Redmond Rocket Scientists Propel Innovation as Space Cluster Grows
Rocket engines designed, built, and tested by a company tucked away at the edge of the Seattle suburbs have travelled to the edge of the solar system, visiting every planet including Mars, where the Curiosity Rover made a successful landing a year ago last week, using rockets from Redmond, WA, for the long interplanetary journey and harrowing descent to the surface.
The solar-system-spanning achievement is unique in the space business to Aerojet Rocketdyne’s Redmond site, says Roger Myers, executive director of advanced in-space programs, and one of those making an argument for Washington state as a center of innovation in the emerging commercial space industry. The state has deep aerospace expertise, facilities, supply chains, and infrastructure built up over nearly a century around Boeing; and a broader technology talent pool and concentration of wealthy individuals looking for challenging and meaningful investments.
Aerojet Rocketdyne, headquartered in California, has a 450-person staff in Redmond working in a cluster of office buildings, machine and assembly shops, and testing labs overlooking a golf course and farmland just a couple of miles from the heart of Microsoft’s main campus. The firm is the most established commercial space enterprise in the state. (Boeing has had space exploration operations in the Puget Sound since the early 1960s and while that division is today based in Houston, a spokeswoman says it still has local employees supporting efforts including Sea Launch and the CST-100 commercial crew capsule, which has interior elements similar to those on Boeing’s latest commercial jets.)
Lately, Aerojet Rocketdyne finds itself with more company in the region. It was one of 18 businesses invited to attend the first Washington space meeting, coordinated by the state Office of Aerospace earlier this year, to discuss ways to nurture the “space” part of the aerospace sector. Gov. Jay Inslee’s aerospace industry strategy, laid out in May (PDF), calls for diversification and a culture of innovation, including strategies to position Washington as “a national center for both private and academic efforts to develop private space exploration and propulsion initiatives.”
Alex Pietsch, who heads the state’s aerospace office, says he is exploring any “unique needs” of the commercial space companies, apart from the many state efforts in support of the broader aerospace industry.
Myers, who helped convene the space meeting, is eager to share what’s happening at his company today, as well as the legacy of space exploration here, which dates back to the late 1950s when Boeing engineers interested in satellites began an independent company in South Seattle called Rocket Research. The company moved out to the country when Willows Road was still dirt, and then went through several name changes, acquisitions, and spinoffs before GenCorp (NYSE: GY) subsidiary Aerojet Rocketdyne bought it from General Dynamics in 2002 for about $90 million. Earlier this summer, GenCorp acquired Pratt & Whitney Rocketdyne from United Technologies (NYSE: UTX) and combined it with Aerojet.
All the while, he says, the Redmond one-stop rocket shop was at the leading edge of space propulsion, and remains there today.
“We’ve been here for a long time, but not many people know about what we do,” Myers tells Xconomy during a recent tour of the facility.
The Redmond site makes 200 to 500 rocket engines a year, generating annual sales of about $100 million, for a wide array of space applications. These range from tiny rockets that deliver fractions of a pound of thrust to keep satellites precisely positioned, to larger ones for maneuvering vehicles docking at the International Space Station, to the Viking Lander engines that put out 600 pounds of thrust. (Derivatives of these engines, used in the 1976 Mars landings, powered the dramatic “sky crane” maneuver during the final stages of the Curiosity Rover landing last year.)
Aerojet Rocketdyne is also building electric propulsion systems and rockets that use less toxic propellants—innovations that could address a key barrier to a broader commercial space industry.
“Right now, the biggest problem for the space business is it’s expensive,” Myers said at a Washington aerospace innovation forum earlier this summer.
It costs roughly $20,000 per kilogram to reach low-Earth orbit (LEO), the zone where the International Space Station orbits, about 340 kilometers up. Going beyond that requires lots more fuel, and fuel doesn’t make money or do science. “A geosynchronous satellite”—orbiting nearly 36,000 kilometers above Earth—”is half fuel,” Myers explains back at Aerojet Rocketdyne, where glass cases display dozens of rocket engines, some used to raise satellites from LEO to geosynchronous orbit. “It’s not transponders that make revenue or help you communicate on the Internet or anything like that. It’s mostly fuel.”
Therein lies one of the grand challenges to “expanding the human economic sphere,” as Myers puts it. To do more business, science, and exploration in space requires either launching more fuel—a costly proposition that can scuttle the economics of a profit-driven rather than government-driven enterprise—or improving fuel efficiency.
“Those are your only two options,” Myers says. “Physics is physics.”
Electric propulsion systems offer significant fuel efficiency improvements. So-called resistojets made at Aerojet Rocketdyne have been flying for 30 years. In this design, Myers says, a “very fancy hair dryer”—actually a tungsten-rhenium heat exchanger—is attached to the exhaust of a standard chemical rocket, heating it further.
To explain how this actually saves fuel, Myers is happy to give an impromptu course on basic rocket science, which he’s able to ramp up or down, depending on his audience. The important point here is that a chemical rocket “is limited in its efficiency by the chemical bond energy in the chemical in the propellant, and the mass of the propellant,” he says.
By introducing electric energy—gathered from a spacecraft’s solar panels—that limit is removed without adding the extra weight of additional propellant.
It can save weight in other ways, too. Aerojet Rocketdyne makes monopropellant chemical rockets that use hydrazine, and more powerful bipropellant rockets in which two chemicals—mono-methyl hydrazine and nitrogen tetraoxide—are combined, combusting on contact. A resistojet can give a monopropellant rocket the same efficiency as a similarly sized bipropellant rocket, without the additional weight of a second set of tanks, pipes, and valves to carry the second propellant.
