Be sure to check out the group’s incredible videos of the hot fire test here and here.
The members of Boston University’s Rocket Propulsion Group gaze steadily at their rocket strapped into its test stand 200 meters away.
The Mk (pronounced mark) IV Quasar, as it’s called, is hooked up to a dozen or so wires feeding data into a computer up on the hill with them, like a test subject being monitored for vital signs.
After an afternoon of bustling activity and enjoying the first warm day of May, they’re almost totally silent as they hang on to co-director Drew Kelley’s every word. The junior majoring in computer engineering sits at a table with the computer, reading out data about the rocket’s systems and the pressure of its liquid fuel. Aside from the eerie sounds of the rocket’s high-pressure fuel as it moves super-sonically from chamber to chamber, his words are the only indication of when ignition will come.
When the igniter’s flame spurs the hybrid rocket’s liquid nitrous and solid rubber fuel to react, that reaction will force screaming flame through the nozzle, producing over 2,500 pounds of thrust, or enough to send the rocket 100,000 feet into the air, three times the height of most commercial flights.
But today is just a test. The rocket is strapped into its test stand, which is buried in a slab of concrete six feet deep, so it’s not going anywhere. In fact, the group has already determined that this rocket, the Mk IV Quasar, will not fly. They couldn’t get it working reliably enough to justify spending the thousands of dollars it costs to ship it to the Black Rock desert in Nevada, one of the few places in the country where it’s legal to launch a rocket like it.
Still, the results from today’s test will give them invaluable information about the rocket’s capabilities and, more importantly, about theirs. If the rocket performs well enough in this test, the group can be confident that they’re on track for next year, when they will set out to finish what they started a year and a half ago.
All their work on the Mk IV this year—and last year’s Mk III—was in preparation for another rocket: the Mk V, which hasn’t even been built yet. If all goes to plan, they will fly that rocket to 450,000 feet. They will fly that rocket to space.
A Radical Idea
Armor Harris is the reason why 18 college students spent the Saturday before finals week at an old quarry in Sudbury, Mass. The junior mechanical engineering major is the mastermind behind the idea to send a rocket to space, and the designer of the rockets that would get them there.
When Harris joined the rocket group two years ago, it was totally different. Up to that point, it was a closed-off collection of six or seven upperclassmen who tested small, horizontal rockets never intended to fly.
For someone like Harris, who got his first model rocket when he was six and has been flying them ever since, that didn’t quite cut it.
“Coming from my background of rockets my whole life and flying them, building little demonstrators on a lab bench was not very interesting to me,” he said in an interview. “I wanted to go fly big rockets and go to space.”
Starting in the summer of 2012, Harris started recruiting people for the team. That fall, he rounded people up, many of them freshmen, and called a meeting at which he presented the plan: to build a series of hybrid rockets over the course of three years and fly the last one to space.
“All the older people thought I was crazy and didn’t come back, and all the younger people thought it was awesome and wanted to be a part of it,” he said. “They were the ones who stuck around.”
At the time, none of those people knew much of anything about rocket science. And for all he’d read about hybrids, Harris said, looking back, he didn’t know anything about what it actually took to build one.
What’s more, for all the research that is out there about hybrids, not many people fly them, especially among non-professionals. If they fly the rocket to 450,000 feet as planned, they’ll be not only be the first non-professional group to fly a hybrid rocket to space, they’ll set the record for the highest anyone, professional or not, has ever flown a hybrid rocket.
Hybrid fuel rockets combine the stability of solid fuel with the efficiency of liquid fuel. The high-pressure fluids involved also make them incredibly complex, but that’s part of the point.
Harris said one of the main reasons for this project is to allow students who have a passion for rocketry “to do the kinds of things that they wouldn’t ordinarily be able to do until they were many years into their professional career, but at the undergraduate level.”
The fact that no one in the group knows what they’re doing when they join just makes what they’re doing all the more remarkable, especially since most of what they learn along the way is self-taught.
The group’s faculty advisor, engineering professor Caleb Farny, has had that role since Harris joined, and he said it’s mostly consultative.
“Largely, they are a self-run group,” he said in an interview over the phone. “I mostly act as a sounding board for them.”
Tom Halstead is a case-in-point. A sophomore mechanical engineering major, he has taken on the role of the aerodynamicist, analyzing how every little thing will affect the rocket’s flight and helping design the parachute recovery system. Everything he knows about aerodynamics he has learned on his own initiative, with some help from various engineering faculty.
“I’ve read through two or three aerodynamics textbooks to get through all of this,” he said during an interview in the group’s fluorescent lab in the basement of the Photonics building.
Halstead shows up every day dressed like a professional in casual slacks and a button down shirt, sleeves rolled halfway up his forearms. Drew Kelley, one of the group’s co-directors, once described him as a book for the baffling amount he knows about weapons.
He’s set that professionalism and love for knowledge on rocketry, not afraid to dive into the theoretical mathematics required to understand the rocket’s aerodynamics. And he comes out on the other end with a smile and a chuckle.
“It wouldn’t be fun if it weren’t hard,” he said. “There’s a challenge in there, and it’s always fun beating challenges.”
In the group, Halstead’s initiative is not so unique. Most of the group’s members are freshmen or sophomores who had to hit the ground running.
Joe Beaupre is a freshman in the electrical engineering track who, after just a few months of working with the group, designed the circuit board that controls the flow of liquid fuel into the rocket.
“It was a lot of learning, cursing, and late nights,” he said in an interview in the electronics room, a back room of the rocket lab scattered with bits of wire and other ambiguous electronics where Beaupre and others have spent many late nights making sure everything will come together.
The project demands an incredible amount of time, enough that of the 50 or more members who start out with the group at the beginning of the year, about 20 to 25 stick around and become regular faces.
