NIAC Phase I Final Report

A key feature of the NIAC program is making the project results available to the public. In that spirit, we are making our complete Phase I final report, “Fusion-Enabled Pluto Orbiter and Lander”, available on our website!

NIAC Phase I Final Report [PDF]

I’ve copied the executive summary below:

The Pluto orbiter mission proposed here is credible and exciting. The benefits to this and all outer-planet and interstellar-probe missions are difficult to overstate. The enabling technology, Direct Fusion Drive, is a unique fusion engine concept based on the Princeton Field-Reversed Configuration (PFRC) fusion reactor under development at the Princeton Plasma Physics Laboratory. The truly game-changing levels of thrust and power in a modestly sized package could integrate with our current launch infrastructure while radically expanding the science capability of these missions.

During this Phase I effort, we made great strides in modeling the engine efficiency, thrust, and specific impulse and analyzing feasible trajectories. Based on 2D fluid modeling of the fusion reactor’s outer stratum, its scrape-off-layer (SOL), we estimate achieving 2.5 to 5 N of thrust for each megawatt of fusion power, reaching a specific impulse, Isp, of about 10,000 s. Supporting this model are particle-in-cell calculations of energy transfer from the fusion products to the SOL electrons. Subsequently, this energy is transferred to the ions as they expand through the magnetic nozzle and beyond.

Our point solution for the Pluto mission now delivers 1000 kg of payload to Pluto orbit in 3.75 years using 7.5 N constant thrust. This could potentially be achieved with a single engine. The departure spiral from Earth orbit and insertion spiral to Pluto orbit require only a small portion of the total delta-V. Departing from low Earth orbit reduces mission cost while increasing available mission mass. The payload includes a lander, which utilizes a standard green propellant engine for the landing sequence. The lander has about 4 square meters of solar panels mounted on a gimbal that allows it to track the orbiter, which beams 30 to 50 kW of power using a 1080 nm laser. Optical communication provides dramatically high data rates back to Earth.

Our mass modeling investigations revealed that if current high-temperature superconductors are utilized at liquid nitrogen temperatures, they drive the mass of the engine, partly because of the shielding required to maintain their critical temperature. Second generation materials are thinner but the superconductor is a very thin layer deposited on a substrate with additional layers of metallic classing. Tremendous research is being performed on a variety of these superconducting materials, and new irradiation data is now available. This raises the possibility of operating near- future “high-temperature” superconductors at a moderately low temperature to dramatically reduce the amount of shielding required. At the same time, a first-generation space engine may require low-temperature superconductors, which are higher TRL and have been designed for space coils before (AMS-02 experiment for the ISS).

We performed detailed analysis of the startup system and thermal conversion system components. The ideal working fluid was determined to be a blend of Helium and Xenon. No significant problems were identified with these subsystems. For the RF system, we conceived of a new, more efficient design using state-of-the-art switch amplifiers, which have the potential for 100% efficiency.

This report presents details of our engine and trajectory analyses, mass modeling efforts, and updated vehicle designs.

Enjoy!

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.

The New Space Age Conference

Charles Swanson of PPPL and Mike Paluszek of Princeton Satellite Systems attended the MIT New Space Age Conference at MIT on March 11. It was held on the 7th floor of building E52 at MIT.

Building

Princeton Satellite Systems was a sponsor of the event. It was a great event! There were a number of interesting presentations including one on the history of the Iridium Program. Iridium was almost ready to deorbit the constellation when an investor cobbled together enough money to keep it flying and then found a new market in places without any cell phone service. They are now  launching Iridium-Next. After the disappearance of the Malaysian Flight 370, the airlines realized that they need to know the position of all planes in real-time. Iridium offered a hosted payload to do that and that payload is effectively funding the new satellites. The speaker showed us a image from their satellite showing the tracks of aircraft.

Professor Loeb gave an overview of the Starshot project to accelerate small sails to 20% of the speed of light. He discussed some of the challenges of the program. The speed was selected specifically so that the probes would reach Alpha-Centauri during the lifespan of the investigators.

