50 years ago: Apollo 16 lifts off for the highlands

April 16, 1972: Apollo 16 makes the final daylight launch in the Apollo program. The last moon mission, Apollo 17, will take flight at night.

***

Hey, Charlie, T. K., get up, time to shine — 7:49 a.m.  It’s April 16, 1972, and today we’re going to the moon.  The weather — forget those few clouds.  It’s absolutely perfect.  And the countdown out there on Pad 39-A is the smoothest ever, they say.  They’re ready; we’re ready — launch set for 12:54 p.m. EST.   A bit of history, I guess — the last daylight launch of an Apollo mission.  We’re Apollo 16.  And with us, Apollo goes fully operational — just as it is ending.

You could say we’re a month late.  At the start of the year we were scheduled to fly on March 17.  A few problems — a with a Lunar Module battery, the explosive bolts used to jettison the LM, and the commander’s spacesuit  — delayed the flight.  In that delay, a fuel bladder ruptured during pressure tests of the command ship’s Reaction Control System (RCS), our maneuvering jets, forcing the bird to be rolled back to the Vehicle Assembly Building.  The launch team fixed it and had us back on the pad without incurring further delay.

Yes, sir, Charlie, time to head for the lunar highlands never explored before.  We’re gonna land in a high plateau — we’re talking 15,000 ft. higher than the Apollo 15 site and 18,000 ft. above the Apollo 11 which landed only 150 mi. away to to the northeast.  Look up just southwest of the center of the moon seen from Earth — that’ll be us.  We’ll set down in rugged terrain between two low mountains, each rising about 1,600 ft. above our landing site.  Scientists believe the mountains are of two volcanic types that formed 200 million years apart.  We’ve got Smokey Mountain to the north, which appears indicative of volcanic forms built up by thick silica-based lava flows.  This is part of the Descartes formation, named for a big crater about 60 mi. away.  And to the south, Stone Mountain looks as if it form of a more liquid type of lava that flooded craters and the spaces between.  This type, the Cayley formation, covers 17 percent of the visible face of the Moon.  Because Cayley is covered with more craters than the Descartes formation, geologists believe it is younger.  With our trusty Lunar Rover, that 450-lb. marvel, we’ll explore the 6 mi. in between these two flat-topped mountains, hoping to also find pieces perhaps 4 billion of the original lunar crust.  And we’ll sample the rays of the bright South Ray Crater, there by Stone Mountain.  We plan to return 195 lbs. of samples during three full days on the surface and three moonwalks of 7 hrs. each.

Ours is the only flight to the highlands, the battered bright territory, as opposed to the darker, smoother mare.  Highlands covers 80 percent of the moon, including most of the far side.  And we’re absolutely 100-percent certain we’re gonna find signs of ancient volcanic activity and come back with a load of volcanic rocks.

But first we gotta get there.   It’s 3 hrs. before launch and we’re about to arrive our office, the command ship we’ve named Caspar (after Caspar the Ghost, and the way astronauts on the moon look like ghosts).  Hey, take a second before getting on the elevator for a look at that magnificent Saturn V, what you can see of it,  364 ft. tall, first stage 33 ft. in diameter with five big F-1 engines soon to produce 7.7 million lbs. of thrust.  Yes, take a second — OK, it’s time to get to work.

Once strapped in, it’s more of listening to controller,s watching displays, and waiting.   Each milestone, each “go” brings us closer to 12:54 p.m.where our destinies intersect with the Moon.

Two minutes.  We call, “Caspar and Orion are go.”   Orion is our lunar lander, named for one of the constellations we use for navigation checks.

T – minus 1 min. 15 sec.   Spacecraft batteries on, as backup to the fuel cells.

T – minus 1 min.  . . . T- minus 42 sec.  We take our last action before launch and call, “Guidance aligned.”

T – minus 30 sec.   The fuel valves open with a whump

Fifteen.  Guidance release . . . 10.  Ignition sequence start.  Those five monsters build up thrust for 8 sec., shaking the vehicle like like a rag in the mouth of a dog.   Thrust exceeds gravity, the four hold-down arms swing up and away.  

Liftoff; we have liftoff.  Slowly inching off the pad, as if on creaky bones.  Can’t even feel the vertical motion at first amid all that shaking and rattling.  “Yaw program”  The Saturn V leaning away from the tower for safety as we crawl along side it, upwards.

Tower clear.  Man, I do believe we’re on our way!

“You are go, Apollo 16.”

We call, “Roll program.”  The roll and pitch programs set us on the proper heading.

The capcom in Houston, Gordon Fullerton, calls, “Good thrust on all five.”

The bird is shaking like an earthquake.  Just 36 seconds, roll and pitch programs complete.  Gaining speed now.  A minute into the boost phase which will take more than 11 min. to reach Earth orbit. 

Our capcom calls, “Feet wet, 16.”   That means that if we have to use the escape tower, we’ll come down in good ol’ cushioning ocean.  We’re climbing the ladder of abort modes.  With increasing velocity and altitude, we gain options for reaching a safe orbit should one engine and then multiple engines fail.  

At the moment, we face the point where air density and our speed conspire to place the maximum pressure on the vehicle — called Max Q in engineering terms.

Only 1 min. 43 sec. since launch.  The capcom calls, “Max Q and everything looks good.”

We’re moving out now.  Feel this baby go — and we do feel it, forces building to 4.5 gs

A half minute after Max Q, the center F-1 shuts down as planned to ease the coming stresses of staging.  “Inboard shutdown” we call.

“Roger, you are go for staging.”

