Slow Enough to Answer
The ledger had two columns and no third column, and everybody who came into that room eventually put a finger on the paper.
Wren Calloway owned the left column. It was hers because the watts were hers, and because in the first week of February the Fund for Planetary Continuity, the Ottinger Foundation, and the Ministry of Long Horizons had all discovered that they could not agree on anything except that something had to be struck out before the hardware freeze, which was in nine weeks.
The left column was labeled CAPTURE. The right column was labeled SAIL.
MASS AT LAUNCH, KG. 1,100 cap. DEPARTURE HELIOCENTRIC SPEED, KM/S. 24.1 both. RELATIVE SPEED AT PROXIMA, KM/S. 45.2 both. SPEED AFTER BRAKING, KM/S. 0.05 both.
The bus and its tankage were six hundred and sixty kilograms, and nobody argued about those. That left four hundred and forty.
Then the columns parted.
CAPTURE needed a despun three-axis bus, because you cannot hold an intake in a relative wind with a spinning one. It needed forty watts for forty days, for the spectrometer and the valves and the heaters and the little heaters inside the little heaters that keep the valves from freezing. Forty watts for forty days is thirty-eight kilowatt hours, and the lightest thing ever built that carries thirty-eight kilowatt hours is a hundred and sixty kilograms of battery. It needed two hundred and sixty kilograms of ingest unit, which was Pilar Mondragon’s, and which had been on a bench in a vacuum tank in a building with a bad roof in Pasadena for nine years.
SAIL needed two hundred and twenty-four kilograms of film and sixty-three of boom and nothing else at all. It needed zero watts for the entire voyage. It needed the bus to keep spinning, forever, about the axis that pointed at Proxima, because a spinning sail is stiff and a sail that is not square to the star is not braking.
“A sail is the only instrument on that ship that works with the power off,” Wren said. “Everything else on it is a device for being alive.”
“Everything else on it is a device for being believed,” said Pilar.
She said it without heat, and looked at Wren until Wren looked away.
Wren looked at the page. The sail was four hundred and fifty meters on a side when it opened, two hundred thousand square meters of eight-tenths-micron film, and everything behind it lived in its shadow. At Proxima b the sunlight was about three-quarters of what falls on Earth, which is a fat, generous star to work with, if you can see it. Once the sail opened, the sunward face of the ship was a disk of aluminized film, and every measurement the sampler needed to make in the next forty days had to be made on the other side of it.
Cyril Boudreau was the Foundation’s science lead and had the board’s ear, and he said reasonable things in a voice that made them land like insults. He had been a planetary astronomer for forty years and had a public profile and a private grudge against the word “eventually.”
“Both,” he said. “Both columns. Find us the mass.”
“There isn’t any.” Wren set her pencil down, parallel to the table edge. “And that isn’t a money problem, so I’m going to say the rest of it in one paragraph and then I’ll stop.”
She did the arithmetic for them, because it was short and because she had done it four hundred times.
The ship coasts at twenty-four point one kilometers a second, and Proxima is closing on the Sun at twenty-one point one, so the arrival is forty-five point two kilometers a second and it happens whether we aim well or badly. The coast is fifty-two thousand years. The reactor makes two hundred and forty watts on the pad, nine percent of that at three hundred years, and nothing worth metering by the time the Sun is a smear behind us. So the sail does the work. It opens at forty-seven hundredths of an astronomical unit, seventy million kilometers out, where the light is about six thousand watts a square meter and the radiation pressure is thirty-nine micronewtons a square meter. Two hundred thousand square meters of film is seven point eight newtons at the open, and it climbs as the ship falls inward, and nineteen days later the ship is doing fifty meters a second relative to the planet, inside seven hundredths of an astronomical unit, with the film hot and the sail still open and still square to Proxima, because that is what held the axis all the way down.
“And then we are bound,” Wren said, “and we are a thing in that system that will still be there.”
“Nineteen days of braking,” Boudreau said, “with two hundred thousand square meters of film that has to open on the first try, on an axis we have to have aimed at a star that is not there yet.”
“The aiming is my problem. It is solved. Or it is solved to ten milliarcseconds, which is a disk two million kilometers across at Proxima, and that is the astrometry campaign’s problem, and the campaign ends on the same day as the freeze.”
“Then the film opens.”
“The film opens.”
“And then for fifty-two thousand years nothing happens and it is a very expensive letter in a bottle with a camera in it.”
“Yes,” Wren said.
Boudreau smiled his press-briefing smile, at the two cameras his own people had brought in without asking.
“That,” he said, “is not a first contact mission. That is a monument.”
