A bar disappearing did not mean the canister was about to stop.
Seo said that first. Darae told him she understood, but her hand stayed tense. A machine that displayed someone’s remaining time in little squares was a singularly unhelpful machine.
“How many bars are there?”
“Five,” Maru answered.
“Is there a more detailed numerical display?”
“He’s opening the screen beside it.”
The first image broke up. The communications window was nearly closed, and the bottom of the picture dissolved. Seo did not write down the number he could make out. With the unit cropped away, it might be a temperature or a remaining capacity.
The Safety Office confirmed the next scheduled contact. Switching relay antennas would leave a gap of several minutes. Nearby space did not guarantee an unbroken conversation. When Raon’s structure passed between the two objects, the signal could not find its own way around a metal wall.
Darae did not keep asking questions into the transmitter. Clinging to a failed connection might only cost the people at the other end more power.
Seo wrote the next questions on paper and passed it to her.
Pressure. Carbon dioxide. Temperature. Humidity. Sorbent capacity remaining. Measurement times and units.
“May I read them out?”
“Please. I’ll compare the incoming values with the system diagram.”
She made room for the answers beside each question. There were more blanks than in an intake ledger, but the principle was familiar. Fill an unknown with a plausible number and the person receiving it could get hurt.
Mujin was reviewing the new approach. Beside the stretch where Narae would meet S-6 lay a narrow gray band. It included the uncertainty in the observations, he said. Sometimes a band was a more honest map than a line.
“How long until we arrive?”
“A little over an hour and a half if we left now. We set departure after the checks and the next observation.”
He added at once, “That’s arrival in the vicinity. It isn’t when we can open a door.”
Darae wrote: before door opening. At the office, delivery and receipt were separate events too. In space, the distance between them was much greater.
Three knocks came at the communications-room door. The duty clerk held out a small pouch: Darae’s spare wrist tether and name labels from the office.
“You tied down your terminal, but not your pen.”
“The pen nearly departed first.”
She slipped the loop over her wrist. There was a pack of barley tea in the pouch too. She thanked the clerk and secured that as well. On the fuel sheet, help arrived as a little extra mass. In her hand, it felt familiar.
At the scheduled time, the reception indicator lit.
Three short signals came first: Maru’s acknowledgment. Once cleared to transmit, Darae answered at the same intervals. Even before a voice arrived, she knew a hand was working at the other end.
“Sai S-6. We have eight minutes in this window.”
“How many people there are involved in this call?” Darae asked.
“I read things out. Haeseong and two other adults check the values.”
Haeseong identified himself and confirmed who was beside Maru. Darae did not demand everyone’s personal details. She needed to know who read the instruments and who was responsible for the count.
The image arrived. This time values, units, and measurement times were visible together. Cabin pressure was within its maintained range. The oxygen system indicated normal operation. Carbon-dioxide partial pressure: 0.46 kilopascals. Temperature: 30.4 degrees Celsius. Relative humidity: 67 percent.
Darae repeated what she had read.
“Carbon-dioxide partial pressure, 0.46. That isn’t a measure of oxygen remaining.”
Seo nodded. “Right. We have to look at the two systems separately.”
The canister display showed 53 percent. One bar vanishing from a five-bar display did not mean the actual capacity had suddenly fallen by the same fraction. It might simply have crossed a display threshold.
Darae wrote 53 beside the single bar on her paper.
The small number did not remove her fear. It gave the fear a shape.
Seo asked about the calibration date and sensor location. Haeseong turned the camera toward a label, while another adult read a separate meter in the occupied waiting area. The values did not agree exactly. Sensor uncertainty and differences in airflow mattered.
“We won’t just choose the best reading,” Seo said. “We need conditions where people are crowded together too. Please send the flow log.”
Haeseong moved away briefly. Maru kept the display awake while the adult beside them aimed the camera at the fixed meter. Darae almost praised the apprentice’s work, then worried that praise might become another reason to keep working.
“You can let someone else take the next contact.”
“I read fastest.”
“Resting has nothing to do with speed.”
Maru took a moment to answer. Haeseong returned and said an adult would operate the transmitter in the next window. Maru could help organize the information. Darae left the arrangements to the people there.
Seo used the readings to estimate a range. The reported head count was still twenty-three. If present activity and ventilation continued without another failure, the backup sorbent capacity would last roughly eight to eleven hours.
He explained it to Haeseong first.
