Residual Momentum and Tank Dynamics in Microgravity Environment (Furphy) - 03.20.19

Overview | Description | Applications | Operations | Results | Publications | Imagery

ISS Science for Everyone

Science Objectives for Everyone
Residual Momentum and Tank Dynamics in Microgravity Environment (Furphy) tests the feasibility of transferring fluids in microgravity from a rigid tank to a flexible tank that launches collapsed and deploys as it is filled. By making it possible to fuel small satellites in orbit instead of prior to launch, potentially saving launch mass and volume, this capability supports future space exploration. This first microgravity test is performed aboard the space station to verify tank dynamics including slosh and retention of angular momentum.
Science Results for Everyone
Information Pending

The following content was provided by Daniel Faber, and is maintained in a database by the ISS Program Science Office.
Experiment Details

OpNom: Furphy

Principal Investigator(s)
Daniel Faber, Orbit Fab, Inc, Cupertino, CA, United States

Co-Investigator(s)/Collaborator(s)
Information Pending

Developer(s)
Orbit Fab, Inc., Cupertino, CA, United States

Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
National Laboratory (NL)

Research Benefits
Information Pending

ISS Expedition Duration
October 2018 - October 2019

Expeditions Assigned
57/58,59/60

Previous Missions
Information Pending

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Experiment Description

Research Overview

  • The Residual Momentum and Tank Dynamics in Microgravity Environment (Furphy) simulates a future capability to fuel small satellites in orbit instead of launching satellites with all the fuel required for the mission.
  • Creating a fueling station in orbit saves launch mass and volume for future satellite missions.
  • The Furphy payload demonstrates how fluid transfer between two tankards - one rigid and one a flexible deployable fuel tank, known as the FlexTankTM, are used to save additional volume for future satellites.
  • The Furphy is handled by the crew aboard the International Space Station (ISS) using water as the transfer fluid to prove the capabilities of the pump mechanics and the slosh dynamics of transferring fluid between two different tanks.

Description

Orbit Fab is building an in-orbit fuel supply business to improve satellite asset utilization, enabling new and improved space-based services for the benefit of consumers and businesses on Earth. Launching fuel tanks in the extra space on any launch vehicle requires integration into the launch preparation workflow, demanding minimum impact on the rocket including loads and dynamics. The Residual Momentum and Tank Dynamics in Microgravity Environment (Furphy) investigation aboard the International Space Station (ISS) verifies the tank dynamics, slosh and the retention of angular momentum.
 
Enabling the capabilities for satellites to take on fuel in orbit may save on launch mass and volume. Orbit Fab seeks to assist in making this solution a reality by employing a flexible tank that launches compressed and deploys as it is filled. Furphy aboard the ISS consists of a FlexTankTM prototype to measure dynamics critical to attitude control.
 
A rigid tanker the size of a 16U CubeSat, is filled with water and delivered to the ISS along with an empty and compressed toroidal FlexTankTM made from silicone elastomer. A crew member spins the tank at approximately 60rpm at an axis before bringing it to a stop as rapidly as possible. The crew member then releases it and allows it to move freely for 30 seconds. The tank is expected to restart its rotation due to the internal fluid’s movement. Sensors measure the accelerations of the chassis, which are compared to numerical models. The test is repeated twice on each of the three principal axes, and then repeated with five different water levels in the tank; full, 3⁄4, 1⁄2, 1⁄4, and empty. After each test, the water is transferred from the tanker to the FlexTankTM to test the pumping system.

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Applications

Space Applications
Fuel tanks on launch vehicles require integration into the launch preparation workflow and affect rocket loads and dynamics. The ability to fuel satellites in orbit could save mass and volume for future launches. This investigation advances this capability by testing transfer of a liquid to a flexible tank that launches compressed and deploys as it is filled.

Earth Applications
A flexible fuel tank has potential applications on Earth, including supporting operations in remote and harsh environments and in disaster relief. Improved understanding of fluid transfer between a rigid and flexible fuel tank supports development of these applications.

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Operations

Operational Requirements and Protocols
The Furphy Technical Demonstration is conducted aboard the ISS using two main hardware components - a rigid tanker filled with water and a flex tank that demonstrates future fuel tank capabilities. The crew connects the two tanks on-orbit using an embedded magnetic coupler, spins the tanks to test the fluid dynamics, and then transfers the water from the rigid tank to the flex tank to test the pump system. Data is collected on Secure Digital (SD) cards during all stages of the experiment. The investigation validates all components of the two-tank transfer system and enables Orbit Fab to proceed on the next stage of development with confidence. At the end of the test, the water is offloaded back to the station water supply. All hardware is returned to Earth after the mission is completed.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Related Websites
Orbit Fab, Inc.

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Imagery

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Furphy's FlexTank computer interface.

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