The sturdy door nearly got torn off its hinges with the first… well, let us be charitable and call it a knock.
Jebediah Kerman, barely half awoke, bided his time as he stepped down the heavily ornamented stairs, confident that if the door’s hard, studded surface would not get the intruder to cool his tempers, the heavy revolver in his bathrobe’s pocket would. Yet the abuse did not ease up. Finally, he reached the door, and waited for the next round of smashing to end before opening it.
Jeb’s nighttime visitor shouldered his way in right through him, water streaming off of his raincoat and leaving sizable puddles on the polished hardwood floor, his eyes darting wildly around the hall, full of unused furniture stowed away under dust covers, before turning to Jeb.
He produced a newspaper – miraculously only slightly wet around the edges – and waved it in Jeb’s face.
“Was that you!?”
“You moron! You absolute bloody smooth-brain! You had no idea what you were doing, did you?” the intruder boomed, the face above his short mustache warped into a grimace of absolute condemnation.
“Well, yes, spinning up the rocket with canted fins turned out to be a bad idea…” Jeb caroled, greatly understating the magnitude of loss of control that occurred during the flight.
“Oh, pray tell, how were you coaxing the propellants into the chamber under such centrifugal load?”
“Evaporated oxygen from the cooling loop.”
“…including the fuel tank? Brilliant. I don’t know how you didn’t get yourself killed at this rate! One day I’m going to get von Kerman and give him a piece of my mind about all the young fools his booklets inspire…”
Jeb didn’t interrupt. He deliberately avoided raising his voice, letting his interlocutor vent before trying to reason with him. Name-dropping Wernher von Kerman meant he wasn’t another pitchfork-wielding ‘concerned citizen’, of which a great many pestered him earlier that day.
“With the forces involved, I wouldn’t even have considered ordinary tanks. Heard nightmarish stories about sloshing, so I decided to completely isolate the ullage with a piston. Had a lot of trouble with the seal and the interactions between oxygen and grease, a few detonations – whenever the seal leaks, the fuel is atomized near-perfectly. Nothing too dangerous, though – the main hull is as thick as a water pipe because of the pressurization, the detonation just always blew out the syphon system and the feed lines.”
“A positive expulsion system? Interesting,” the intruder, now becalmed, squinted. “You must have hit the ceiling on dry mass pretty quickly.”
“Oh, yes, between the main hull and the overbuilt combustion chamber I had serious trouble getting the thing off the ground, plus lots of unburnt fuel in the exhaust!”
“What’s your best guess on cause of failure?”
“I don’t believe there was a major failure even after the rocket went off-course; the way the systems were built, orientation should have had zero effect. So, we’re looking for whatever could send it off course, which could have been anything, really.”
“Unsatisfactory,” the intruder grumbled, “but a good start. I’ll see you again in the morning.”
“Wait, I don’t think I’ve caught your name,” Jeb interjected.
“Doctor Robert Kerman, C5 Aeronautics. And here, you should have these,” the stranger said, handing Jeb six revolver rounds, before unceremoniously marching out the door.
Jeb closed the door and checked his weapon. The drum, fully loaded a mere ten minutes ago, was empty.
The next knock on the door came at 9:00 sharpish, and to Jeb the choice of time was hardly surprising.
“Please don’t rifle through my pockets this time,” Jeb greeted him acerbically.
“Old habits die hard.”
“Indeed. Take a walk, shall we?” Jeb asked, already cloaked in a greatcoat.
“So, I made some calls this morning,” Jeb continued as they came out of the cul-de-sac, “you’re the entirety of C5 Aeronautics.”
“And all you have is a shed, two barely-literate apprentice machinists and a launch rail,” his new friend grumbled, averting his eyes.
“Now-now, it’s two launch rails… Had a falling-out with the military contractor business?”
“Jeb, I’m an expert in behavior of very hot gasses. There’s not that much work for people like me.”
“Really? What about the next jet engine?”
“Same as the previous one. The whole market for jet engine R&D is about to collapse, and I didn’t want to be around when it does.”
“What happened to ‘faster, higher, further’?”
“Mk 1 Eyeball happened, Jeb! Our jarhead friends realized they can barely hit the broad side of the barn as is, so greater cruising speed is actually undesirable. So, they canceled all contracts for advanced engines. Give them a year, two, and the industry will lose the very ability to go off the beaten path – not that the military would really want to bother with rearmament either. Do you remember how it took them three centuries to embrace the wireless?”
Jeb nodded appreciatively.
“It’s the Golden Age,” he picked up, “everyone’s better off than they were fifty years ago, mere hard work pays off, so nobody wants to rock the boat. We can only hope that this doesn’t lead to permanent civilizational stupor, because sooner or later something will happen and we’ll have forgotten how to handle change, let alone lead the way.”
“Something – or someone,” Bob noted.
“So, just to be on the same page,” Jeb stopped before asking the key question, “are you here for the advanced propulsion tech, or for interplanetary travel?”
“The latter. I’d much rather study the storms are that bound to ravage Jool’s atmosphere, then to keep measuring turbine blades until I keel over.”
“Then I suppose we should get to it.”
“Yes, indeed. So, the three big improvements you need are guidance, propellant feed, and probably major changes to the engine itself. What do you call your oversized firecracker, by the way?”
“Experimental Reactive Apparatus dash one.”
