Let us now mourn the end of an era: the Space Shuttle. With the 2011 Atlantis launch, itâ€™s over. It was the E-ticket ride of a lifetime, atop millions of Newtons of main-engine thrust, including rocket energy from the two solid-state boosters that launched it. The experience was memorable and engaged hundreds of millions of earthbound mortals and a few lucky astronauts. This pilot was fortunate to see one small step in its history.
â€œ. . . five . . . four . . . three . . . two . . . one . . . we have liftoffâ€â€”familiar words in my headset. I am about to fly the worldâ€™s biggest and costliest glider, the billion-dollar Space Shuttleâ€”well, actually, the Shuttle Mission Simulator, or SMSâ€”at NASA-Houstonâ€™s Manned Spacecraft Center. The SMS, a core element in astronaut training, simulated most Shuttle evolutions. For me: the RTLS (Return To Launch Site), flown only as a simulation, never in life. With the Shuttleâ€™s retirement, it will never be undertaken. Just as well. Itâ€™s a full-fledged emergency.
The bird is poised on the â€˜launch pad.â€™ Atop the â€˜stackâ€™â€”orbiter plus main-engine tank and boostersâ€”I lie on my back in the cockpit, right hand on the stick, feet on the rudder pedals, the gantry visible in the left window.
Except for the ADI (Attitude/Direction Indicator) and compass, the cockpit instruments are unfamiliar, especially the vertical â€˜ribbonâ€™ indicators (Iâ€™m still a â€˜round gaugeâ€™ or â€˜clock shopâ€™ pilot, though MFDsâ€”Multi-Function Displaysâ€”are handy). Like the early astronauts, Iâ€™m the metaphorical â€˜spam in a can,â€™ nothing to do until later. My instructor pilot is in the left seat. If he is anxious about how I will fly, he hides his emotions carefully.
Launch and initial flight are managed by quadruple-redundant computers (cynics say those computers had less processing power than a modern cell phone but they took man to the Moon and back successfully). We are just passengers, like it or not.
At an initial 350,000 FPM climb rate, it makes the U.S. Navy F/A-18 Hornet I flew at the Naval Strike Warfare Center, Fallon, Nevada, with aÂ â€˜mereâ€™ 50,000 FPM, seem anemic in retrospect. But this is a test. Iâ€™m on trial, willingly. I am . . . crazy.
The test: a hand-flown Shuttle final approach. Here we go again. Repeat after me: â€œThis is only a simulator. Relax. Only a simulator.â€ Yeah, right. The SMS duplicates well the rolling, rumbling sensation of raw launch thrust, tangible through the seat, visible in the shaking of the entire cockpit. Sensations of an altered reality invade my mind and body.
As we â€˜ascendâ€™ from launch, a booster rocket fails, as programmed, within the first three and a half minutes. Lacking sufficient thrust, we cannot attain orbit nor reach an alternate landing site such as the Azores or Africa. RTLS is our only salvation. First we must burn off fuel, flying more nearly vertical to stay within range of the Cape. Shuttle orientation is now reversed with thrusters, pointing us back to the Cape, timed so that MECO (Main-engine Cutoff) has left enough energy for a safe return. Tank and booster separation will occur over the Atlantic. I will hand fly the landing.
Now, the cockpit instruments indicate, weâ€™re traveling in near space at Mach 10, but backwards to about 400,000 feet altitude, with â€˜reverseâ€™ thrust slowing us down. We stop, literally, and head home. Newton (Isaac: flowing locks, quizzical gaze), at 1G, waiting patiently 24/7, strikes againâ€”we need him now. Reynolds (Osborne: bearded, serious mien) and Mach (Ernst: glasses, frown) are waiting to contribute their famous numbers, once enough virtual â€˜air moleculesâ€™ flow over our virtual wings. Enough with this historical nonsense. Focus, concentrate.
The flight computer will position us for landing. Ahead: black space speckled with stars there is no time to identify, earth curvature, the Florida coast below. What a view! This is what Richard Bransonâ€™s Virgin Galactic will give civilians soon, at $200,000 per. We decelerate to subsonic, arriving at 10,000 feet, at 235 knotsâ€”landing-gear limiting speedâ€”eight miles from touchdown. I select â€˜downâ€™ on the gear actuator and see a satisfying â€˜three greenâ€™ indication, take the air-brake handle in my left hand to adjust airspeed and touch-down point. In the bag? Maybe.
What hath that computer wrought? It has placed us in the energy window that should put us â€˜on the numbersâ€™ at a cleverly simulated, virtual Cape Canaveral, with 16,000-foot main runway. Can I fly the approach competently, without prior stick time? Do I have delusions of adequacy? I yearn briefly for Edwards AFBâ€™s 15,000 feet of concrete, plus 9,000 more of Rogers Dry Lake for undershoot. I glance at my instructor. He remains impassive, mercifully silent.
The distance/altitude equation yields a 4:1 glide angle, but itâ€™s just another glider, right? Through the HUD (head-up display) I note a broken undercast at ~5,000 feet. We punch through and the runway lies ahead, in the clear. I want to float it onâ€”like the delicate arrival of sailplanes I fly in the Sierra Nevada. Itâ€™s . . . just another glider. Not!
Minimal kinesthetic feedback through the stick, negligible â€˜pullâ€™ G forces and absent vestibular sensations makes control motions unnatural, somewhat like a video game. One must use visual cues, but the three-axis controlsâ€”pitch, roll and yawâ€”respond conventionally. I fly the HUD velocity vector at 185 knots, as required, flare over the threshold, alight on the centerline. The virtual drag chute deploys on touchdown, then departs as we decelerate smoothly to a stop.
Long pause. Resume breathing. Phew! I look over at my instructor. He is smiling.
In real life, the SMS let Shuttle crews experienced complete simulations of entire flights, liftoff to landing, the outside world represented faithfullyâ€”the launch pad, the sky field with stars in place, the earth-sky interface and every part of Earth the Shuttle overflew. Crews spent up to 480 SMS hours to train for each flight, starting at launch minus 480 daysâ€”16 months earlier. Serious stuff.
We are down on Cape Canaveralâ€™s â€˜runwayâ€™ after 22 nail-biting minutes. But one never really comes down from a space flight, even if only simulated.
The Space Shuttle: gone, but not forgotten. Former astronaut, astronomer Dr. George W. â€˜Pinkyâ€™ Nelson said it: â€œThis must be the best job in the world.â€ Or out of it.