Space Systems

The Space Systems research group is creating innovative electric propulsion systems to make space travel more feasible, efficient, and economical. These systems have a higher potential exhaust velocity than their chemical counterparts and require less fuel to reach orbit. This group is home to the Ion Space Propulsion Laboratory, where the first bismuth-fueled Hall-Effect thruster was built and demonstrated outside of the Soviet Union. Work continues toward a full-bismuth system.

The group also addresses the immediate challenge of integrating plasma-propulsion systems into existing satellite technology. Researchers are developing methods and devices to improve real-time performance; they are building micro-thrusters using electron emitter arrays with self-regenerating nanotips, solving the problem of nanotip degradation, and allowing an extended system lifetime.

Additionally, researchers are creating methods to identify and mitigate common issues associated with electric propulsion, with projects that investigate refractory powder metallurgy, thruster thermal modeling, magnetic field topology, electron trapping, and sputter erosion. The group intends to expand its research expertise and build a foundation of experimentalists in attitude-control technology, robotics, chemical propulsion, power systems, lightweight structures, and astrodynamics. The group is poised to shape the future of space exploration.

Faculty + Research = Discovery

Our department boasts world-class faculty who have access to numerous innovative research labs and are committed to discovery and learning. This encompasses a range of research areas, experiences, and expertise related to space systems. Learn more about our faculty and their research interests:

Research Projects

Our faculty engage in a number of research projects, many of which are publicly funded. A sample listing of recent research projects focused on agile interconnected microgrids appears below. You can also view a broader list of research projects taking place across the mechanical engineering department.

Ongoing Projects

Stratus Meteorological CubeSat: Payload Integration and Mission Level Design:

Principal Investigator: L. King
College/School:  College of Engineering
Department(s): Mechanical Engineering-Engineering Mechanics
Understanding of the atmosphere and its processes draws from many fields of science and engineering due to its global scope and importance to life on this planet. The most visible and well known facet of this system would be cloud formations. The varied nature of clouds allows them to act as a herald for near-future meteorological events and as indices for general climate trends. Gathering more data on cloud properties will improve global climate models and forecasting, benefiting the scientific community and general population. This data can be collected via the use of CubeSats.
Stratus is a pathfinder mission whose goal is to build, deploy, and demonstrate a low-cost
CubeSat platfon11 capable of measuring Cloud Fraction (CF), Cloud Top Height (CTH), and Cloud
Top Wind (CTW). If successful, several inexpensive Stratus spacecraft could be deployed in the future to gather accurate and extensive data relevant to cloud-driven climate forecast models at a continuous rate across the world. Stratus will measure CF data while in Nadir-Pointing Mode. Stratus will then measure CTW and CTH data utilizing spin-stabilized stereoscopic imaging. The Stratus mission shares similar goals to NASA as described in the 2014 NASA Strategic Plan document. It is most with objectives 2.2, 2.3, and 2.4 of Goal II: "To advance the understanding of Earth and develop technologies to improve the quality of life on our home planet."
Research Goals & Desired Outcomes
The goals of the payload integration and mission-level design is to produce documentation which can wholly describe the mission operations of Stratus, and to design, implement, and document the payload of the satellite to ensure successful integration. The desired mission outcome is that Stratus is completed, launched, and performs at or above the levels indicated in the mission-level documents. The long-term functionality of Stratus would demonstrate the cost effectiveness of using CubeSats to gather cloud data. This could justify the efficacy of a swarm of Stratus craft to gather global hyper-local weather data.
The desired subsystem outcome is a fully integrated payload subsystem which can accurately image data during nadir-pointing and stereoscopy phases of the mission. This fully characterized subsystem would have all interactions with other subsystems described in Interface Control Documents to ensure safe and correct integration of the payload into Stratus.
Research Plan
The plan of attack for completing research on the Stratus is as follows: (I) Develop mission-level design documentation so stratus is developed with a clear direction. (2) Research and develop methods to improve the ability of the payload to produce accurate, on-demand data retrieval. (3) Document the Stratus payload and its interactions created with other subsystems via Interface Control Documentation. (4) Characterize the payload through rigorous and through testing procedures to ensure intended functionality. Note that some of these processes are cyclic in nature due to redesigns that may occur during the development process.

