April 12 belongs to Yuri Gagarin . . . And Columbia

Yuri Gagarin — April 12, 1961 . . .
. . .And 20 years later, the first flight of the Shuttle, missing tiles visible on the OMS pods

*

*

            Ready for a leap into the unknown?  We’re up again at about 2:25 a.m.  It’s April 12, 1981.  We, the two pilots for the first Shuttle flight, STS-1, repeat the pre-launch rituals we went through two days ago.  Ready. In our orange Launch & Entry Suits, we leave for the pad in the pre-dawn darkness.  Ready.  Is the Shuttle?  The count is going smoothly, but so many unknowns, including the first manned launch on those twin Solid Rocket Boosters flanking the stack.  

            Yet smooth is the word of the morning.  We’re once more in the flight-deck cockpit, running through systems checks.  And waiting.  Even the weather is looking perfect. 

*****

            It’s April 12, 1961. Ready for a leap into the unknown? It’s 5:30 a.m., Moscow time, and at the Baikonur Cosmodrome in Kazakhstan near the village of Tyura’tam, the Chief Designer enters the cosmonaut quarters and flips on a light, waking Yuri Gagarin and his backup, Gherman Titov.  He jokes, “What’s this, my dears, a lie-in?”

            Gagarin was only selected for the flight two days before.

*****

 

           It’s getting close now. Will we really go?  T – 20 minutes.  Coming up to the point where the computers transition to Terminal Countdown Mode 101 and the backup computer comes online.  Unlike two days ago, it synchs up perfectly.

            Events move faster now. T – minus 6 min. 15 sec.  Launch Control calls, “You are go for APU prestart.”  We’re ready to start the Auxiliary Power Units that power our hydraulic systems.

            T – minus 5 minutes. “You are go for APU start.” We flip the switches.  For the first time, it feels like we really might go this morning.

            Just under two minutes to go, we hear, “You are go for launch.”  And a voice adds, “Smooth sailing, baby.”

            At T – minus 31 seconds. “We’ve gone for Redundant Launch Sequencer.”  Our onboard computers are now controlling the final seconds of the count.

*****

            At 6:50 a.m., Moscow Time the van carrying both Gagarin and Titov arrives at the pad, the same that launched the world’s first satellite, Sputnik.  The Chief Designer is already there at the base of the pad, wishes Gagarin a good flight and says, “Well, it’s time to go.” Gagarin climbs the metal steps to the elevator, turns and waves.

*****

 

           At T – minus 6.6 seconds, go for Main Engine Start.  Columbia’sthree main engines start in a staggered sequence and begin building thrust with a bang.  It takes about a second before we feel it — the rumble.   The asymmetric force of the thrust causes the stack to sway — what we call the “twang” — bending through a 2-ft. arc.  To us, it appears the tower is moving.  When the stack snaps back to vertical — pow — the two solids fire, gaining full thrust — 2.65 million lbs. of kick each — in a fraction of a second.   And we leap from the pad, everything ringing with a violent vibration.  In the blur, we can barely read the instruments.

******

            Yuri Gagarin is strapped into an ejection seat in the spheroid descent module of the great Korabl-Sputnik, renamed Vostok (“East”).  The sphere is strapped at its bottom against an equipment module shaped like two cones joined base to base.  The module houses oxygen/nitrogen supplies, batteries, and the liquid-fueled retro-rocket system.  Both are surrounding by a launch shroud and sit atop the Chief Designer’s R-7, the same rocket as launched Sputnik-1 but with the addition of a third stage.

            A minute before launch, Gagarin calls, “I am feeling fine, and I’m ready for launch.”

*****

 

           And in a second’s time, the vibration eases.   And we’re moving out — in just six seconds, we’re past the 247-ft. tall launch tower.

            That quick vibration we felt signaled something more violent.  It was caused by shock wave from SRB ignition that rebounded off the pad and struck the Shuttle.  The acoustic pulse, which lasted only 20 milliseconds, was ten times stronger than predicted, a prediction based on faulty calculation.  The force deflected the moveable body flap at the tail, crucial for hypersonic flight, by 5 degrees.  It struck the twin OMS pods with an effect soon to be visible.

            And caused struts holding an oxidizer tank in the nose for the forward Reaction Control System to buckle.  Luckily, the propellant lines didn’t burst.  

            In the first second of flight, we escaped disaster.  Barely. We didn’t know it, nor did Mission Control

            Actually the force of acceleration doesn’t slam as hard as you would expect.  Not bad.  Not bad at all.   And we’re in the roll/ pitch program, the vehicle pirouetting so the orbiter is underneath the stack as the vehicle slants to a east-northeast course that will take us toward Gibraltar.

