STUDY OF THE DYNAMICS OF CONTAMINATING SUBSTANCES EMISSION FROM
CONTROL LIQUID PROPELLANT LOW-THRUST JET ENGINES DURING THEIR PULSE FIRINGS AND
VERIFICATION OF THE EFFECTIVENESS OF DEFLECTORS FOR THE PROTECTION OF ISS EXTERNAL
SURFACES FROM FROM CONTAMINATION (KROMKA)
Research Area: Spacecraft Materials
Expedition(s): 3, 4, 5, 9, 11, and 13
Principal Investigator(s): ● Yuriy I. Gerasimov, S.P. Korolev Rocket and Space Corporation
Energia, Korolev, Russia, Keldysh Institute of Applied
Mathematics of the Russian Academy of Sciences, Moscow,
Russia
RESEARCH OBJECTIVES
Study of the Dynamics of Contaminating Substances Emission from Control Liquid Propellant
Low-Thrust Jet Engines during Their Pulse Firings and Verification of the Effectiveness of
Deflectors for the Protection of ISS External Surfaces from Contamination (Kromka) studies the
dynamics of contaminating substance emissions from control liquid propellant low-thrust jet
engines during their pulse firings and studies the verification of the effectiveness of devices for
the protection of ISS external surfaces from contamination.
SPACE BENEFITS
The introduction of deflectors on the control liquid
propellant low-thrust jets will significantly decrease the
deterioration of solar arrays, radiators, and other ISS
components by extending their on-orbit service lives, and
will decrease the risk of crewmembers’ spacesuit
contamination upon contact with surfaces during
extravehicular activity.
RESULTS
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
ISS005E05422 - Shows the location of the
Kromka tablet near the attitude and pitch
thrusters unit (view from DC1 window).