August 18, 2020: SpaceX Founder Elon Musk announced on Twitter yesterday that the Raptor engine, an incredibly powerful ox staged metal combustion engine, reached a main combustion chamber pressure of 330, about 4800 psi during a controlled burn. The raptor did not explode and produced approximately 225 tons (half a million pounds) of force. The tweet came with a picture of the Raptor test with a graph showing the level of pressure.
Although the exact model of the raptor was not revealed, speculations guess that it was the 39 (SN39) serial number (since he mentions in the comments that SN40 is yet to be tested and has “several upgrades over 330 bar engine). The engine uses a staged combustion cycle that is more efficient and is powered by subcooled liquid oxygen and subcooled liquid methane.
Pushing the engine to this level has broken all previous records. The record outside of laboratory tests so far has been held by the Soviet Union, that in the 1980s reach pressures of 290-300 with the RD-701. Unfortunately, the engine had to be canceled. Now, with the 330-chamber pressure, SpaceX has beaten this record.
It is likely that SpaceX will further push Raptor’s Chamber pressure, but it is not known yet if the Raptor is able to burn for longer than 90 seconds. To reach the orbit, Raptor still has to mature and develop more. However, given that SpaceX has not revealed a lot of information about the Raptor, it is possible that many advances have already been made.