AIAA ASCEND 2023 Papers: Liquid Rockets and Solar Parasols

We presented two papers at the 2023 AIAA ASCEND conference in Las Vegas on October 25, featuring the work of our interns William Huang and Aniesha Dyce. All GN&C analysis and simulations were performed using our Spacecraft Control Toolbox, while the parasol model was built in Fusion 360.

Thanks to the session chairs Dr. Erica Rodgers (NASA), Evan A. Bell (NASA), Melodie Yashar (ICON), and John Carsten (MEI). Our sessions included a variety of intriguing research including optical payload development, robotics from GITAI, deep space internet, a student smallsat design using a solar sail and a study of perceived spaciousness in astronaut living spaces.

Here are the abstracts for our papers:

All Liquid Fuel Space Launch System

The recent Artemis launch demonstrated the performance of the NASA Space Launch System (SLS), specifically the SLS Block 1 configuration. The launch vehicle has a central core stage with four RS-25 engines and two 5-segment solid rocket boosters (SRB). The second stage uses an RL10C-3 engine. This paper presents a conceptual design of an SLS variant using the same core vehicle but with five liquid boosters, each with a single RS-25D. This launch vehicle provides the same performance with two-thirds the launch mass. This is conceptually similar to some Shuttle variants. This paper provides an analysis and comparison of the launch vehicles’ performance and presents simulation results. In addition, it shows how the add-on boosters can be used independently as part of a high-performance two-stage to orbit (TSTO) launch vehicle. Payload and performance are given for the single boosters with a 2nd stage powered by an RL10C-3 engine. Comparison with other commercial available launch vehicles show that the TSTO vehicle proposed in this paper is a competitive in terms of the payload mass it is able to carry to low earth orbit (LEO). This launch vehicle is more complex than comparable launch vehicles. Additional work will be required to determine the cost per kilogram of the two stage launch vehicle and the cost of operating SLS with liquid boosters.

DOI: 10.2514/6.2023-4742

Gateway Momentum Unloading using a Solar Parasol

This paper describes the use of a robotic arm for momentum unloading and orbit control. A panel is attached to the end of a robotic arm. It is positioned, in angle and position, to optimize unloading. The robot arm can move about the spacecraft giving additional degrees of freedom. The panel can be stowed when necessary. The work is based partially on a technology developed by the Canadian Space Agency. The parasol can be grabbed and deployed by the robot arm whenever it is needed, to remove momentum. When it is not needed the parasol is retracted and stowed. The system can be used in high orbits for both momentum and orbit control using solar pressure. In lower orbits, it can use atmospheric drag for the same purpose. This paper focuses on its use for momentum unloading for the NASA Gateway space station. The paper includes a complete GN&C design using single gimbal CMGs with thrusters for orbit control and backup attitude control. The dynamical equations are derived and simulation results are presented for all modes of operation. This includes an optimal attitude profile for minimizing solar and gravity gradient torques over the Gateway orbit.

DOI: 10.2514/6.2023-4781
CAD model of Gateway with a solar parasol in orbit around with moon.
Gateway with Notional Solar Parasol

It was great to be part of the ASCEND conference and share our work!

Beyond Earth Symposium

The Beyond Earth Institute is conducting the

Beyond Earth Symposium

LEO to Lunar to Living Beyond Earth:
Policy Pathways to Space Migration

November 1-2, 2023

There will be attendees from the U.S. Space Force, The Japan Aerospace Exploration Agency (JAXA), NASA, and many private companies. The Beyond Earth Institute is a non-profit think tank that conducts research and provides analysis for decision-makers. I’ll be attending!

Space Movies

Movies about space, both fiction and historical, have inspired engineers and scientists since movies were first produced. Here is my list of movies. I’ve included links to IMDB.

Moon. This movie is a realistic depiction of helium-3 mining on the moon, with an interesting twist. Helium-3 is an isotope of helium used for a wide variety of applications including quantum computing. would be used to fuel our Princeton Field Reversed Configuration Reactor and Helion‘s fusion reactor. An alternative to lunar mining is gas giant mining. We recently wrote a paper on the subject.

