RD-180: can the US make rocket engines?

This photo perfectly illustrates the absurdity of the question that sounds in the title of the article. However, the enthusiasm with which conspiracy therapists “expose NASA deception” corresponds to the ignorance of their arguments. This article discusses one of them. According to which the United States depends on Russian LREs, as a result of which the Americans could not be on the Moon (having made 6 landings + 3 more flights) and did not even fly into space until the space shuttles. Although there are super-vigilant moon-fighters who have already reached them).

A natural question arises: since we do not consider shuttles filmed in Hollywood, on which engines did the Challenger, Discovery, Endeavor, Columbia and Atlantis ships perform 134 flights in total (the Challenger crash at the start and the experienced Enterprise do not count)? Meanwhile, in addition to a pair of solid-fuel boosters with a monstrous burden of 1,225 tons each, the shuttle was launched into space with three of its RS-25 LREs, created by the legendary Roketdyne.

Just in case, it is worth explaining: Russia has nothing to do with this LRE. In the XXI century, the Russian Federation does not produce at all and does not use hydrogen / oxygen engines, although the USSR was able to create such an engine. It was RD-0120, developed by the Voronezh NPO Chemavtomatika and successfully tested at the second stage of the Super-powered Energy rocket. Technology that is lost over the years of Putinism! Following the "logic" of the Lunoborians, who deny the existence of the Saturn-5 rocket on the grounds that it is not being manufactured today, one could also doubt the reality of Energy. However, the one and the other did exist, although the fate of Saturn-5 turned out to be more successful. We also note that all rights to the low-power hydrogen engine RD-0146, jointly developed by NPO Himavtomatika and Pratt & Whitney, belong to an American company. In addition, it is not produced in Russia.
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RS-25 and RD-180

For a correct comparison with the RD-180, you need to split the latter in half. In essence, it is a pair of engines in one “harness”. The most critical and technologically complex node in the LRE is the combustion chamber + nozzle. They must withstand heat from hot gases, as well as their pressure on the walls. If this very nontrivial problem is solved, then everything else is relatively easy to do. We also need a turbopump assembly (THA), which supplies fuel with a preliminary pumping through the cooling jacket. In the engine F-1, standing on the 1st stage of Saturn-5, the cooling circuit was not. His very combustion chamber was recruited from the tubes through which kerosene was fed. This courageous decision allowed Roketdyne to build a unique, single-chamber engine that in many respects predetermined the success of the Apollo program. Considering the attempts of the Lunoborians to dispute the reality of the F-1 extremal-mechanics.org/archives/23662, it is pertinent to note that it appeared in the late 50s and was created with a view to the US Air Force, but did not find an application there. But NASA was great!

The RD-180 has one turbopump unit for two combustion chambers, which gives a formal basis to consider it as one engine. But nothing prevents to divide this assembly into two liquid propellant rocket engines, equipping each chamber with separate THA. What was done when two RD-181s were produced from one RD-180, dividing the traction in half. Interestingly, the RD-180, in turn, was similarly obtained as a result of “dividing in half” the RD-170 propulsion system, which in Russia is considered the most powerful engine in history. With a load of about 800 tons, it surpasses even F-1 from its ~ 700 tons at ground level, but the RD-170 consists of four combustion chambers. This unit was assembled specifically for Energy carrier (2 launches in 1987). After Russia's voluntary refusal of this magnificent rocket and the reusable Buran ship (which became irreversible at the beginning of “getting up off its knees”), the question arose of using the RD-170. This is where the RD-180 and 181 came from.

Now you can correctly compare RS-25 and RD-180. The latter develops 187 tons of thrust per combustion chamber, while the RS-25 gives 182 tons at ground level. However, in a vacuum, this hydrogen fuel rocket engine is slightly ahead of the kerosene RD-180 (223 tons versus 203 tons). Naturally, the RS-25 has a larger specific impulse (452 ​​seconds in a vacuum and 366 seconds at ground level against 338 seconds and 311 seconds for the RD-180). In terms of thrust to weight, the Russian LRE looks better (78.4 vs. 73.1), which is obviously related to the mass savings due to a single TNA into two combustion chambers.


System Energy-Buran and RD-170

So, comparing the RD-180 with the RS-25 is already enough to refute the delirium about the inability of the US to make powerful rocket engine. The American engine has a fundamental difference - it is reusable. RS-25 can be repeatedly turned on / off to full traction, which is what happened when space shuttle launches. At the same time, the RD-180, like any other Russian LRE, is designed only for one space flight. In runet can be found allegations that the RD-170 and 180 are reusable, but the grounds for such statements are not given.

Against the background of such a spectacular superiority, there are ridiculous claims that the procedural work in preparing the RS-25 for flight is too expensive. If workers, engineers and scientists in the United States received the same beggarly handouts, as in Russia, the cost of the shuttles and their launches would be much lower. This partly explains the low cost of the RD-180, which cost the US $ 10 million apiece (RS-25 costs 5-6 times more). Another reason is that Russia spent almost nothing on the development of LRE, trading in the fact that she got a gift from the USSR.

The RD-Amross joint venture with headquarters in Florida established by NPO Energomash and Pratt & Whitney was involved in the supply of the RD-180 in the United States. Back in 2002, it bought 101 engines, paying it in advance. Apparently, stocks of these LREs that remained after the 90s were bought up this way. Thus, the States not only provided themselves for a long time with a cheap, reliable and powerful engine, but also deprived the Russian cosmonautics of development under its capabilities. The RD-180 does not stand on our launch vehicles, and under it could be developed a more powerful and modern rocket than the Proton-M. That this did not happen, we can only blame our worthless government.

