Spotlight | Digital Solid State Propulsion

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SAN FRANCISCO — In 2004, Wayne Sawka was in Rancho Cordova, Calif., working with two propellant chemists at ET Materials LLC, a small firm that went out of business in 2007. He loved tinkering with a specific propellant his colleagues had given up on and was using it to power a tiny microthruster when he noticed something surprising. When Sawka hooked it up to a power supply, he could hear it turning on and off with the 60 cycles of the alternating current. “I thought, ‘Holy cow! These switch on and off super fast,’” he said.

It was that discovery that persuaded Sawka to license the propellant formulation and establish Digital Solid State Propulsion (DSSP) LLC, a firm based in Reno, Nev., focused on developing and marketing electric solid propellants, which rely on electrical charges to turn ignition off and on.

Although many potential customers initially were skeptical of Sawka’s claims that he could deliver solid propellant that could be held in fire without igniting, turned on and off without moving parts and produced without any toxic chemicals, DSSP was able to demonstrate those claims with the help of Mike McPherson, who left a career of more than 30 years at Sacramento, Calif.-based Aerojet in 2010 to become DSSP vice president of research and development. “When Mike came to DSSP people started paying a little more attention, saying if somebody like that came to this little company, there must be something there,” Sawka said.


Digital Solid State Propulsion LLC at a Glance

Mission: To commercialize green, safe, solid energetic materials
Top Official: Wayne Sawka, founder and chief executive
Established: 2005
Location: Reno, Nev.
Personnel: 17

 

DSSP also was able to show customers the versatility of electric solid propellants through a series of Small Business Innovative Research (SBIR) projects with the U.S. Missile Defense Agency, U.S. Navy and U.S. Army Materiel Command, Sawka said, adding that DSSP has received more than $3 million in SBIR contracts over six years. Through those contracts, DSSP’s “tiny microthrusters have been scaled up to rocket motors that produce hundreds of pounds of thrust,” Sawka said.

 
DSSP’s electric solid propellants have potential applications in many markets, including military training, missile defense, entertainment, commercial space and enhanced oil recovery, which relies on various processes including heat to increase the amount of fuel extracted from underground reservoirs. Commercial space was one of the first markets Sawka sought to address when he established DSSP because Bob Twiggs, one of the inventors of cubesats who now serves as an astronautics professor at Kentucky’s Morehead State University, told him that the miniature satellites would need propulsion. To date, cubesats have flown without onboard propulsion due largely to restrictions placed on the payloads by the primary missions that carry them into orbit. Cubesat developers, however, are eager to employ small propulsion systems to enable their satellites to remain in their desired orbit, form constellations and conduct proximity operations, said Jordi Puig-Suari, cubesat co-inventor and an aerospace engineering professor at California Polytechnic State University in San Luis Obispo.

Switch On, Switch Off

DSSP’s technology is uniquely suited to cubesats because it poses no risk of accidental ignition, Sawka said. “Our propellants will not create any safety hazards whatsoever,” Sawka said. “You could put our stuff in fire and nothing would happen.” The only way to ignite the propellant is to run a current of the required voltage through it. Once ignited, the propellant continues to burn until the voltage is removed. It can then be reignited repeatedly, Sawka said.

The U.S. Naval Research Laboratory plans to conduct the first space-based test of DSSP’s technology by using thrusters powered by electric solid propellant to spin a spacecraft and then stop its rotation. “The spin rate will be monitored by onboard instrumentation as well as ground based assets,” Andrew Nicholas, who leads the sensor development and applications section in the geospace science branch of the Naval Research Lab’s Space Science Division, said in an email. “The spacecraft, called SpinSat, will be deployed from the International Space Station in a flight provided by the [Defense Department] Space Test Program tentatively scheduled for Fall 2013. I am very excited about this game-changing technology and the potential it represents for the space industry.”

DSSP also is developing a cubesat deorbit module. International guidelines call on satellite developers to ensure spacecraft are designed to re-enter Earth’s atmosphere within 25 years of the conclusion of the mission. Certain customers want to bring cubesats out of orbit much more quickly than that, Sawka said. To meet that demand, DSSP is developing a small motor for a customer who plans to test it in space within two years, Sawka said. He declined to name the customer. DSSP also plans to develop a slightly larger version of the motor that powers the deorbit module to provide cubesats with the ability to move safely into desired orbits and to conduct on-orbit maneuvers, he added.

In-Q-Tel, the independent, not-for-profit organization established by the U.S. Central Intelligence Agency to encourage firms to develop commercial technology with the potential to meet intelligence community needs, announced plans in 2011 to invest in DSSP. At the time, Bill Strecker, In-Q-Tel executive vice president and chief technology officer, said in a 2011 statement that DSSP’s electric solid propellant offered capabilities beyond those of “legacy technologies, which have not changed much in 50 years.”

The lack of technological innovation in solid propellants actually worked against DSSP when Sawka established the company in 2005. “When little has changed in over 50 years, it’s hard to get people to believe you’ve really got a game changer,” Sawka said. However, the firm’s initial government customers have been stalwart allies, he added. Initial SBIR contracts have led to follow-on orders. As a result, business is picking up rapidly and DSSP will earn more than $2 million in 2012 and more than $3 million in 2013, Sawka said.

In July, Sawka presented plans to raise $6 million to expand DSSP’s commercial ventures during the Space Frontier Foundation’s NewSpace conference in Santa Clara, Calif. DSSP won second place in the NewSpace Business Plan competition, receiving a $10,000 prize.