Awarded Amount: $2500

Auris: A CubeSat to Characterize and Locate Geostationary Communication Emitters

Principal Investigator: L. King
Co-Investigator:  Ossama Abdelkhalik
Co-Investigator:  Michael Roggemann
College/School:  College of Engineering
Department(s): Mechanical Engineering-Engineering Mechanics
Dozens of commercial and government spacecraft occupy the geostationary belt to provide global telecommunications service for their customers and operators. As more spacecraft occupy the GEO region the potential for interference grows. Spacecraft in GEO can interfere with each other by (1) close physical proximity, which increases collision risk, and (2) electromagnetic interference (antenna beam overlap) which can degrade communication performance. We propose a mission called Auris, Latin for "the ear," to characterize the interference potential of GEO communications satellites. Using CubeSats in LEO, Auris can spatially map out the antenna spot beam pattern of a GEO comsat and also pinpoint the physical location in space of the GEO emitter. The spot beams are mapped by registering received signal strength, latitude, longitude, and altitude as the CubeSat passes through the beam during multiple orbits. The emitter location is established via time-difference-of-arrival measurements from multiple receivers.
The Auris mission data has actionable relevance and will be useful for SMC's Space Superiority Directorate (SMC/SY) and they will be the data customer for the proposed mission; Auris will serve as a pathfinder to mature technologies for future programs of record supported under SMC/SY's strategic direction. The Auris project's data output is aligned to AFSPC tech needs, most directly with TN1022 "Next Generation Space C2 Information Display and Visualization," related to JMS.
The nanosatellite design activity will be perfom1ed by an interdisciplinary team of undergraduate students through the Michigan Tech Aerospace Enterprise Program. The Aerospace Enterprise team has participated in the UNP competition three times, earning two Third Place awards (UN3 and UN5) and one First Place Award (UN6). The team's Oculus-ASR nanosatellite is presently being readied for flight on the 2016 STP-2 mission that will be launched on a SpaceX Falcon Heavy.
Proposed Mission
We propose a mission called Auris, Latin for "the ear," to characterize the interference potential of GEO communications satellites. The Auris mission was inspired by, and heavily leverages, LaSarge's concept to gather intelligence on GEO emitters using cubesats in LEO. Our proposed mission has two goals:
(1) Spatially map out the antenna spot beam patterns radiated from geostationary communications satellites
(2) Demonstrate the ability of cubesat-based receivers to locate the position of RF emitters using multilateration
Mission Goal 1:  As CubeSats traverse their LEO orbits they fly through the path of spot beams transmitted from GEO. The CubeSat operates as a simple detector, registering the time and location when it receives the signal from the target emitter. After many orbits the locus of "hits" reported by the CubeSat maps out the shape of the antenna spot beam pattern. The time required to converge on an adequately filled beam map can be accelerated by using multiple CubeSats.
Mission Goal 2: Is to demonstrate a technique to locate the position of a spot beam emitter. LaSarge's original work explored this objective using angle-of-arrival (AOA) information at the CubeSat receiver to detem1ine the line-of-sight vector to the source. This technique was shown to require unreasonable attitude knowledge on the CubeSat in addition to bulky directional antennas. To physically locate an RF emitter we propose, instead, to use time difference of arrival (TDOA) information recorded from multiple receivers.

