So fusion fans, there are two new ways to see DFD explored as fusion propulsion in the popular media:
- The Living Universe documentary series now on Curiosity Stream
- “The Enceladus Mission” novel now in English from Amazon
The Living Universe is both a feature film for IMAX theaters and now a four-part documentary series. We blogged about our interviews in January and the series is now available on Curiosity Stream, a service dedicated to documentaries! Episode 2,”The Explorers” features a segment on DFD narrated by PSS engineer Stephanie Thomas, in addition to discussing plasma and antimatter propulsion. Here is an article about the series from Broadway World. You need to sign up for an account on Curiosity Stream to watch, which is free for 7 days and then $3 per month.
“The Encedalus Mission” by internationally best-selling hard science fiction author Brandon Q. Morris was originally written in German, and features the DFD as the propulsion technology on a mission to study newly detected life in the Saturn system; an array of six DFDs power the spaceship. Early reviews are favorable! The book is available in paperback or for Kindle.
Send us a comment and tell us what you think if you watch the show or read the book!
Princeton Satellite Systems had a table at the Princeton University Science and Technology Job Fair on Friday, October 12. Many companies attended including the IBM Thomas J. Watson Laboratory, Facebook and Siemens.
We had on display hardware and software that involved the work of interns at PSS. The exhibits were of great interest to the many students who came by our table.
From left to right is an iPhone App for talking with a reconnaissance satellite, a lunar landing simulation on the LCD monitor, parts of an optical navigation system, a Class E RF amplifier, a reaction wheel and a frame for a small satellite. Many students who came by were very knowledgeable about our work.
Here I am talking with one of the students.
It was great event! We look forward to talking with the students when we interview for summer and full time jobs in January.
Hello PSS fans! This is Charles Swanson, recently minted doctor of plasma physics and PSS’s newest employee. It’s my distinct pleasure to discuss our most recent NASA contract: A Phase III SBIR to integrate our Low Energy Mission Planning Toolbox (LEMPT) into NASA’s open source Orbit Determination Toolbox (ODTBX).
Have you read about the kinds of maneuvers conducted by Hiten and AsiaSat 3 that allowed them to reach orbits that would seemingly be outside their Delta-V budgets? Have you always wondered how one goes about planning such maneuvers?
What about the Lunar Gateway from which NASA plans to stage missions to the surface of the Moon in the coming decades? What kinds of clever orbital tricks can we use to get to, from, and about the Moon with the minimum possible fuel?
That’s what LEMPT is for. LEMPT is a suite of tools written in MATLAB for the planning of low energy missions, the kinds of missions that loop way outside the target orbit of the Moon and deep into chaotic regions of the gravitational landscape. Here’s an example:
To go from LEO to a low lunar orbit usually takes almost 4 km/s of Delta-V. The maneuver depicted takes only 2.8 km/s. This is the kind of planning capability that NASA would like for their ODTBX. From now until December, we’ll be integrating the LEMPT into ODTBX, where it will help NASA mission planners evaluate all of their options along the trade-off of mission time and Delta-V.
The orbit above doesn’t look anything like the Keplerian ellipse that we know and love. That’s because this is a four-body system, with the Sun, Earth, Moon, and spacecraft all interacting gravitationally. Even the three-body system is famously chaotic: here are two examples of the kind of distinctly weird-looking orbits you can get:
It’s this chaos that the LEMPT leverages to plan exotic and efficient maneuvers.
We are pleased to announce that our Phase II STTR proposal, “Superconducting Coils for Small Nuclear Fusion Rocket Engines,” was one of 20 selected for award by NASA in this year’s round! The full list of winners is posted on NASA’s website.
We will be building a testbed with a split-pair superconducting coil (two windings with a gap between them) and performing experiments to assess the impact of operating the magnets in the vicinity of the FRC plasma. Applications of the technology go beyond fusion reactors, for example science payloads and high-performance motors for hybrid electric aircraft.
At long last, we have a professional animation explaining how the Direct Fusion Drive works. Enjoy!
The audience learns, watching the movie “Solo,” that the Millennium Falcon has a nuclear fusion power plant! The Millennium Falcon is a modified YT-1330 Corellian light freighter manufactured by the Corellian Engineering Corporation.
The first soft moon landings were accomplished in the 1960’s by the Soviet Luna 9 and the U.S. Surveyor Spacecraft. These were followed by the U.S. Lunar Module landings during the Apollo program. The Soviets had their own LK Lander lunar lander for landing humans on the moon but it never flew. China’s Chang’e-3 landed on the moon on December 13, 2013. India plans to land the Chandrayaan-2 on the moon in 2018. South Korea intends to land a spacecraft on the moon in 2020.