Boeing gave a talk on composite structures. The speaker, Dr. Naveed Hussain, VP of Aeromechanics Technology, The Boeing Company, showed how established companies are innovating.

Spaceflight gave a talk on their launch services. We plan to work with them to launch our test satellites.

At lunch Charles and I sat with a group of students from Mechanical and Aerospace Engineering Department at Princeton University. We were joined by Mark Jernigan, Associate Director, NASA/JSC Human Health and Performance Directorate. We talked with him about the challenges of human spaceflight to Mars.

Charles and I were on the propulsion panel. Charles gave a spectacular overview of the plasma physics of our nuclear fusion engine. I filled in the DFD system details. We had a few questions from the audience.

Our 2017 extern, Eric Hinterman, gave a great talk on the oxygen from carbon dioxide project that will be tested on Mars. It would produce the oxidizer for return missions thus saving money. My wife, Marilyn, took pictures of the panel.

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At the reception we were the only sponsor with a table display.

Table

It was a great event! We look forward to attending next year!

 

Opening for a part-time bookkeeper/administrator

We are looking for an energetic, results-oriented person able to combine the responsibilities of financial manager and coordinator of back office operations, working part time (16-20 hours/week).

Responsibilities include but are not limited to:

  • financial planning and budgeting;
  • accounting and bookkeeping;
  • customer invoicing and cash management;
  • procurement;
  • HR record keeping and benefits management;
  • coordinating payroll working with an external service provider;
  • managing office facilities.

A candidate must have financial education and a proven record of at least 3 years independently performing on a job with similar responsibilities, possession of skills in QuickBooks or a similar financial package along with MS Office. Excellent communication skills are anticipated.

Please send resumes to info@psatellite.com! Also see our post on LinkedIn.

MIT Externs at Princeton Satellite Systems

Every year during MIT’s Independent Activities Period in January MIT students can apply for externships at alumni’s places of business. Externships last from one to four weeks. Over 300 undergraduate and graduate students participate each year. As part of the program, MIT also helps students find housing with alumni who live near the businesses sponsoring the externship. Externships are a great opportunity to learn about different types of career opportunities. Students apply in September and go through a competitive selection process run by the MIT Externship office.

This year Princeton Satellite Systems had two externs, Tingxao (Charlotte) Sun, a sophomore in Aeronautics and Astronautics and Eric Hinterman, a first year graduate student in Aeronautics and Astronautics. Eric started January 9th and Charlotte on the 16th after spending time on the west coast visiting aerospace companies as part of an MIT Aeronautics and Astronautics trip. Eric took a break during the externship to attend a meeting at JPL on an MIT project.

Both externs worked on our Direct Fusion Drive research program to develop a space nuclear fusion propulsion system. An artist’s conception is shown below.

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This project is currently funded by NASA under a NIAC grant. Eric worked primarily on the Brayton cycle heat recovery system that turns waste energy from bremsstrahlung radiation, synchrotron radiation and heat from the plasma into power that drives the rotating magnetic field (RMF) heating system. He produced a complete design and sized the system. He also wrote several MATLAB functions to analyze the system. Charlotte worked on the design of the superconducting coil support structure making good use of her Unified Engineering course skills! Here is a picture of Charlotte and Eric in front of the Princeton Field Reversed Configuration Model 2 test machine (PFRC-2) at the Princeton Plasma Physics Laboratory. Dr. Samuel Cohen, inventor of PFRC, is showing them the machine.

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Both Charlotte and Eric made important contributions to our project! We enjoyed having them at Princeton Satellite Systems and wish them the best of luck in their future endeavors!

MATLAB Machine Learning Book is Now Available

Apress just published our new book, “MATLAB Machine Learning”

9781484222492

written by Michael Paluszek and Stephanie Thomas. The book covers a wide variety of topics related to machine learning including neural nets and decision trees. It also includes topics from automatic control including Kalman Filters and adaptive control. The book has many examples including autonomous driving, number identification and adaptive control of aircraft. Here is a view of a neural net tool included with the book.

MultiOutputNet

Full source code is available. For more information go to MATLAB Machine Learning.

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.

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