Person:

Lightsey, E. Glenn

Permanent Link

https://hdl.handle.net/1853/71462

Associated Organization(s)

Organizational Unit

Daniel Guggenheim School of Aerospace Engineering

Organizational Unit

Space Systems Design Laboratory (SSDL)

Full item page

Publication Search Results

Now showing 1 - 10 of 34

Development of an Autonomous Distributed Fault Management Architecture for Spacecraft Formations Involving Proximity Operations

(Georgia Institute of Technology, 2023-08) Paletta, Antoine ; Arunkumar, Ebenezer ; Lightsey, E. Glenn

CubeSat formations have been identified as a new paradigm for addressing important science questions but are often early adopters of new technologies which carry additional risks. When these missions involve proximity operations, novel fault management architectures are needed to handle these risks. Building on established methods, this paper presents one such architecture that involves a passively safe relative orbit design, interchangeable chief-deputy roles, a formation level fault diagnosis scheme, and an autonomous multi-agent fault handling strategy. The primary focus is to enable the reliable detection of faults occurring on any formation member in real time and the autonomous decision making needed to resolve them while keeping the formation safe from an inter-satellite collision. The NSF-sponsored Virtual Super-resolution Optics with Reconfigurable Swarms (VISORS) mission, which consists of two 6U CubeSats flying in formation 40 meters apart as a distributed solar telescope, is used as a case study for the application of this architecture. The underlying fault analysis, formulation of key elements of the fault detection and response strategies, and the flight software implementation for VISORS are discussed in the paper.
Design of the Hosted Software Application for the VISORS Mission

(Georgia Institute of Technology, 2023-08) Arunkumar, Ebenezer ; Paletta, Antoine ; Lightsey, E. Glenn

The VIrtual Super Optics Reconfigurable Swarm (VISORS) mission is a distributed space telescope consisting of two 6U CubeSats that utilize precision formation flying to detect and study the fundamental energy release regions of the solar corona. The inherent complexities and risks associated with two spacecraft operating in close proximity, as well as the unique restrictions of the spacecrafts’ design, make careful autonomous execution crucial to the success of the mission. To address these challenges, this paper outlines the development of the Hosted Software Application (HSA) flight software which manages the Guidance, Navigation, and Control (GNC) algorithms, the payload finite state machine, and the spacecraft and formation level fault management system. An overview of the HSA provides context for the motivation and requirements driving the design of the flight software system. The architecture of the HSA is presented and shown to be derived from the Mission Events Timeline (MET) for each of the relevant phases of the mission. Finally, this paper briefly discusses the software's implementation and test campaign.
The Journey Of The Lunar Flashlight Propulsion System From Launch Through End Of Mission

(Georgia Institute of Technology, 2023-08) Smith, Celeste R. ; Cheek, Nathan ; Burnside, Christopher ; Baker, John ; Adell, Philippe ; Picha, Frank ; Kowalkowski, Matthew ; Lightsey, E. Glenn

The Lunar Flashlight Propulsion System (LFPS) was developed as a technology demonstration to enable the Lunar Flashlight spacecraft to reach Lunar orbit and to desaturate onboard reaction wheels. While the system produced over 16 m/s of delta-v and successfully managed momentum, variable thrust performance, most likely due to debris in the propellant flow path, kept the spacecraft from reaching the Moon. This paper details the in-flight journey of the LFPS, highlighting both successes and challenges met throughout the mission, and provides lessons learned applicable to future CubeSat missions and additively manufactured propulsion systems.
Design to Delivery of Additively Manufactured Propulsion Systems for the SWARM-EX Mission

(Georgia Institute of Technology, 2023-08) Tong, Kevin ; Hart, Samuel T. ; Glaser, Mackenzie ; Wood, Samuel ; Hartigan, Mark C. ; Lightsey, E. Glenn

