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Purdue University — Steven Collicott Zero-Gravity Slosh Cluster

Last updated: Session 66, 2026-04-07

Summary

Steven Collicott at Purdue has 15 FO projects (13 as PI, 2 as co-I) — by far the highest FO involvement by any single PI in the portfolio. His zero-gravity fluid dynamics research spans 30+ years (since 1991) and focuses on propellant slosh behavior in spacecraft tanks. He flew an FO-funded experiment on Virgin Galactic Galactic 07 (June 8, 2024 — the last VSS Unity commercial flight), and is now crew on "Purdue 1", an all-Boilermaker Virgin Galactic suborbital mission scheduled for 2027. His AAE 418 course ("Zero Gravity Flight Experiments") puts ~10 students per semester on parabolic flights.

Archetype: "FO Knowledge Payload" — pure science and educational pipeline, no commercial outcome. But the upcoming crewed spaceflight makes this story unique.

Session 20 correction: Discovered 6 additional Collicott PI projects from earlier FO periods, raising total from 9 to 15. Collicott's FO arc spans from 2013 to present — a 13-year continuous research program.

FO Projects

# Project Title TRL Role Period
1 106651 Spacecraft Pointing Control and Zero-Gravity Slosh 4→5 PI 2019-10 to 2025-01
2 106602 Nucleation of Cryogenic Bubbles in Spacecraft LADs 7→7 PI 2021-03 to 2026-02
3 106630 Zero-g Slosh Model Technology 4→6 PI 2019-01 to 2025-01
4 106718 Green Propellant Zero-G Control Methods 4→5 PI 2022-03 to 2026-12
5 106637 FEMTA Micropropulsion System 4→6 Co-I 2019-01 to 2025-01
6 106655 Medical Suction + Surgical Facility 4→6 Co-I 2021-01 to 2024-12
7 106664 Lander Plume-Structure Heat Transfer Monitoring 4→6 PI 2021-01 to 2025-10
8 106582 Cryogenic Gauging Technology Geometry Development 4→6 PI 2018-01 to 2020-04
9 91665 Low-Gravity Flow Boiling on Modern Textured Surfaces 4→5 PI 2015-04 to 2017-08
10 89309 Zero-g Condensation Droplets and Flow in Phase-Change Loops 4→6 PI 2016-09 to 2019-05
11 91656 Zero-gravity Green Propellant Management Technology 4→5 PI 2018-01 to 2019-10
12 91657 Advancing Diaphragm Modeling for Propellant Management 4→6 PI 2015-07 to 2017-08
13 106643 Automated Control of Hi-Def Video Systems (Suborbital) 4→6 PI 2020-12 to 2023-12
14 106672 Small-Sat Propellant Management Technology 4→6 PI 2020-10 to 2023-09
15 91424 Stratospheric Parabolic Flight Technology 4→5 PI 2013-05 to 2018-04

Total: 15 FO projects (13 PI + 2 co-I). (Session 20: discovered 6 additional PI projects spanning 2013-2023)

Note: [106582] explicitly describes work supporting GRC's RFMG orbital demo [12177] — Collicott provided Surface Evolver low-gravity fluid modeling for the RF mass gauge. This connects his work directly to the GRC cryogenic arc.

Note: [106602] has TRL 7→7 (no advance) because it's a "Knowledge Payload" — the purpose is gathering data to resolve questions from a prior ISS experiment, not advancing the technology itself.

Technology

Propellant Slosh in Zero Gravity

When a spacecraft rotates (e.g., to dock at a station), liquid propellant in its tanks sloshes. In 1-g, slosh behavior is well understood. In zero-g, surface tension dominates and the liquid can unexpectedly climb tank walls, form bridges, or oscillate in ways that affect spacecraft pointing accuracy and propellant delivery.

Collicott's research measures: - Loads on propellant tanks (liquid pressure, viscous shear) during and after maneuvers - Non-linear contact line motion in zero-g - How hydrophobic vs. hydrophilic tank surfaces affect slosh damping - Cryogenic bubble nucleation in liquid acquisition devices (LADs) — critical for Artemis cryogenic propellant transfer

Connection to ISS

[106602] directly extends an ISS experiment that found unexpected vapor bubble creation during tank depressurization. The FO parabolic flights explore the thermodynamic states that caused this anomaly — providing ground truth data for ISS results.

Downstream Impact

Virgin Galactic Galactic 07 (confirmed)

Collicott's "Rotational Slosh" experiment flew on Galactic 07 (June 8, 2024) — the last commercial flight of VSS Unity. The experiment was fully automated: accelerometers detected rocket ignition and initiated rotation of transparent fuel tank models, while cameras recorded liquid behavior in microgravity. This was funded through NASA FO.

