’re suppose to be the active partner in this rendezvous, vital to show we can control the docking process.  “I can’t see what my attitude is, Dave,” McDivitt calls.

Scott helps guide us in.  “Now you’re coming in.  That’s much better . . .  There you go.  I think you have a handle on it.”

Contact.  “I have capture.”

Scott says, “That was a very nice docking.”

“That wasn’t a docking.  That was an eye test.”

And with it, all the major goals for Apollo 9 have been achieved.   After transferring back to the command ship, we cut Spider loose.  By remote, its Descent Engine is fired for six minutes, until fuel depletion, placing it in a high orbit.  A derelict, will not reenter the earths atmosphere until October 1981.

We still have five days to go, easier days, filled with more tests of the command ship and earth photography.   For now, we tell the ground to let us sleep in.  “Don’t call us — we’ll call you.”