“That does not mean it stops exactly eleven hours from now. We’ll prepare support using the lower end. If the next measurements shorten the range, we change the plan.”
Darae opened 7-B’s deadline separately.
The clock for deciding what to do with a box still had well over thirty hours. Beside it was the estimate of eight to eleven hours. At last she could look at the two clocks on one screen without treating them as the same.
“This is the real urgency.”
“This is the estimate for the sorbent alone,” Seo said. “Heat, power, and people’s health need separate checks.”
One generous number did not open every door. Darae added a new measurement time beside the temperature. Telling something to cool down did not make its heat disappear into space.
On the video, Maru looked around. Someone passed over a water pouch. After a sip, Maru passed it from hand to hand instead of pushing it toward the next person. No one had to chase a floating object.
Darae reconsidered the number twenty-three. They needed more than enough sorbent for that many people. They needed room to reach out to one another in a crowded place.
The Safety Office sent a regular contact plan: minimum readings for each window and retry times if contact failed. After Narae departed, the vessel would connect directly when line of sight allowed it.
Haeseong checked the power budget.
“We can’t keep video running. Mostly voice and numbers from now on.”
“Only the photographs we need,” Darae agreed.
Her face appeared in the dark screen when the picture vanished. The people had not disappeared. They had returned the power used to show themselves to the people inside.
She took a sip of barley tea. It was not warm, but it tasted familiar. Only after confirming that they had drinking water too had she noticed her own thirst. She tied the pouch back to the wall.
Before the window closed, Haeseong called her name.
“I heard you’re sending a cartridge. Have you checked that we can fit it?”
Seo was about to answer when Darae raised a hand. There was something logistics needed to say first.
“We’ve prepared a sound replacement. We aren’t returning faulty 7-B. We’ve sent its physical inventory number too.”
Haeseong let out a short breath.
“I was worried you were coming to collect the broken one.”
For a moment she could not speak. They were waiting for help and still worrying that someone might come for the equipment first.
“I’ll read the purpose of the transfer again. Emergency assistance. This is not a demand for return.”
She read out the actual field. Beside her, Jingyeong checked its authorization. This was more than a change of words. It specified what they were sending and who took responsibility.
Darae wrote down questions for the next window. Could anyone who needed medical assistance speak to a medical coordinator separately? Could personal health information stay off the shared channel? She did not want the person at the screen made responsible for disclosing twenty-three people’s conditions.
The Safety Office provided a separate consultation route. With communications intermittent, an urgent change could first be reported as a hazard on the shared channel. Individual details would follow during available contacts. Darae read Haeseong the coordinator’s identifier. She made no medical assessment herself.
“Can everyone here leave together?” Haeseong asked.
Mujin took the microphone.
“Narae can’t transfer everyone in a single trip. The first approach brings supplies to keep conditions inside viable, and personnel to assess them. We decide the transfer plan after verifying the people and the support they need.”
“Understood. I’ll tell everyone exactly that.”
Haeseong paused.
“Send the explanation with it, please. So they don’t hear that you’re taking some people and abandoning the rest.”
Mujin restated the plan in short sentences. The first approach’s purpose. The transfer order still undecided. Even docking remained unverified. Darae lowered the transmitter while Haeseong relayed the explanation. She could not list the residents as cargo waiting for Raon’s permission.
A handover needed time for questions at the receiving end.
She added a recipient acknowledgment to the equipment sheet. Even if Haeseong signed for it, the people using the supplies should understand the assistance. Seo would provide the technical explanation. She would make the packaging labels larger.
Her wrist tether pulled tight when she raised her pen. The new loop was a little short. It felt awkward, but stopped the pen before it struck a cup. Today, objects were teaching her first how a small limit could prevent a much larger movement.
Mujin pointed out the remaining contact time. Darae made one final request: the system connection diagram. Haeseong understood that they needed the present arrangement in S-6, rather than an old manual.
“We made temporary connections after separation. I’ll include them.”
The images arrived at the edge of the window. Half dissolved into gray blocks. Seo selected the photograph numbers he needed resent next time. Beside a hand-drawn arrow, Darae made out the words:
REGENERATION HEAT SOURCE NOT CONNECTED.
Seo looked down at his equipment list. His finger stopped beside the sound replacement cartridge.
“The cartridge fits,” he said. “But fitting it won’t be enough to restore normal regeneration.”
Darae looked at the box secured in the port. Even after finding the right object, they still had to find the conditions that would let it work.