Awarded Amount: $113,000

Electrospray from Magneto-Electrostatic Instabilities

Principal Investigator: L. King
College/School:  College of Engineering
Department(s): Mechanical Engineering-Engineering Mechanics

The term "electrospray" refers to the charged droplets and molecular ions that are emitted from the meniscus of a conducting liquid due to a strong electric field. The applied electric field induces a layer of surface charge on the liquid resulting in an electrostatic stress on the surface; if the stress is strong enough to overcome liquid surface tension the result is an ejected beam of charged particles. In 2013 Meyer and King demonstrated a completely new mechanism of electrospray that is fundamentally different from anything observed to date. This new electrospray was enabled by a unique and exotic fluid that was synthesized for the first time by Jain and Hawkett in 2011. This new fluid is called an ionic liquid ferrofluid (ILFF), which is a superparamagnetic, electrically conductive, room-temperature molten salt. Because the ILFF is superparamagnetic it can be stressed by magnetic fields; because the ILFF is also electrically conductive it can be stressed by electric fields. Meyer and King induced a magnetostatic instability in the ILFF surface known as a Rosensweig instability, which caused a regular array of static fluid spikes in the free surface. An applied electric field then further stressed and deformed the magnetically formed peaks causing their amplitude to increase and tip radius to decrease. A sufficiently strong electric field was shown to cause electrospray emission from the tip of each spike in the array.

This combined magneto-electrostatic instability has never before been observed and hence no description is available. The phenomenon was observed in two different fluids and under various values of applied electric field, but systematic investigation of the effect has not yet been addressed. This document proposes an integrated experimental, theoretical, and numerical investigation of electrospray from Rosensweig-Taylor instabilities that is designed to uncover the governing processes in this new phenomenon. The goal of work proposed here is to quantify how the combination of electric and magnetic surface stress components affect electrospray behavior in a superparamagnetic liquid. A two year research effort is proposed to

• Design and fabricate an apparatus that isolates a single Rosensweig-Taylor tip and permits controlled variation of both electric and magnetic field

• Measure rheology, surface tension, magnetic nanoparticle concentration, and electric conductivity for each ionic liquid ferrofluid tested

• Measure the critical voltage required to induce electrospray from a magneto-electrostatic instability as a function of (I) fluid magnetization, (2) magnetic field strength, (3) and fluid conductivity

• Establish the relationship between applied voltage, spray current, and total spray mass flow as a function of magnetic field strength

• Measure the angular divergence of the emitted electrospray beam as a function of electric and magnetic field strength

• Numerically model the fluid emission site using molecular dynamics simulations

• Measure the mass-to-charge ratio of emitted products using mass spectrometry

• Attempt a theoretical description of the static instability as a function of fluid parameters and electric/magnetic field strength.

Awarded Amount: $921,051

Past Projects

Oculus-ASR Nanosatellite Flight Integration

Principal Investigator: L. King
College/School:  College of Engineering
Department(s): Mechanical Engineering-Engineering Mechanics
Statement of Work
Michigan Technological University is presently preparing the Oculus-ASR nanosatellite for launch and in-space operation. The final development activity will be to assemble the satellite structure so that it is compliant with launch vehicle mechanical requirements. This will require integration of flight-quality structural fasteners as well as electrical wire harnessing equipment.  Acquire aerospace-grade fasteners and wire harnessing components, and to install and test these components in the Oculus-ASR flight vehicle. Specific tasks include:
(1) Purchase space-flight-quality stainless-steel fasteners
(2) Purchase space-compatible wiring, electrical connectors, and strain-relief components
(3) Acquire and/or build electrical and mechanical testing apparatus to ensure proper installation of fasteners and harnessing
(4) Assemble the Oculus-ASR nanosatellite into a launch-ready configuration

Awarded Amount: $19,372

Stratus, a NASA CubeSat, and the Utilization of Effective Project Management to Enhance Student Learning

Principal Investigator: L. King
College/School:  College of Engineering
Department(s): Mechanical Engineering-Engineering Mechanics
In order to maximize the student learning experience through a project that consists of the design, test, and fabrication of a cubesat, Sam Baxendale proposes conducting research into effective Project Management skills for student satellite teams. Sam Baxendale will serve as Project Manager of Stratus, a NASA cubesat proposed to image cloud movement from geostationary orbits in order to optimize solar power generation applications. Managing a team of 60 undergraduate Michigan Technological University Students, Sam Baxendale will work with Faculty Advisor Dr. Lyon Brad King to promote an environment in which students are presented the opportunity to gain hands-on experience through the development of a spacecraft that will be ultimately launched and utilized to serve the strategic interests of NASA.

