It Really is
Firefly Space System designs rocket with Stampede supercomputer
“A mural of Secretariat will be the finishing touch on our new building,” says engineer Alex Weldon, as he shows off Firefly Space Systems’ nearly completed manufacturing facility located in Cedar Park, Texas. Secretariat, the award-winning racehorse, is a metaphor for the blistering pace Firefly has adopted towards the development of the world’s first “small” satellite rocket.
Back in 2014, Firefly CEO Tom Markusic noticed a void in the space industry. Small satellites, which have many uses from telecommunications to scientific research, could not easily launch into space. To fill this niche, Markusic founded Firefly Space Systems, the Austin-based startup that aims to provide low-cost space launch capabilities for the small satellite market.
“Our goal is to make it inexpensive and easy for people to access space,” said Chris Craighill, Firefly senior analyst. “Right now, small satellites have to ride on rockets that carry large satellites and are tied to their schedule and orbit, which is costly and limits mission flexibility.”
While most space companies can take up to a decade to design and launch a new rocket, Firefly plans to do it in less than two years. From concept to execution, their first engine test in September took less than a year — nearly inconceivable for the space industry.
How do you make a small satellite rocket, and how do you make it fast? One key ingredient is supercomputing, which provides the power to rapidly test and retest design variations.
For this supercomputing prowess, Firefly turned to their next-door neighbor, the Texas Advanced Computing Center (TACC). Through TACC’s Science Technology and Research Affiliates (STAR) program, Firefly runs simulations on Stampede, the 8th most powerful supercomputer in the world. In addition to allocations, the startup also receives technical support, visualization resources, and expertise from TACC staff, allowing them to make better business decisions.
“Firefly’s research on Stampede is helping them get closer to launch more quickly, with more accurate designs,” said Melyssa Fratkin, TACC’s industrial programs director. “It’s very rewarding for TACC to be able to support small companies that are poised to do great things.”
“That’s one of the reasons Firefly chose Austin,” said Weldon. “Having TACC in our backyard is great. The more we can keep things local, the better.”
The Race to Space
Designing a rocket is a bit like constructing a Rube Goldberg machine. Every piece of the rocket must work in tandem, which also means the design process must function in the same way.
Weldon describes the workflow as a “converging iterative process,” with Stampede used in every step. Weldon, who leads the materials and processes team, focuses on the specific materials that comprise the rocket’s structure.
“Working with TACC has been an easy experience. It only took us a couple of weeks to get up and running. The staff has also been super responsive and provide good solutions every time we have questions.”
— Chris Craighill, Firefly senior analyst
By running ANSYS simulation software on Stampede, the engineers can look at material properties at the microscale and observe behavior to analyze its performance during rocket flight.
“The tanks we use are 40 feet long,” said Weldon. “Without the power of supercomputers, it would take forever to run and get real data on performance, for instance to see parts where the tank could crack. We’re able to probe more finely, more so than people have been able to do before.”
Firefly’s innovative materials are part of the reason the company can keep their costs lower than other aerospace companies.
Historically, rocket launches cost $100- $200 million. With the rise of the private space or Newspace industry, the current price for a launch hovers around $50 million. But Firefly plans to launch their small satellite rocket for $8-$9 million. One way of doing this is relying on cost-effective yet strong and safe materials, such as carbon fiber.
“On the structural side, we’ve been able to do a lot of novel things,” said Weldon. “Traditionally, people use metal tanks, or there’s a very thin metal liner with carbon fiber on top of it. Our tanks are made only of carbon fiber composites— no other company flies all-composite tanks.”
Another novel component of the Firefly rocket is the aerospike, serving as the first stage engine. Firefly’s rocket engine consists of 12 rocket nozzles oriented in an aerospike configuration, which directs thrust and ensures that exhaust gas expands at the correct rate to launch the rocket into space. As exhaust exits through the aerospike, it’s crucial to understand the heat transfer and recirculation of gas as it re-enters the engines.
Craighill, who leads these efforts, evaluates the performance and structural characteristics of the propulsion system. With Stampede, Craighill could build a model to show how aerospike plumes interact when they collide.
“Firefly’s research on Stampede is helping them get closer to launch more quickly, with more accurate designs.”
— Melyssa Fratkin, TACC Industrial Programs Director
“We saw some interesting effects from the simulations,” said Craighill. “When two exhausts come together, they impinge down on the surface of the aerospike and can create a hot spot. Seeing these interactions lets us know to be careful and make sure we have that hotspot covered.”
While mathematical models help the engineers understand what is happening through time, visualization helps the team physically see the limits of what the rocket’s structure can withstand.
“Using Stampede’s visualization nodes, we can see results in real time instead of letting the simulation run for eight hours, then realize everything is flowing backwards,” said Craighill.
Aside from the materials and propulsion teams, other engineers at Firefly are dedicated to designing structural components of the rocket and the test site, among others. Craighill and Weldon estimate that ten out of the 35 engineers directly use Stampede, but all have benefitted from analyses from TACC.
“Working with TACC has been an easy experience. It only took us a couple of weeks to get up and running,” said Craighill. “The staff has also been super responsive and provide good solutions every time we have questions.”
From Simulation to Flight
On a blistering September day, Firefly’s CEO, engineers, and manufacturing team gather to watch the first engine test, a culmination of their work over the past year. The test site, which lies on 200 acres in an isolated Texas town, was built from the ground up and will be the location for many future tests.
Firefly’s rocket engine was tested horizontally on an innovative test stand which extends 40 feet into the earth can withstand over 150,000 lbf of force.
“The successful testing of our first engine represents a quantum step in the technical maturation of our company. We have demonstrated that our core engine design can reliably start, stop and operate at a steady state without combustion instabilities,” Firefly Co-Founder and CEO Thomas Markusic said.
This test is one of many in the upcoming months as the finish line approaches with breakneck speed. In the fall, Firefly will test their pressurizing tank; in 2016 their first suborbital launch; and 2017 a full orbital launch. From there, they aim to build up to a rocket launch every week.