Pilar Mondragon closed her folder. She was forty-five and had the flat, unhurried courtesy of somebody who has sat on too many panels where the science was winning.
“Monuments photograph well,” she said. “Samples don’t. A sample has a mass on it and a date and my name and a chain of custody with forty-one links in it, and anybody on any planet in any century can check every link and disagree with me. That is the point of a sample. If you want a thing to be believed, you make it falsifiable. If you want a thing to be seen, you send a camera.”
She turned to Wren.
“And you know this. You signed off on the falsifiable end of every launch I have ever worked on.”
Wren did not answer.
“Half past four on Tuesday,” Wren said. “The board will want the amendment. I’ll bring the ledger.”
Pilar’s instrument had been nine years in the making and had the aspect of a plumbing fixture.
It lived in a vacuum tank in Building 4 at a small institute in Pasadena that had two air handlers and one of them worked. The tank was a converted swimming pool from a marine science program that had lost its grant, lined with stainless steel, and it could pull a hard vacuum down to about a millitorr, which was as good as it got and good enough, because the gas you were pulling in was the gas you brought with you.
“You have to understand the regime,” Pilar told the new student, the tall one from Lisbon with the tape on his glasses. “Nobody has ever measured the air of a world outside this one. Proxima b has an image. It is a hundred and twenty kilometers a pixel of nothing in particular, and the atmosphere is a limit on the star’s light that nobody can lift off the noise floor. Every committee on Earth calls a spectrum a measurement. It is not a measurement. It is a rumor with a color attached.”
She crouched at the tank’s service panel with a wrench and a rag that smelled like machine oil and the coffee she had been drinking since six.
“So we make a ship. The ship goes down into the atmosphere, and the intake is a tube with a scoop on the end, and the scoop is the oldest idea in the trade.
“And the tube has to survive the entry heating, and the sample has to survive the entry heating, and then for forty days it has to sit in the upper atmosphere on the day side, near the substellar point, because that is where the chemistry is interesting and the whole reason Proxima b is on anybody’s list, because it is tidally locked, so the air near the star is the air that has been cooking in the sunlight for a hundred million years, and you want that air and not the nightside air, which is frozen and boring and full of condensate.”
“And the wind?”
“Nine hundred kilometers an hour, more or less, and mostly along the terminator.”
The student whistled.
“The intake has to be upwind of the exhaust, not downwind,” Pilar said, “so the exhaust doesn’t eat the sample. That is the entire trick. Forty days of it.”
The valve had failed twice. The seat on the third iteration had a hairline in it that only opened when it was cold, and the only way to find a cold valve seat is to put the valve in a chamber that is cold, and the chamber in Building 4 is a refrigerator with a vacuum port hacked through the side of it, and it holds at ninety kelvin, and the valve had to be operated in there by hand, by a person, through a glove port, while somebody else read a gauge.
That was the part nobody put in the proposals. The proposals had “valve cycling, cold case, 400 K and 90 K” on a line. It took four people and two shifts and a thermos of coffee and a bad song on a speaker, and twice the seat chipped and the whole run had to start over, and the second time it took eleven days to find a new seat made by a shop in Long Beach that had no idea what it was for.
“The money’s not in the launch,” Pilar told the student once, at two in the morning, with the glove port fogged. “The launch is money anyone can spend. It’s the glove port at two in the morning. Nobody budgets the glove port at two in the morning.”
By the end of the ninth year she had a flight article, a ground article, a second ground article, and a paper with eleven coauthors. She had also, twice, been told by a program office that the atmosphere ingest unit was a nice idea for a later mission.
The first time was a watts dispute in 2015, over a Mars sample return that got cut in a budget meeting for reasons that were written down somewhere in a way that did not include “watts.” The second time was this.
When they gave Wren the corner office with the window, she moved her meetings into it and kept working from the corner of the sixth floor that the heating plant had claimed. Eleven years now.
The scar lived in the lower drawer of that desk, under a box of cable ties, and it was a printout from 2015 with pencil on it in her own handwriting.
MERIDIAN, NIPO-7. CRUISE POWER MARGIN. REQUIRED: 1,940 W. AVAILABLE AFTER ALLOCATION: 1,599 W. SHORTFALL: 341 W.
She had been thirty-one and the shortest-tenured systems lead on the program. She had written the number down, taken it to the meeting, and sat down, because the man across the table had been on the board of a national laboratory since before she had a driver’s license, and he said the 341 watts would not move a meter of anything. He was right, and it moved the whole mission anyway, because the shortfall was a schedule item and the schedule item was a cancellation, and Meridian never left the tank.
