My valve timing shift created a cold spot. How bad? Manageable. I need to add a preconditioning step to the restart sequence. A brief turbo pump speed increase 40 seconds before restart initiation.
Warms the inlet, eliminates the cold spot, preserves the phase offset. He was already writing. It adds complexity to the sequence. Complexity means more opportunities for failure. Yes. which is why the preconditioning step needs to be simple enough that the risk of the step itself failing is lower than the risk of the cold spot.
He looked up. I need the turbo pump's thermal response data. How fast it gains temperature under increased rotational load. Full data set, not the summary. Daniel was already on his laptop.
At 8:51, Richard Vale walked into the lab. Hi didn't come alone. There was a man with him that Malcolm didn't recognize. older suit that cost real money. The particular stillness of someone whose importance is measured by how little explaining he needs to do when he enters a room. He scanned the lab once, let his eyes pass over Malcolm with practice neutrality, and went to speak with someone on the far side of the room that Malcolm couldn't see from his position.
Daniel leaned toward Malcolm and said quietly, "That's Harlon Brooks. He's the program director." Veil's direct line to senior management. Malcolm sat down his pencil. When did he get here?
I don't know. I didn't see him come in. Malcolm looked at Rebecca Sloan, who was at her workstation near the center of the lab. She was watching Brooks with the expression of someone who has just had a variable introduced into a system they were managing carefully. She caught Malcolm's eye across the room.
Her expression said, "I didn't know he was coming." Malcolm went back to his calculations. At 9:15, Brooks crossed the lab and stopped beside Malcolm's table. Dr. Reed.
The voice was unhurried, confident with the specific confidence of altitude. The view from high enough up that the details below look manageable even when they aren't. Harlon Brooks, program director, Artemis Upper Stage Initiative. Mr. Brooks, I understand you've been working through the night.
Brooks glanced at the pages on the table. productive. I believe so. Richard tells me you've identified what he's calling a fundamental reinterpretation of the instability mechanism away from a discrete component issue toward a resonance coupling model. Malcolm looked at him steadily. That's accurate.
And your proposed solution involves modifying the ignition control sequence. Also accurate. Brooks clasped his hands in front of him. Dr. Reed, I want to be direct with you.
We have 16 days to launch window. The propulsion system on this vehicle is flight certified. The ignition control software has been through a full review cycle. What you're proposing modifying the certified control sequence under an emergency waiver based on analysis performed in a single day by a consultant who has been outside the industry for 8 years is not a decision I can make based on enthusiasm alone. He paused, giving the pause exactly the weight he intended it to carry.
What can you give me that isn't in what I've already read in the overnight briefing. Malcolm stood up. He walked to the central monitor and pulled up the overlay that Daniel had generated the previous afternoon. The 14 simulations, the 14 curves, the 14 intersections at 11 seconds. He let Brooks look at it for 30 seconds.
Then he said, "The intersection is not coincidental. 14 independent simulations, three different measurement systems, raw sensor data with no filtering. The probability of that alignment occurring by chance at that specific time marker across all 14 runs is less than 1 in 40 million. He paused. The resonance is real.
The coupling is real. And the reason every previous correction made it worse is because every previous correction was aimed at a symptom instead of the mechanism. Brooks studied the screen. What does your revised sequence give us? It moves all three systems outside the coherence window simultaneously.
No coherence, no resonance, no oscillation. And you're certain of that? I'm certain the physics is correct. The question is whether my calculations account for every relevant system behavior. That's why we run a test.
Veil's voice came from across the room. The question, Harlon, is whether we risk flight hardware and launch schedule on an unverified modification from an outside consultant with a history of Richard. Brooks turned his head. One word. Veil stopped.
Brooks looked back at Malcolm. What would you need to verify your model before we commit to a ground test? Full access to the engine specifications, the ignition controller firmware source code, and the cryogenic system thermal model. and I need Daniel Cho working directly with me." Brooks glanced at Daniel, who was sitting very still at his workstation, clearly aware that people were talking about him. "Done," Brooks said.
"You have until the end of today to give me a preliminary verification. If the model holds, we'll schedule a ground test." He extended his hand. I look forward to being wrong about my concerns, Dr. Reed.
Malcolm shook it. I'm trying to make sure we're both right about what matters. Brooks walked away. The room exhaled collectively without anyone meaning to. Daniel rolled his chair toward Malcolm.
Did he just give us access to the firmware source code? He did. That's Daniel caught himself. Okay. Okay.
Let's go. They went. The next 9 hours were the most technically demanding Malcolm had worked through in years. Not because the individual problems were harder than what he'd faced before, but because the pace was relentless and the stakes of each calculation compounded the one before it. The firmware source code revealed two timing dependencies that weren't documented in the specifications legacy code from a previous engine iteration that the current team had inherited and partially understood.