The Colonel pressed his PROCEED computer key on the small keyboard by his gloved right hand.
“TIG minus 5, 4, 3, 2, 1. Ignition!” the AC called out.
Eighty-five feet behind the pilots, each OMS rocket in Endeavor’s tail thundered to life with each engine pounding away with three tons of thrust. As the two engines fired, the flight computers automatically began to dump overboard the unburned propellants trapped in Shuttle’s internal fuel lines from the quiet main engines. First, 3,700 pounds of liquid oxygen spewed out through the cooling center main engine. When this was completed, 1,700 pounds of unused liquid hydrogen would be dumped into space through the umbilical vent on the starboard side of Endeavor’s tail. Helium gas would then flood the frigid fuel lines to drive out any traces of unburned propellants to avert an explosion in Shuttle’s bowels.
“Shutdown!” the AC called as Mother pulled the plug on the two OMS rockets after 87 seconds. “Looks good, Jack. Delta-V right on at 165 for an orbit of 132 by 57 nautical miles. On our way now, Buddy!”
Endeavor, well clear of the tumbling external tank, climbed toward her higher, safer orbit in pursuit of LACE. Their new orbit’s low point of 57 nautical miles was still fatally low. But the OMS-2 burn in 28 minutes would fix that.
“MPS inerting routine is continuing, Skipper. Major Mode 105 now running.”
“Roger, Number One. Douche ’er out, Jack.”
The cleansing of the Main Propulsion System would continue for another ten minutes.
“Close your doors, Jack.”
The copilot anxiously watched five lights on the cluttered instrument panels at his right side.
“ET umbilical doors closed and latched, Skipper.”
Enright pushed five lighted pushbuttons which confirmed that two large doors had closed and sealed on the underside of the rear of Endeavor’s black wings. Through these two doors in the ship’s belly, the ET’s 17-inch-wide pipes had passed into Shuttle’s insides to feed propellants from the ET into Shuttle’s three main engines, which remain permanently attached to the ship’s square tail section. Failure to seal the doors, each four feet square, would spell doom during re-entry’s searing heat.
“OPS-2, Major Mode 205, running in the GPC.”
“ ’Kay, Skipper.”
“And at 15 minutes out, let’s secure the APU’s, Jack.”
Endeavor coasted silently on her back above the middle of the cold North Atlantic. From this height, the hazy blue horizon of the sea was 957 statute miles distant from the forward cockpit’s six large triple-paned windows. Creeping toward them over the far eastern horizon, the islands of the Azores emerged from the planet’s fuzzy, curved edge. The upside-down crew could have seen the small islands but for the haze at the Earth’s distant comer and the achingly white sun directly overhead where it was noon in mid-Atlantic.
“APU shutdown, Skipper. My side, Panel Right-Two: APU coolant pumps, Loops A and B, off. APU automatic shutdown to inhibit. Hydraulic circulation pumps One, Two, and Three, off. Ignition switches lever-locked off, off and off. Fuel tank valves lever-locked close, close and close. APU controller power One, Two, and Three, lever-locked off. Okay, Skip, three auxiliary power units secured.”
With Endeavor’s three main engines cooling, and with the wings’ elevons and the tail’s rudder not needed until re-entry and landing, the ship’s three hydraulic systems were put to bed for two days.
Directly beneath Endeavor, the seven small islands of the Azores glowed blue-green in a sparkling sea.
“God! Looky there, Skipper!” Enright pressed his helmet to his side window. The tiny islands glistened in sunlight, where under Shuttle it was 2 p.m. on a sunny winter day. Shuttle’s clocks set on Houston time read 9:15 a.m.
“Endeavor, Endeavor: Houston remote, Madrid local. We have solid S-band lockup at sixteen minutes. How do you read?”
Enright started as his reverie was broken by the crackling radio in his ears. After crossing the Atlantic from one end to the other in 16 minutes without radio traffic from Earth, it was easy to forget that a legion of technicians far below were anxious to invade Endeavor’s weightless privacy as the ship hurtled eastward and crossed a new time zone every four minutes.
“With you, Houston,” a Kentucky voice drawled 780 miles west of the Spanish coastline, a distance to be flown in only 2½ minutes.
