Verification of the Effectiveness of Devices for the Protection of the Exterior Surface of ISS from Contaminants Deposited by Pulsed Cycling of Liquid-Jet (Kromka) - 10.25.17

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

ISS Science for Everyone

Science Objectives for Everyone
Kromka investigates the contamination of critical external surfaces (such as radiators, solar arrays, etc) caused by propulsion thrusters of the various vehicles flying to the ISS and is assessing the efficiency of various gas-dynamic protective devices to minimize thruster contamination.
Science Results for Everyone
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The following content was provided by Yu I. Gerasimov, and is maintained in a database by the ISS Program Science Office.
Experiment Details

OpNom:

Principal Investigator(s)
Yu I. Gerasimov, Keldysh Research Center, Russia

Co-Investigator(s)/Collaborator(s)
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Developer(s)
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Sponsoring Space Agency
Russian Federal Space Agency (Roscosmos)

Sponsoring Organization
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Research Benefits
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ISS Expedition Duration
August 2001 - December 2002; November 2002 - May 2003; April 2003 - September 2006

Expeditions Assigned
3,4,5,6,7,8,9,10,11,12,13

Previous Missions
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Experiment Description

Research Overview
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Description
Checkout of the efficiency of operation of gas-dynamic protective devices accommodated on the Service module and designed to protect the ISS surfaces against contaminants produced by pulse activation of control liquid-jet thrusters. Study of the effect of contaminants deposition on the characteristics of materials specimens and external coatings of the ISS elements (radiators, solar array panels, etc.).

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Applications

Space Applications
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Earth Applications
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Operations

Operational Requirements and Protocols
Boards with materials specimens.
Installation of boards with materials specimens on the external surface of the Zvezda Service module (SM) of the ISS RS in the periphery area of the jet of the thrusters nozzles during extravehicular activity. Passive exposure of the boards on the SM external surface. Dismounting of the boards after long-duration exposure during extravehicular activity and their return to the ground for processing of the experiment results.

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Decadal Survey Recommendations

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Results/More Information

The studies included analysis of the chemical composition of fuel/oxidizer reaction products (FORP), visual and instrument-aided analysis of the composition of FORP deposits samples, analysis of the changes of sample optical characteristics, and densitometry of the images of control tablets. Using a specially developed procedure, the balance between the mass of deposited and vaporized FORP was determined. It was established that a deflector effectively limits the contamination area from roll thrusters with an angle of ~45°, thus preventing contamination of structural elements of the ISS Service module. Based on the study results, an angular distribution of FORP in the plume was obtained and used to calculate the predicted contaminating effect of ISS Service module roll thrusters on structural elements and exterior surfaces. During the 4 stages of the Kromka space experiment, the assumptions on the mechanisms of FORP emissions from attitude thruster nozzles into the surrounding area were confirmed, which were determined based on the results of experiments in pressure chambers using actual thrusters and simulated nozzles.

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Results Publications

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Ground Based Results Publications

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ISS Patents

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Related Publications

    Rebrov SG.  The Contamination Impact on Spacecraft of Control Liquid-propellant Low-thrust jets Using Nitrogen Tetroxide and UDMH Components. 3rd International Conference on Small Satellites, Korolev, Russia; 2002

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Related Websites
Energia - Science Research on the ISS Russian Segment

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Imagery

image One of the specimen boards.
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