RD-180: space workaholic retires?

In August last year, the head of the United Launch Alliance (ULA, a company that unites Lockheed and Boeing), Tony Bruno, issued the good news: the RD-180 engines produced by the Russian Federation, which are equipped with Atlas launch vehicles, will no longer be purchased. The statement brought "a feeling of deep satisfaction" to members of the US Congress, who are following a clear political line to abandon the power plants manufactured by Energomash (the last 6 units were purchased in April). In reality, the Americans simply purchased a sufficient number of Russian "engines" in advance. And by the mid-2020s, they plan to abandon the Atlas V launch vehicle and switch to Vulcan, which will be equipped with BE-4 units developed by Blue Origin (its head is Jeff Bezos).

From the history of RD-180

In the 70s, the USSR developed and put into production the RD-170 kerosene power rocket launcher, which had a solid thrust of 740 tf (ton-force). During perestroika, when we had “friendship-peace-chewing gum” with the Americans, the United States ordered a “half” of this installation, which received the index “180”, for its own needs.



NASA had its own RS-68, but its price was 2 times higher than that of the Russian unit. Here we should not forget about the huge differences in salaries of designers and workers of space enterprises in the USA and Russia at that time (and even now). The engine was designed in the mid-90s and is manufactured by the Energomash enterprise, which is part of Roscosmos. A power plant of this type was specially developed for the American Atlases and in 1992 it began to be successfully used. Moreover, Energomash did not just get the order - it won the competition organized by Lockheed. By mid-2021, 92 successful (!) launches had been made. After the introduction of sanctions against Russia in 2014, the Americans stopped buying engines. However, the ban was lifted almost immediately. Then the American media wrote that the United States did not have engines for light rockets and the Pentagon, together with NASA, would not be able to do without Russian equipment until 2025.

And what about the American BE-4 engine?

His debut was supposed to take place at the very beginning of 2022. But alas, Blue Origin, which took over the production of the engine, clearly did not expect such stringent requirements from the customer, cooperating with the Pentagon. In general, the process of creating an American space power unit is shrouded in darkness. What is known is that the relationship between Blue Origin and ULA is becoming increasingly strained. The problem is that the US Department of Defense has already spent $ 255,5 million on the program to create "its own" engine, and "things are still there." In addition, the Pentagon demanded the development of a reusable power unit: simply burning millions of dollars in the earth's atmosphere is not "American".

Elon Musk and more

ULA is considering partly shifting rocket engine development to SpaceX. Only such an odious person as Elon Musk is unlikely to be able to guarantee a positive result: the Americans themselves think so. It is curious: the head of the private company SpaseX won the competition for the development of a rocket for delivering cargo to the ISS. But it was not possible to make a launch vehicle for launching military satellites. There are already completely different requirements for design and momentum, power, reliability, etc.

AR1 by Aerojet Rocketdyne

This 250 ton-force engine, currently undergoing testing, is expected to replace the RD-180 for the first stage of the Atlas 5. Previously, an $800 million contract was signed with the Air Force, which will be spent on launching, testing and certifying the power plant. However, after ULA shifted its focus to the BE-4, Aerojet Rocketdyne's funding was cut to $350 million. Somewhat earlier, the company entered into an agreement with the US-Ukrainian project Firefly Aerospace, which involves the development of a promising missile. Also, the AR1 engine can be installed on the Firefly Alpha and Firefly Beta carriers being created.



Rocketdyne has extensive (since the 60s) experience in the development of rocket engines. The company supplied LRE for all Saturn launch vehicles. On the first model, the H-1 power plant was used, on the subsequent ones - F-1, J-2, J-2X. The SSME engine was developed for the space shuttle, and the RS-4 was mounted on the Delta-68 first stage. It is assumed that the Ares-5 carrier will be equipped with the same power plant. By the way, the RL-10 hydrogen-oxygen engine was also installed on the Atlas instead of the Russian RD-180.





There is another option - to establish its own production of RD-180 under a license purchased from the Russian Federation. Under the agreement, Americans can use it until 2030. But this is a very short period and it makes no sense to invest money in such a project: it is more expedient to start producing your own engine in 8 years.

According to The Verge, at least 30 RD-180s are stored in ULA warehouses today. Considering that the United States launches its Atlases about 5 times a year, it becomes clear that Russian units will last for several more years. During this time, it is quite possible to “bring to mind” your own BE-4. The desire of the Americans not to depend on the supplies of a "potential enemy" is quite natural and logical.

Replacement of RD-180

In Russia, they understand that the era of these "workhorses" is coming to an end. Today, the latest RD-171MV engine has passed all the necessary tests and in October 2021 entered the Progress RCC for installation in the first stage of the Soyuz-5 launch vehicle. In the Rocket and Space Center (Samara), testing of the unit in the "field conditions" will continue.



The power of the power plant is comparable to a large power plant or five Lenin nuclear icebreakers. Unofficially, the unit, running on kerosene, was given the nickname "king-engine". This is the first “brainchild” of Energomash, developed not on paper drawings, but using 3D models.

Creation and characteristics of RD-171MV

The development of the engine began in 2017, after a couple of years the first tests were completed, which ended by September 2021. Some parameters of RD-171MV:

• ✅ fuel used - kerosene with oxygen
  
• ✅ purpose - for launch vehicles STK and Soyuz-5 (Irtysh)
  
• ✅ thrust - no data, the previous model RD-171M is 740 tons
  
• ✅ specific impulse - unknown, predecessor has 309 seconds
  
• ✅ dimensions - height 4,15 m and diameter 3,565 m

The engine is reusable, the approximate cost is 1 billion 200 million rubles. The head of Energomash, Igor Arbuzov, noted that there are no foreign analogues for the RD-171MV. The closest competitors have traction several times less. The new engine will be installed on super-heavy launch vehicles capable of launching cargo weighing up to 100 tons into space.