“Okay, Endeavor. We’re getting a good solid downlink from you. We see Major Mode 202 running for rendezvous with your target. You’re clear to run GPC Number One for GNC functions, GPC Two for rendezvous, and GPC Three for systems maintenance in Major Mode 801. Computers Four and Five to standby in Major Mode 106. We show your target at range 206 miles and closing. Slight out-of-plane error of point 0-0-7-5 degree. Your OMS-2 burn will therefore be a combination mid-course correction with the programmed Delta-V and a plane change. No need to induce a nodal crossing with the target vehicle. Your OMS-2 burn pad follows: TIG at 40 minutes 51 seconds; Delta velocity plus 151 point 9 and 03 feet per second plus Y; BT of 91 seconds. Backroom boys are Go for a closed loop solution for an ‘M equals One’ rendezvous. And we have some SM data for you when you’re ready.”
“Okay, Houston,” the Mission Commander called. Both pilots flew headsdown over the North Atlantic toward the west coast of Morocco. They rode in their bulky orange pressure suits but without their gloves. Inside their helmets with the laser-proof visors in position, two microphone booms reached to their slightly swollen lips, puffy from only 18 minutes of weightless spaceflight.
“ ’Kay, Houston. Understand Go for on-board rendezvous solution. Super. Copy OMS-2 burn at 40 minutes plus 51 seconds; burn time 91 seconds; velocity change 151 point niner feet per second with half a mile plane adjustment. What do you have for systems management?”
“Endeavor: Houston by Madrid. We want you to go to Loop Mode on the signal processor. And we recommend going to water Loop One on the ARS. Inhibit water Loop 2. We show you carrying a tad excess heat in the freon loop. Keep an eye on flash evaporators. We don’t see any problem at this time in keeping the bay doors closed until your first pass Stateside. But we may have you initiate PTC over Australia.”
“Understand, Flight. Water Loop One up, Two down. Let us know about the passive thermal control. We would rather not be in rotisserie mode when we shoot the TPI.”
Rotisserie mode referred to having to put the ship into a very slow roll, wing over wing, to even out the shuttle’s exposure to the sun’s ferocious heat in airless space. This would prevent one side of the vessel from baking while the other side remains frozen in the hot side’s shadow.
“Rog, AC. We concur on remaining in stable minus-Z during your terminal phase initiation. We’re looking for TPI and rendezvous over the states at about ninety-nine minutes, MET.”
“Mother agrees, Flight. We should be closing on the target at mission elapsed time of ninety-seven and one-half minutes.”
“Thanks, Jack. So how’s the ride, right seat?”
Enright turned his face from the right television screen to the three windows wrapped around his helmeted face.
“Incredible simulation, Flight! This is just breathtaking. Nineteen minutes out of KSC and I’m looking down on Rabat, Morocco! The old clock on the wall here says 9:20 in the mornin’ Houston Time, and we’re flying upside down over Morocco where it’s 3 o’clock in the afternoon. Truly amazing! The terrain is pretty hazy. With the sun’s sub-point about forty-five degrees west of us, the sun angle is too shallow for very much detail below. But there is no doubt that Morocco is very pink, red almost. It’s just bizarre to sit here heads-down with Rabat out my forward window and Casablanca just over my right shoulder. Casablanca! ‘Of all the gin joints in all the towns in all the world . . . What a morning, Flight! And I can see the eastern shadows off the Atlas Mountains extending into Algeria!”
“Sorry to interrupt the tour, Jack, but we’re going to lose you in about two minutes over Algeria. You’re about eleven minutes from first sunset. We’re hopin
g that’ll cool you off enough for the flash evaporators to carry the heat load. Next comm by IOS when you cross Kenya in fourteen minutes.”
“Okay, Flight. Next AOS by Indian Ocean Ship in fourteen.”
“And, Endeavor, for your burn pad, we have Day Zero de-orbit burn times for Edwards: De-orbit Rev One, BT at 00:52:18; Rev Two, burn in at 2 hours, 25 minutes, 18 seconds; Rev Three, BT at 03:59:08; Rev Four, burn at 05:33:12; Rev Five burn in at 07:06:44; and Rev Six, BT at 08:41:21. Your de-orbit burn times for landing at Kennedy, Day Zero follow: Revolution One, BT 58 minutes plus 51 seconds; Rev Two, at 02:33:17; Rev Three at 04:07:49; Rev Four, BT at 05:42:17; Revolution Five at 07:14:49. Then KSC de-orbit Rev 15 at ignition time of 21 hours, 39 minutes 04 seconds; and Rev 16, BT at 23:11:58.”
