Engineers Test a Jet Engine That Ran 70 Hours on Zero Fuel Using Plasma For over a century, jet engines have relied on combustion—burning fuel to generate thrust. Now, engineers are challenging that foundational principle with experimental tests showing a jet engine operating for 70 hours without traditional fuel, using superheated plasma instead of combustion. This breakthrough represents a radical shift in propulsion research. By using electrically generated plasma to energize airflow, scienti