Beaupre estimates he spends an average of 20 hours a week on rocket work, and even more in the weeks leading up to tests when there’s lots to do and not much time. Halstead said he devotes as much as 40 hours a week to the group. But Kelley and Harris, the two directors, spend anywhere from 50 to 70 hours every week on the group.
Even with all those hours of work, it’s nearly impossible to think of everything that could go wrong and plan for it.
“It’s terrifying,” Beaupre said. “You don’t know you missed something until it bites you in the ass. Hindsight’s 20/20. That’s especially prevalent in engineering.”
A Close Call
As silence falls on the dusty hill overlooking the rocket, the group is still missing solid evidence that the rocket can perform at 80% efficiency, which would serve to convince them they’re on track to launch the Mk V.
They were hoping to prove that two weeks ago at what was supposed to be the last test of the year, but an electronic match failed to light the igniter, leaving fuel to pour out of the rocket cold. They tried again last week too, but a software glitch kept a valve from closing all the way and caused the liquid fuel tank to fill with gas too quickly, raising its pressure until a safety feature kicked in and blew it open without damaging the tank.
Now, it’s the first weekend in May and finals week is looming large, meaning this really will have to be the last test of the year.
So when the computer freezes and the electronic valve controlling the flow of nitrogen–which regulates the pressure of the rocket– is not doing what it’s supposed to, everyone tenses up. The members of the group are no strangers to failure, but right now, they need to prove this rocket works.
Kelley and Harris run out to the rocket while it’s still safe to get a closer look and discover the problem, and with a huge, collective sigh of relief, everyone realizes it’s not fatal. They won’t be able to properly pressurize the rocket, but they can fuel it. A quick reboot of the ground control computer and they’re back on track.
“The classic IT solution,” the group’s secretary, Mehmet Akbulut says with a smile.
They Do It for Themselves
The late nights and torturous uncertainty begs the question of why anyone sticks around in the group at all. At the test in Sudbury, Akbulut, a well-spoken sophomore mechanical engineering major, said the motivation is internal.
“We’re not trying to launch a rocket for the rocket propulsion group,” he said. “We’re trying to launch a rocket for ourselves.”
He said he covets the opportunity to be a part of something groundbreaking that he can’t do anywhere else. Other people talked about the satisfaction of seeing their hard work turn into something so complex, the bragging rights that go along with that, and the pure fun.
During an interview a few weeks ago back in the rocket lab, Kelley, the co-director, also talked about the strong community they’ve built after weeks of late nights in the lab together.
“As cliché as it is, we’ve become sort of a small little family down here,” he said.
And then there’s Harris, the one whose idea it was to build the rocket in the first place. He wants to go to Mars.
“My childhood dream was to be an astronaut, and I guess I never quite gave up on that,” he said.
That’s why he wants to work on SpaceX’s project to go to Mars, and eventually go there himself one day.
After fixing the problem with the valve, Kelley settles back into his seat in front of the computer and continues the sequence to ignition. When the liquid fuel tank reaches 900 pounds per square inch (psi), he gives the electronic order to light the igniter, which failed just two weeks ago.
This time, it works, sending the wild flame of the igniter tumbling awkwardly out of the nozzle.
With one more stroke of a key, all 900 psi of nitrous oxide shoots into the combustion chamber, explosively reacting with the solid rubber fuel.
For three and half glorious seconds, the rocket shoots a focused flame out of its nozzle, instantly kicking up a cloud of dust that shrouds the bottom half of the rocket.
But the burn was supposed to last between 10 and 12 seconds, and when the smoke settles, the bottom half of the rocket is lying on the ground next to the test stand, melted off of the rest of the rocket. But right then nobody, not even Harris, cares.
Kelley just told him that in those three and a half seconds, the rocket produced about 2547 pounds of thrust, which is close to 100% performance efficiency.
“We can fly this baby!” Harris yells as the two directors grab hold of each other, laughing and hugging in the brutish way men filled with excited adrenaline do.
As the day is called and people start getting ready to pack everything back up into the Uhaul, spirits are high, and so are hopes.
“This was phenomenal,” Harris tells a group of members gathered in a circle before they began packing up. “This is all we needed from the Mk IV.”
Two days later, at the group’s weekly meeting in the rocket lab, Harris declares that they are on track for next year, even though the rocket melted in half. That problem can be easily fixed with more insulation, he explained.
The more important thing is that their hybrid rocket performed at close to 100% efficiency, something only one other group—a professional company, actually—in the world has been able to achieve.
Still, moving forward, they have a lot of work they have to do, he said. At the meeting, he outlined seven challenges the group faces for next year, not the least of which is being able to sustain a burn for 45 seconds. As of now, the longest they’ve gone is three and a half.
There’s also the matter of funding. The Mk V is estimated to cost $93,000, which the group will raise through a combination of money from the school and corporate donors.
That price tag presents another problem: they can’t afford to test the Mk V and break it, so they have to figure out a way to carry out tests on a smaller scale. At the same time, when they go out and shoot it to space, they have to be sure it’s going to get there and come back in one piece.
“With something like this, your first flight is your first test flight,” Harris said, “so it has to work bar none.”
Beaupre lives within driving distance of the city, so he and a few other members of the group plan to spend part of their summer rebooting a smaller rocket, the Mk II, and using it to test out plans for the Mk V.
Meanwhile, Harris, Kelley and Halstead will be interning with SpaceX in California. Harris interned there last summer and said it’s more or less what the group does, but bigger. Kelley is graduating early, so he’s hoping the summer gig will turn into a full-time job.
Halstead is just excited at the prospect of being able to work solely on rockets. “Honestly, not having to worry about classes and all that seems like a dream,” he said.