*****

            Gagarin feels a shuttle as valves open.  At 9:07 a.m. Moscow time, the engines light. He feels a slight shutter at liftoff and shouts, “Poyekali.”  (“Let’s go.”)

*****

 

           Columbia‘s three liquid-fueled engines — SSMEs, we call them — Space Shuttle Main Engines, producing a combined 1.12 million lbs. of thrust — throttle back to 65 percent just before we hit Max Q — the maximum dynamic (air pressure, if you will) 53 seconds after liftoff.  We pass through this “wall,” and Houston calls, “Columbia, Houston, you’re go at throttle up.” 

            The ride on the solids is loud and a bit rough.  Just a bit. Not bad.  Yet something is not nominal.  Our instruments show we’re pitched up, damn near off scale.  We’re lofting.  Because the SRBs, it will be determined, are producing more thrust than expected.

            A couple minutes into it, Houston calls, “You’re go for SRB sep.”

            “Roger on the sep.”

            When those things separate, there’s no doubt about it.  The small separation rockets toss a tongue of smoke a flame licking the side windows.  The SRBs were projected to separate at 164,000 ft.  Because they ran hot, the sep occurs at 174,000 ft.    

*****

            Two minutes into flight, the R-7’s four strap-on boosters separate, followed a minute later by the launch shroud.  Gagarin can now see outside through the Vostok’s three portholes.  “I see the Earth.  I see the clouds.  It’s beautiful — what beauty!”

            At 9:12 a.m. Moscow time, the core (second) stage burns out and the the third stage fires.  The noise decreases. 

*****

  

          And the ride on the SSMEs smooths out.  Very quiet.

            At three minutes, Houston calls, “Columbia, you’re looking a little high.  All your calls will probably be a little early.” The computers adjust the trajectory to erase the lofting caused by the “hot” SRBS.  We’re given a go to continue.

            “Columbia, standby for negative return . . .  Negative return.”  A sweet call — means we won’t hear a call no one wants, “abort RTLS.” That’s Return To Launch Site,” a damn tricky, nearly impossible maneuver to abort the launch and fly back to Kennedy. We’re beyond the point where it could be attempted and are counting through milestones toward the big call: MECO — Main Engine Cutoff — that culminates the launch sequence.

            When we reach an altitude of 76 mi., the Shuttle pitches over to gain more speed.  And there it is — the blue ocean of Earth.  “What a view, what a view!”

            The beautiful words come from Houston:  Press to MECO.”  Press on to orbit.

            “Columbia, you’re go at eight [minutes].”

            And a half minute later, we call.  “MECO.”

            “Roger, MECO.”

            Events continue to occur rapidly.  A few seconds later, we separate from the spent External Tank.  Look at that thing — no longer white, it’s been scorched black, at the base, nose, here and there.  Looks like it’s been through a war.

*****

             At 9:21 a.m., the Vostok’s third stage is jettison. Yuri Gagarin is the first human to enter Earth orbit.  

            He reports, “Weightlessness has begun.  It’s not unpleasant, and I feel fine.”

            Twenty minutes into flight, the Vostok sweeps over Siberia, touches the Arctic Circle before its orbit arcs towards the North Pacific and begins a southward track.  At 9:49 a.m., the spaceship enters Earth’s shadow — very abruptly, to Gagarin.  His track takes him down the Pacific, west of the Americas.  He can see the stars, bright and distinct.  He reports, “I’m in a good mood.  I am continuing the flight.”

            At 10:02 a.m., Radio Moscow announces the launch of the world’s first space traveler.  “The world’s first spaceship, Vostok, with a man on board was launched from the Soviet Union on 12 April 1961.  The pilot space-navigator of the satellite-spaceship is a citizen of the USSR, Flight Major Yuri Gagarin.  

*****

  

          Every experience is new. The three SSME swivel to their stowed position — and it’s enough to cause the Shuttles nose to pitch up a few degrees.  That triggers the big nose jets to fire — with a sound that startles us, like howitzers going off.  For a second, we wonder if something has gone wrong.

            We’re in space, weightless — but not quite in orbit.  We need two engine burns to step us into a low, circular orbit.   We do these with the smaller OMS engines in the pods at our tail.  The two Orbital Maneuvering Engines each produce 6,000 lbs. of thrust.  They’re used for all our major orbital changes.

            The OMS #1 burn comes less than 11 min. after launch.  We lose contact with Houston through the Bermuda tracking station just as the burn begins.  The capcom calls, “You’re looking good going over the hill.  See you at Madrid.”