Forbidden Planet   From the 1950s. It was a major influence on Star Trek. It is based on Shakespeare’s “The Tempest”.

2001: A Space Odyssey. Released just before Apollo 11. It influenced aerospace engineering in a major way. HAL 9000 is also quite famous, the first AI with a major role in a movie.

Marooned About an Apollo spacecraft that can’t reenter and a rescue mission to save the crew. Technically accurate! It is what NASA might have done for Columbia. Gregory Peck is the head of NASA.

The Right Stuff About the Mercury astronauts and test pilots in the 1950s. Test pilot Chuck Yeager is a major character. While based on real events, it is a black comedy.

Apollo 13 About the near disaster during the Apollo program. One of the best engineering movies ever made. A famous quote from John Aaron, “Power is everything!” and one from Gene Kranz, “Let’s not make things worse by guessing!”

Hidden Figures. A movie about the African-American female mathematicians who made critical contributions to the U.S. space program, but were ignored by the press.

India’s Chandrayaan-3 Lands on the Moon!

Congratulations to the Indian Space Research Organization for the successful landing of the Chandrayaan-3 spacecraft on the moon! This is the first spacecraft to land near the Lunar South Pole. The spacecraft includes a rover. The spacecraft will return information that will help future missions.

Final Titan Aircraft Paper Published in Acta Astronautica

The final version of our paper, “Nuclear Fusion Powered Titan Aircraft,” by Mr. Michael Paluszek, Ms. Annie Price, Ms. Zoe Koniaris, Dr. Christopher Galea, Ms. Stephanie Thomas, Dr. Samuel Cohen, and Ms. Rachel Stutz is now available, open access, on the Acta Astronautica website. As described in our earlier post, the paper discusses a mission to Titan using the Direct Fusion Drive on the transfer vehicle, and a Princeton Field Reversed Configuration reactor to power an aircraft, that could fly around Titan for years. The reactor allows for high-power instruments, some of which were first proposed for the NASA Jupiter Icy Moon Orbiter Mission. The paper was first presented at IAC 2022 in Paris.

Two key figures were updated from the preprint version of the paper – Figure 11 and Figure 12, showing the power flow and mass breakdown of the PFRC for the electric aircraft. The earlier figures were from a larger version of the engine. The final engine design produces 0.5 MWe and has a mass of 1006 kg. This is now consistent with the system masses presented in Table 6. Vehicle Power and Payloads.

Universe Today has published an article about our mission study, “What if Titan Dragonfly had a fusion engine?”

PSS appears on the Space Business Podcast to talk about nuclear fusion propulsion

Mike Paluszek and I appear on the newest episode of Space Business Podcast to talk about nuclear fusion propulsion, Direct Fusion Drive, and the Princeton Field-Reversed Configuration (PFRC) concept!

We had a great conversation with the host of this podcast, Rafael Roettgen, who asked us thoughtful questions. In this episode, we discuss topics such as: the future of space propulsion, the history and benefits of field-reversed configurations and how they compare with other fusion reactor concepts, mass and power budget considerations of a fusion rocket, and the road ahead for research and development to get us to a prototype for space. We additionally talk about terrestrial (on earth) applications of the PFRC concept as a globally-deployable power plant for remote areas and look forward to even more futuristic space concepts that could follow after the PFRC.

You can access this episode on podcast platforms including Apple Podcasts and Spotify as well as directly on their website. Enjoy!

Our Titan Mission Paper preprint is now online in Acta Astronautica

Our IAC paper on a fusion-powered Titan mission is now available in preprint on Acta Astronautica online, with the final version to come soon! Our mission concept utilizes two PFRC reactors: one configured as a Direct Fusion Drive rocket for the journey to Titan, and a second configured as a power source for the electric aircraft that will survey Titan. The paper includes a detailed design of the aircraft and analysis of optimal entry into the atmosphere and landing on the moon’s surface.

Fusion-propelled transfer vehicle shown in orbit around Titan. The transfer vehicle would serve as an orbital science platform and communications relay to Earth. The 2.4 MW fusion reactor provides 1.4 MW of thrust power and 100 kW of electric power.
Fusion-powered electric aircraft for Titan science exploration. The aircraft has six ducted fan engines. The onboard reactor provides 500 kW of electric power.

