Nine days later this situation on the ISS is closing in on critical. What were previously written up as apparent low-voltage electrical failures are in fact much more serious problems with the smaller, more sensitive components of the thaumic systems up there, particularly the interface with the Microgravity Solar Aura Containment project module which, though not explicitly running off magic in any way, uses it quite extensively to catch and bottle fragments of solar wind for study. There is air. Copious quantities. The system will run mechanically for as long as there still is air. Like the ASTS the magical systems are retrofitted.

Laura Ferno calls a meeting with Mission Control Director Eric Whitehead and half a dozen senior engineers where she explains her theory.

"This has been exceptionally difficult to pin down and I apologise for the delay. I had to be 99% certain before I felt comfortable coming forward. The fault was in the connection between the external fuel tank and the orbiter, the Elliptical Torsion Lock. This is an elongated electrically-triggered thaumic binding ring-- two of them, in fact, with a complex toothed interlocking assembly. The purpose of this lock is to keep the orbiter and EFT mated together up until the tank is jettisoned at T plus four minutes eleven seconds. To be more specific it is an oversized, elliptical Heinewitz pseudomagnetic connector. As you know, magnetic binding rings are typically circular or as close as possible because ellipticality introduces a long-period resonating wave - about two point eight seconds in a ring of these dimensions. That resonation induces a degradation which means the Heinewitz attractor drops over time. After fourteen minutes and one second give or take ten seconds it has become too weak to keep the EFT and orbiter mated against the strongest external accelerations and at nineteen minutes and thirty-one seconds give or take twenty there is no practical attraction at all and disconnection occurs.

"This is acceptable for this purpose because the ring only has to bind for less than ten minutes. There is no substantial physical, mechanical connection between the two components. At T minus three minutes and thirty seconds, as you know, but I'll repeat it for the sake of clarity, a designated individual in a building adjoining Mission Control primes and then remotely casts the binding spell which mates the orbiter and EFT together. In the case of this mission the individual in question was Dr. Grigor Mebidev who is here today. The casting has to be performed word-perfctly and takes twenty-five to thirty seconds. If a pronunciation error is made, the first attempt at the spell is scrubbed and there is time for a second attempt to be made. Once the countdown passes two minutes and fifty seconds, however, there isn't enough time for the Pre-Connection Support Gantries which hold the orbiter in place up to that point to be withdrawn before the launch, and the mission countdown can be suspended if necessary. Again, as we know, Dr. Mebidev's spell was performed word-perfect on the first attempt and the launch countdown proceeded.

"The rings are supposed to stay bound until T plus four minutes eleven seconds when the spell is negated by computer and the EFT is disconnected and falls into the Atlantic.

"The problem was not in the degradation of Dr. Mebidev's spell but an incorrect reading of the mechanical tolerance of the spell. While the ring was functioning within expected parameters, while in flight it experienced an unexpectedly strong pocket of wind which strained the ring more than had been allowed for when it was manufactured. This strain is registered on the ring's telemetry and other systems, as seen here, and here. The additional strain partially deformed the ring, setting up a stronger resonating wave which grows more quickly than expected. The ring itself never actually fails but the resonation is what causes the right SRB to begin to experience a stronger Korolov rotator effect than expected, breaking off the right SRB's lower physical connector and instigating the crash. The rest, I think, is known."

There is a lot of uncertainty in the room and a lot of scepticism. Not because of the lack of credibility of the person speaking to them. But it's a conclusion which came too fast.

"I can see that there is some hesitation here," continues Ferno. "But to the best of my knowledge this is what happened and I have concurrence with Doctors Yewland and Hataki and with Mr Understall and Mr Blue who are working with me on the investigation. Much more remains to be done, but for the near term, there is a quite simple way to assure the safety of the Polaris launch and that is for me to lay down a 'primer layer' spell on Polaris' Elliptical Torsion Lock. This spell adds a light additional layer of binding to the Lock which will persist for approximately eight hundred days but can be cancelled by the same Computerised Negator servo as the Heinewitz Lock meaning that separation will proceed exactly as promised.

"If there's a bus going in the direction of the Polaris launch complex, I can get that done inside of two hours. I have all the equipment I need right here. You can hit Wednesday evening's launch window. After which, of course, the entire fleet will have to be grounded for a year while the investigation is fully completed."

"Two hours, nothing," says Whitehead.

"I know. A figure of speech. There's a procedure for it, like everything. Show me the engineers and the paperwork, and Dr. Mebidev and I can get to work immediately. But you can hit that window."

*

It's going on sunset at Launch Complex 39B. Laura Ferno's wrapped up in a billowing coat because even though it's Florida she's eight storeys up in the air on a gantry alongside the Elliptical Lock. It's a fantastically complex piece of equipment. The most impressive thing, she finds, is the sheer volume of paper documentation attached to every last duct, wire, pipe and gout of smoke. It all has a purpose. It all has a reason, and not just a reason, but a paper specification and an owner and an original designer. The whole thing is run by human beings.

While Mebidev lurks behind her elbow she holds her staff vertically above her head. (And it literally is just a thick aluminium cylindrical pole, four fifty-nine centimetre components screwed together to make a convenient focal point for precision brandishing of broad-reaching energetic thaumic releases. It hardly even has any engraving on it. If you found it in her luggage, you'd think she was smuggling flat-packed furniture.)

