“Larry, what happened?”
“Dan, before you-”
“Nothing here moves until I have an answer. What. Happened?”
“We saw it coming in all his log entries Dan. Catastrophic failure in SCRAM number two through turbo pump seven. It was a faulty fuel valve. He couldn't have known.”
“Elaborate.”
“Dan...”
“The details first, Larry... In. Detail.”
“Okay... Dan. He was right to replace the turbo pump rotor components when he discovered they had been eaten up. But all he did was fix the symptoms, not the cause. The cause of the first incident was the fuel valve leading into turbo pump seven. On his first ascent, the valve was stuck in full open position and wouldn't close.”
“Full open is a hundred and thirty percent power. The avionics computer on an XR-2 doesn't even register that rate.”
“Right. The max safe performance rate is a hundred and five percent, and the max the sensors pick up before they read out of range is a hundred and ten percent. The turbo pump was overdriven, but that was merely the symptom to the problem. He fixed it, but never bothered to check upstream. He's Avionics, Dan, not mechanical. He couldn't have known.”
“Well-”
“Two things went wrong, Dan. The valve had been stuck open, but was able to close long before he docked with his... guests at the Arrow. But I suspect the valve was still sticking, and probably stayed closed.”
“Closed until his second ascent.”
“Yeah... Telemetry shows the valve stuck at thirty-six percent open right about the time he was pushing through the second throttle-up. Right around mach ten... That alone wasn't catastrophic. Procedure is to run the throttles for the scrams down and up through their ranges to see if the fuel flow would free up.”
“And it did?”
“Unfortunately, the valve popped open from fuel pressure... A side effect of the vacuum pressure generated by the turbo pump itself. It dumped a hundred and thirty percent fuel flow into SCRAM two while the flow rate was running at only seventy percent for the set. SCRAM two flared, offsetting the vehicle yaw enough to flame-out SCRAM one.”
“Auto-correction from the RCS thrusters should have stopped that.”
“They would have if the emergency cutoff could close that fuel valve. But apparently once it slammed open, it stayed open. SCRAM 2 pushed the vehicle further out of its envelope and choked. The lean mixture underwent uncontrolled detonation and blew the whole SCRAM assembly off.”
“It compromised the avionics, didn't it?”
“Dan, the Raven tumbled out of control for over a minute and disintegrated at an altitude of thirty-seven kilometers traveling at a speed of mach 18... But-”
“Larry, I want you to ground every XR-2 in the fleet. I want every single one of those fuel valves pulled and examined. And I want custom valves ordered to replace them. We're not going to use any more equipment meant for the XR-5s.”
“Dan-”
“And I want anything else we might have been sharing between the small and large STOs double checked to see if such faults can occur. I don't care if it takes a year. I don't want a repeat of this incident. Ever.”
“Dan...”
“He didn't deserve it. After what he got to experience, that's just not-”
“DAN!”
“What?!”
“Before you fly off the handle... Check your inbox.”
“...”
“Well?”
“Larry... Is this. Is this real?”
“Authentic to the last pixel.”
“Larry?”
“Yeah?”
“Bring our man home.”