Thomas Fairhead had meant to talk about how Waterloo Rocketry runs its projects. He changed the plan. “Our project management kind of sucks,” Waterloo’s propulsion lead told the Launch Canada conference in Timmins, Ont., on Sunday, and gave half an hour of technical advice instead, aimed at any team thinking of building a liquid rocket engine.
Student teams build engines in three kinds, in rising order of difficulty. Solid motors burn a premixed block of propellant and cannot be turned down or shut off once lit. Hybrids burn a solid block of fuel with a liquid oxidizer sprayed through it, so the crew keeps some control. Liquids feed fuel and oxidizer in separately from their own tanks. That is how most orbital rockets work, and very few student teams anywhere attempt it.
Waterloo flies liquids, and Fairhead opened by explaining why anyone should listen to him. The team flew the first amateur liquid-fuelled rocket in Canada, he said, and holds the fourth-highest amateur liquid flight in the world. It has gone higher every year, and this week it is trying for more than 60,000 feet. The asterisk, he said, is that it never seems to get the rockets back.
Then the list. Never let fuel reach the chamber before the oxidizer, and build that rule into the plumbing rather than the software, because the team’s one failed engine test was a hard start: fuel pooling in the chamber before it lights, then going off all at once. Swirl injectors, which spin the propellant to mix it as it enters the chamber, threw perfect cones on water and fell apart on carbon dioxide, the stand-in the team uses for nitrous because both boil as they spray. An attempt to weigh the propellant tank during a firing came back saying it was 10 kilograms lighter than it was.
Asked what the work costs, Fairhead said the rocket had been more than a full-time job through the whole 2024 school year. “I almost failed some of my classes, so don’t do that.” The way to avoid it, he said, is delegation and keeping the scope reined in.
The other talks ran much the same way. Teams described what they had built, then what it had cost them to find out.
The engine that did not survive
Oronos Polytechnique, from Polytechnique Montréal, destroyed its first liquid engine before it ever got to Timmins. The nozzle and injector head were aluminum with a protective thermal coating, chosen on the strength of the team’s own simulations. “We thought it would work,” said Patrick Zvezdin, who co-leads the propulsion department. “It did not work.” A static fire in June, the engine bolted down and run in place, wrecked the nozzle, burned through the head and cracked the liner. The team lost its chamber pressure readings on the same test. The parts going into this week’s fire are stainless steel.
Ronik Jagdev of Arbalest Rocketry at York University claimed the first Canadian flight under active roll control: small moving fins that stop a rocket spinning about its own axis, a spin that at worst couples with a wobble and tears the airframe apart. The team flew nine times over the year and got the control working on two of them. Another went up with the sign reversed, so the rocket drove the spin instead of killing it and went out of control.
Dylan Peters and Ethan Akerman brought Western University’s answer to a manufacturing problem. A hybrid engine burns a cast block of fuel, usually wax, and any void or crack in that block makes the burn unpredictable. Their machine spins the mould while the wax sets, so centrifugal force packs it evenly against the walls. They were given about $1,600 to work with, at a university with no aerospace program, and went a little over. They looked for anyone else doing it and found nothing public — the work exists, they said, but not without a non-disclosure agreement. The rig snapped a drive belt almost immediately on its first full run.
Khephren Gould of UVic Rocketry spent the year turning a rocket into an instrument. Strain-gauge rosettes, which measure how much the airframe flexes under load, went onto the structure, and a probe and pressure ports in the nose measured airspeed and the angle the vehicle was flying at. The team tried this once before, four years ago, and gave up when the gauge wires broke while being cured into the fuselage. He was candid that the lower ring of gauges never got installed this year because they ran out of time, and that the model in his slides is not what flew.
The constraint nobody funds
Esteban Perrault, technical director of the McGill Rocket Team, has a problem no amount of engineering fixes. The university has told his team that an engine failure would probably close its test site. “We’re forced to the very cautious side of things,” he said, “and we don’t have that margin of manoeuvre that maybe some other teams or institutions have.” McGill spent a full year building a test stand before it fired anything, and now runs a miniature version of its engine that it can test five times a day instead of five or 10 times a year.
Two days earlier, on the same stage, the Department of National Defence had announced $1.2 million for Launch Canada. Not to produce the engineers who presented on Sunday, who are already here, but to widen the path they took. Adam Trumpour, Launch Canada’s founder, said the money will let the organization reach more Canadians and build permanent training and test facilities, rather than a range it erects in the bush each August. Some of it will go directly to projects run by teams like these.
Sunday was a fair account of what that path costs now. A year of building a test stand before anything fires. One destroyed nozzle. And, as Fairhead put it, almost failing some classes.
More SpaceQ coverage: Launch Canada Competition · Launch Canada · Launch Canada Challenge returns to Timmins for fifth year of student rocketry.