Crowdfunding for fusion development closing at the end of April

Our crowdfunding opportunity at is scheduled to close at the end of the month. We’ve raised over $100K so far to support fusion development and specifically, the PFRC-2 experiment at Princeton Plasma Physics Laboratory as we close in on our ion heating milestone. This is the last two weeks to invest in our raise on SpacedVentures!

Aerospace Engineering Winter Internship

I worked on two projects during my winter internship at Princeton Satellite Systems: a two-stage-to-orbit (TSTO) launch vehicle design proposal related to the NASA Space Launch System (SLS) and a satellite conjunction maneuver demo. These both used the Spacecraft Control Toolbox for MATLAB.

One of the main ideas behind the TSTO launch vehicle project is to propose an all-liquid variant of the SLS. Currently, the SLS first stage is mostly powered by two solid rocket boosters (SRB) upgraded from the Space Shuttle SRBs. However, our proposal is to replace the two SRBs with five liquid boosters (LB), each mated with an RS-25 engine. The second stage would remain the same. Using MATLAB, I analyzed the launch and trajectory performance of both variants and found similar performance. Additionally, the total mass of the all-liquid SLS variant would be approximately two-thirds the mass of the SRB-powered spacecraft. An approximate CAD model of the all-liquid SLS version is shown below.

In addition, the LBs can be used independently to power smaller high-performance TSTO launch vehicles that carry around 8,000 kg of payload to low earth orbit. Trajectory plots and a preliminary CAD model are shown below.

My other project this internship was to help out with a satellite conjunction avoidance demo with Ms. Stephanie Thomas. The goal was to create a solution in MATLAB to identify potential satellite-debris conjunctions and develop a method/algorithm to avoid the conjunctions. I mainly worked on testing the code and relevant functions and providing feedback about the solution’s comprehensiveness.

Overall, I greatly enjoyed this internship and the opportunity to work at PSS. I saw firsthand how even a small company can make significant contributions to aerospace and engineering through diverse interests yet specific, impressive skill sets.

Producing Terrestrial Power with Helium-3 from Uranus using PFRC/DFD

Our latest paper on DFD applications, “A Fusion-Propelled Transportation System to Produce
Terrestrial Power Using Helium-3 From Uranus”, is now available from AIAA. This paper was part of the Future Flight Propulsion track and AIAA SciTech 2023. For those with AIAA membership, there is a video recording of the presentation as well! Download the paper here.

Our goal with this paper is to create a framework within which we can study the potential cost of electricity produced on Earth using helium-3 mined from Uranus. The scarcity of terrestrial helium-3, along with the radioactivity of methods to breed it, lead to extraterrestrial sources being considered as a means to enable clean helium-3 fusion for grid-scale electricity on Earth.

This paper builds on the work of Bryan Palaszewski who has published numerous papers on mining the atmospheres of the outer planets. Palaszewski’s work assumed fission-based power and propulsion systems, with a much lower (worse) specific power than we anticipate from a PFRC-based Direct Fusion Drive. We consider both transport and mining vehicles that are instead fusion-powered, including a fusion ramjet. This ramjet may be able to be both the mining vehicle and the orbital transfer vehicle to bring the refined helium-3 to the interplanetary transport,

Components of a conceptual fusion-propelled and -powered Uranus atmospheric mining infrastructure

The results allow us to estimate levelized cost of electricity, LCOE, for the electricity produced on Earth as a function of assumed cost of the fusion transports and mining system, cost of the PFRC reactors, amount of helium-3 stored on each transport and numbers of trips per year, etc. You can learn more about LCOE from the NREL website. Uranus is likely the most economical outer planet for mining due to its lower gravity and radiation environment and high concentration of helium in its atmosphere, about 15%. We find that with our set of assumptions, the resulting cost of electricity could potentially be competitive with wind and solar.

Future work will include analysis of the fusion ramjet trajectories between mining and transfer altitudes, and research into sizing a mining payload using membranes and adsorption to separate the helium-3 from the helium, rather than depend on heavy cryogenic techniques.