In just 2 min. 42 sec., that big first stage had burned 4.5 million lbs. of propellant and finished its job.   And the shock of shutdown and tossed forward against our straps.  We’re rung by a metallic hammer, like being in a train wreck, as we discard the spent stage.

“Staging” we call.  We see debris fan past the only window we have at the moment, the center one.  The g forces release, with a feeling as if we’ve stopped for a moment, then two seconds later . . .

“Ignition S-2”   The S-2 is our hydrogen-fueled second stage, powered by five smaller J-2 engines producing a combined thrust of more than a million lbs.   As smooth as glass, she leaps from the gate.  

The capcom calls,  “Go on all five on the S-2.”  

And at 3 min. 20 sec. — pow — the escape tower above us, no longer needed, blasts free, taking with it the protective boost cover that has blocked most of our windows.  “Tower jettison.”   

As smooth as glass for about the first 3 min. of the second stage.  Then we pick up some high-pitched vibration from the S-2.  Every small sensation and sound grabs our attention.

“Sixteen, Houston.  Four minutes and everything looks good.”

“And it looks good up here, too.”

We’ve pitched over so the five engine fire perpendicular to earth, our nose is down enough that we can see the horizon and Atlantic below.  “Just gorgeous.”  We are really up here!   Look at that sky — pure black.  We feel exhilaration as well as acceleration.

At 7 min. 42 sec. the center engine, just like on the first stage, shuts down.  And 9 min. 20 sec., the stage reaches the end of its lifespan and is kicked away.

“S-4B ignition.”  We on the single, restartable J-2 engine of the third stage which will remain with us.   After two orbits, it will use the bulk of its fuel to send us on our way to the moon.  Right now we just need a bit of a boost to reach the low parking orbit where we’ll check everything out before heading out for our rendezvous with the Moon.   

Houston predicts a cutoff at 11 min. 49 sec.   That’s called SECO, sustainer engine cutoff.  They call, “Apollo 16, you’re go for orbit.”

And there it it.  “SECO — right on!”

The capcom calls, “The orbit is go.”

“Roger.  It’s just beautiful up here, looking out the window.  It’s just really fantastic.  And that thing worked like a champ.”

As we ride toward sunset over the Indian Ocean.  For you veteran astronauts, “Sunsets are as beautiful as ever.”

*

Our short time for viewing the Earth from low orbit is over.  We’ve dealt with our first problem, an overpressure in the S-4B’s helium tank that causes the tank to start venting.  The helium is used to pressurize the stage’s Auxiliary Propulsion System that maintains its position.  We’re advised if the helium runs out before the big burn that’s coming up, we’ll have to maintain the orientation of the stack using our Service Module’s RCS control jets.  We’re trained to do that.  But on the second orbit, Houston determines the helium supply will hold out.  We receive the word all Apollo crews love to hear:  “You are go for TLI.”

TLI

That’s Translunar Injection.  

What an injection it is — re-ignition of the third stage,  2 hrs. 33 min. 36 sec. after launch.  The burn takes 5 min. 42 sec. and boosts our velocity to nearly 24,000 mph, enough to break out of earth orbit.  

Now it’s our Command Module Pilot’s turn to take the spotlight for transposition and docking.  T.K. separates the command/service modules of the mother ship from the spent stage — and atop it, the garage for our LM, Orion.  We drift out 50 ft. and turn around.  

Four panels — like flower pedals, are jettisoned to unveil our lander perched atop the stage.  T.K. noses us in — slowly.  We’ve got the TV on to show the world the docking

As he does, we’re seeing something that causes our hearts to leapfrog.  A stream of particles coming from the area of the propellant tanks for Orion’s RCS maneuvering jets.   Glinting in the sun — I’ll swear it’s a stream of ice crystals.  As in a propellant leak.  And if we’re losing fuel, we’ve already lost the landing.  No way can we land with a leak like that.  Does Houston see it?   

Concentrate on the job at hand — and T.K. does, taking us in nice and slow.

“OK, we’re captured there, Houston.”

Captured, but not fully docked.   T.K. takes his time, letting vibrations damp out before he fires the twelve latches at the rim of the connecting tunnel to pull us tight.  We hear the ripple bang of the latches closing.  “OK, Houston, we’re hard docked.  And there’s no question when you get the latches.”

Right now, we’re not speculating on those particles of — who knows.   We’ve got a half hour before we pull the LM free of the spent third stage and take a moment here train the TV on a beautiful look at the receding Earth.  The Capcom exclaims, “We can see the southwestern United States, lower California.  Very nice.”

“You just can’t believe how beautiful it is — the red of the desert down there in southern United States and northern Mexico.  From here you can see the Great Lakes and straights of Florida out there.  It’s just absolutely something!”  Something we don’t have much time for.  “We’re going back to work.”

And that work includes checking about those particles still floating away from Orion.  About 8 hrs. into the flight we turn the TV on again, to show the particles drifting from Orion’s skin:  Is it a stream of particles or just flakes?  Well, before docking, it sure seemed a stream.  But since the sun angles have changed, it doesn’t look so.  It appears to be a silicone-based paint applied as insulation on the thin skin of the LM flaking off.  Indeed, some of that insulation looks like shredded wheat.

Still, we want to be sure we don’t have a fuel leak, and are delaying our sleep period to make sure.  As T.K. works the camera, we Entering the LM, a day early, powering up systems for a check of the RCS propellants.  Both the propellent quantities and pressures look perfect.

The peeling paint presents no concern, Houston tells us, you’re go for the moon.  It was a scare, though — and we sure don’t want another like it.  No, sir.

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