
Elon Musk @elonmusk
@Erdayastronaut @SpaceX Great video. Couple notes: Raptor designed for subcooled CH4/O2, so propellant density & thrust increase up to ~8%, as needed for mission. 380 Isp & up to 50% thrust/weight improvement over time. Merlin thrust/weight doubled from V1, but Raptor is closer to optimum. — PolitiTweet.org