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Terry Stevenson

Publications and source records attributed to Terry Stevenson.

6 records
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Biosentinel: Mission Summary and Lessons Learned From the First Deep Space Biology CubeSat Mission

Launched on Artemis-1, BioSentinel carries a biology experiment into deep space for the first time in 50 years. A 6U CubeSat form factor was utilized for the spacecraft which included technologies newly developed or adapted for operations beyond Earth orbit. The spacecraft carries onboard budding yeast, Saccharomyces cerevisiae, as an analog to human cells to test the biological response to deep space radiation. This was the maiden deep-space voyage for many of the subsystems, and the first time to evaluate their performance in flight operation. Flying a CubeSat beyond LEO comes with unique challenges with respect to trajectory uncertainty and mission operations planning. The nominal plan was a lunar fly-by, followed by an insertion into Heliocentric orbit. However, some possible scenarios included lunar eclipses that could have severely impacted the power budget during that phase of the mission, while others could have resulted in a “Retrograde” hyperbola at swing-by resulting in the spacecraft traveling inward toward Earth or even towards a collision with the lunar surface. The commissioning phase of the mission was successful and completed a week ahead of schedule. It did not come without its exciting moments and challenges. First contact with the spacecraft uncovered that the vehicle was unexpectedly tumbling after deployment, a situation that needed to be corrected urgently. The mission operations team executed a contingency plan to stabilize the spacecraft, with just moments to spare before the battery ran out of power. The BioSensor payload onboard the spacecraft is a complex instrument that includes microfluidics, fluid systems, sensor control electronics, as well at the living yeast cells. BioSentinel also included a TimePix radiation sensor implemented by JSC’s RadWorks group. Dose and Linear Energy Transfer (LET) data is compared directly to the rate of DSB-and repair events measured by the S. cerevisiae cells. BioSentinel mature nanosatellite technologies included: deep space communications and navigation, autonomous attitude control and momentum management, and micro-propulsion systems, to provide an adaptable nanosatellite platform for deep space uses. This paper discusses the performance of the BioSentinel spacecraft through the mission phase, and includes lessons learned from challenges and anomalies. BioSentinel had many successes and will be a pathfinder for future deep space CubeSats and biology missions.

BioSentinel↗
NASA NTRSDate not supplied

Biosentinel: The First Deep Space Biology CubeSat Mission- Mission Summary and Lessons Learned

Launched on Artemis-1, BioSentinel carries a biology experiment into deep space for the first time in 50 years. A 6U CubeSat form factor was utilized for the spacecraft which included technologies newly developed or adapted for operations beyond Earth orbit. The spacecraft carries onboard budding yeast, Saccharomyces cerevisiae, as an analog to human cells to test the biological response to deep space radiation. This was the maiden deep-space voyage for many of the subsystems, and the first time to evaluate their performance in flight operation. Flying a CubeSat beyond LEO comes with unique challenges with respect to trajectory uncertainty and mission operations planning. The nominal plan was a lunar fly-by, followed by an insertion into Heliocentric orbit. However, some possible scenarios included lunar eclipses that could have severely impacted the power budget during that phase of the mission, while others could have resulted in a “Retrograde” hyperbola at swing-by resulting in the spacecraft traveling inward toward Earth or even towards a collision with the lunar surface. The commissioning phase of the mission was successful and completed a week ahead of schedule. It did not come without its exciting moments and challenges. First contact with the spacecraft uncovered that the vehicle was unexpectedly tumbling after deployment, a situation that needed to be corrected urgently. The mission operations team executed a contingency plan to stabilize the spacecraft, with just moments to spare before the battery ran out of power. The BioSensor payload onboard the spacecraft is a complex instrument that includes microfluidics, fluid systems, sensor control electronics, as well at the living yeast cells. BioSentinel also included a TimePix radiation sensor implemented by JSC’s RadWorks group. Dose and Linear Energy Transfer (LET) data is compared directly to the rate of DSB-and repair events measured by the S. cerevisiae cells. BioSentinel mature nanosatellite technologies included: deep space communications and navigation, autonomous attitude control and momentum management, and micro-propulsion systems, to provide an adaptable nanosatellite platform for deep space uses. This paper discusses the performance of the BioSentinel spacecraft through the mission phase, and includes lessons learned from challenges and anomalies. BioSentinel had many successes and will be a pathfinder for future deep space CubeSats and biology missions.

BioSentinel↗
NASA NTRSDate not supplied

Flight Experience and Lessons Learned From Biosentinel: A 6u Deep Space Cubesat

This paper reviews the flight experiences of the BioSentinel propulsion and At-titude Determination and Control System (ADCS) teams. BioSentinel, a 6U CubeSat, launched as a secondary aboard the Space Launch System (SLS) maid-en flight in November of 2022 and is now operating in an Earth trailing helio-centric orbit. The development and performance of a novel approach to gyro bias estimation in the spacecraft’s Sun safe controller is discussed in detail. Further-more, the development and in-flight experience with the spacecraft’s propulsion system is discussed. Finally, we present the development and execution of an angular momentum management approach developed in flight after a propulsion system valve failure.

BioSentinel↗
NASA NTRSDate not supplied

Flight Experience and Lessons Learned from BioSentinel: A 6U Deep Space CubeSat

This presentation reviews the flight experiences of the BioSentinel propulsion and At-titude Determination and Control System (ADCS) teams. BioSentinel, a 6U CubeSat, launched as a secondary aboard the Space Launch System (SLS) maid-en flight in November of 2022 and is now operating in an Earth trailing helio-centric orbit. The development and performance of a novel approach to gyro bias estimation in the spacecraft’s Sun safe controller is discussed in detail. Further-more, the development and in-flight experience with the spacecraft’s propulsion system is discussed. Finally, we present the development and execution of an angular momentum management approach developed in flight after a propulsion system valve failure.

Jesse Fusco↗
NASA NTRSDate not supplied

Flight Results and Lessons Learned from the Starling Propulsion System

NASA’s Starling mission is a swarm of four 6U Cubesats flying in formation in Low Earth Orbit to demonstrate scalable swarm technologies, particularly related to crosslink networking. In order to maintain and modify their formation, the Starling spacecraft use a cold gas propulsion system called Hamlet, which provides each spacecraft with 30 m/s of delta-V, as well as attitude control during maneuvers. Hamlet is a fully self-contained system, incorporating propellant tanks, valves, nozzles, and control electronics. Most of the structure of Hamlet is a single piece of stereolithography-printed composite, which simplifies assembly and allows for unusual tank geometry that maximizes propellant volume in the allocated space. An extensive qualification campaign was conducted for Hamlet, including performance characterization that has been largely validated by in-flight measurements. Since the start of nominal mission operations in late summer 2023, Hamlet has conducted weekly or bi-weekly maneuvers of up to 0.29 m/s to assemble the swarm, maintain formation, and change swarm configurations as required by the experiments. Operations have not been without challenges, including a propellant leak on one unit and thrust variability issues on all four. This paper describes the design and implementation of Hamlet, as well as in-flight performance data, anomaly investigation and resolution, and lessons learned.

Starling↗