While today’s rocket engines are sophisticated and powerful, they mostly rely on traditional — and, of course, volatile — fuels such as hydrazine or liquid oxygen and kerosene. Firehawk Aerospace has safer and more stable new fuel, new engines and millions of new funding to take it through the next round of testing to its first launch.

Firehawk came on the scene two years ago with a fresh take on hybrid engines – engines that use a fuel with both solid and liquid properties. The breakthrough from CEO Will Edwards and chief scientist Ron Jones was to structure that fuel and 3D print it in a specially developed matrix.

The structured, semi-solid fuel is more stable and easier to transport than other fuels and burns in a very predictable way. The company designed engines around this concept and tested them on a smaller scale, but recently moved to the kind of engine you could use when going into space.

“It’s a unique engine with its throttling capability, low manufacturing cost and parametric design, so we can design for a missile interceptor system or a second stage booster,” said Edwards.

The company recently completed full engine fire tests at the Stennis Space Center under NASA’s supervision, and they are ready to fly — the final step before reaching a technology readiness level that could allow the company to increase its revenues.

Firehawk chief executive Will Edwards (left) and chief scientist Ron Jones are holding 3D-printed fuel tubes.

In addition to better safety, printing the fuel pellets differently makes it possible to create different thrust characteristics. And the whole thing can be safely slowed down, stopped, and restarted multiple times — not something you often see in a launch vehicle rocket engine. They normally shoot up at 100% until they run out of fuel, meaning you only get one shot at them and your power vector options are limited – more like a drag racer than a normal car.

“Our engine can replace solid rocket motors with something that has a significantly lower cost, comparable to the fuel performance, but you can control its combustion — that’s something the industry finds incredibly attractive,” Edwards noted.

A Firehawk engine is being tested at Stennis. Image Credits: Firehawk Aerospace

Not in the sense of first-stage launch vehicle engines, where that fire at full blast is desired, but for systems where a little more complexity would be welcome: second-stage thrust (e.g., are out of the atmosphere) and missile interceptor systems, where precision is a priority.

Edwards also suggested space propulsion, such as maneuvering with satellites, as a possible application, because because of the volatility of fuels, lower impulse methods such as ion engines are often used. Firehawk’s fuel is ‘naturally inert’, making it a lot less cumbersome in a multi-charge launch, for example. Want to keep your satellite next to a barrel of kerosene?

The new Series A funding round will allow for more testing, more R&D and the production of more engines to meet demand – although predictably with a company working with Raytheon, NDAs prevent the nature of that demand from being described with any specificity. . They have raised $15.5 million so far, but expect to close at $17 million soon.

The list of financiers is a bit long, but for the record: Star Castle VC led the round, with participation from Raytheon, Draper and Associates, Goff Capital, Cathexis Ventures, Plains VC, Victorum Capital, Stellar VC, Capital Factory, Echo Investments, and Hemisphere Ventures.

While the engines currently being tested are almost ready for customer use, Edwards emphasizes that this is just the beginning. New applications may be just a few keystrokes away:

“We can create really unique fuel grain geometries and by changing the design we can improve performance. It’s just a matter of rewriting some code and uploading it to our 3D printers,” he said, adding that the new funding has allowed them to buy and customize their own printers, CNC machines and test rigs for deployment at a new location in Addison, TX. — “We’ll be able to move through our next test campaign much faster.”

This is the happy team at the new headquarters:

Image Credits: Firehawk Aerospace

More testing should come next month, which should pave the way for a launch of some sort in the near (but unspecified) future.