The head of Space Exploration Technologies Corp. (SpaceX) Elon Musk has announced that his company will increase the production rate of its Raptor rocket engine. The Raptor is SpaceX’s staged combustion engine designed specifically for the company’s Starship launch system, which aims to be the world’s largest rocket. SpaceX plans to expand its payload delivery capability to various planetary orbits and bodies, and Starship is at the center of all of those plans. The Raptor is essential to its success, which is central to all plans for a Martian colony thanks to its ability to burn easily achievable fuel from the common environment.
SpaceX achieves first generational leap in crucial engine design for its next-generation rocket
Judging from statements Mr. Musk made earlier today, it appears his company has successfully refined the design of its new rocket engine to mark a collective upgrade from the original. The Raptor, which will power Starship, is the first full-flow staged combustion engine made in the United States. It uses methane as fuel, with higher efficiency than the Merlin engines powering SpaceX’s Falcon line of rockets. Merlin engines use a rocket propellant (RP-1) or kerosene to produce thrust.
In a series of tweets, the executive pointed out that SpaceX plans to produce at least 800 Raptor engines per year, with a maximum production rate of 1,000. Since only one Raptor aims to produce 230 ton-force of thrust if SpaceX uses all the engines it produces in one year, then overall the company’s rockets will have generated 184 kilotons of thrust in one year.
In comparison, during the first half of this year, Falcon 9 rockets generated fifteen kilotons of thrust by launching 20 Falcon 9 flights. The Falcon 9 uses nine Merlin 1D open-cycle gas-generating rocket engines capable of producing 95 tons. confidence to generate a total thrust of 855 tonnes.
Musk’s comments came after he announced that SpaceX would build a new rocket factory in McGregor, Texas, where it is also developing its rocket engines. So far, five flights of the first or upper stage of the system have taken place in Boca Chica, Texas, two of which have landed safely on the landing pad to meet key reusability design criteria.
SpaceX will now perform an orbital flight test that will also rely on Starship’s largest first-stage rocket that will propel it through all of its space missions. This milestone aims to use 33 Raptor engines for 7.6 kilotons of thrust, allowing just two Starship launches to generate all the thrust SpaceX has achieved in 2021 so far.
However, it is uncertain, if not unlikely, that the test will include all engines. Musk has been silent on details, having shared his concerns at a conference last year about the risk of losing too many engines during testing.
The Texas plant will focus on what Musk has dubbed the “Raptor 2” engines. These engines will power the Starship’s first and second stage booster, and the latter will also be equipped with Raptors optimized to operate in the vacuum of space.
Sharing more details on the Raptor’s current performance last week, Musk also shared his indecision regarding the engines powering the Starship’s second stage. While the first stage engines have nozzles designed to operate in one atmosphere, the second stage engines have more latitude in their nozzle width. Greater width allows for more thrust, and Musk deliberated on whether to use six vacuum-optimized engines on the second stage instead of the 3 + 3 atmospheric vacuum combination that SpaceX focused on until present.
The central engines of the vessel will be the same as the booster engines.
This is basically Raptor 2.
Raptor Vacuum would only be a variant. To be determined whether to communicate R-Vac with Raptor 2 (more thrust), keep the same or tighten the throat (more Isp).
Addition of 3 additional R-Vac to ship with max Isp maybe …
Two key differences between vacuum and sea level engines are their specific thrust and impulse. Engines at sea level generate less thrust and achieve a lower specific impulse than vacuum engines due to the Earth’s atmosphere which dictates the mass flow and fluid dynamics for their operation.
Specific impulse is the ratio of the speed of an engine’s exhaust gas to the speed of gravitational acceleration, and a higher value indicates efficient design. According to latest from Musk, the Raptor vacuum engine has an Isp of 378, which implies that it can produce thrust much faster than gravity accelerates an object falling to Earth. Its Isp is slightly higher than that of the engine at sea level, which is currently said to be around 360.
The latest production plant will be at the heart of SpaceX’s plans to establish a human settlement on Mars, and the production levels shared by Musk should allow his company to produce around 20 Starships per year. These rockets will also allow SpaceX to rapidly develop its Starlink satellite Internet constellation and potentially respond to a lunar crew lander for the National Aeronautics and Space Administration (NASA) Artemis program.