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!

 

PSS NASA project on SciShow

We just discovered that our NASA NIAC project on the DFD mission to Pluto was covered in a SciShow episode from June 14, 2016.

Hank Green does a great job talking about our project, and I love that he called it a “Pluto Explorer”, which rolls of the tongue better than “Pluto Orbiter and Lander”. However, he did get our fuel wrong: we are using deuterium and Helium-3, a reaction which produces no damaging neutrons. Hank cited “two types of heavy hydrogen”, which would imply deuterium-tritium fusion; this produces most of its every in very damaging neutrons, and is a reaction we go to great lengths to avoid in our machine. There will always be some tritium produced from the side reactions of deuterium with itself, but our machine is designed to exhaust it before it can fuse.

The comments from the viewers were interesting, including several along the lines of, “wait, did I miss fusion becoming a working technology?” Of course the fusion rocket is still theoretical, but it’s based on a real plasma heating experiment going on now at Princeton Plasma Physics Lab! And its true that many people don’t realize that fusion itself has been achieved in many machines, just not break-even fusion. Our machine is very different from the large tokamaks most people are familiar with.

NASA Innovative Advanced Concepts (NIAC) Selection

We are very pleased to announce that Ms. Stephanie Thomas of Princeton Satellite Systems has been selected to be a 2016 NIAC Fellow. This Phase I study, entitled “Fusion-Enabled Pluto Orbiter and Lander,” will explore the possibility of using Direct Fusion Drive (DFD) to deliver an orbiter to Pluto complete with a lander. DFD is a fusion propulsion concept built upon a small, clean field-reversed configuration fusion reactor with a naturally linear geometry. The reactor becomes a rocket engine when additional propellant flows through, providing power as well as propulsion in one integrated device. This engine could halve the transit time to Pluto to 5 years from the nearly 10 years needed for New Horizons, while delivering 1000 kg worth of payload into orbit and providing up to 2 MW of power. This will enable remarkable data collection such as high-definition video and drilling into the planet’s surface. The technology provides a path to terrestrial fusion as well as eventual human missions across the entire solar system. The Phase I study will focus on creating higher fidelity models of the engine performance to enable optmization of possible mission trajectories and better quantification of the predicted specific power.

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PPPL’s Young Women’s Conference

Princeton Satellite Systems had a booth at the PPPL’s Young Women’s Conference at Princeton University. Stephanie Thomas and Gary Pajer talked with students about our work in aerospace and energy.

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Our booth featured a CubeSat frame designed by our mechanical engineers, a simulation of a lunar lander which could be controlled via a joystick, a copy of our new textbook MATLAB Recipes, and a Lego model of our Space Rapid Transit space plane.

The girls were divided into three large groups that rotated through the various attractions available to them, so every hour or so the the attendees changed.   And every hour or so we had a fresh cohort of faces to meet.   Many of the girls  were very interested in what we are doing, and asked insightful questions.  For example, one girl asked “What happens when a satellite loses track of where it is?   Does it just get lost?”   Of course, that’s an important issue, one that we at PSS have spent considerable time addressing.

Some girls were very interested to learn about tiny CubeSats (“This isn’t a model, this is the actual size of the satellite!”), and still others were interested in horizontal launch possibilities as shown by the Lego model – i.e. most rockets launch vertically, but this could take off at any airport. Both of these are examples of systems that we regularly model using our commercial software packages.

For more information see the 2016 Young Womens’ Conference

Rutgers Engineering Honors Council Keynote Speaker Event

Mike Paluszek gave a talk on the Pluto Orbiter mission to the Rutgers Engineering Honors Council Keynote Speaker Event on March 22, 2016. The talk covered the mission and spacecraft and outlined the design process. Mike also discussed engineering careers and how to make the most of one’s own career.

From a member of the audience, “Just wanted to thank you once more for the wonderful talk you gave last Tuesday evening!”

This is a photo of the group.
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A photo of Mike with the officers.

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Lunar Orbit Insertion Maneuver

New functions in the Lunar Cube module in 2016.1 allow you to easily plan lunar insertion and orbit change maneuvers. In the following pictures you can see a lunar orbit insertion from a hyperbolic orbit. In all figures the lunar terrain is exaggerated by a factor of 10.

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The same maneuver looking down on the orbit plane. The green arrows are the force vectors.

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The following figure shows a two maneuver sequence. The first puts the spacecraft into an elliptical orbit. The second circularizes the orbit.