Purdue 1 Mission (confirmed, planned 2027)

An all-Boilermaker crew of 5 will fly on Virgin Galactic's next-generation Delta-class spacecraft: - Steven Collicott — PI, liquid spreading experiment (how liquids spread over surfaces in zero-g) - Abigail Mizzi — grad student, rotational slosh experiment (liquid oscillation in zero-g) - Jason Williamson — alumnus - Two additional alumni (TBD)

Virgin Galactic will remove one seat to accommodate a research payload rack. Two onboard experiments will be monitored in real time by the crew. Delta-class spacecraft expected to enter service in 2026.

Session 47 update — mission scope expanded (Apr 2026): Purdue announced two additional autonomous locker experiments joining the mission: - In-space chip manufacturing — semiconductor fabrication in microgravity - Quantum technology experiment

These autonomous payloads ride in research lockers on the payload rack, operating without crew interaction. The expansion from 2 crew-tended experiments to 4 total (2 crew + 2 autonomous) makes Purdue 1 a more comprehensive research mission than originally scoped. This is a direct continuation of the FO-funded slosh research program.

Session 66 update — Virgin Galactic Delta status (Apr 2026): Delta-class structural assembly nearing completion. Ground testing beginning April 2026. First spaceflight targeted Q4 2026, with commercial research flights to follow. Private astronaut flights (including Purdue 1) 6-8 weeks after research flights — consistent with 2027 timeline. Delta-class carries 6 passengers (2 more than Unity), with one seat removed for Purdue research payload rack. Ticket price: $750,000. Collicott's seat paid by NASA through FO.

Educational Pipeline (confirmed)

AAE 418: Zero Gravity Flight Experiments — Offered fall, spring, and summer at Purdue. ~10 students per semester since 2019. Students design, build, and fly zero-g experiments on parabolic flights. This is one of the most active FO educational programs in the country.

Scientific Foundation

Collicott's slosh data feeds directly into spacecraft propellant tank design — both for NASA programs (Artemis cryogenic transfer) and commercial spacecraft. The data validates computational fluid dynamics models used by tank designers. No commercial product or spinoff, but the science is used by the broader space industry.

PI Profile

Steven H. Collicott — Professor, Purdue School of Aeronautics and Astronautics since 1991. PhD from Stanford. Research: low-gravity fluid dynamics, capillary surfaces, spacecraft propellant management. Advocacy for commercial suborbital spaceflight as a research platform. He has personally flown research experiments on both Virgin Galactic and parabolic flight campaigns.

Significance

Archetype: FO Knowledge Payload — PI as Platform User — Collicott's pattern is distinct from technology maturation. He's not developing a product or advancing a TRL toward deployment. He's using FO as a research platform to gather fundamental data about fluid behavior that informs spacecraft design across the industry.

FO → crewed spaceflight is unique. No other FO PI is known to be transitioning from FO-funded parabolic experiments to personally flying as crew on a suborbital mission. The Purdue 1 mission represents an extension of the FO research paradigm — same PI, same experiments, higher-fidelity environment.

Highest PI involvement in FO — by a wide margin. 15 projects is roughly double the next-highest PI count (Crosby at Carthage with 9). Collicott spans slosh, cryogenics, green propellants, condensation, diaphragm modeling, video systems, conformal tanks, and stratospheric parabolic flight. FO is the backbone of his research program.

The educational pipeline is the real output. Dozens of Purdue students have gained hands-on experience with zero-g experiments through Collicott's course. This workforce development is invisible in TRL metrics but significant for the space industry.

Surprise level: MEDIUM-HIGH — Expected a prolific academic with no commercial outcome. The Virgin Galactic Galactic 07 flight and upcoming Purdue 1 crewed mission were unexpected findings. The scale of the educational pipeline (10 students/semester, 3 semesters/year) was also larger than expected.

Verification

  • Sample size: 15 FO projects, 1 PI
  • Queries: techport_get_project batch [106651, 106602, 106630, 89309, 91656, 91657, 106643, 106672, 91424]; web search "Steven Collicott Purdue zero-gravity slosh"; web search "Purdue 1 Virgin Galactic 2027"
  • Evidence: Purdue newsroom (Galactic 07 experiment, Sep 2024); Virgin Galactic press release (Purdue 1, Sep 2025); Purdue AAE faculty profile; AAE Aerogram 2024-2025 article; Purdue course catalog (AAE 418)
  • Counter-query: Has Collicott's slosh research led to any commercial product or specific NASA mission design change? No specific citation found — the data feeds general propellant management models.
  • Confidence: Confirmed for FO involvement and Virgin Galactic connections; suggestive for scientific impact on spacecraft design

Cross-References