The Raptor, SpaceX’s engine used to power the Starship, reached new levels of power during its development.
On Monday, CEO Elon Musk announced that the engine reached 330 bar room pressure without exploding. That is 31 bar higher than what the engine returned in February 2019, when it beat the previous record holder for an operational engine, Russia’s RD-180. Teslarati notes that the engine beat the Soviet Union’s RD-701 engine, which at 300 bar, previously held the public record for the highest pressure of the combustion chamber for a rocket in the orbital class.
It’s great news for the Starship, which needs all the help it can get to complete its ambitious missions. The ship is designed to send humans to Mars, the moon, and beyond with the ability to carry a maximum of 150 tons or 100 people into space at a time.
The Raptor engine uses liquid oxygen and methane, unlike the Merlin engine, powered by rocket propulsion that powers the Falcon 9. which, combined with the fully reusable Starship design, allows humans to travel to Mars, harvest the planet’s resources and use that to fuel the return journey.
The new plate gives the Raptor engine more power to achieve these goals.
A new era of engines – A rocket engine is, as NASA explained, in principle a system in which fuel is generated in a combustion chamber. This produces a high temperature, high pressure exhaust gas that passes through a mouth and produces steering. The system is based on Newton’s third law of aerodynamics, where each action has an equal and opposite reaction. This means that the chamber pressure is linked to the resulting pressure.
In Musk’s post, the chamber pressure was measured in bars. Under these units, the ambient pressure at sea level is 1.01325 bar. Another measure sometimes used is pounds per inch, as psi, where the same measurement would display as 14.6959 psi.
The chamber pressure of the Raptor engine is greater than that of the Merlin 1D, which in a NASA document states a pressure of 1,410 psi than 97 bar. The new record beats the previous success of the engine back in February 2019, when it reached 269 bar. Following that success, the Raptor engine had defeated the Russian RD-180 engine, which offers 258 bar and has been flying on the ULA Atlas V rocket since 2000. But the 2020 result, which not only defeated this, is also Musk’s goal for the Raptor, who in September 2016 he claimed to reach 300 bar.
Musk also notes that the Raptor can reduce their power in the same way as the Merlin:
“Max demonstrated Raptor steering is ~ 225 tons & min is ~ 90 tons, so they are actually pretty similar. Both Merlin and Raptor could run a bit lower with added design complexity. Raptor preburner and Merlin gas generator flameout are somewhat limited bottom line.”
What does all this mean for steering? On Monday, Musk claimed that the engine would deliver half a million pounds of power, if around 225 tons. In May 2020, Musk stated that the Super heavy booster used to take the Starship off Earth, currently uses 31 engines, instead of the 37 engines he explained earlier. The SpaceX website lists the Super Heavy booster as finally offering 16 million pounds of shipping.
How does that compare to the Falcon 9, the rocket that could eventually replace the Starship? The current rocket offers 1.7 million pounds at sea level. That means, on the whole, the Starship packs an impressive punch.
De Inverse analysis – The Raptor’s power levels are impressive, and their strength should become clearer with more hop tests. The ship looks set to stand at 400 meters altitude when paired with the Super Heavy booster. If SpaceX intends to host more “hop tests” beyond the 150-meter mark, the visuals of a giant ship storming into the air will likely do more to communicate the Raptor’s impressive power to the general public.
