Ian Sales: Adrift on the Sea of Rains

They were trapped, but now there is an escape. All but Kendall gather in the wardroom to discuss their options, squeezing about a single table but, unlike at meal-times, confidently, keenly , meeting each other’s gazes. It occurs to Peterson that he has lived with these men for two years but he barely knows them. He sees seven men he knows chiefly by their reputations and the psychological profiles in their records. Their faces are as familiar to him as his own, but they might as well be the gold visors of spacesuit helmets for all their expressions tell him what each is thinking. Not once since they became isolated on the Moon have they worked together. He trained extensively with Curtis for the trip here, but once they had landed each had their separate duties… and since they lost the Earth, he has barely exchanged a dozen words with the man. And now… Now, the Curtis he knew is not the fevered-looking man on the other side of the table with arms folded across a stack of ring-binders.

The Moon has changed them all; despair has made strangers of them.

But now, with salvation a very real possibility, they are no longer uncomfortable in each other’s company. Hope has made amiable strangers of them.

Hope: half a dozen modules in Low Earth Orbit. An elusive hope: they need to find a way to reach the space station. They have one ALM ascent stage left—and Peterson gives thanks it still remains, not launched out of desperation by one of them during the past two years.

A thought occurs to him: how to get from lunar orbit to Earth?

We need another engine for TEI, Peterson says.

We can rip a DPS out of one of the descent stages, says Bartlett. They’re throttleable.

What about fuel? demands Fulton. How you going to fuel the burn? You think maybe we can just brew up some Aerozine 50 out of Moon rocks?

Both the Descent Propulsion System and Ascent Propulsion System are powered by Aerozine 50 and dinitrogen tetroxide. The latter they can perhaps manufacture through the catalytic oxidation of ammonia, but Aerozine 50 is beyond their capabilities. For it, they need sodium hypochlorite as well as ammonia. The third ingredient of Aerozine 50, unsymmetrical dimethylhydrazine, requires a chemical plant.

Bartlett gestures dismissively. All those descent stages on the mare, he says, each one has a minute, maybe half a minute, of Aerozine 50 left in the tanks.

So where we put the DPS? asks Neubeck. There ain’t no room in the LM.

There is a defeatist whine in the man’s voice, and it is a moment before Peterson calms himself enough to reply:

We bolt it to the goddamn back, he snaps.

Bartlett shakes his head. We’re going to have to put it on the top, he says, or we throw off the centre of gravity. We don’t need the drogue assembly in the docking tunnel, so we rip it out and we build us a frame to put in there for the DPS.

Fulton is not convinced: You reckon we can get 20,000 lb fuel from all the descent stages?

Why not, says Bartlett. Say you burn about ninety percent of that on the way down. That’s got to leave between 150 and 200 lb per LM.

There’s gonna be some losses decanting it, Fulton replies.

Peterson watches the two argue back and forth. The others are content to let them thrash it out. Fulton has always played the sceptic—but for that, he might have been commander of Falcon Base. Bartlett is a smart guy; perhaps, after Alden, the smartest guy on the Moon—

It won’t work, says Alden in his slow, careful way.

Bartlett turns on him. Sure it will work, he insists.

Alden shakes his head. How much does the ascent stage weigh?

10,024 lb, says Curtis from memory.

You add a DPS onto that, plus 20,000 lb of fuel, continues Alden, and the APS is not going to reach lunar escape velocity.

APS thrust is 3,500 lbf, says Curtis. You can get maybe 12,000 lbs into lunar orbit with that.

We don’t need 20,000 lb of fuel, Bartlett points out. We only need enough for the TEI burn.

Again, Curtis quotes figures from memory: The CSM is 66,871 lb fully loaded, the SPS has 20,500 lbf thrust. You need a 203 second burn for TEI.

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 v e and I sp , 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.