SpaceX’s key milestone is cranking up the heat. SpaceX founder Elon Musk posted photos of the new Raptor rocket engine. The company is preparing to test fire the Starship Raptor engine designed for use on a future Moon and Mars mission.

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 Moon, refuel using harvested resources, and come back. The founder of Tesla tweeted photos and video of the new Raptor rocket engine, which is supposed to power a prototype Starship that will take people around the world. One day Musk envisions the rocket will take people to Mars.

The photos were interesting, but Musk added comments about the engine that revealed much about how the company is proceeding with the overall design of the vehicle it will power.

The company is initially comprised one 200 metric ton thrust engine for both the booster and the ship on top, but the next version will split this between a vacuum-optimized version with specific impulse over 380 seconds, and a sea-level version optimized for around 250 tons of thrust.

Taking Musk’s latest Tweeter posts, 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.

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. The starship will have seven new engines which might take a test-fly by mid-year.

Recently Musk also Tweeted videos and pictures revealing the first firing of the new Raptor rocket engine that will power SpaceX’s prototype Starship, the vehicle designed to carry humans on quick hops across the world and eventually to Mars. It seems that SpaceX’s approach is focused on moving as quickly as possible towards a launch of the Starship spacecraft and Super Heavy rocket in early 2023.