The RD-180 engine is placed on the 1st stage of Atlas-V carrier. This is a product of the evolution of the Atlas-Centaur family, which NASA has used since the early 70s (Pioneer probes 10 and 11, which first reached Jupiter and Saturn, after which they left the Solar System, were launched by Atlas-Centaur rockets in 1972 and 1973). In 1977, Titan-III worked on the epic missions of Voyager 1 and 2 with the same overclocking module Centaur.

From the beginning of operation to the present, United Launch Aliance (ULA) has conducted 79 launches of Atlas-V rocket www.wikiwand.com/ru/Atlas5#/Carrier launch rocket_Atlas_V . Almost half of them - 38 fell to military needs: early warning satellites, spy satellites, etc. The closest - 80th launch is scheduled for July 17, 2019 ... also for military purposes. For all of this, the “energy superpower” received $ 1 billion, including kickbacks to “effective managers.” It is worth noting that Russia lost its own, satellite-based early warning system grouping in the process of rising extremal-mechanics.org/archives/14681 from its knees.


Left Atlas-V, right Atlas-II (100% American rocket)

It looks like the US dependence on Russia, inspiring our hurray-patriots? It should also be borne in mind that NASA did not have a pressing need to modify its Atlas-II (in Atlas-III and almost immediately in Atlas-V). The installation of the RD-180 at the 1st stage increased the launch mass and the size of the rocket by ~ 20%, the payload increased slightly more. However, heavy versions of Atlas-V take off at the expense of not so much the RD-180, as solid-fuel boosters. And if someone believes that without our engine, NASA would not have built a heavy rocket, then I would have to disappoint him.

Delta-4 Heavy, flying on its RS-68 engines, significantly exceeds not only the (most powerful) Atlas-V 551, but also our Proton-M. The payloads delivered by these rockets to the geostationary orbit are 6.6 tons, 3.85 tons and 3.7 tons, respectively. At the same time, they are capable of bringing 28.4 tons, 18.85 tons and 23.7 tons to a low, near-earth orbit.

It can be seen that the most powerful rocket in the 21st century is the Delta-4 Heavy. Falcon Heavy is already on her heels, but he is still in the test stage (albeit highly successful). This rocket, roughly speaking, is three times stronger than Proton-M. It flies on Space-X's own Merlin-1D engines, using solid-fuel boosters at launch. Merlin-1D develops about 90 tons of thrust, but, as can be seen, the thrust of the engine of the 1st stage is not a critical indicator when creating heavy missiles. Although 90 tons is not so little in light of the question of whether the United States is able to make rocket engine. In addition, the Merlin-1D works on kerosene, so you should not indulge in fantasies about the fact that, at least, they do not know how to use kerosene engines. Even as they can, just hydrogen is the most efficient fuel!

Thus, with the Delta-4 carrier since the beginning of the 21st century, NASA did not need a heavy, disposable rocket if the economy was not taken into account. And it is better for Atlas-V due to the low cost of the RD-180 engine (RS-68 is estimated at $ 15-20 million, for Delta-4 Heavy there are 3 of them), and also because the operation of hydrogen / oxygen RS-68 is more expensive than kerosene / oxygen RD-180. In addition, the heavier Delta-4 is naturally more expensive than the lighter Atlas-V. From an economic point of view, the modification of the Atlas-II rocket with the installation on the 1st stage of the RD-180 engine paid off. America saved money in space without reducing the frequency of flights and without losing quality, while Russia remained with the old rockets, giving its most powerful LRE to its overseas partner. In fact, in the 21st century, the Russian Federation lost its independence in space and became the youngest partner of the United States, and essentially became a cab driver on someone else’s ISS.



And what is the RS-68, created by the same Aerojet Roketdyne? This hydrogen rocket engine is nothing less than the most powerful engine today, if you don’t deal with tricks with the summation of thrust from several combustion chambers. RS-68 develops 289 tons at sea level and 307 tons in a vacuum. But it is not reusable, therefore it is much cheaper than RS-25. The myth that the RD-180 and RD-170 are the most powerful fuel rocket engines finally destroyed along with the myth that the United States depends on Russian engines.

In 2012, Roketdyne proposed NASA to install on a promising, super-heavy SLS carrier a modified F-1 engine (the same one that “did not exist”). In the F-1B variant, he had to develop 800 tons of thrust at sea level. It was supposed to radically alter the cooling system of the nozzle exhaust gases from the THA. In order to restore the skills of handling this rocket engine in 2013, it was even carried out with a small thrust. However, NASA did not support this idea, which could give a second life to the flaming engine of Saturn-5.

In 2005, Roketdyne offered NASA to build a RS-84 kerosene engine with a 470 ton load, but also found no support. At the moment, Roketdyne, on its own initiative, developed an AR-1 engine capable of developing about 250 tons of thrust. The installation of two paired AR-1 could replace the RD-180 on an Atlas-V rocket, but competition among the manufacturers of LREs makes it difficult to make the final choice, so the engine is still in the testing stage.

The final touch to the picture, in which "the US depends on the Russian Federation." Blue Origin has created a methane engine, Blue Engine-4, with a tonne of 240 tons to replace the RD-180 with a pair of such LREs. Space-X is experiencing Methane Raptor. The problem is not that there is nothing to replace the RD-180, but that it is difficult to choose one of several options for what it should be changed. It is clear that, with all the bureaucratic drags of time, in the near future the United States will get rid of the RD-180, since this is strongly demanded by Congress.