“Then let us get to it, Flight,” the AC interrupted from the aft flightdeck.
“We’ll let you work, Endeavor, as we review your downlink. We are still feeding your state vectors to you. Your REFSMAT looks remarkably close on guidance. And, Will, we’re getting real fine modulation on the payload bay television. Leave the lens setting as is.”
Endeavor arced down her ground track toward San Diego three minutes and 1,500 miles away to the southeast. The fierce sun hung high to Shuttle’s left and burned ferociously into the open bay. Below, it was 2 o’clock on a North Pacific winter afternoon.
In the rear of the flightdeck, Parker set the remote arm to its fully automatic mode. The AC’s shoulders still ached and the throbbing pain in his right leg had not been seduced to sleep by another injection. He was beyond the therapy even of horse medicine.
As the unloaded end of the mechanical arm was steered by Mother toward the rear of the open bay, the arm repeatedly stopped automatically at memorized pause points. Parker punched the PROCEED button at each rest-stop. His eyes darted between the view out the windows and the panel meters which read out the position of the end effector fifty feet out at the end of the half-ton arm.
Up front in the captain’s seat, Enright worked Shuttle’s coolant systems to manage the high heat load. Seven hours of flying with the open bay’s radiators exposed to unrelenting sunlight for half of each 90-minute orbit taxed the radiators to their limits. With so much time spent flying on her side instead of upside down for passive thermal control, Endeavor’s glass brow sweated and her hot black boxes complained at last.
“We’re getting a temperature C and W from the forward avionics bay and from midships instrumentation, Skipper.” Enright called Parker by the voice-activated intercom without pressing his microphone button, which would have radioed his alert to the ground.
“Can you manage it, Jack?”
“Think so, Will. But I’m on high flow rate Loop Two already. Watching it.”
“Endeavor: We’re getting a Systems Alert on your freon outlet temps.”
“We have a handle on that, Flight. But keep an eye on it while you have us.”
“Copy, Endeavor… Will, we show the end effector passing 930 inches X0. Halfway there.”
“Ah, yeh, Flight,” Parker called weary from the fire in his right leg. The AC assisted Mother’s control of the arm which stretched toward the rear quarter of the bay.
Over the port sill of the bay as Endeavor flew on her side, the California coastline passed beneath Shuttle, LACE 15 yards away, and Soyuz twenty yards behind Shuttle’s silent main engines. At 07 hours 48 minutes, the white highways around San Diego were visible as fine spider webs 149 statute miles below.
“Afternoon, California,” the AC radioed.
“And to you, Will. You’ll be feet-wet this time next rev.”
“Hope not too wet,” chuckled Parker with his hands full of RMS.
“Roger that, Endeavor.”
“And so long, California,” a tired AC sighed without pressing his mike button. Thirty seconds after passing San Diego, Shuttle was over the narrow strait of the Gulf of California half a minute from landfall over the Sonora region of western Mexico.
“We see the end effector at Keel Three, X0 at 1003 inches, Will. Be losing you here at 07 plus 52. Configure UHF for Northrop station.”
As Endeavor flew over Monterrey, Mexico, out of radio range of the California antenna, Enright turned on the UHF radio otherwise only used for landing. Compared to the clarity of normal FM radio traffic, the UHF air/ground was grainy and full of static like old Mercury days.
“Shuttle listening UHF,” Enright called.
“With you by Northrop,” Colorado replied via the White Sands, New Mexico, antenna. “LOS in 55 seconds. Advise when you are PAM rigid, Will.”
“Almost there, Flight. How’s our time?”
“Looks like… ah, 24 minutes to SAA transit.”
“ ’Kay. Thanks.”
Nestled in the rear quarter of the payload bay, the boxy Payload Assist Module rocket, the PAM, was locked in its cradle. Built by McDonnell-Douglas, the three-ton PAM was packed with 5,325 pounds of solid propellant in its single Thiokol Star-48, rocket engine. The PAM booster first performed on the Shuttle Columbia in November 1982. One PAM was then attached to the Satellite Business Machine SBS-3 satellite, and one to the Telesat Canada Anik-C bird. Each PAM flawlessly launched its satellite from the Shuttle Five bay.
With his eyes glued to the television monitor at his right shoulder, Parker handflew the end effector the last six inches to the PAM grapple probe. A squeeze to the trigger on the pistol grip in his right hand closed the wire snare of the end effector unit around the spike sticking up from the PAM.
“Rigidize,” the AC called.
“Copy, Will… Jack: Configure AOS by MLX.”
“With you, Canaveral. Sounds much better.”
“Believe it, Jack. We have good CCTV modulation from the arm camera.”
At 07 hours 53 minutes, Shuttle spoke with the Space Command in Colorado through the Kennedy Space Center as the ship crossed Mexico’s east coast over Tamaulipas for the Gulf of Mexico.
“With you for five, Endeavor. We would like to have PAM ejection before we lose you here. Backroom advises your PDP data dump was very dirty during the Anomaly proximity pass last rev. You plowed through knee-high flux for a good two minutes. Garbage everywhere, guys. Let’s get the PAM deployed and you out of there.”
“Tryin’, Flight,” the AC grumbled as sweat beaded on his face. In zero-G, perspiration sticks and it does not run.
The remote arm’s EEU held tightly to the PAM probe atop the five-foot-high, three-foot-wide rocket pod. Working the arm’s panel, Parker configured its electronics to its arm-loaded logic. When Mother was told by the AC that a three-ton mass was dangling from her 50-foot-long remote arm, she adjusted the arm’s gears within the joint motors to bear the burden.
At 07 hours 55 minutes, Shuttle led LACE and the Soyuz-TM across the Yucatan Peninsula leaving the Gulf behind.
“Load secure, Jack. Ready to cut loose.”
“Whenever, Will.”
“Okay… PAM latches arm; RMS logic loaded; eject program running; READY light on… And the PAM is free.”
The PAM did not move to the command pilot’s eye 14 yards away. But the arm twitched as the end effector lifted the heavy package an inch out of its mooring cradle. The remote manipulator arm automatically stopped at its first programmed Pause Point.
“We see PAM free, Will,” the ground confirmed. “With you another 2.”
Eight minutes from San Diego, Endeavor flew over Belize, British Honduras.
“Running in Manual Augmented. Movin’ her out.”
Slowly, making only two inches per second, the loaded arm lifted the PAM unit upward as seen by Parker at the rear window of the flightdeck. Since Shuttle still flew on her left side to keep the bay’s reflective blankets toward LACE, to Uri Ruslanovich in Soyuz the arm appeared to pull the PAM sideways, parallel to the hazy, late-afternoon horizon. Endeavor crossed Honduras in twenty seconds.
“Endeavor: At 07 hours 56 minutes, you’re LOS in 90 seconds. Shuttle then out of radio contact for 39 minutes. Sunset at 08 plus 01 in 3 minutes. SAA transit in 18 minutes… Jack, watch your coolant loop temps. You’re yellow-lined both loops. As soon as possible after your evasive maneuver, shoot an IMU alignment. Then configure headsdown, PTC, for the duration. After we lose you here, you’re AOS by Botswana for a one-minute status report at 08 plus 26 after SAA transit. And we show your downlink breaking up already… Godspeed…”