“We got it, Flight. You getting our PM downlink in doppler tracking?”
“Affirmative, AC. Solid lock. Starting to breakup slightly as you go over the edge at twenty-two minutes.”
“Roger, Houston. Catch you by IOS. Endeavor is right and tight up here.”
“Copy, AC. Configure LOS Madrid at . . .”
“And we’re on our own again, Number One.”
The copilot nodded as he watched the mountainous border between Morocco and Algeria pass overhead beneath his upside-down office.
“MPS inerting and purge is complete, Will.” Enright studied his green television which told him that Shuttle’s three main engines were safed and clean of explosive fuel vapors.
Two and a half minutes from Morocco, Endeavor coasted silently over the Fazzan Oasis in Libya. A glance out the thick window revealed a lush speck of green the size of a fingernail far below, which tracked its 25-second transit across the window. Shuttle sped at 17,500 miles per hour over the arid pink wastes of central Africa, over Libya and Chad, bound for the Sudan only 150 seconds southeast of the Libyan oasis. Chad’s 11,000-foot-high Tibesti Massif pointed snowy peaks toward Endeavor’s white body.
Both pilots startled when a Caution and Warning siren wailed in their earphones. At the center top of the main forward instrument panel, a yellow caution light glowed at one of the 40 annunciator lamps. In front of each pilot on the glareshield overhanging the instrument panel, a Master Alarm light flashed red. Parker pushed his Master Alarm pushbutton light, which extinguished the alert tone but not the RGA yellow caution light on the annunciator’s second row of eight lights.
“Rate gyro assembly!” Enright called.
“Run it down, Jack.”
Enright scanned the system failure checklists which he called up on the right television screen. He summoned the proper checklist by tapping a coded sequence of numbers into his computer keyboard unit on the right side of the center console by his left thigh. The wide console separated his seat from Parker’s.
“Looks like RGA Number Three, Skipper. Damn.”
“Take ’er out, Number One.”
“Rate gyro assembly Number Three, Overhead Panel-16, off. RGA secured.”
The yellow caution light went out.
“One down, three to go,” the AC said dryly as Endeavor skimmed over the Sudan’s deserts 100 miles west of Khartoum, only 30 minutes away from Pad 39-A, now more than 8,000 miles behind Endeavor.
Shuttle’s four Rate Gyroscope Assemblies, now reduced to three, work together with the ship’s inertial measurement units to feel Endeavor’s position and attitude in space. One rate gyro disabled was a serious but not critical failure. Two lost would be dangerous; three down would dictate an emergency landing at the first opportunity. And four out of four lost would be all she wrote as a doomed crew struggled to bring home a 200,000-pound glider by the most basic of scarf and goggles flying by the old turn-coordinator and air-speed indicator.
“Take a minute outside, Jack,” the AC said calmly to break the tension. “Reckon we can spare the gas to crank her around for a minute.”
The Colonel powered up the Rotational Hand Controller between his knees and set the ship’s Reaction Control Systems to Pulse Mode.
Nudging the control stick toward his right knee, the command pilot fired a minuscule, pre-programmed burst from the RCS jets in the right OMS pod in Shuttle’s tail. Two RCS jets popped loudly like cannon and shot a 30-foot flame past the ship’s tail section.
Endeavor’s upside-down nose rotated smoothly clockwise as she would be viewed from the ground. She made a half circle flat on her back. As the nose swung toward 180 degrees after 60 seconds, another pulse from the two RCS thrusters fired with 870 pounds of thrust from each jet. Endeavor’s slow rotation stopped as the starship came about flying tail-first. With her nose looking back across Africa along the track already covered, Endeavor’s cockpit faced west toward the rapidly setting sun. Thirty-two minutes out, Shuttle rode backward over the 13,000 foot peak of Mount Amba Farit in Ethiopia 75 miles northeast of the capital Addis Ababa.
From the upside-down flightdeck, the crew had a 200-degree panoramic view through the six forward windows of their first sunset in space.
“Take a look, Jack.”
“God, Skipper,” Enright breathed with his face and open mouth close to the wide windshield.
Below, the arid mountains of Africa’s east coast were already in darkness. Far to the west, the sun sat blindingly white just at the hazy blue horizon above the Sudanese desert. Within half a minute, the white globe sank into the horizon’s ribbon of pale atmosphere. The sun flattened as if its upper and lower limbs were squeezing out the middle of the solar disk. The Earth’s far western corner exploded into gold and orange. And after a final dazzling burst: darkness, the moist and star-filled blackness of nighttime in heaven.
