Gershon snapped shut his visor and squeezed his eyes closed. “Let me bust my neck, Ted. It’s my neck. What do you care?”

“Okay,” Curval said at length. “Okay, you win.”

Curval, with York, went over to the control truck and clambered in the back. In a moment, Gershon heard Curval’s crisp voice sounding in his flight headset. “Okay, Ralph. What we’re going to do is take the MLTV up fifty feet, twice around the block, and back home again, just as nice as pie. Just to let you get the feel of her. And then you’re coming out for an eye bath. You got that?”

“Sure.”

Gershon kicked in the jet, and there was a roar at his back. Dust billowed up off the ground, into his face. Vapor puffed out of the attitude nozzles, as if this was some unlikely steam engine, a Victorian engineer’s fantasy of flight.

The runway tarmac fell away. The lift was a brief, comforting surge. The MLTV was like a noisy elevator.

Gershon whooped. “Whee-hoo! Now we is hangin’ loose!”

Of MLTV Number Three’s four cousins, two had crashed during the last half year. The pilots had ejected and walked away. Nobody was sure about the cause. Well, vertical takeoff and land vehicles were notoriously unstable; maybe you had to expect a percentage of failures. The hope was that these crashes weren’t showing up fundamental flaws in the design of the MEM itself.

Anyhow, the MLTV itself still needed test flights. Nobody was too keen to risk it, so far away from the Mars landing itself.

Nobody except somebody so desperate to get on the selection roster he’d do almost anything.

Gershon took the MLTV up to maybe sixty feet and slowed the ascent.

The principles of the strange craft were obvious enough. You stood on your jet’s tail. You kept yourself stable with the four peroxide reaction clusters, the little vernier rockets spaced around the frame, squirting them here and there. In fact, he found, he didn’t even need to work the RCS control when he was trying to hold the craft level; the little rockets would fire by themselves, in little solenoid bangs and gas hisses.

He experimented with his controls. He had a full 360-degree yaw capability, he found; he could make the MLTV rotate around its vertical axis, back and forth. He whooped as the world wheeled around him. And he had some pitch and roll control: he could make the vehicle tip this way and that. But when he tried it, of course, the thrust of his single big downward jet was at an angle to the vertical, and he’d find himself shooting forward, or sideways, or backward across the painted tarmac -

Curval shouted in his ear. “Hey, take it easy!”

— and that was evidently the way you had to fly a MEM. But he had to take care not to tip too far in any direction, or he could feel the stability start to go.

The low sunlight got in his eyes, which were still watering, and made it hard to read his instruments.

He came to rest perhaps a hundred feet above the ground, facing the control truck.

“Maybe you should get back down here for that eye bath, Ralph,” Curval said.

“So how much fuel does this thing carry?”

“Enough for maybe seven minutes.”

“And how long would a landing sequence take?”

“Ralph—”

“Tell me.”

“Three, four minutes.”

He checked his watch; he’d been up no more than two minutes. Time to spare.

He took the MLTV straight up in the air.

“Ralph, get your ass down here!”

“There’s only one way I’m coming down, bubba, and that’s by a Powered Descent.”

“You’re not trained for this.”

“I’ve done over fifty sims. Come on, man. I know what I’m doing. This bird is working as sweet as a clock. Let me bring her in.”

Curval sounded as if he was choking. “Goddamn it, you asshole, you smash up that trainer, and I’ll sue you myself.”

Gershon grinned. “Sure.” What, after all, could Curval do? Nothing, as long as Gershon was in the trainer, and Curval was stuck on the ground.

Gershon took her to three hundred feet. “This high enough to initiate?”

He could hear Curval take a few breaths. “Find the button for the automatic control sequence.”

Gershon found it and pushed. The jet throttled back, and the MLTV dipped briefly. Then a new, throaty rocket roar opened up, and the trainer stabilized.

“All right,” Curval said. “Now, the secret of the MLTV is that it has two independent propulsion systems. Right now, your turbofan jet is throttling back to absorb two-thirds of your weight. So if everything else cut out, you’d fall under one-third of a G — just like on Mars. You got that? The jet is knocking out gravity, just enough to make it feel like Mars.”

“Sure.”

“But you don’t fall, because of the two hydrogen peroxide lift rockets under your ass which have just cut in to hold you up. And it’s the lift rockets which are emulating the landing system of the MEM, and that’s what you have to control to bring her in to land. You throttle down the rockets until you land. Like an ICBM trying to land on its tail.”

“Okay.”

“You have two more controls there, Ralph. Your attitude control on the right, and your thrust control on the left. You want to try those babies out?”

“Sure.”

The controls were familiar to Gershon from his sim runs. The attitude control moved in clicks; every time he turned the control the reaction rockets would bang and the MLTV would tip over, by a degree at a time. The thrust control was a toggle switch; every time Gershon closed it the lift rockets roared, to give it a delta-vee of a foot per second.

After the free-flight mode it was surprisingly difficult to handle the trainer; it was like being immersed in some viscous, sticky liquid. Because of the one-third effective gravity, he had to tip the bird three times as far as before to get the same push in any direction. And once he started moving, he just kept on going, until he changed the attitude again, and the craft took some time to respond because of the sluggishness. He found that he had to think out the simplest maneuver well in advance.

Flying like this — balancing on a rocket — was harder than he’d expected, harder than any of the sims had led him to believe. Everything he had painfully learned in a lifetime of flying planes, he realized, was useless.

“Okay, guy. Now, you’ve got a little computer up there running a PGNS program for you.” Curval pronounced it pings. PGNS was a guidance and navigation software package. “If you’re such a hotshot sim jockey, you don’t need me to tell you how you have to let the computer fly you down. All you get to do is to point and squirt—”

“I know it. Come on, Ted. I’m running out of juice out here. Let me bring this thing down.”

“Okay. First off, look through your windshield and pick a place you want to come down. And you’ll see a number on your CRT—”

Gershon peered out. He saw a fat number “three” stenciled on the tarmac, maybe a quarter mile away; it would be kind of fitting to come down slap in the middle of that, in this MLTV Number Three.

He used his attitude controller to tip up the MLTV until the numbered marking on his windshield overlying the target matched the number displayed by the computer on the CRT. “Thirty-eight,” he called out to Curval.

The MLTV started to float toward the target. Now, the PGNS program was computing a trajectory to take him to the “three” — or rather, to a position just above it.

“I don’t know the math behind it,” Curval said, “but you’ve got to know the basics, Ralph, to follow the logic of this thing, here.”

“I know it.”

“The PGNS works by the same system, basically, as the old Lunar Module. And there’s enough equipment on the MLTV, a computer and a radar, to let you do a complete Powered Descent. What you have is your computer taking your current position and velocity, and your target vector — which will be hovering, just above the ground — and it works out a nice smooth curve between the two for you to follow. Every couple of seconds, it recomputes, and figures out another curve. And the numbers it flashes up on the CRT tell you where to look on your reticles, and you should see your computed landing site right there, behind the mark.”