In race to space, one startup is betting on candle wax

Companies are trying all kinds of things to find their way in the increasingly competitive space industry.

A German startup is adding candle wax to that list.

HyImpulse Technologies last week launched a sounding rocket powered by a combination of liquid oxygen and solid paraffin – a petroleum byproduct that’s a key ingredient in candles. 

Mario Kobald, who co-founded the company in 2018, is taking this approach because he saw too many young companies trying to develop rockets similar to Elon Musk’s industry giant SpaceX, which uses liquid oxygen and kerosene to fuel its workhorse Falcon 9 rockets.

“You cannot compete with the costs of a system that’s already on the market for many years when you have established players like SpaceX,” says Kobald, who started HyImpulse with several former classmates from the University of Stuttgart, where he received a PhD in aerospace engineering.

Instead, HyImpulse says its mission is to make access to rocket trips more affordable and environmentally friendly with “space-grade candle wax”  as a key part of its strategy. The material is “cheap compared to kerosene,” Kobald says.

Paraffin also is “non-toxic and very safe to handle,” he says. The material’s stability allowed the company to transport a rocket — complete with the paraffin fuel — as ordinary cargo on a container ship from Germany to Singapore to Australia, without the need for expensive restrictions to prevent explosions.

“All of this translates into competitive costs for the customers,” says the 42-year-old Kobald.

Paraffin is a derivative of gasoline production, so it’s not exactly a green alternative to standard rocket fuels. In the future, though, Kobald wants HyImpulse to use paraffin created from carbon dioxide and water.

HyImpulse isn’t the first to consider paraffin’s potential. Researchers at NASA and Stanford University studied the material more than a decade ago, looking at its ability to burn quickly and provide the thrust needed by a rocket.

Last December, researchers from MIT’s Media Lab sent wax aboard a Blue Origin New Shepard flight to study the impact of microgravity on the material and its ability to be used as a fuel for de-orbiting spacecraft.

HyImpulse performed its biggest test of its technology on May 3 from a site operated by Southern Launch, a spaceport company with ambitions to become a leader in Australia’s nascent space industry.

The mission’s slogan of “light this candle” managed a twofer by highlighting the innovative fuel, while also hearkening back to US astronaut Alan Shepard’s memorable comment before he became the first American in space on a suborbital flight in 1961.

HyImpulse’s single-stage SR75 rocket went up 50 kilometers (31 miles), according to media reports. The company said in a statement that the test was a success, but didn’t disclose details about the altitude or landing.

In its statement, HyImpulse said the SR75 is capable of reaching 250 kilometers, which would be high enough to send small satellites to very low-Earth orbit.

The company already has its sights set on more lucrative markets. It’s developing a larger rocket, also powered by liquid oxygen and paraffin, that will be capable of reaching altitudes of more than 500 kilometers and is scheduled to launch by the end of next year.