Asteroid Day

June 30 is Asteroid Day. Asteroid Day is a reminder that we need to protect the Earth from asteroids. We need both an early warning system and a means for deflecting asteroids. The B612 Foundation is working on an early warning system. Direct Fusion Drive, a nuclear fusion rocket engine technology under development jointly by Princeton Satellite Systems and the Princeton Plasma Physics Laboratory could provide the means to deflect asteroids that are on a course to collide with the earth. We published a paper in October 2013 on how this might be done

Direct Fusion Drive Rocket for Asteroid Deflection [PDF], J. Mueller, Y. Razin, S. Cohen, A. Glasser, et al, 33rd International Electric Propulsion Conference.

Samuel Cohen, inventor of the Princeton Field Reversed Configuration reactor that is the core of our engine, co-authored a paper on comet deflection.

We are currently supported by a DOE grant, two NASA STTRs and a NASA Phase II NIAC grant! For more information go to our nuclear fusion page.

Foundations of Interstellar Studies Workshop

Dr. Sam Cohen and I had a good time at the Foundations of Interstellar Studies Workshop this week in NY! While we were only able to stay for the first day on “Energetic Reaction Engines”, there were many thoughtful discussions on applying fusion technology to interstellar travel. Here I am in the group photo from the welcome event Monday night, held at the Harvard Club with an interesting and wide-ranging display of interstellar art! (I’m in the first row on the far right).

Group photo

Group photo from Foundations of Interstellar Studies workshop

The workshop was almost a mini-NIAC reunion, as NIAC fellows Phil Lubin and Ray Sedwick were there, and Heidi Fern was due to present her Mach Effect thruster on Thursday. Also NIAC External Council member Lou Friedman of the Planetary Society was in attendance (very back of the photo).

Our presentation for this conference focused on how the PFRC addresses the key parameters needed for a “net positive” fusion reactor: energy confinement, current drive, plasma heating, and plasma stability. We are often asked “why fusion will work this time”, and this paper does a good job of explaining why the PFRC is different enough from other approaches to work! The workshop is going to submit all of the papers to the Journal of the British Interplanetary Society, which is the oldest astronautical journal in the world (1934).

We also discussed the parameters the propulsion system will need to achieve to reach Alpha Centauri in various time scales, as well as a more near-term mission deliver a gravitational lens telescope to 550 AU. Reaching Alpha Centauri in anything close to a human lifetime remains a significant challenge, but PFRC could be part of an architecture to reach the star in 300 to 500 years, and slow down enough to go into orbit around the potentially Earth-like planets there! The 550 AU telescope mission, however, could be achieved in as little as 12 years with just one small PFRC and is an exciting new mission possibility.

Our next interstellar appearance will be at the Tennessee Valley Interstellar Workshop in October in Huntsville, AL!

DFD paper accepted for Workshop of Interstellar Flight

Our paper “Direct Fusion Drive for Interstellar Exploration” has been accepted for the Workshop of Interstellar Flight that will be held at CUNY City Tech, 13-15 June 2017! The workshop is organized by the Institute for Interstellar Studies and City Tech’s Physics Department and Center for Theoretical Physics.

We will present the latest results from our NASA NIAC work on DFD design as well as applications to interstellar missions, including:

  • A mission to 550 AU to perform gravitational lensing imaging of exoplanets;
  • Flyby missions to the nearest star;
  • A mission to go into orbit about a planet orbiting either Alpha-Centauri A or Alpha-Centauri B.

NASA NIAC Phase II selected!

We received notice today, March 31, 2017, that our NASA NIAC Phase II proposal was selected for award! We will be able to continue working on the Direct Fusion Drive with PPPL for two more years. Hooray! Dr. Joseph Minervini of MIT will be joining our team to help advance our understanding of the trade space for the superconducting coils, using the very latest data from high-temp superconductor manufacturers. It’s going to be exciting research!

Here’s a link to NASA’s official project summary.

