“Where?”

“On one of the right OMS engine pod propellant lines.”

“EECOM, you got a comment on that? It’s your heater.”

“It’s possible, Flight. That heater might be down. We don’t have the data.”

In which case that fuel line could be frozen. Or melting, depending on the situation.

“All right. Prop, talk to me.”

“Prop” was the propulsion engineer. “I’ve lost nitrogen tet and hydrazine pressure in the OMS tanks,” Prop said miserably. Nitrogen tetroxide was the oxidizer, monomethyl hydrazine the fuel for the OMS engines. “If my telemetry’s right.”

“Which tanks?”

“Both.”

“What? Both pods? But they’re on opposite sides of the bird.” And besides, the OMS engines — because of their importance — were among the simplest systems in the orbiter. They were hypergolic; fuel and oxidizer ignited on contact, without the need for any kind of ignition system, unlike the big main engines. There was hardly anything that could go wrong. “How the hell is that possible?”

“We’re working on that, Flight.”

“How much of a loss are you seeing?”

“I’m down to zero. It’s as if the tanks don’t exist any more. There has to be some telemetry screw-up here.”

But we have that report from Lamb, she thought. We know the OMS have shut down. This is something real, physical, not just telemetry.

Another call came in. “Flight, EGEL I got me an unhappy power unit. Number two is in trouble.”

“What’s the cause?”

“We can’t tell you that yet, Flight.”

“Can you keep it on line?”

“For now. Can’t tell how long. Anyhow performance should still be nominal with two out of three APUs.”

“Could that be linked to this OMS issue?”

“Can’t say yet, Flight.”

Christ, she thought.

“Flight, Capcom.” Joe Shaw, at the workstation to her right, was still looking across at her. “What do I tell the crew?”

For a moment she listened to her controllers, on the open loops.

Every one of them seemed to be reporting problems, and batting them back and forth to their backrooms. Fido and Guidance were worried how the orbiter was diverging from its trajectory. EECOM was concerned about excessive temperatures in the main engine compartment at the rear of the orbiter. He was shouting at DPS, worrying about the quality of the rest of his telemetry following the heater defect. And Egil, in addition to his worries about the power units, thought the warning systems, pumping out their multiple alarms, were giving false readings.

Thus, most of the controllers seemed to think some kind of instrumentation problem or flaky telemetry was screwing their data. They couldn’t recognize the system signature they were getting. In such situations controllers had a bad habit of retreating into their specialisms, thinking in tight little boxes, blaming the data.

Except there had also been a crew report. Something real had happened to her ship up there.

Behind her, the FCR’s viewing gallery was starting to fill up. Bad news travelled fast, around JSC.

STS-143 was falling apart, and on her watch.

Another call: “Flight, Prop. I’m reading RCS crossfeed. It’s Tom Lamb, Flight. I think he’s going to burn his reaction thrusters.”

He’s trying to complete the burn, Fahy thought.

Lamb thumbed through a checklist quickly. “All right, Bill, I’m going to feed the RCS with my left pod OMS tank. I’m assuming I’ve still got some pressure in there, despite what these readouts say… Here we go. Aft left tank isolation switches one, two, three, four, five A, three, four, five B to close, left and right…”

Lamb was, Benacerraf realized, intending to burn the reaction control engines, without waiting either for the okay from Houston or even for burn targets. He was just, in his can-do 1960s kind of way, going ahead and doing it.

Angel was watching Lamb. He was working switches on an overhead panel. His gestures were hurried, careless, Benacerraf thought. His blue eyes were shining; he grinned, and his face was flushed. He was enjoying this, she realized, enjoying being stuck in the middle of a deorbit burn with two failed engines. Relishing a chance to show off his competence.

She felt a deep and growing unease.

Lamb grasped his flight control handle. “Initiating burn.” He pushed the handle forward, keeping his eye on his displays. “Houston, Columbia. RCS burn started.”

“Copy that.”

“Please upload burn targets for me.”

“We’re working, Tom. Hang in there.”

Benacerraf said, “Are we committed to the deorbit yet? Maybe we could just abort the burn and stay up a little longer.”

Tom Lamb glanced back at her, still holding down the flight stick. “The rear RCS bells are back in the OMS engine pods, remember. If something big has taken out the OMS, we don’t know how long we’ll have the RCS.”

My God, she thought. He’s right. We have to use the reaction control system while we have it, use those smaller thrusters to try to complete the burn. Because it’s all we have, to get us home.

Her perspective changed. It was, she realized, perfectly possible that she wasn’t going to make it through; that suddenly — so quickly — it had become her day to die.

For the first time since the events of this incident had started to blizzard past her, she felt real fear.

And, she thought, Lamb figured all of that out, in the first couple of seconds, in the middle of this roller-coaster ride. And made the right choice, took the appropriate action.

“Okay, Columbia, Houston.”

“Reading you, Joe,” Lamb said.

“We want to confirm you’re doing the right thing. We’re figuring those burn parameters now. Uh, I have the targets. They’re being uplinked now. And I’ll voice up the parameters to you, Tom.”

Lamb nodded at Angel, who fumbled for a scratch pad, and copied down the timings the capcom read up.

The residual burn lasted a full seven minutes.

“Okay, Columbia, Houston. Counting you down out of the burn.”

“Good. My arm’s getting kind of stiff, Joe,” Lamb said.

“Ten. Five. Three, two, one.”

Lamb released the flight control stick. He checked the orbiter’s attitude, altitude and velocity using his analogue instruments, and compared them to the CRT. “Hey, we got a good burn. How about that.”

“Copy that, Columbia. Residuals are three-tenths. You’re a little off U.S. One, a little delayed, but we figure you can recover on the way in.”

Benacerraf found she was gripping her checklist so hard her fingers hurt.

Is that it? Is it over?

The master alarm sounded, jarring.

More lights appeared on the caution/warning array, and on another display to Angel’s right hand. Lamb killed the alarm.

“Uh oh,” said Angel. “There goes power unit two.”

The capcom said, “Copy that, Columbia. We confirm, APU two down.”

Lamb said evenly, “Well, we still have two out of three APUs up and running, so we’re still nominal.” But Benacerraf thought she could see something in the set of his shoulders.

The auxiliary power units sat in back of the orbiter, close to the OMS engine pods. And they already knew something serious had happened back in that part of the ship. Lamb, she sensed, was starting to fear that the problem back there, whatever it was, might be spreading.

The cabin darkened; Columbia had flown for the last time into the shadow of Earth.

Hadamard took his seat on the podium for NASA officers, astronauts and guests, at the end of the press line. The PA was intoning the usual incomprehensible timeline technicalities, mixed in with the crackle of air-to-ground loops. A bunch of Morton Thiokol executives came to sit with Hadamard; they were clutching their blank commemorative stamp covers, that they could get stamped at the Base post office later. Everybody loved spaceships and astronaut pilot heroes, even these crusty aerospace types. Hadamard felt sour.