WASHINGTON — Blue Origin has completed testing of one engine it is developing for its own suborbital vehicle as it continues work on a second, much larger engine for United Launch Alliance’s new orbital launch vehicle, the company announced April 7.

The company said it had recently completed acceptance testing of the BE-3 engine after several years of work, allowing the company to move forward with test flights of its New Shepard vehicle later this year from its test site in West Texas. Those flight tests will ultimately lead to commercial suborbital flights later this decade.

“The acceptance testing came at the tail end of a very, very long development program,” Blue Origin President Rob Meyerson said in an April 7 teleconference with reporters. That included 450 tests of the engine, with a cumulative running time of more than 500 minutes.

BE-3 uses liquid hydrogen and liquid oxygen propellants, which the company said makes it the first engine with that propellant combination developed in the United States in more than a decade. The engine can generate up to 110,000 pounds of thrust, but can be throttled down to 20,000 pounds. Such “deep throttling” is useful for vehicles that, like New Shepard, plan to take off and land vertically.

Blue Origin designed the BE-3 specifically for its New Shepard vehicle. “When we started Blue, we were unable to find the propulsion that we needed at an affordable price, so we decided to develop our own,” Meyerson said. The company first worked on other engines, including some that used hydrogen peroxide and kerosene propellants, before moving on to the BE-3.

With the BE-3 completed, Meyerson said that Blue Origin was ready to begin test flights of the New Shepard suborbital vehicle later this year, also at its Texas test site. “We expect a series of dozens of flights over the extent of the test program,” he said. “We expect, over the next couple of years, to be flying regularly with the New Shepard vehicle.”

Those flights will be flown autonomously, without a crew on the vehicle. Ultimately, the company plans to use New Shepard to fly people, either for tourism or on research missions. Meyerson said the vehicle will be able to accommodate three or more people, depending on the vehicle’s payload of experiments, on flights to altitudes of at least 100 kilometers.

Meyerson declined to give a specific schedule for beginning commercial service, other than it was still years away. “We’re probably a few years away from selling tickets,” he said. “We’re getting close, and we’re excited about where we are.”

He added that while Blue Origin developed the BE-3 for its own vehicle, it is making the engine available commercially as well. The company is working on a version of the engine, designated BE-3U, for use in upper stages, including a future orbital launch vehicle in the company’s long-term plans.

As Blue Origin wraps up development of the BE-3, it is also developing the BE-4 engine for ULA’s next-generation launch vehicle. That engine, powered by liquefied natural gas and liquid oxygen propellants, will generate five times the maximum thrust of the BE-3.

Like many other Blue Origin activities, work on the BE-4 has been shrouded in secrecy since its announcement in September 2014. Meyerson said the company was working on two BE-4 development programs in parallel, one testing a set of valves and pumps called the powerpack, and the other testing subscale versions of the engine’s injectors.

Meyerson did not go into details of the status of those efforts, but did state that tests of the powerpack started last fall, with another round of tests scheduled to start April 9. Injector tests have been taking place “on and off” for the last six to eight months, he said.

“We are actively in testing on the BE-4, we’re learning from that testing, and continuing with an aggressive test program,” he said. Meyerson said the company is on schedule to start full-scale engine tests in late 2016 and complete development of the engine in 2017.

That development schedule, Meyerson argued, means the BE-4 will be available to ULA “two to three years ahead of any alternative engine out there.” Meyerson did not name those alternatives, but Aerojet Rocketdyne is working on a large engine called the AR-1 that uses kerosene and liquid oxygen propellants that, like the BE-4, has been proposed as a replacement for the Russian-manufactured RD-180 on ULA’s Atlas 5 vehicle.

Meyerson claimed that, despite the company’s secretive reputation, it was more open about its activities in recent years. Nonetheless, he said that initial test flights of New Shepard, at the company’s remote test site approximately 200 kilometers east of El Paso, Texas, would be closed to media and the public. “As we get more experience with the vehicle, there’s going to be many opportunities to have people there real-time to watch,” he offered.