Authors: Stephen Baxter
Ralph Gershon couldn’t help himself.
‘That’s
the MLTV? Holy shit,’ he said.
Ted Curval, from Phil Stone’s prime crew, was the senior astronaut assigned to oversee them for the day. Now, he just grinned. ‘Your regulation Mars Landing Training Vehicle, Number Three. Brutal, ain’t she?’
The Mars Landing Training Vehicle was an open framework, set on six landing legs. Gershon could see a down-pointing jet at the center, surrounded by a cluster of fuel tanks. Reaction control nozzles were clustered at the four corners of the frame, like bunches of metallic berries, and there were two big auxiliary rockets, also downwards-pointing. The pilot’s cockpit was an ejector seat partially enclosed by aluminum walls, with a big, bold NASA logo painted on the side, under a black stenciled ‘three.’ The whole thing stood maybe ten feet high, with the legs around twelve feet apart. There was no skin, so you could see into the guts of the thing, jet and rockets and fuel tanks and plumbing and cabling and all; it was somehow obscene, as if flayed.
In the low morning sunlight the bird’s complicated shadow stretched off across the tarmac of the wide runway.
‘Shit,’ Gershon said again, coming back to Curval. ‘It’s like something out of a fucking circus.’
‘Tell me about it,’ said Curval. ‘But it’s the nearest thing we got to a MEM trainer. You want to fly a MEM, you got to learn to handle one of these things, boy.’ Curval was grinning, laughing at him.
Ted Curval was one of the Old Heads. A classic astronaut profile: a Navy test pilot, he’d even been an instructor at Pax River, and he’d logged up a lot of time in space already. Now, in the endless battle to climb up the Ares selection ladder, Curval had the great advantage of being from an earlier recruitment class than Gershon,
and had already accrued plenty of live, free-flying MLTV experience. While the best Gershon had managed, for all his angling and hours spent at Columbia, had been some rime on the tethered facility at Langley, where a MEM-type mockup dangled from cables.
So Curval was in Phil Stone’s crew, and was on his way to Mars. And Ralph Gershon was still on the outside looking in.
But what the hell. As of today, Ralph Gershon would be able to add MLTV experience to his list of accomplishments. So screw Ted Curval, and all the other complacent assholes.
As far as Gershon was concerned the contest wasn’t over until the bird left the pad, on April 21, 1985.
Gershon jammed his helmet on his head. He jumped up into the MLTV’s open frame. With a single twist he was able to lower himself into the single seat. ‘How about that. Just my size.’
Curval stepped forward. ‘Hey, Gershon –’
Gershon was strapping himself in. ‘The seat’s a Weber zero-zero, right?’
‘Come on down from there, man, you’re not prepared. You’re not supposed to –’
‘And the jet back there is a General Electric CF-700–2V turbofan. Come on, Ted, I know the equipment. I’ve come out here to fly the thing, not listen to you yack about it.’ He glanced down at the control panel: a few instruments, a CRT, a couple of handsets. Just like the sims.
He found himself blinking; the sun was strong, almost directly in his face, and his eyes hurt. On the plexiglass windscreen in front of him he could see reticles – fine lines – etched in there, labeled with numbers –
But suddenly the pain in his eyes amplified. ‘Yow.’ He threw his arm across his face. His eyes itched unbearably, and started to flood.
‘For a start,’ Curval called up dryly, ‘you can close up your visor. You’re being hit by hydrogen peroxide leaking from the attitude controls. You
sure
you know what you’re doing, guy?’
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, right now, so far away from the Mars landing itself.
Nobody except somebody so desperate to get on the selection roster they’d do all but 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 three hundred and sixty 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 downwards jet was at an angle to the vertical, and he’d find himself shooting forwards, or sideways, or backwards 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 here 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 up here, and Curval was stuck down there.
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 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 got 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 her 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 now, was useless.
‘Okay, guy. Now, you 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 got 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 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.’
‘I got it.’ He swept across the tarmac, smooth, easy.
‘If you want to change the landing site you just use your attitude control to swivel and point your window, and the PGNS starts recomputing. You can set to ATTITUDE HOLD and just glide for a while, if you like. And you can change your down velocity by –’
‘I know it, Ted. I –’
Now York came on the line. ‘Ralph. It’s Natalie. I think you ought to pull out.’
‘Huh? Why?’
‘You’re coming in too fast. Too low.’
He checked over the crude instrument panel. Everything looked fine to him. It was true he was coming in low and fast, but that was intentional; he knew Curval’s gassing hadn’t left him a lot of time, and he didn’t want to run out of fuel. ‘What’s your problem, York?’
‘I think you’re going to overload the PGNS.’
‘Come on. Everything up here is sweet as a nut.’
‘It’s not as simple as that, Ralph.’ She started talking about best-fitting polynomials and higher-order curves, and a lot of other crap that went right over Gershon’s head.
He just tuned her out.
He watched the tarmac roll away under him. He swept along, the PGNS working smoothly; he barely needed to touch his controls. He felt a surge of success, of achievement.
Here’s something else I can do, ma. Another step on the long fucking ladder I’m climbing to Mars
.
He’d just let her land, this first time through. He’d made his point; he didn’t want to antagonize Curval too much. Maybe he could persuade Curval to get the MLTV refueled and he could take her up again. Next time he’d try changing the landing site a couple of times.
That big old ‘three’ started to loom up toward him, upside down as he looked at it, slightly obscured by the dust his rockets and the jet were kicking up.
Now the MLTV tipped itself back, to slow his forward velocity. He checked his numbers; the CRT display evolved smoothly to match what he saw through his plexiglass screen.
The MLTV started to drop down as the auxiliary thrusters throttled themselves back.
Maybe that dip down
was
a little sharp.
York was still yammering in his ear. He needed to think. He watched his trajectory and tried to visualize where he was going.
Something was wrong, for sure. He was coming down too quickly.