            We burn the engines 1 min. 27 sec. to lift our orbit’s high point to 130 mi.   And 20 min. later, as we reach apogee,  we fire again, OMS #2, just a 44-sec. burn, to lift our perigee and circularize.  In the course of the first seven hours of flight, we will fire the engines three more times to raise our orbit to 170 mi.

*****

            At 10:09 a.m. Moscow Time, Gagarin experiences orbital sunrise for the first and only time on his one-orbit mission, a bright orange strip curving along the horizon.  He reports the flight is going “as smooth as silk.”  His orbit swings over Cape Horn and northward to Africa, on a course back toward the Soviet Union.  Already he must be prepare for retrofire, confirming the automatic systems — which control all aspects of the flight have oriented the capsule properly.  (Manual controls are locked, only to be used in an emergency.) 

*****

           Everything is just going fine.  We can get out of our seats now, move to the rear workstation with windows that look into the payload bay, empty for this flight except for test instrumentation boxes. Our next big task is opening the twin payload bay doors to expose the 60-ft.-long payload bay to space — and most importantly, free twin 15 – by – 10 – ft. radiator panels that serve to cool all our electronics.  If we can’t deploy the doors and hence the radiators, we’ll have to come down after only a couple orbits.

            And of course just as vital is the ability to close the big doors.  They are the largest graphite-epoxy structures ever flown in space. Will they warp out of shape and refuse to latch?   We’ll repeatedly open and close them to make sure they function.

            When we open the doors, they flex a bit — seem good.  But what they show at the rear of the Shuttle startles us.  “Hey . . . We’ve got some tiles missing.”

            Everyone’s worst fear — those touchy, fragile heat-protection tiles.  At the start of the second orbit, 1 hr. 53 min. into the flight, in a TV pass over the U.S., we show the twin pods.  “We want to tell y’all here — we do have a few missing tiles off both of them.  Off the starboard pod, it’s got basically what appears three tiles and some smaller pieces.  And off the port pod . . . I see one full square and a few little triangular shapes missing.”  We don’t know it, but we shed the pieces at liftoff.

*****

            At 10:25 a.m. Moscow time, Vostok’s retrorockets fire for 40 seconds.  Gagarin feels the force.  The equipment module separates 10-12 seconds later.  The retaining straps release and Gagarin sees the module’s indicator lights go out, as they should when a bundle of electrical cables is severed.  Then the lights come back on — meaning the lines still connect the two modules, which begin swinging around each other wildly.  

            The spherical capsule is weighted to point the heaviest shielding into the path of reentry.  It cannot do so.  Gagarin hears a crackling sound, sees a glow seep around the shutters covering the portholes. 

***** 

 

           We’re concerned about the missing tiles.  Damn right. Yet we also see a visible reason for confidence.  We can see that the red compound — RTV — used to bond the tiles is still there. In itself, it will protect the pods from heat of 600 – 700 degrees.  And would act as an ablative, like the old heat shields on capsules — carrying off heat as it boils away.  And the pods do not receive the high heat on reentry — they receive more on launch. We’ve got reason to be confident. And all the other tiles we can see, on the vertical stabilizer, on the leading edges of the wings, look in great shape.  Yes, we have reason to be confident.   Yet . . . 

            On the ground, they are shocked at the sight.  Worried, although they don’t let on to us.  And quickly begin to marshall military surveillance “assets” — high-powered cameras in Hawaii that can image a satellite.  And two KH -11 spy satellites, highly classified, to try to take pictures of the critical black tiles on the bottom of the Shuttle. Opportunities are few when the orbits cross, and time is short.

            Meanwhile, we put it out of mind.  We can’t do anything about it — so let’s get on with our job, testing and evaluating every aspect of the Shuttle.  It’s operating magnificently, and to the world, all seems well.  “Columbia, Houston.  You guys did so good, we’re going to let you stay up there a couple days.”   

*****

            The fires of reentry finally burn through the cables.  The capsule is flung like a shot put, spinning at high speed.  Gagarin’s vision blurs, he nearly passes out.

            Luckily when the capsule reaches the denser layers of the atmosphere, the violent rotation lessens

            The capsule, with a diameter of 7 ft. 6.5 in., weighs more than 5,000 lbs.  Its parachute is not big enough to slow it to a safe speed for a human to endure.  All along, it’s been planned that the cosmonaut will eject at 23,000 ft. and land with on personal parachute.

            With the capsule still unstable, Gagarin punches out early.   This, at least, goes well.  He softly touches down at 10:55 a.m. in a plowed field near the village of Smelovka in the Saratov Region.  His flight into history has taken 108 minutes.

            Workers from a farm rush to him.      

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