But getting it to ignite properly when underwater was the main challenge.
Telemetry revealed the boron ramjet was achieving a specific impulse of over 4,700 Newton-seconds per kilogram.
That’s one-third better than even SpaceX’s latestRaptor rocketengine.
The researchers say that engines like this could alter the future landscape of warfare.
These could prove deadly since militaries currently lack countermeasures against such “cross-medium” hybrid weapons.
Image credit:SCMP