Recent progress in miniaturized spacecraft propulsion technology has allowed for the development of complex, multi-vehicle missions which enable the cost-effective realization of science goals that would previously have been prohibitively expensive. The upcoming NSF-funded Space Weather Atmospheric Reconfigurable Multiscale EXperiment (SWARM-EX) mission leverages these swarm techniques to demonstrate novel autonomous formation flying capabilities while characterizing the spatial and temporal variability of ion-neutral interactions in the Equatorial Ionization Anomaly and Equatorial Thermospheric Anomaly. SWARM-EX will fly a trio of 3U CubeSats in a variety of relative orbits with along-track separations ranging from 3 km to 1300 km. To achieve the required orbital variability, the mission uses a novel hybrid approach of differential drag and an onboard cold gas propulsion system. Mission requirements necessitate a propulsion system that provides each spacecraft with 15 m/s of ΔV and a maximum thrust greater than 5 mN in a volume of roughly 0.7U (7 cm x 10 cm x 10 cm). Unlike many other CubeSat-scale cold gas propulsion systems which are used to provide attitude control and perform reaction wheel desaturation burns, the primary objective of the SWARM-EX propulsion system (SEPS) is to provide ΔV during maneuvers. The Georgia Institute of Technology Space Systems Design Laboratory (SSDL) is conducting the design, assembly, and testing of three identical SEPS. By leveraging additive manufacturing technology, the propellant tanks, nozzle, and tubing are combined into a single structure that efficiently utilizes the allocated volume. The propulsion system uses two-phase R-236fa refrigerant as a propellant, which allows for the storage of the majority of propellant mass as a liquid to maximize volumetric efficiency. The final design allows for 17 m/s of total ΔV per spacecraft and a measured maximum thrust of approximately 35 mN for short pulse lengths at room temperature. Each individual propulsion system has a volume under 0.5U (489 cm3), making them among the smallest formation-flying CubeSat-scale propulsion systems developed thus far. Owing to their two-phase propellant storage and single nozzle, the SEPS have a high impulse density (total impulse provided per unit of system volume) of 176 N-s/L. Additionally, process improvements to mitigate known failure modes such as propellant leaks and foreign object debris are implemented. This paper describes the entire design-to-delivery life cycle of the SWARM-EX propulsion units, including pertinent mission requirements, propulsion system design methodologies, assembly, and testing. Major lessons learned for future small satellite propulsive endeavors are also detailed.
Performance of a Model Predictive Control Based Autonomous Rendezvous and Docking Algorithm for CubeSats using Hardware Emulation

(Georgia Institute of Technology, 2023-02) Fear, Andrew J. ; Lightsey, E. Glenn

Hardware emulation of typical CubeSat flight computers is utilized to benchmark the performance of a three-phase Model Predictive Control (MPC) algorithm for autonomous rendezvous and docking (AR&D). The length of the MPC prediction horizons affects the computational complexity and therefore the solution time of finding an optimal control sequence. This study investigates the limitations, if any, of current state-of-the-art CubeSat flight systems regarding the ability to take advantage of this type of guidance algorithm. A virtual machine with an ARM processor typical of CubeSat available hardware is used to test the performance of the algorithm. Monte Carlo simulations are run to calculate the average computation time per optimal control solution and compare these values across varying prediction horizon lengths.
Recovery of a Lost Satellite: The ARMADILLO Mission

(Georgia Institute of Technology, 2022-08) McDonald, Dillan ; Lightsey, E. Glenn ; Peet, Sterling

After 949 days in space, contact with the ARMADILLO CubeSat from the University of Texas at Austin has been established. After a complete reconstruction of the ground command software, the Space System Design Laboratory (SSDL) at Georgia Tech has commanded and received acknowledgements and data downlinks from ARMADILLO as well as commanded a hard reset. The Georgia Tech Ground Station Network (GT GSN) has leveraged its autonomous contact capability to maintain consistent contact with ARMADILLO, enabling it to remain online for longer than a week. Something ARMADILLO had previously never accomplished due to the ground contact condition for onboard reset never being satisfied. This has prompted the development of a late-life commissioning plan that currently indicates that ARMADILLO has the potential to accomplish its original science goals.
Systems Integration and Test of the Lunar Flashlight Spacecraft

