Summary: Princeton Plasma Physics Laboratory has licensed the technology for Direct Fusion Drive (DFD) a fusion-powered rocket engine that could take people on a mission to orbit Mars for 30 days with total trip duration of 310 days.
Original author and publication date: Brian Wang – May 22, 2020
Futurizonte Editor’s Note: Just another example that the science fiction of the past was only a documentary about the future.
From the article:
Direct Fusion Drive (DFD) FD is a conceptual fusion-powered spacecraft engine. It should produce between 5-10 Newtons thrust per each MW of generated fusion power, with a specific impulse (Isp) of about 10,000-20,000 seconds. They would have 200 kW – 2MW available as electrical power. Approximately 35% of the fusion power goes to thrust, 30% to electric power, 25% lost to heat, and 10% is recirculated for the RF heating. The design uses a specially shaped radio waves (RF) “antenna” to heat the plasma.
The ISP is about 20,000. 5 to 10 newtons are generated per megawatt of fusion power. They are looking at 1 to 2 megawatts for the initial space system. This would thus produce 10 to 20 newton using a 2-megawatt system. They want to get their machine cycle down to 3 years. They want to complete the system for less than $100 million.
They believe they can also make a pure energy generation system. They refer to this as closed loop mode.
It would produce thrust from fusion without going through an intermediary electricity-generating step. It will use magnetic confinement and heating system, fueled with a mixture of helium-3 (He-3) and deuterium (D), to produce high specific power, variable thrust and specific impulse, and a low-radiation spacecraft propulsion system. They will heat plasma to 100 keV (which is 1,120,000,000 degrees K)
The plasma is confined in a torus-like magnetic field inside of a linear solenoidal coil and is heated by a rotating magnetic field to fusion temperatures.
Bremsstrahlung and synchrotron radiation emitted from the plasma are captured and converted to electricity for communications, spacecraft station-keeping, and maintaining the plasma’s temperature.