Also in that drawer, under the same box of cable ties, folded in four and soft at the creases, a fax with a Miami number on it and a Cuban customs stamp in the corner. Pilar had known about the fax for eleven years and had never once asked what it said.
Cyril Boudreau found her in the corner in March, with the good manners of a man who has decided to be a friend before the vote.
“You’re not going to win the public argument,” he said.
“I know.”
“It’s not about the public argument.”
“Then what is it about?”
He leaned on the corner of the desk, which she hated, and looked at the penciled printout she had not covered.
“You know what the real thing is,” he said. “It’s not that the sample is better science. It’s that a sample is a receipt. The board can hold a receipt. A receipt says somebody spent something and got something and can be audited. Your sail is a promise made by a committee to a future that has not been staffed yet. Nobody has been hired for the year fifty-two thousand. There is no auditor.”
“That is the idea,” Wren said.
“I know it is. I am telling you what the board hears.” He took a folded paper out of his jacket and gave it to her. “Publicity for the launch window. The Foundation’s donors want to see something in the news that is not a subsidy for a parking orbit at Jupiter. In my lifetime, Wren. I am sixty-eight. I would like one thing on the record that somebody can point at and say, here, we went.”
“A monument.”
“A monument,” he agreed, “is a wonderful thing, and it is a story about a thing we will not see.”
Wren looked at his sheet. It was the public affairs plan for the launch window, with dates, and she checked the arithmetic. The launch window was in eleven weeks, the freeze and the astrometry campaign came due on the same day, so the publicity and the aim point arrived together.
“You want the camera,” she said.
“I want the camera plus a sentence at the podium that ends with ‘and it will be waiting there,’ which is true, and which does not require a person to be alive to receive it.”
“It is a true sentence,” Wren said, “about a monument.”
The ministry review went ninety minutes.
Wren put the two columns up and did not argue for either. She showed them the margin, which was four hundred and forty kilograms, and the sail, which was two hundred and eighty-seven, and the ingest unit with its battery, which was four hundred and twenty, and she sat down.
“The two objectives are compatible in principle,” the Foundation’s lawyer said.
“They are compatible in a paper,” Wren said. “They are not compatible in a ledger.”
The board voted three to two to preserve the sample, which they called “the primary science objective.” The two were Wren and a man from the office of the Vice President for Exploration who had voted his minister’s confidence and gone home. The three were Boudreau and the Foundation’s lawyer and the chair of the committee, and they were polite about it.
Then the chair asked whether the CAPTURE variant could be delivered with the sail, since the sail was the more popular item. The Foundation’s lawyer asked whether the Foundation could be told that both objectives were aboard. The chair looked at the ledger and at Wren and asked her, in front of everybody, whether that was possible.
Wren said it was not.
“Say the reason.”
“Because there is one margin of four hundred and forty kilograms,” Wren said, “and the sampler and its battery are four hundred and twenty, and the sail and its boom are two hundred and eighty-seven, and both is seven hundred and seven, which is two hundred and sixty-seven kilograms over. The sail wants the bus held square to Proxima all the way down. The sampler wants the bus despun and pointed at the terminator with the intake into the wind. That is two different spacecraft. I have the mass for one of them.”
“Alternatively,” the Foundation’s lawyer said, “you can keep both columns and let the sampler fail. It is a machine. Machines fail.”
“It is a machine that never gets switched on,” Pilar said, “because the battery is a clock and the clock runs out before the sail is down. It fails in that atmosphere, drowned.”
She picked up her folder.
“The launch is in eleven weeks,” she said to Wren, “and I am not going to argue with you in this room, because you have already argued with yourself, in public, twice, and lost, and I would only be making a third.”
The chair let the room empty and then asked Wren to stay.
“Somebody has to certify the ledger as it flies,” he said. “The mass board sits Thursday. It will be the person who owns the watts, and that is you, and you will sign one line or the other.”
“I voted against the majority.”
“I know what you voted. On Thursday you certify.” He closed his folder. “This committee votes for a mission. It cannot vote a mass into existence. On Thursday you are not signing a policy, you are signing a number, and the number is the number. The majority does not certify it. You do. Bring the page.”
Thursday took two hours. The mass board read the numbers back and asked the same questions in a different order, and at the end the chair put the page in front of her and uncapped a pen and did not slide it across.
“Which line, Dr. Calloway?”
Wren looked at the two columns. She put two fingers on the page, on line 41, and held them there.
Two hundred thousand square meters of film with no clock in it. Forty watts, forty days, thirty-eight kilowatt hours, and a receipt with her name on it.
