LOS ANGELES — XCOR Aerospace plans to conduct a full-scale, extended-duration, hot-fire test of its piston pump-powered rocket engine as it moves closer to flight tests of the two-seat suborbital Lynx vehicle at Mojave, Calif.

In preparation for the long-duration test, XCOR is installing a flight-sized liquid oxygen tank in the Lynx fuselage. The propulsion system was mounted to the flight-weight airframe and recently tested for 67 sec., marking the first firing of a full-piston, pump-powered rocket engine.

The automotive-style piston pump concept has not been used for a spaceflight application before. Fuel and oxidizer in liquid-fueled rocket engines are traditionally forced by turbopumps, or use gravity-fed systems. XCOR, which describes the event as a “first in aviation and space history,” adds that Boeing provided additional funding for the testing.

XCOR Chief Executive Officer Jeff Greason says that using the piston pump concept to deliver kerosene and liquid oxygen to the Lynx’s four engines eliminates the need for heavy, pressurized fuel and oxidizer tanks. “It also enables our propulsion system to fly multiple times per day and last for tens of thousands of flights,” he adds. An earlier version of the system, which is also aimed at lower overall operating costs, was used to pump-feed kerosene to a rocket powering the X-Racer aircraft.

Speaking to Aviation Week before the recent rocket test, Greason says aside from the continuing propulsion development work, the focus remains on assembly of the vehicle itself. “I’m happy with the progress, but not always with the schedule,” says Greason, who adds that the company “still has a way to go” before entry into service. We have a flight test program to go through, and there are times when we do a test and the pieces don’t all work.”

The major structural core of the initial Lynx Mk. 1 vehicle includes the cockpit pressure vessel, fuselage, liquid oxygen tank and strakes. “We’re focused on putting that together,” Greason says. After initial tests with the Mk 1, follow-on production Lynx Mk. 2 vehicles will be used for research and suborbital space tourism flights.