It’s not easy to contradict Congress, but its legislation to bar the use of the Russian RD-180 rocket engine from launching U.S. security payloads, as Robert Bunn so eloquently points out, is truly a classic example of shooting oneself in the foot. The relatively minuscule economic benefit Russia gains from the sale of these engines is dwarfed by the loss their eradication created in operational capability of U.S. security systems.

It was on my recommendation to Michael Wynne, then president of the General Dynamics Space Systems Division (GDSSD), that he issued the purchase order to NPO Energomash to develop the RD-180 for the Atlas launcher, designed and then operated by GDSSD. My recommendation was based on the fact that there was then (over 20 years ago!) no U.S. engine of comparable quality, performance, cost and reliability. By the way, there still isn’t.

Note that at that time, in 1992, the RD-180 did not exist. My recommendation was to convert the 1.7-million-pound-thrust, four-chamber RD-170, the well-proven boost engine for the Soviet Energia launcher, into a half-scale (850,000-pound-thrust) two-chamber engine that used all the same proven elements of the RD-170.

Here is a quote from my recommendation (I was then a member of the GDSSD Executive Advisory Board):

“The 2-chamber version [of the RD-170] could be derated by 20% and still deliver more thrust than you need for all Atlas configurations, including 2AS [the solid-propellant-boosted version of Atlas, then its highest-thrust configuration]. The extra thrust margin of the derated two-chamber configuration would be extremely useful in allowing simplification of other Atlas systems. It also provides for evolutionary payload growth via incremental upgrades to full rated thrust. … Because the two-chamber RD-170 engine provides more-than-adequate thrust at little or no additional cost, operating derated significantly increases its reliability, with attendant economic benefits to Atlas. …

“The next step would be for you … to write up a set of specifications for the propulsion system and solicit a proposal from Energomash to perform and deliver a preliminary design study which meets those specifications. The study should of course include the specifications, schedule, and cost of the development effort needed to deliver a flight-qualified engine to GDSSD, as well as production-phase data such as delivered engine prices, reliability information, performance and schedule guarantees, and details of the Atlas interface modifications GDSSD would need to provide. …

“I believe, incidentally, that the [then-current] political barriers to hardware transactions will fall (or at least be substantially weakened) within the next year.”

The contract with Energomash was subsequently fulfilled, and when GDSSD later merged into Martin Marietta and then into Lockheed Martin, the RD-180 was integrated into the experimental Atlas 2AR (“R” for Russian), which evolved into the Atlas 3 and then into today’s Atlas 5, which has now flown 59 times with 100 percent success. Wynne, who later became secretary of the Air Force, has often cited the RD-180 decision as the best one he made during his tenure at GDSSD.

Meanwhile, however, the U.S. Air Force had expressed concern over reliance on a Russian engine for its national security payload launches, so Energomash and (then) Pratt & Whitney created a joint venture, Amross, to develop and manufacture a U.S. version of the RD-180 (and meanwhile to serve as the contracting agent for RD-180 purchases from Energomash). I had then worked as a consultant to Pratt & Whitney on that “U.S. RD-180” effort, which never succeeded due primarily to the paucity of funding from the Air Force, exacerbated by what appeared to be irreconcilable differences in Russian and U.S. shop practices and materials specifications.

So what is arguably the best heavy-lift liquid-propellant rocket engine in the world today continues to be manufactured exclusively in Russia.

There’s an interesting sidebar to the argument that the United States can and should develop such an engine, one that would be comparable to (or better than) the RD-180. When Orbital ATK suffered an engine failure on its Antares launch vehicle loss in October 2014, its intensive search for a replacement came up with the RD-181, another Russian engine (closely related to the RD-180) as the best choice. Moreover, the company’s interim launch choice for the Cygnus capsule, until the RD-181 could be integrated into the Antares launcher, was the Atlas 5 — powered by the Russian RD-180. And Orbital ATK has a well-deserved reputation as a very technically savvy company.

I do agree with Mr. Bunn that the United States should devote maximum effort to the development of an indigenous heavy-lift rocket engine comparable to the RD-180. Despite the still-smooth coordination with Russia on the International Space Station and the successful post-shuttle use of Russian Soyuz vehicles to transport crew and supplies to the station, Congress’ concern about reliance on Russia following its invasion of Crimea is certainly justified. But the development, integration and reliability demonstration of a new large U.S. liquid-propellant rocket engine cannot be accomplished for years to come. Therefore, Congress should recognize, as Mr. Bunn has so clearly stated, that until that happens, U.S. economics and national security require us to continue using the best large rocket engine in the world — the Russian RD-180.

Jerry Grey was a member of the General Dynamics Space Systems Division Executive Advisory Board when the RD-180 was created. He was a professor of aerospace engineering at Princeton University, director of science and technology policy at the American Institute of Aeronautics and Astronautics, and president of the International Astronautical Federation. He is an honorary fellow of the AIAA and a fellow of Great Britain’s Royal Aeronautical Society.