The U.S. Lunar Module was flown by a crew but had a digital computer that performed guidance, navigation and control. A great new book by Don Eyles, Sunburst and Luminary an Apollo Memoir explains how that was accomplished with a computer less powerful than those in toaster ovens today. Don played a key role in saving the Apollo 14 mission when an abort light appeared on the crew’s console prior to descent. Read the book for for the whole story.
NASA intended follow-ons to the Lunar Module that would have been fully automated for delivering materials to the moon in preparation for a permanent human presence. Unfortunately, those plans never materialized.
As we are always looking for new missions for testing our Precision Attitude Control System, we added guidance, navigation and control for lunar landings. We use a really simple guidance algorithm called 2nd order guidance. It is nothing more than a Proportional Derivative (PD) controller with the landing spot as a target. You can adjust the damping ratio and undamped natural frequency of the controller to mimic more sophisticated, “optimal” guidance algorithms. The 2nd order guidance works until the lander gets near the surface and then it switches to landing algorithm that hovers, nulling any remaining translational velocities and then descends to the surface. Lidar would be used as guidance. Once it is hovering it would need to search for a flat spot for landing. NASA has developed Hazard Detection Software for Lunar Landing that uses lidar. It is available for licensing from Caltech.
Here is one simulation in our Simulation Framework. Once the descent is initiated, the spacecraft reorients so that the main engine thrust vector is in the desired direction. The display on the left shows the attitude errors (the two boxes) and the throttle setting (which is zero during the attitude maneuver.)
A close up of the attitude display. Pitch and yaw are offsets of the green rectangle. Roll is rotation of the rectangle. This is quite primitive but it is easy to add your own displays if you know a little OpenGL!
Descent starts and the throttle is about 50% at this point. The two plots are of altitude and velocity. The maneuver starts at 15 km and the target is 600 km along track. The lander has solar panels on a two-axis gimbal and a high gain antenna, also on a two-axis gimbal.
The spacecraft has landed! You can see the terminal descent phase on the altitude and velocity plots. The lunar surface is featureless because we have not added close up maps of the landing zone to the planet display.
The descent page shows the throttle settings. You can monitor the guidance force demand and simulated force.
The graphics are from our VisualCommander product that runs on Mac OS X.
This GN&C system is capable of autonomous flight from LEO all the way to the moon. It uses our Optical Navigation System, developed under a NASA Phase II SBIR for trajectory determination on the flight to the moon and lunar orbit entry.
For more information contact us directly!
Back in early September, PSS and PPPL were visited by a film crew from Australia. The project? Living Universe: An Interstellar Voyage, which will include a feature documentary, a 4 episode TV miniseries, and a podcast. The documentary touches all aspects of an interstellar mission, from exoplanets to astrobiology, including transportation – which is where our fusion engine work comes in. The film is in production now and the producers expect to launch in late 2018.
The PFRC experiment at PPPL is the only hardware the documentary team could find with a path to fusion propulsion! Dr. Cohen was able to run the machine for the film crew, and both Mike and Stephanie were interviewed extensively. We discussed the rocket equation and the fundamental speed of fusion products, and how DFD moderates that speed with additional propellant to produce higher thrust. For an interstellar voyage, DFD would have to be much, much lighter than we know how to make it today – but who knows what innovations in magnets are possible in the future!
How will you be able to watch the film and TV series? The film should do the rounds of museums and IMAX theaters. The TV series will be available for streaming from Curiosity Stream, a service which specializes in science, history, tech & nature documentaries. We will post an update when we have a firm release date!
I attended the 2017 Fusion Power Associates meeting in Washington, D.C. on December 6 and 7. Fusion Power Associates is a non-profit, tax-exempt research and educational foundation, providing timely information on the status of fusion development and other applications of plasma science and fusion research.
The annual meeting brought together experts in all areas of nuclear fusion research including scientists and engineers from ITER, the Princeton Plasma Physics Laboratory, TAE Technologies, General Atomic and many others! The meeting gave a great overview of the state of nuclear fusion power generation. We learned that ITER is 50% complete and on its way to first plasma in 2025. Planning has begun on Demo, the follow-on to ITER.
The Joint European Torus plans a D-T campaign in 2019 and hopes to set new fusion benchmarks. We learned about Korea Superconducting Tokamak Advanced Research (KStar). It has achieved longer than 70 second pulses in H-mode and has suppressed ELM for more than 34 seconds. KStar has in-vessel control coils.
There were several speakers from the University of Rochester along with colleagues from the national laboratories talking about advances in laser compression of fuel pellets. This work is for nuclear weapons research but could be applied to inertial confinement fusion.
I gave the last talk of the meeting on Princeton Satellite Systems and PPPL’s work on DFD, nuclear fusion propulsion for spacecraft.