“…the jarhead is infectious!”
Bob was looking over the sorry pretense of ERA-1’s blueprints.
“Remote mechanical activation, burst diaphragms, but at least you bothered with check valves,” he observed.
“We just ignite a flare in the exhaust chamber and then open the valves on compressed air tanks on the stand to give the initial pressurization.”
“How do you ensure the propellants arrive simultaneously?”
“We don’t. We give oxygen a good lead and control for its arrival by flare brightness before introducing the fuel.”
“So, you risk ending up with lOx in your ullage.”
“…Potentially. What are your suggestions?”
“Semi-automated electronic start. Reusable valves, so that ideally you don’t have to rebuild the whole thing between firings.”
“And the feed system?”
“Get rid of the pistons, use suction.”
“Not just any pump. The throughput is such that we’re probably looking at a turbo-powered turbopump.”
“Sounds like a jet engine.”
“In principle, yes, but the gas turbine and the compressor – two separate compressors, of course – would be different systems. We can’t get the rocket exhaust to temperatures that turbine blades can handle, so we’ll need a separate source of less hot gas, a separate combustion chamber.”
“Can’t we try tapping off the main chamber?”
“…And build a complex heat exchanger system? Not sure it’s worth the dry mass.”
“Alright, so we now have one and a half rocket engines, which need to start in sequence.”
“…hence the need for more controls and greater automation.”
“We’ll need a few calculators just to support the design of that thing,” Jeb complained, “but I see your reasoning. Anyway, we should try improving the performance of the combustion chamber. I’m familiar with the theoretical work on nozzles but putting it to work has been tough. I’ve only been able to wrap a few cooling loops around the throat.”
“Mounting the cooling system around the main load-bearing structure is folly,” Bob observed, “it has to be built on the inner surface of the chamber – or even be the load-bearing structure.”
“Is it even possible to build a rocket nozzle bell out of hollow tubes?”
“…Have you ever played golf, Jeb?”
It took two months, but at least not much needed inventing. Bob knew who to call to get the junior staff, the shop floor workers, even the non-standard machinery, and could rattle alloy properties off the top of his head. Designated “Poruchik” upon his insistence, the rocket was twice as long as its predecessor. Instead of an inert steel cone, the nose hid a modified gyro platform from an aircraft autopilot, coupled along two axes with hydraulics that could angle the entire engine package. No attempt at active roll control was made; the launch rails were rebuilt at an angle, avoiding the need to program any actions on behalf of the autopilot.
The engine was truly a massive leap forward. A separate gas turbine firing a fuel-rich mixture spun two large turbopumps through a reduction gearbox. Test-bench work resulted in the addition of an impeller and an oil pump; combined with the need for a hydraulics pump, and storage for hydraulic fluid, oil and compressed air, the complexity of the vehicle was exploding out of control; C5 Aeronautics grew to fifty people. The old start system concept was, however, retained, with an external tank providing pressure to spin up the turbopump, and a flare stuck up the main nozzle.
The chamber and nozzle design turned out to be an interesting albeit tiresome element. Bob’s proposal called for brazing together a bundle of steel tubes with variable rectangular cross-sections, altering the speed of the flow of liquid oxygen that was initially input at the nozzle end through a single large manifold. As it turned out, the only people that had experience shaping and bending hollow steel structures were the golf club industry.
Jeb’s past experience with the same propellants made launch prep relatively easy. Gone were the days of spills, minor fires, or finding out the supplier sold you liquid air instead of lOx. They were done in merely an hour. The rocket stood on the modest pad, venting boiled-off oxygen and beginning to ice up.
“Bob, any objections?” Jeb asked.
The technician began to crank the air raid siren.
Jeb turned the key that spun up the gyro; the nosecone emitted a small stream of excess gas from the spin-up powder charge. The platform needed but a second to calibrate.
He then pressed the engine firing button. The first thing that happened was the oxidizer blow-off valve closing with a loud clank; for a few seconds the propellants were flowing down the lines under gravity, until the sensors in the turbopump detected their presence. The flare in the combustion chamber ignited, its glow reflecting off the skirt, and the turbopumps spun up with a whine.
The glow turned into a chaotic inferno for a brief second, and then the exhaust took shape. The rocket wrenched off the rails, tearing away the electrical, pressure and propellant lines as it went, angled southwards.
Jeb had set arranged for the launch to be filmed from several directions, and for the cameras to be capable of tracking the rocket’s ascent for as much as possible. Beyond visual range, the rudimentary radio beacon was their only resort.
“Looks like thrust’s normal,” Jeb noted as the flare of the rocket engine disappeared in the blue.
“Azimuth’s on point, looks like pitch has held so far.”
“Chief, I’m losing the signal!”
“What do you mean? Is it lost or not?”
“It’s lost strength, quite rapidly.”
“Ignore it,” Bob suggested.
“Burnout,” another assistant, Gene, announced, holding a stopwatch.
“…or not. By then was almost empty, so it must have picked up incredible speed while in the stratosphere. High-temperature gas gets ionized, which should seriously interfere with radio.”
“Current altitude?” Jeb demanded.
“Stand by… 72 km. Expected apoapsis around 800 km.”
“So, we’ve reached space…” Jeb sighed.
“We’ve made the first step, and we’re almost broke already,” Bob complained, as the rocket began falling towards the ice desert in the distant south.