"Alokokaa unamidth baranamidthst bo'azpa azgo'alanumkaa, azgo'apakaa, aranam tchokk eight point eight one, ee plus five."

She holds the staff steady for a couple of seconds after finishing the pronouncement (while long and involved and unpleasantly complicated, the syllables become more familiar over time; it is not much more difficult than it is for an actress to learn her lines), then lowers it and checks the computer where Mebidev is standing. At the bottom of the launch stack a team of engineers is looking at the results of what she just cast. The main concern is side-effects on the solid rocket boosters and the magical systems inside the orbiter. But everything comes up green. There is a horrendous number of boxes which have to be ticked before a space rocket can be modified in this way and twice that many more before it can be permitted to launch, but they put a good dent in that number tonight and by tomorrow it should be a matter of a few formalities-- of course, the simple "routine" of spaceflight.

"Good stuff. And the weather should be nice," Ferno remarks, but Mebidev doesn't do small talk.

*

The Polaris launch itself, Ferno herself can't bring herself to watch in person but it looks genuinely frightening for the problem solver who gave the flight her blessing to not actually watch it happen so she stands there in Mission Control and fixates on the big bank of aerodynamics numbers as a substitute for the actual video of the thing as it rises.

It's beautiful. It's magical. It goes without a hitch. Zero to orbit in fifteen minutes flat. A rendezvous in space happens, a whole heap of crew are switched out and a whole cargo hold full of oxygen, water and food is transferred in. Polaris leaves the ISS laden with eight personnel, circles the globe at some unimaginable speed and, in the way that NASA has grown accustomed to doing, hits a target just twice the size of a conventional airstrip, right outside their door, first time, no holding pattern, no do-overs.

Breathe in. Breathe out.

*

"You lied to me."

"I lied to you. I couldn't tell you the truth. You've told the ISS to shut down their thaumic equipment?"

"That's not even any of your concern. Explain why. I knew it in that briefing, at that second. Nothing is ever that simple."

"I'm sorry it had to be that simple and I'm sorry I had to insult your intelligence. You're right. I always thought spaceflight was like a bunch of slices of Swiss cheese, all sliding over each other. There are always holes, we just can't ever let the holes line up and a tragedy pass through the gap. No NASA failure has a singular cause, that's nuts. Yes, the Elliptical Torsion Lock could have been stronger. And that is where the light came from and it explains a bunch of blips on the graphs. But there wasn't a wind pickup. I had to fabricate as complex a story as I could think of.

"The clue is that the light went away. There was a moment when the Lock's integrity was flirting with failure but it passed and it came back. And it stuck back. It was human error. Human error on the flight deck. One of the men on the flight was Brian McRime. It was his first Shuttle launch. McRime was a civilian scientist whose area of expertise was biology, going into space to study the effects of space on himself and his fellow astronauts. He had no background in magical engineering. He had a grasp of procedures, sure, but he didn't know much about magic.

"In fact he didn't trust magic sufficiently. Have you seen that scene in that movie where they call the Shuttle a ten-storey pile of high explosives built by the lowest bidder?"

"I hate that movie."

Laura Ferno spits on the ground in agreement. "But that's what he was thinking. He distrusts the whole concept. That doesn't stop him getting on a spaceship. You can think general relativity is bunk and still use a satellite navigator in your car. There's a dissonance there."

"But the mission psychiatric reports would have caught that."

"They did. And it wasn't substantial enough to be problematic. He wasn't vocal. The report gives McRime's personality as obedient to proven superior authority and willing to trust others' judgement provided they showed they were willing to trust his in his own area of expertise. He went through the thaumic motions and understood the importance of the motions and that was enough for him to be a safe bet on the Constitution flight.

"Item two: thaumaturgic technology is only ever used in the construction and flight of NASA spacecraft, to date. In fact, it's almost never been used outside of the field of view of trained, qualified thaumic engineers. Item three, the fact that the mission had been delayed slightly made McRime edgier. And we have voice recordings from the mission. He can be clearly heard to say, 'Uhhhhh...', just a second before the first flash of light. Then he reassures himself and the light fades. The damage has been done, but the visible effect completely goes away. There's no wind effect, but the whole system has just been hit by a pretty big knock of uncertainty. Then, as the roll program completes, he gets properly scared and that's why the mechanical disconnection happens."

"His lack of confidence caused a mechanical fault?"

"Remember the flare. That was a magical outburst but it signified something more important, a slight resettlement in the configuration of the orbiter and EFT. The resettlement modifies the graphene paint layer. This is in addition to the flexing Elliptical Ring which does have a real resonant property here. And that SRB connector isn't wholly mechanical. It has a similar spell to the one I just cast which enhances the tensile strength of the thing. McRime's concern reversed that effect. He was seated on the right side of the Shuttle, remember.

"I lied to you because you needed to be confident. I lied to you because if you didn't believe the problem was solved and the Shuttle was flightworthy, it wouldn't be flightworthy. Those worries are what was making the ISS failures happen, too. We need to remove magic from the space program entirely. Permanently. It's not like aerodynamics or electrical engineering! It won't work properly if you don't believe in it! And if it doesn't work properly unless you believe in it, then it doesn't work."