Rocketeers target cubesat market and conventional wisdom

By Debra Werner|March 23, 2020

Hybrid rocket would launch cubesats one at a time — pending licenses

A small hybrid rocket that will burn solid and liquid propellants gleams on a stand in a municipal airport hangar in Hollister, California, about 150 kilometers south of San Francisco. Among the concepts being pushed by the dozens of companies seeking to capitalize on the small satellite boom, this one stands out partly because it is a hybrid, and also because its development was not funded by venture capital or led by recent aerospace graduates.

The vehicle is the brainchild of William Colburn, 83, a former Apollo engineer and National Security Agency veteran, and Ronald Winston, 79, a Massachusetts Institute of Technology-trained chemist and former luxury jeweler. They established Celestium Space to deliver a payload to orbit aboard a hybrid rocket, something that Colburn and my review of the record says has never been done.

They invited me to see the 11-meter-long rocket during the weeks before the coronavirus pandemic hit.

Plans call for selling cubesat launches for $1 million apiece, a price so low “it would break all barriers,” Winston says. Because one cubesat would be launched on each rocket, customers could choose when and where to launch, rather than hitchhiking on larger rockets.

A mutual friend introduced the men about a decade ago, after Winston combined a rubber solid rocket propellant with a high-energy solid additive to achieve performance comparable with that of liquid propulsion. Colburn, whose love of amateur rocketry dates to his childhood in the 1940s, performed a few calculations and told Winston, “We could go into orbit with this propellant.”

That claim is surprising, because the assumption has been that the specific impulse, or fuel efficiency, of a hybrid rocket can’t be driven high enough to reach orbit. Hybrids have been relegated to atmospheric sounding and suborbital flights. Winston and Colburn say their three-stage rocket with a kick motor will reach orbit because of its unique solid propellant and a hydrogen peroxide liquid propellant that requires no catalyst. Eliminating the catalyst pack helps trim weight from the direct injection hybrid propulsion, in which high-strength liquid hydrogen peroxide reacts in the combustion chamber with solid rubber grain to create thrust.

“We are some of the only people who’ve ever figured out how to make hydrogen peroxide work without a catalyst,” Winston says.

How? Winston and Colburn won’t say except it was a lengthy process of trial and error that included 500 to 600 hot-fire tests over nine years. “We’d put the whole system together, change one thing and discover that, uh-oh, we’ve changed five things,” Colburn says. “It’s a process of learning.”

Colburn and four employees, including an electronics technician who’s in charge of information technology and attitude-control software, have constructed Celestium’s rocket for less than $1 million. “We are trying to show what can be done with good old American ingenuity instead of just throwing money at it,” Winston says.

For example, Colburn turned a flowerpot into a mold for a rocket nozzle extension. For tracking the vehicle during tests, electronics technician Mike Mittnacht purchased a microcontroller on Amazon.com and paired it with a commercial gyroscope-magnetometer-accelerometer chip and radio.

Winston is funding the project after spending much of his life away from rocketry. He left graduate school at New York University in 1965, where he was studying rocket propulsion, to join the Manhattan jewelry business founded in 1932 by his father, Harry, who famously donated the Hope Diamond to the Smithsonian Institution in 1958. The younger Winston retired from the Harry Winston company in 2008 and now divides his time between Southern California, where he raises bees, and a biochemistry lab at New York’s Stony Brook University.

If all goes as planned, the rocket will send a 1-kilogram cubesat into orbit within a couple of years. First, Celestium will need a launch license from FAA, a State Department export license in case any rocket components land outside the United States and a NOAA remote sensing license for its first payload: an infrared video camera.