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Lunar Cube Module for 2016.1

We are adding the Lunar Cube Module in 2016.1 to our CubeSat Toolbox for MATLAB! It allows users to analyze and simulateCubeSats in lunar transfer and lunar orbit. It includes a new dynamical model for CubeSats that includes:

  • Earth, Moon and Sun gravity based on the JPL ephemerides
  • Spherical harmonic lunar gravity model
  • Reaction wheels
  • Thrusters
  • Power generation from solar panels
  • Battery energy storage
  • Variable mass due to fuel consumption
  • Solar pressure disturbances
  • Lunar topographic model
  • New graphics functions for lunar orbit operations
  • Lunar targeting function
  • Lunar mission control function for attitude control and orbit control

The module includes a script with a simulation of a 6U Cubesat leaving Earth orbit and reaching the moon. The following figure shows the Earth to Moon trajectory.

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This figure shows the transfer orbit near the moon. The lunar topography is exaggerated by a factor of 10 to make it visible. It is based on Clementine measurements.

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Here are results from the new LunarTargeting function. It finds optimal transfers to lunar orbits. The first shows the transfer path to the Moon’s sphere of influence.

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The next shows the lunar hyperbolic orbit. In this case the transfer is into a high inclination lunar orbit.

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Contact us for more information!

Stofiel Aerospace and Princeton Satellite Systems at CES

Stofiel Aerospace LLC had a display at the Consumer Electronics Show. They invited Princeton Satellite Systems to display its products on their table. The booth is shown in the following picture. You can see Stofiel’s rockets.

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Here is a closeup showing our 3U CubeSat with a camera mounted in one of the bays.

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Members of the Stofiel team:

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More members of the Stofiel team:

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Stofiel Aerospace LLC is an aerospace solutions company created by five U.S. military veterans from Cleveland, Ohio. Stofiel Aerospace LLC is currently developing a portable micro/nano-satellite launch system. Their revolutionary system drastically reduces the wait time for small payloads to reach low Earth orbit to days, not years. By utilizing solid rocket motors and Hydrogen-filled balloons, their system finally offers CubeSat manufacturers and clients the opportunity to be considered a “primary payload” for orbital missions. Currently, they are partnered with the Ohio Aerospace Institute in Cleveland, Ohio and working for further funding to continue development of this industry-changing technology. For inquiries, please contact Jason Beeman, CFO at (440) 994-9035.

Reaction Wheel CAD Project

Hello!

I’m a sophomore at MIT who joined PSS as an extern over Independent Activities Period (IAP). Free to choose how to spend the month of January, students can take an extended vacation,  attend short, intensive classes, do research in MIT’s various labs, etc. Many like myself choose to participate in short internships with MIT alumni – the correct lingo for this type of job experience is “externship”.

I was assigned the task of 3D modeling a reaction wheel for a 25 kg satellite. Essentially, the wheel controls the orientation of the satellite in space. Comprised of a small axial flux motor and a flywheel for added inertia, the wheel sits at 40 mm tall and 80 mm wide. It must spin in both directions, and meet tight dimensional constraints. I believed I really had my work cut out for me.

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SunStation in October

The following image shows SunStation in operation on a bright October day! The load for the day was 12.4 kWh. This includes charging a Nissan Leaf and a Toyota Prius Plugin-in. The total power generated was 40.3 kWh and 21.4 kWh was sold to the grid. As you can see, the installation is much more than carbon neutral with regard to electrical power. It has a gas heating system so is not completely carbon neutral.

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The orange line is the state of charge for the batteries. The 14.4 kWh of batteries is enough to keep the home running, charge the Prius fully and the Leaf partially, when the grid is down. The system automatically disconnects itself from the grid when there is an outage.

The house itself is fairly energy efficient with mostly LED lights and a few CFLs. The heating system is high efficiency with a 60 W fan that operates most of the time. The house is air-tight and has a whole house air exchange system that operates continuously. The refrigerator is 10 years old and the washer and dryer are less than 10 years old. As you can see, the typical load is 500 W except when the cars are charging. The efficiency could be further improved by installing a state-of-the-art central air system and replacing the refrigerator.

The Nissan Leaf is 100% electric. On a normal day the Prius operates on battery stored energy about 80% of the time. It visits the gas station once every 3 weeks or so.

Besides saving money on power, the system produces 7 Solar Renewable Energy Credits (SRECs) yearly. At current SREC prices, that is about $1500 a year in revenue. The homeowners own the system so all the revenue goes directly to them.