“The sail,” she said. “Strike forty-one.”
Pilar was not in the room. Wren had checked.
“Why,” the chair said.
“Because I have spent my whole career certifying numbers that expire. Forty watts for forty days is a claim with a date on it, and on day forty-one the battery is dead and there is nothing left in that system that anyone can check against. A tube of valves that stops on day thirty-nine is just spent. The sail is the only part of that ship that will still be answering when somebody gets there.”
The chair did not look up from the page for a while.
“Three of five voted the other way on Tuesday,” he said.
“I know.”
“Then you understand what you are doing. You are not certifying a mass. You are overruling a vote with a pen, and the pen does not get to be anonymous.” He turned the page around. “Write the amendment. Four pages. Your signature, mine, and a witness. And sign your own name on it, not the board’s.”
The amendment was four pages. Nobody told Wren what to write after her signature block, so she wrote it herself, and it went to the Foundation and the ministry and the board, and it was signed in ink at 4:40 in the afternoon on the twenty-sixth of March, in the ministry’s anteroom, which still had the fax machine from 1998 in the corner, and which the ministry’s protocol still required for the transmission of any document of record that was not wet ink.
Wren had brought the ledger with her. It was the third draft, printed on the good stock, with the weights in a face she liked.
Line 41 read:
ATMOSPHERE INGEST UNIT, P. MONDRAGON, PI. 260 KG. 160 KG BATTERY. 40 W, 40 d. ATMOSPHERE CAPTURE, AEROBRAKING, DAY-SIDE, 40 d.
She read the fax before she picked up the pen. It was in her jacket pocket, folded in four, soft as cloth now.
E. Calloway to W. Calloway, 11 March 1998.
Mija: I am writing this on the office letterhead because I want it to look like an engineering memo and not like a letter from a man who has been told to slow down.
In 1979 I signed a certification for a heat exchanger that had a weld in it I never saw. I told myself the weld was another man’s line. By the time the ink dried it was mine, and it stayed mine for nineteen years, and the man who asked me to sign it retired to Vero Beach and does not remember my name.
Your mother wants me to ask about your classes. What I want to know is what you will put your name on.
Do not be sentimental about it.
Your father.
She had been fourteen. She had kept it because of the letterhead, and then because it was a question.
She folded it back along the creases and put it in her jacket, and picked up the pen.
The witness was a man from the ministry named Halvard Nyström, who had been instructed to witness the signature and not to have an opinion. He said that in his experience the only documents that ever mattered at his ministry were the ones that arrived with a fax number in the corner, and then he looked at Wren with an expression she did not care for. It was sympathy, and she did not want it.
Blue ink. One horizontal line through line 41, struck through, dated and initialed.
The board had asked for a summary. Wren gave them one page, no adjectives, with the mass on it and the watts on it and the reason: the CAPTURE column cannot be carried with the SAIL column installed.
The first fax went out at 5:12 and came back at 5:19 with a smudge across the signature line, because the ministry’s machine was thirty years old and had opinions. They faxed it a second time. That one came back at 5:26 and was legible. Nyström took a hard copy of the second one and put it in the ministry file. Then, on his own initiative, he put a copy in a second file and wrote the time on the tab.
The Foundation’s lawyer sent a one-line note at 6:40. The Foundation accepted the amendment as filed and requested that Dr. Calloway recuse herself from the launch readiness review, effective immediately, in the interest of an unambiguous chain of certification. Wren read it twice on the platform at Union Station and put the phone away.
She carried the struck page out of the building folded into her jacket, next to the fax, and took the train to Pasadena. It was after nine when she got there and Building 4 was still lit, one air handler running.
Pilar was at the tank with a rag in her hand and did not ask how the vote went.
“It went,” Wren said.
Pilar folded the rag twice and set it on the flange.
“Which line?”
“The sail. Yours is struck.”
Wren took the page out of her jacket and laid it on the bench, face up, the strike showing.
Pilar put her thumb on a bolt head and left it there. Then she looked at the tank for a while. Nine years of tank, and the service panel with its chipped paint, and the glove port gone yellow.
“Did you do it for me?” she said.
“No.”
“Good,” Pilar said. “I would have had to be grateful.”
Then she picked up the torque wrench and held it out.
“Hold the light,” she said. “The seat’s still in the chamber. I am not leaving it in there for some intern with a crowbar.”
Wren took the light. Pilar went down on one knee at the flange and started on the bolts, and the tank gave them up one at a time.
The gauge on the wall crept up to atmosphere. Behind them on the bench, the corner of the struck page lifted in the draft and settled.
“Next one,” Pilar said.