SERVICE MODULE/MICRO-PARTICLES CAPTURER AND SPACE ENVIRONMENT EXPOSURE DEVICE
(SM/MPAC AND SEED), TWO INVESTIGATIONS
Research Area: Near-Earth Space Environment
Expedition(s): 3-11
Principal Investigator(s): ● Yugo Kimoto, PhD, Japan Aerospace Exploration Agency,
Tokyo, Japan
RESEARCH OBJECTIVES
The space environment can have very severe and complex effects on materials depending on
the orbit into which the spacecraft is placed. In low-Earth orbit, interaction with both high-
energy particles in space and the dominant neutral gas, atomic oxygen, causes performance
problems. The SM/MPAC and SEED experiment involves exposing materials to the space
environment, and returning them to Earth for analysis, in order to provide an understanding of
the effects of the space environment on materials.
EARTH BENEFIT
The MPAC investigation captures objects to determine the
existence of original extraterrestrial objects with unknown
mineralogical character. It can offer clues to help understand
what happened in the early stages of the birth of the solar
system.
The SEED investigation tests new materials to determine
survivability in the space environment.
SPACE BENEFIT
The MPAC investigation collects micro particle data, which
includes flux, size, energy, and components.
The SEED investigation examines the actual degradation data
for space material (polymeric materials, paint, adhesives,
bearings, compound material, etc.) from space radiation,
atomic oxygen, and from where UV is obtained. A considerable
improvement in developing space material protection
technology is expected.
RESULTS
SM/MPAC and SEED revealed the space environment and its effects after periods of 1, 2, and 4
years of space exposure in the same position.
Three identical Service
Module/Micro-Particles Capturer and
Space Environment Exposure Device
(SM/MPAC and SEED) components
were installed on the Russian
Service Module (SM), Zvezda in
October 2001. On August 26, 2002,
the first unit of SM/MPAC and SEED,
MPAC and SEED #1, was retrieved
by EVA after 315 days of in-orbit
exposure. Subsequently, MPAC and
SEED #2 was retrieved on February
26, 2004, (after 865 days) and MPAC
and SEED #3 on August 18, 2005
(after 1,403 days). JAXA image.