(Georgia Institute of Technology, 2022-08) Cheek, Nathan ; Gonzalez, Collin ; Adell, Philippe ; Baker, John ; Ryan, Chad ; Statham, Shannon ; Lightsey, E. Glenn ; Smith, Celeste R. R. ; Awald, Conner ; Ready, W. Jud

Lunar Flashlight is a 6U CubeSat launching in late 2022 or early 2023 that will search for surface water ice content in permanently shadowed regions at the south pole of the Moon using infrared relative reflectance spectroscopy. The mission will act as a technology demonstration of an Advanced Spacecraft Energetic Non- Toxic (ASCENT) green propulsion system and active laser spectroscopy within the CubeSat form-factor. This paper provides an overview of the entire Systems Integration and Test campaign which took place at the Jet Propulsion Laboratory and the Georgia Institute of Technology. From initial testing of the isolated avionics and payload subsystems to the final tests with a fully integrated spacecraft, the project’s integration and test campaign is reviewed, with a focus on lessons learned.
Development of a Lunar Mission Operations Center for the NASA JPL Lunar Flashlight Mission

(Georgia Institute of Technology, 2022-05-01) Medisetti, Jishnu ; Lightsey, E. Glenn

With advancements in small satellite technology being seen, these low cost, small form factor systems are being considered for interplanetary missions. NASA’s Jet Propulsion Laboratory’s (JPL) mission, Lunar Flashlight is a 6U CubeSat which aims to orbit the Lunar South pole and detect craters for water ice. This mission is a technology demonstration which hopes to prove the viability of low cost CubeSats for interplanetary missions. This low resource model for satellites extends to its mission operations as well. Georgia Institute of Technology’s Space System Design Laboratory has been contracted to perform mission operations for Lunar Flashlight. The operations team was able to develop and expand the capabilities Georgia Tech Mission Operations Center (MOC) to support this Lunar mission. Hardware integration was established to connect various operations machines to each other and the Deep Space Network. Interfaces were defined between the operations team and external parties including the Mission Design and Navigation team at JPL. Using the certified MOC, the operations team was also successfully able to perform and complete their first operational readiness test which simulated the first phase of the Lunar Flashlight mission.
Assembly Integration and Test of the Lunar Flashlight Propulsion System

(Georgia Institute of Technology, 2022-01) Smith, Celeste R. ; Littleton, Lacey M. ; Lightsey, E. Glenn ; Cavender, Daniel P.

The Lunar Flashlight Propulsion System (LFPS) was created to perform a Lunar Orbital Insertion maneuver for the Lunar Flashlight spacecraft so it can conduct its search for water in the lunar South Pole. The focus of this paper is on the late-stage design, integration, and test of the LFPS. The structure of the LFPS is 3D printed and further 3D printing was utilized to assist in the assembly process. The design will be reused to build a second unit and its heritage is already being leveraged on other early concept propulsion systems.
Lessons Learned from the GT-1 1U CubeSat Mission

(Georgia Institute of Technology, 2021-08) Kolhof, Maximilian ; Rawson, William ; Yanakieva, Radina ; Loomis, Andrew ; Lightsey, E. Glenn ; Peet, Sterling

With more universities conducting low-cost small satellite development programs, resources for students starting off in satellite design are essential to avoid common pitfalls. Hardware integration and testing of the GT-1 CubeSat revealed both design flaws and strengths that led to a comprehensive list of lessons learned applicable to future CubeSat missions at the Georgia Institute of Technology Space Systems Design Laboratory (SSDL) and within the broader academic community. GT-1 was originally slated to be designed, built, and delivered in nine months with an orbital lifespan of around seven months. However, various schedule delays resulted in the mission spanning over two years. This paper provides a resource to those beginning a small satellite development program at the university level by presenting a case study of lessons learned from the GT-1 mission. Detail will be provided for topics including best practices for enabling modular design, creating effective documentation, structural design for proper fit-up and manufacturability, testing, and planning a realistic mission scope.