Key Blue Origin officials have begun dropping hints about the impending hot-fire test of the company’s new rocket engine, the BE-4. Jeff Bezos recently said he expects a full engine test “in the next few weeks”. And last Wednesday, the company’s director of business development, Brett Alexander, said during a panel discussion at the Center for Strategic and International Studies that the test was “coming soon.”
For many people, a rocket engine is just a rocket engine. But Blue Origin’s new engine is important for a number of reasons, not the least of which is its 550,000-pound thrust at sea level, more powerful than a space shuttle’s main engine, which had 418,000 pounds of thrust. However, in addition to muscle strength, there are other reasons to expect a successful test.
A new kind of engine
During a tour of his rocket factory in Kent, Washington last year, Bezos explained the philosophy behind the BE-4 engine. “Basically, rocket engines are simple, but that’s the last place rocket engines are ever simple,” he said. Nevertheless, Blue Origin tried to make an engine that was neither too complex nor required ultra-premium materials. The designers didn’t want to create a piece of art that pushed the boundaries of engineering, but they wanted a reliable workhorse that could be flown again and again, perhaps 100 times as the company pushed the boundaries of reusable spaceflight.
Blue Origin began developing the engine for its own purposes in 2012, but in 2014 the rocket company United Launch Alliance approached them about a replacement engine for its next-generation rocket, Vulcan. The company, which launches the majority of U.S. military payloads with its Altas V missile, had to stop using the Russian RD-180 engine because the national security community was no longer comfortable amid mounting tensions. buy Russia. .
The RD 180 is a very powerful motor that operates at extreme temperatures and pressures. Higher pressure translates into marginally better performance, but at a high cost of development time, money, and uncertain reusability. “Our strategy is that we like to choose a mid-performance version of a high-performance architecture,” said Bezos. “The RD-180 is both: a high-performance version of a high-performance architecture. That’s a very challenging engine to develop, and it really complicates things. With lower pressures you can still achieve very high performance.”
As a result of his design philosophy, Bezos said the BE-4 engine should cost about 30 to 40 percent less than the RD-180 engine. It should also, in theory, be more durable and reusable without worrying about component failure due to the extreme pressures and temperatures in an RD-180 engine, which is flown once and then discarded .
The BE-4 also uses a new type of fuel for a first stage engine, liquid methane. While hydrogen has a higher specific impulse (which is good), it is difficult to work with and requires large and bulky tanks to store because it is not compact. In some ways, due to its ease of use and ability to harvest on worlds like Mars, methane is the rocket fuel of the future. When Elon Musk was trying to design his Raptor engines for his rocket to carry humans to Mars, he also chose liquid methane-liquid oxygen fuel.
Prove doubters wrong
Earlier this month, Ars first reported on efforts by some members of Congress to push United Launch Alliance away from the BE-4 engine to another engine being developed by Aerojet Rocketdyne, a traditional aerospace company with a heritage of developing of large, powerful rocket engines. The BE-4 engine “is unproven at the size and power required,” the letter said. Congressmen appeared to be pressuring Aerojet for promising to manufacture its AR-1 engine in Huntsville, Alabama, creating 100 new jobs near NASA’s Marshall Space Flight Center.
This is the kind of bias SpaceX has had to battle against for the better part of a decade as it sought funding from NASA, the US military and other government agencies for its lower-cost Falcon 9 rocket. There remains a general distrust among some in Congress of “new space,” a newer generation of space companies whose stated goal is to lower the cost of access to space, rather than just land the next government contract. to fetch.
The Center for Strategic & International Studies recently reported on five different options the U.S. Department of Defense had as it attempted to move from the RD-180 rocket engine for national security launches to a U.S.-made rocket engine. If the key factors are minimizing costs and supporting the long-term competitiveness of the US industrial space launch base, the Air Force should choose the BE-4 or AR-1 engine, according to the report. Furthermore, if the BE-4 hot fire tests are successful, the report argues, the Blue Origin engine appears to be the obvious choice, as it costs less, is paid almost entirely by the private sector and will be ready sooner .
If it works, then…
Successful testing of the BE-4 engine would therefore prove in one stroke that “unproven” companies can get the job done in space and validate the use of a relatively untested new rocket fuel – methane – in a large engine. It would also lead a blue-blood rocket company, United Launch Alliance, to choose the launching BE-4 engine over that of a traditional aerospace company, Aerojet Rocketdyne.
A proven engine would also go a long way toward making Blue Origin’s New Glenn rocket a reality. Powered by seven BE-4 engines, this reusable, heavy-lift booster could fly by 2020 and become a major player in the global satellite launch industry — eventually putting hundreds of people into orbit, too.
So the promise of the upcoming test is quite simple. SpaceX has long stood on its own as a new space outlier in the global launch community, competing against traditional aerospace companies and government-owned launch companies in Russia, China and Europe. It’s possible to dismiss a tech entrepreneur who dreams of reusable rockets as a naive optimist or a wealthy rocket boy pretender. But it’s much harder to fire two of them who both developed their own engines.