See, says Bartlett. Our LM will be maybe one-fifth that. As long as we can get the delta vee for TEI from the DPS—
It’s too heavy, Alden repeats.
He reaches for one of Curtis’ manuals and opens it to the back. He takes hold of a blank page, looks questioningly at Curtis, and gestures removing the page from the binder. Curtis nods warily. Alden rips out the page; Curtis winces. Alden pulls a pencil from a pocket and, brow furrowed, begins jotting down equations and solving them.
The others watch him. They sit in silence and watch as Alden fills a page with closely-written maths.
Peterson leans close. He thinks some of the equations might look familiar. He sees Δv and ve and Isp, and he remembers a classroom at the Johnson Space Center and some pencil-neck with pocket-protectors and a blackboard covered in alphabet soup.
No one says a word for the fifteen minutes it takes Alden to work through his calculations. When he finishes, he looks up from the piece of paper, and his distant gaze cannot hide his disappointment.
Well? demands Peterson.
Alden shakes his head heavily. That 3,500 lbf, he says, is not going to get us more than 6,000 feet per second with all that weight.
Lunar escape velocity, quotes Curtis, is 7,800 feet per second.
Goddamn, says Fulton.
So why not leave the DPS in situ? asks Scott.
Hot damn, says Fulton. That could work.
We don’t need most of the descent stage, Scott says, so we can save weight by leaving some of it behind like a launch cradle.
Alden frowns. He takes another blank page from the manual—without asking for permission from Curtis—and sets about recalculating specific impulses, weights, thrusts and lunar escape velocity. He does so quicker than previously, but still it takes almost ten minutes. He nods slowly as he solves the final equation, and says, It adds up; we can do it.
We can do what, exactly? asks Peterson.
We can use the DPS to get the ascent stage into lunar orbit, explains Fulton. Then we use the APS for the TEI burn. You only got 10,000 lb of LM. You can easy get the delta vee.
You can’t throttle the APS, Bartlett argues. It’s 3,500 lbf or nothing.
It’s about the delta vee, not the thrust, replies Fulton.
The numbers, Alden says to Bartlett, don’t support your solution. The only way to get to 60,000 feet is using the DPS.
Bartlett stiffens, and his features adopt a look of stubborn intensity. He is used to getting his own way; Alden is never wrong. And Bartlett knows it.
Goddamn it, he says. We need the throttle for the TEI.
It won’t work if you can’t get into orbit, Alden insists. He slides his two pages of algebra across the table to Bartlett. You check my numbers, he says. There is no suggestion in his tone that the calculations might contain a mistake. Alden wants Bartlett to check his figures to see for himself the truth of Alden’s solution.
Bartlett continues to argue, but Peterson knows Alden has already won. Bartlett is just saving face: he can see the others’ expressions, he knows they expect him to fold. To bow out with a final zinger to leave him the last word. They have all seen it before. It is the way Bartlett operates.
Okay, José, Bartlett says, I guess we’re on our way.
The joke, an old one when Peterson qualified for the astronaut corps, prompts wan smiles.
Curtis opens a manual and flips through pages to a cutaway of the LM’s descent stage. He points to each of the fuel tanks, and says, We pull these out and re-fill them with salvaged fuel. Then we cut here, here, here and here, and loosen these bolts here, so when the DPS fires it lifts right out of the descent stage.
Bartlett pulls the manual to him from under Curtis’ hand, ignoring the other man’s hurt look. Peterson thinks about intervening but then decides this is too important.
We’re going to have put in some bracing, Bartlett says. Or this thing’s going to fold like a cheap sofa.
Now that they have all agreed on a way to get into lunar orbit, the discussion moves onto the next stage of the journey: how to get to LEO. Modifying an ALM is something they can do with their hands. It is real. They have a workshop, they have tools. They may be aviators but they are also practical men: happiest when they are using their hands—control stick in one, throttle in the other. They fly by feel as much as by instruments.
But getting their modified ALM from lunar orbit to LEO is not something they can do with a wrench or a screwdriver. They can’t even rely on the ALM’s Primary Guidance Navigation Section to do the hard work for them: those fifty-five switches, forty-five circuit breakers and thirteen indicators can only be used to land an ALM on the Moon and, later, fly it to Lunar Orbit Rendezvous with a CSM, as per flightpaths programmed into the LM Guidance Computer. Perhaps they can reprogram it; they certainly cannot rewire it—the wires are so fine, using spacesuit gloves they’d just break them. They will have to calculate manually when to light the APS for TEI, and for how long, and where in the LM’s orbit about the Moon they must light it. And they must do it exactly right in order to hit a target eight thousand miles in diameter 250,000 miles away.
How the hell do I navigate? asks Peterson.
They look at him.
I? says Bartlett.
Goddamn right, replies Peterson. Who you think was going?
On your own? asks Scott. The ALM can fly four into orbit.
It’s three days to Earth, Peterson says. We put the consumables for that aboard and we’re going to be close to the weight limit. One man is safer.
We should draw straws, complains Neubeck.
You should obey goddamn orders, snaps Peterson.
You’ve got the optical telescope, says Scott, deflecting the argument. You use that. We’ll have to do some number-crunching on the computer here to get you the values to input on the DSKY, but the LGC should handle it.
Peterson had flown the ALM that brought him to Falcon Base down from lunar orbit to Mare Imbrium. In truth, he’d had little to do—the Lunar Module Guidance Computer had done everything. He’d kept his hand by the hand controller, but he’d not needed to take over.
It’s been a year since he abdicated his command, but Peterson feels the mantle of leadership settle once again on his shoulders. They might resent his decision to fly the mission himself, but they are looking at him now and it’s clear he is in charge. He organises them in teams.
Alden, who knows the maths, and Curtis, who has memorised the manuals, will calculate the variables for TEI and Earth Orbit Insertion. They will also draw up a list of the verbs and nouns Peterson will need to pilot the mission.
Peterson, because he has the most EVA experience, McKay and Fulton will salvage the fuel tanks from the ALMs on the Sea of Rains. Bartlett, Neubeck and Scott will build the equipment needed to transfer fuel from those tanks into something they can use to refuel the ALM Peterson will fly.
While Alden gets started on the calculations, Bartlett, Scott and Curtis help Peterson, McKay and Fulton into their spacesuits. It is crowded in the suiting up area, especially with three of them in bulky A7LBs, but no one complains. They are doing something; they have something to do. Peterson is ready first, his polycarbonate helmet locked on, LEVA in place, his PLSS on his back and hoses plugged into the connectors on his torso. He steps over the coaming into the airlock, turns about clumsily and watches as both McKay and Fulton have their helmets lowered onto their heads and the locking rings twisted into place.
Outside on the lunar surface, Peterson hurries ahead. All this is second nature to him, the lunar jog, leaping from one foot to the other, graceful despite the bulk of his backpack. McKay struggles to keep up, but his breathing is not enough to trigger the microphone so he appears to suffer in silence. Fulton has gone in the other direction, to fetch the LRV. They will need it to drag the tanks back to Falcon Base.