“Remember that to tell your grandchildren, Jacob.”
The copilot of Endeavor could not speak.
“Endeavor, Endeavor. Greetings from the Seychelles Islands. We have solid downlink. How you read by IOS?”
“Ah, with you Indian Ocean. Jack and I are fine at thirty-four minutes. Blew an RGA a while back.”
“Copy, Endeavor, we’ll look at it. You’re over Mogadiscio in Somali. You cross the Equator in two minutes. We see you flying in minus-Z, tail first. Be with you six minutes this pass. We show you thirty-five miles behind the target and 40 below it.”
“Roger, IOS.”
“Your OMS-2 will be as planned at MET 00:40:51. At OMS shutdown, you’ll be twenty-three miles behind target and closing at an R-dot of 178 feet per second. We’ll lose you about one minute into the burn . . . Your temps are coming down nicely in the dark. You may inhibit Loop One and go to Loop Two on the freon for the night pass. LOS this station at forty-two minutes out, with AOS Australia at fifty-one minutes. As soon as you null the residuals after the OMS burn, we want you to roll upright to align the platforms with star trackers and COAS.”
“Okay, Flight. Yawing about now.”
The computers on command from the AC brought Shuttle’s tail around until the ship was flying upside down and nose first.
“Got you in Y-POP now, heads down in OMS-2 attitude, Endeavor. We’re watching your downlink. OI playback looks a bit noisy.”
“Understand. Operational instrumentation data dump noisy,” Enright replied. “Want us to switch quads?”
“Negative, Jack. Leave the antennas as they are. We may have you change signal processors later for the phase-modulated downlink. Backroom thinks you’re just breaking up a bit over the mountains. Should clear up when you’re over water momentarily.”
“ ’Kay.” Enright brought the second OMS firing numbers up on the right and center televisions called CRTs for cathode ray tubes. The center screen showed the OMS-2 checklists. “CRTs on-line with OPS-2 and Major Mode 205 running.”
“Copy, Jack. Operational Sequence Two. We’ll leave you alone with your burn prep. Configure data dump to high bit rate, please.”
“You’re looking at it, Flight.”
“Data real clean now, Jack. Thanks.”
As Endeavor coasted southeast over the nighttime shoreline of East Africa, the two flie
rs readied each of the two OMS pods in Shuttle’s tail for the upcoming rocket burn. The firing of the two engines for a minute and a half would change Shuttle’s lopsided orbit, 132 by 57 nautical miles, to a near circular orbit of 130 nautical miles all around, synchronized with LACE ahead.
The crewmen directed their attention in the cabin’s floodlights to Overhead Panel-Eight located on the flightdeck ceiling above Enright’s left shoulder. The AC read the preburn checklist printed on the center CRT as Enright touched each switch.
“Helium pressure, Loop A, left and right, talk-back open; Loop B, left and right, to GPC; propellant tank isolation, Loop A, left and right, talk-back open; Loop B, left and right, to GPC; left and right crossfeeds, Loops A and B, to GPC; engine valves, left and right, on, at Panels Overhead-14 and -16. And, engine arm, left and right, Panel Center-Three, lever-locked arm.”
“OMS ready, Will.”
“Okay, Flight. We’re cranked up and ready for OMS-2 in two minutes on my mark . . . MARK! Two minutes. We’re in inertial attitude mode with attitude deadband of 3 point 5 degrees, rate deadband of three-tenths degree per second, and discrete rate at two-tenths degree per second. DAP in automatic.”
“Copy, Endeavor. We’ll have a work-around for the RGA failure this afternoon. Expect sunrise over Samoa at seventy-four minutes MET. We remind you to keep a close watch on coolant loops when you hit daylight. We see you flying flight control channel Two.”
“Roger, Indian Ocean. Running FC channel Two. I have the con with CSS fly-by-wire in attitude hold in Roll-Yaw. Mother is steering the alpha angle and OMS TVC.”
“Copy, Will, as to control stick steering and GPC thrust vector control. You’re fifteen seconds to OMS ignition, 1 minute 12 seconds to loss of signal . . . 5, 4, 3, 2, 1 . . .”
The Glass Lady Page 14
