Jeff Bezos Instagram – First hotfire of our #BE7 lunar landing engine just yesterday at Marshall Space Flight Center. Data looks great and hardware is in perfect condition. What you’re seeing at the bottom is a water cooling system and the green flame is the ignition system. The engine plume you see is very clear because the fuel is hydrogen. Test went full planned duration – 35 seconds. Kudos to the whole @BlueOrigin team and grateful to @NASA_Marshall for all the help!