Awarded Amount: $2,500

Characterization Test-Bed for Nanostructured Propellants

Principal Investigator: L. King
College/School:  College of Engineering
Department(s): Mechanical Engineering-Engineering Mechanics

At present there exists no single propulsion technology capable of meeting both orbit-raising and stationkeeping requirements for communications satellites. Contemporary satellites thus carry two completely separate propulsion systems and incur the mass penalty associated with each. It is conceivable that a single propellant could be used for both a high-thrust chemical thruster that performs orbit raising as well as a high-specific-impulse electric thruster to perform stationkeeping. In this case the mass burden on the spacecraft bus would be significantly reduced simply by eliminating one of the large propellant storage vessels. Although no single propellant has been identified yet, recent developments suggest that it is possible to synthesize custom nanostructured propellants that could be used in both chemical combustion-based thrusters as well as electrostatic thrusters.

The goal of work proposed here is to fabricate and implement an experimental test bed that is capable of fully characterizing the electrostatic acceleration and chemical combustion of nanostructured propellants for spacecraft propulsion. The instruments will be developed through collaboration between Michigan Technological University and the University of Maryland. The proposed test-bed represents the first-ever facility devoted to combustion and electrospray research on nanostructured colloidal propellants.

The investigators on this project together are presently engaged in DoD research with total funding exceeding $4M. Agencies supporting this research include Office of Naval Research, Air Force Office of Scientific Research, and the Defense Threat Reduction Agency. All of this work is devoted to studies, in one form or another, of the behavior of nano-structured propellants for either chemical or electric propulsion. The test equipment proposed here will be directly relevant to these on-going activities.

Awarded Amount: $456,539

Trajectory Optimization for Solar Electric Propulsion Satellites

Principal Investigator: Ossama Abdelkhalik
College/School:  College of Engineering
Department(s): Mechanical Engineering-Engineering Mechanics

The investigation of a low cost SEP microsatellite capable of launching within an ESP A class rideshare opportunity. The research is focused is on optimizing the low-thrust trajectory to minimize satellite hardware and operation costs while maintaining the ESPA class requirements. In particular, the solar array and mission operation costs as a function of array power and inclination of the spacecraft orbit as it transits the radiation belts. As power increases, trip time and thus radiation exposure and operation costs decrease. However, large solar arrays increase cost and the mass reduces payload capability. Also, varying inclinations follow different trajectories through the radiation belts as they reach their final orbits. Trajectories that start at a higher inclination have a longer path, but pass through lower intensity radiation bands. This can decrease the size and costs of the solar arrays, but requires larger Δ Vs and reduces payload capabilities

Tasks and Deliverables:

1. Provide a trajectory optimization of the SolRider vehicle to minimize cost of the following orbit transfers:

2. Analysis should consider the following variables/factors. Values are provided in the Solar Rider specification.

    a. Radiation degradation of solar arrays

    b. Solar Array $/W

    c. Solar Array kg/W

    d. Propellant & Tank Mass

    e. Mission operations cost: $/day

    f. Thruster shut down and start up due to eclipse

    g. Atmospheric Drag

3.   Deliverables:

    a. For each transfer orbit:

        i. Normalized Cost vs. Array Power

        ii. Trip Time vs. A1Tay Power

        iii. Payload Mass v. Array Power

        iv. Radiation Degradation v. Array Power

    b. For the LEO to GEO transfer orbit

        i. Normalized Cost v. Initial Inclination

        ii. Trip Time v. Initial Inclination

        iii.. Payload Mass v. Initial Inclination

        iv. Radiation Degradation v. Initial Inclination

c. Input files

d. Raw Output Data

Awarded Amount: $10,000

Trajectory Analysis for NASA Asteroid Redirect Mission

Principal Investigator: Ossama Abdelkhalik
College/School:  College of Engineering
Department(s): Mechanical Engineering-Engineering Mechanics

