Space Debris Sensor (Space Debris Sensor) - 09.19.18

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ISS Science for Everyone

Science Objectives for Everyone
Space Debris Sensor is a calibrated impact sensor mounted on the exterior of the International Space Station (ISS) that monitors impacts caused by small-scale space debris for a period of two to three years. The sensor records the time and scale of impacts from relatively small space particles using dual-layer thin films, an acoustic sensor system, a resistive grid sensor system, and a sensored-embedded backstop. Data provided by the Space Debris Sensor improves ISS safety by monitoring the risks and generating more accurate estimates of how much small-scale debris exists in space.
Science Results for Everyone
Information Pending

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

OpNom: Space Debris Sensor

Principal Investigator(s)
Joseph Hamilton, NASA Johnson Space Center, Houston, TX, United States

J.-C. Liou, Ph.D, NASA Johnson Space Center, Houston, TX, United States
Robert Corsaro, Waldorf, MD, United States
Frank Giovane, Lottsville, VA, United States
Mark Burchell, Ph.D., University of Kent, Canterbury, England

NASA Johnson Space Center, Houston, TX, United States

Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
Technology Demonstration Office (TDO)

Research Benefits
Space Exploration

ISS Expedition Duration
September 2017 - February 2018; October 2018 - April 2019

Expeditions Assigned

Previous Missions
Information Pending

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Experiment Description

Research Overview

  • Space Debris Sensor is needed because orbital debris impacts to the International Space Station (ISS) represent a significant risk to human life and critical hardware. Ground-based radars or telescopes only measure a subset of the debris environment. The main objective of Space Debris Sensor is to improve the situational awareness of the Micro Meteoroid Orbital Debris (MMOD) environment by accurately measuring the sub-millimeter region in order to provide reliable MMOD impact risk assessments for critical U.S. space assets.
  • It is worth noting that very little data on millimeter-and-smaller debris since Shuttle retirement in 2011 have been collected and the new Orbit Debris Engineering Model (ORDEM 3.0) predictions indicate that the ISS pressurized module perforation risk is driven by steel debris approximately 1 to 1.5 mm in size. This investigation improves ORDEM as well as Probabilistic Risk Assessments (PRA) and safety analysis.
  • Additional objectives of the Space Debris Sensor are to define accurate spacecraft shielding requirements to enable mass effective impact shielding design for future spacecraft constructions.
  • The Space Debris Sensor allows testing of the Debris Resistive/Acoustic Grid Orbital NASA-Navy Sensor (DRAGONS) in a relevant environment. Extensive testing with ground assets are ready to take the next step.


The Space Debris Sensor is a calibrated impact sensor designed to directly measure the International Space Station (ISS) orbital debris environment. The sensor has about 1 m2 of detection area mounted at an external payload site facing the velocity vector to maximize detections. It combines observation techniques to measure the size, speed, direction, time, and energy of small debris impacting the sensor. The front layer of the Space Debris Sensor is a thin film of Kapton with acoustic sensors and a grid of resistive wires. These acoustic sensors measure the time and location of a penetrating impact, while a change in resistance on the grid when lines are broken provide a size estimate of the hole. The relationship between object size and hole size is determined by hypervelocity testing under controlled conditions at the White Sands Test Facility in New Mexico and at the University of Kent at Canterbury, UK.
Located 15 cm behind the first layer is a second thin layer of Kapton with acoustic sensors to measure the time and location of the second penetration. Velocity is determined by dividing the distance travelled between the first and second impact points by the time it took to travel that distance. An instrumented back layer stops the debris and measures the amount of energy in the collision. With energy (E) and velocity (v), solve for mass (m) in the equation: E = ½ mv2. Finally, the density of the object is estimated if the object volume is assumed to be about the same as a sphere with a diameter determined from the hole size. Density is an important feature of debris because an object made of steel (7.9 g/cc) does more damage than a similarly sized piece of aluminum (2.8 g/cc).
The SDS detects debris as small as 50 microns and collects statistics on objects below 1 mm. Results from this experiment update information previously obtained by inspecting hardware returned from space by the Space Shuttle. This flight demonstration also proves the viability of the technology for future missions at higher altitudes where risks from debris to spacecraft are greater than at the ISS altitude.

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Space Applications
Development of effective spacecraft shielding systems depends on accurate estimates for the abundance and size distribution of orbital debris. Space Debris Sensor provides important quantitative information, which can improve risk management for the growing number of Earth-orbiting missions.

Earth Applications
The Earth Application for this investigation has yet to be identified.

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Operational Requirements and Protocols
Space Debris Sensor automatically records data when an impact occurs. The data are sent to the ground for analysis to determine the speed, direction, size, and density of the object. This information is added to a database to gather statistics for the environment models.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Related Websites

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Graphic representation showing the Space Debris Sensor (SDS) mounted on the exterior of the Columbus module on the International Space Station. The SDS collects information on small orbital debris. Image courtesy of iGoal Animation/NASA.

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