SpaceX: Elon Musk Gears Up to Test the Starship Raptor Engine
Elon Musk is cranking up the heat. Work is underway at SpaceX’s Boca Chica facility in Texas, where the company is preparing to test fire its Starship Raptor engine designed for use on a future Mars mission. On Friday, Musk shared new images of preparations ahead of the big test.
It’s a key milestone in the company’s efforts to build its most ambitious rocket to date, designed to use liquid oxygen and methane as a propellant to enable astronauts to fly to Mars, refuel using harvested resources, and come back. Musk explained the company is initially designing one 200 metric ton thrust engine for both the booster and the ship on top, but the next version will split this between vacuum-optimized version with specific impulse over 380 seconds, and a sea-level version optimised for around 250 tons of thrust. While the ship will use seven engines, the booster will use a staggering 31 engines — although Musk admits the team will “probably fly with fewer initially in case it blows up.”
The engine, first announced in 2008, is designed as an alternative to the Merlin engines used by the Falcon 9 and Falcon Heavy. These older designs use liquid oxygen and rocket propellant as fuel, making them unsuitable for exploring and refueling. Musk has spoken before about his goal to set up Raptor propellant plants on other planets and transform humanity into a planet-hopping species.
The rocket has undergone several iterations, the most recent sporting a Tintin-inspired stainless steel design with three fins. The system is designed to use transpiration cooling to prevent heat damage. Musk explained that while the material has a number of benefits, he’s “confident that a stainless steel ship will be lighter than advanced aluminum or carbon fiber, because of strength to weight vs temperature & reduced need for heat shielding,” adding that “rocket mass ratio is about the same for aluminum-lithium vs 301 stainless full hard at cryo, but latter costs way less, is tougher & doesn’t even need paint!” Musk also noted that the design is important as “the ship must be easy to repair on the moon and Mars.”
If Musk’s latest Twitter posts are to be believed, the miniature “hopper” version of the Starship could fly from the facility relatively soon. The rocket is expected to perform short “hop tests” to demonstrate its effectiveness.
If successful, it could pave the way to a full-blown orbital prototype as early as 2020.