A newer generation of electric rockets replaces the “hair dryer” with an arc of electric current—like in an arc welder—coursing through the exhaust gas. This allows the gas to be heated even more, because the melting temperature of the material is no longer a constraint. An arcjet, as it’s called, can deliver twice the fuel efficiency of a similarly sized bipropellant or resistojet rocket, Myers says.
Art Veyna, program manager for resistojet programs, overhears Myers explaining the products and pulls us into his office. After checking my credentials—jokingly, I think, though Aerojet Rocketdyne does provide propulsion systems for satellites used in defense and intelligence—Veyna unrolls a poster-size diagram of a resistojet. He points out the fine components, many of which took years of development to perfect, manufactured to exacting tolerances.
“This is one of the most complex engines that we’ve built,” Veyna says, clearly proud of the work. “There isn’t anything in this engine that is simple or easy.”
Aerojet Rocketdyne builds other electric propulsion systems that use electrical energy only, rather than using electricity to augment chemical energy. These have the potential to triple and quadruple efficiency again, though these gains come at the expense of lower thrust levels, Myers says.
Gridded ion thrusters, for example, strip an electron off of an atom of xenon gas, resulting in xenon ions that drift toward a pair of gridded plates, set 30 thousandths of an inch apart with a 2,000-volt charge between them. The xenon ions are attracted by the gridded plates, creating the exhaust that accelerates the rocket.
NASA recently completed a record 48,000-hour (five-and-a-half-year) life test of a gridded ion thruster built by Aerojet Rocketdyne and NASA’s Glenn Research Center in Cleveland, where Myers previously led electric propulsion research. It would take more than 10,000 kilograms of conventional rocket fuel to produce the same impulse the thruster in the test achieved using only 870 kilograms of xenon.
This is all possible thanks to increasing solar panel efficiency, and the shrinking size and power requirements of electronics, making more energy available for electric propulsion.
Greener Pastures and Fuel
In addition to electric energy sources, Aerojet Rocketdyne is working on a project to use less-toxic chemical propellants.
For decades, hydrazine has been a rocket fuel of choice for the monopropellant engines Aerojet Rocketdyne makes. “We’ve got 40 years of experience with it, and it has many very appealing characteristics,” Myers says. “On the other hand, it’s toxic so you have to handle it very carefully.”
That means added costs for the additional training and safety measures required to work with hydrazine.
The NASA Green Propellant Infusion Mission, led by Boulder, CO-based Ball Aerospace with Aerojet Rocketdyne and researchers from the U.S. Air Force and NASA as co-investigators, would use a hydroxyl ammonium nitrate blend to replace hydrazine. The replacement promises a lighter environmental footprint, improved fuel efficiency, and reduced safety hazards, among other advantages, according to NASA. The space agency aims to perform orbital maneuvers using the alternative fuel during a mission in early 2015.
Aerojet Rocketdyne has made a new rocket engine from the ground up for the mission. “It’s a very different fuel. It operates at a much higher temperature, so we have to use different materials,” Myers says. “The viscosity of the propellant is different.”
The rocket completed an end-to-end checkout last month.
Meanwhile, Aerojet Rocketdyne is growing in Redmond, Myers says. The company hires people with a range of aerospace, mechanical, and electrical skills. About 40 percent of the current staff is “pure technical,” including about 20 people with PhDs, Myers among them. Another 30 percent are highly-skilled machinists and assembly technicians. The remainder are in business management and administration.
The rocket-engine-building process starts with design and analysis. Then a model is made using 3D printing, a time-saving technology employed by Aerojet Rocketdyne for the last three or four years. (The company is working with researchers at Washington State University through the new Joint Center for Aerospace Technology Innovation, established by lawmakers last year, on ways to use 3D printing for actual flight hardware, too.) The model is analyzed and design issues are corrected, and then an aluminum model is made. After yet more analysis and design, the machinists make the final parts from titanium, high-strength steels, refractory metals, and other materials. Technicians assemble the engine before sending it in a covered “dog cart” to the testing labs at the other end of the property.
Aerojet Rocketdyne’s acceptance testing program is rigorous, and for good reason.
“A typical spacecraft will run a couple hundred million dollars, and you don’t want to be the cause of a bad day,” Myers says.
First, an engine is mounted on a programmable vibration table that simulates the intense shaking from the big rockets of a launch vehicle.
After it has survived that, it is mounted on a thrust stand inside one of several mini-submarine-sized vacuum chambers that approximate certain conditions in space, such as extreme temperatures—using hot plates, lamps, and liquid nitrogen—and near-zero pressure. (Zero gravity, Myers explains, is not a significant issue for rocket-engine operation.)
The testing facility has many layers of safety and environmental controls to keep the toxic and highly combustible chemical propellants tightly controlled until they are ignited in live-fire tests within the vacuum chambers. The facility is hard-wired into area fire departments, which conduct training exercises here, just in case. “Nothing’s ever happened, but we’re very careful,” Myers says.
Engineers verify that the rockets perform in the tests as they should. Then the engines are cleaned, carefully packaged, and shipped—via standard commercial carriers—to spacecraft manufacturers, to be joined up with other complex systems, and continue on journeys that may extend for millions of miles.
Myers sees lots of opportunities for his company and others in the commercial era in space. Propulsion efficiency improvements benefit a range of existing and emerging space businesses, from communications to tourism to asteroid mining.
“If we’re going to grow this business, we need innovations that help us reduce the cost and create new demand for space applications,” he says.