Awarded Amount: $10,256

Michigan AFRL Center of Excellence in Electric Propulsion (MACEEP)

Principal Investigator: L. King
College/School:  College of Engineering
Department(s): Mechanical Engineering-Engineering Mechanics

This five year research program consists of research in three areas: electrospray propulsion, field-reversed configuration devices, and non-invasive plasma optical diagnostics.

1. Electrospray Propulsion

MTU has pioneered a unique micromachining technique for fabricating all-metal electrospray structures for space propulsion. Unlike devices built using silicon MEMS protocols, the all-metal emitters are suitable for use with reactive propellants such as AF315. The all-metal structures can also tolerate very high temperatures. The electrode needles in this array are solid tungsten, while the substrate is solid molybdenum.  MTU will investigate the use of externally wetted emitters - as well as internally wetted capillaries for use as electrospray sources for space propulsion. Research will focus on the use of AF315 as a propellant. Investigations will address fabrication challenges, device performance, plume characterization, and spacecraft interaction.

2. Field-Reversed Configurations

The FRC presents a unique plasma geometry that is well suited for plasma propulsion.

Because the FRC plasmoid is not linked to the structural magnetic flux, the plasma is not attached to the open field lines and can be ejected from the formation region as a self-contained entity. Furthermore, FRCs result from inductive "electrodeless" formation, avoiding the failure mode imposed by electrode erosion that is common to contemporary plasma thrusters. Motivated by the surprising stability of FRCs and their ability to translate while remaining coherent, MTU and the Air Force Research Laboratory (AFRL) at Edwards AFB will collaborate on an investigation into the feasibility of FRC space propulsion. MTU has designed and built a unique co-axial FRC mounted to a large expansion chamber that will be used for MACEEP research.

The goal of MACEEP research will be to determine the optimal physical and electrical configuration of a coaxial FRC for space propulsion and to characterize the conversion of stored electrical energy into plasmoid kinetic energy during translation and ejection. MTU researchers will employ a number of diagnostic techniques - to include magnetic field probes, electrostatic probes, and optical diagnostics - to quantify the energy conversion process during FRC formation and ejection. Thrust will be estimated from exhaust plume properties.

3.  Non-invasive Optical Diagnostics

MTU is currently developing an optical diagnostic technique that can, for the first time, obtain direct measurements of electron density and electron energy distribution function (EEDF) within the discharge chamber and near-field plume of a Hall thruster. The MTU technique uses a

1,000-mJ-per-pulse Nd-YAG laser to induce laser Thomson scattering (LTS) from the free electrons in a plasma. The scattered radiation is measured using a triple-grating spectrograph and electron-multiplied CCD camera with single-photon detection capability. The scattered spectra can directly provide density and EEDF without perturbing the plasma. Researchers will use MACEEP funding to demonstrate this technique and apply the measurement to Hall thrusters and FRC plasmas. It is anticipated that knowledge gained from LTS measurements will provide insight into Hall thruster cross-field mobility as well as FRC internal energy storage and coversion.

Awarded Amount: $939,442

Mass Measurements of an Electrospray Beam from a Single Emitter Ionic Liquid

Principal Investigator: L. King
College/School:  College of Engineering
Department(s): Mechanical Engineering-Engineering Mechanics

NASA Space Technology Research Fellowship: PhD Graduate Research - Mass Measurements of an Electrospray Beam from a Single Emitter Ionic Liquid Ferrofluid Electrospray Source.

Awarded Amount: $284,000