Princeton Satellite Systems Awarded Nuclear Fusion Patent in Japan

Princeton Satellite Systems was awarded its first patent in Japan, “Method to produce high specific impulse and moderate thrust from a fusion-powered rocket engine”. This technology was licensed from Princeton University’s Princeton Plasma Physics Laboratory. It is for a compact, low-neutron, nuclear fusion reactor that can be used as a rocket engine or as a power generator. The reactor can be built in sizes from 1 to 10 MW. A typical robotic spacecraft would use two engines. A human mission to Mars or the outer planet might use six 5 MW engines.

Here is the Japanese patent certificate.



US-Japan Compact Toroid Workshop 2016

Mike Paluszek of Princeton Systems, Sam Cohen of the Princeton Plasma Physics Laboratory and Charles Swanson also of PPPL attended the US – Japan Compact Toroid 2016 meeting in Irvine California this past August.

We presented papers related to Sam’s Princeton Field Reversed Configuration nuclear fusion reactor research program. Charles presented, “Extracting electron energy distributions from PFRC X-ray spectra,” Sam presented “Long pulse operation of the PFRC-2 device” and Mike presented, “Fusion-enabled Pluto orbiter and lander”.

Here are the workshop attendees.


It was fascinating to listen to all of the papers at the workshop! John Santarius, who has done cutting edge work on space propulsion and small fusion reactors presented his talk, “Aspects of Advanced Fuel FRC Fusion Reactors.” He gave a very informative overview of small fusion reactors and advanced fusion fuel technology. Thomas McGuire discussed the Lockheed Martin research on small reactors. There were several presentations by Tri-Alpha Energy scientists on their beam heated FRC.

We look forward to the next Compact Toroid Workshop!

NIAC Pluto mission talk now available online

On Tuesday, August 23rd I had the privilege of giving my talk on our Fusion-Enabled Pluto Orbiter and Lander at the 2016 NIAC Symposium. The video of the LiveStream is now archived and available for viewing. My talk starts at 17:30 minutes in, after Michael VanWoerkom’s NIMPH talk.

The talk was well-received and we had some good questions from the audience and the LiveStream. In retrospect I did wish I had added a slide on our overall program plan in terms of the PFRC machine and temperature and field strength, since I got quite a few questions on those specifics at the poster session. PFRC-1 demonstrated heating electrons to 0.3 keV in 3 ms pulses. The goal of the current machine – PFRC 2 – is heating ions to 1 keV with a 1.2 kG field. The next machine I refer to in the talk, PFRC 3, would initially heat ions to 5 keV with a 10 kG field, and towards the end of its life we would push the field to 80 kG, heat ions to 50 keV, and add some helium-3 to get actual fusion events. The final goal would be 100 second-duration plasmas with a fusion gain between 0.1 and 2. A completed reactor would operate in steady-state.

Thank you NIAC for this opportunity!!

NIAC Orientation

I had a great time at the NIAC orientation in Washington DC last week, where I got “mugged” with program manager Jason Derleth:

Stephanie Thomas and Jason Derleth posing with a NIAC mug

Stephanie receiving her NIAC mug from Jason

The meeting was at the Museum of the American Indian, which was a great venue with so much beautiful art to see, and a cafe featuring unusual native foods from across America (elderberry sauce on the salmon). I had the opportunity to meet the other NIAC Fellows, and put names and faces to the other creative projects selected, as well as meet the illustrious NIAC external council. These experienced folks provide advice and encouragement throughout the NIAC process from their experience as physicists, engineers, biologists, science hackers, and even science fiction authors.

I have to say, my poster on the fusion rocket engine was popular, and everyone wanted to know how it works, why it hasn’t been funded already, and how soon the engine can be ready. Of course, we have yet to actually demonstrate fusion using Dr. Cohen’s heating method, but that is why we need the NIAC study – to flesh out the science and engineering of the rocket application to help bring in funding for building the next generation machine. And yes, let’s get to Pluto in only 4 years the next time! I’m really looking forward to working on the project in the next few months and presenting it at the NIAC symposium in August!