In addition, SM/MPAC and SEED discovered new extraterrestrial objects with a mineralogical
characteristic, which was named “Hoshi,” meaning “star” in Japanese. The object consists of a
micro-particle, the origin of which relates to interplanetary dust and micrometeorites. It is also
characterized by an unprecedented formation
and mineral composition and represents a
world-first discovery of this object.
SEED consists of 28 samples, in which the
actual degradation data of these materials
were acquired. In addition, analysis of AO
fluence samples indicated that substantial
contamination had occurred. The contaminant
was sufficiently extensive to protect the
surface of the AO fluence monitor sample from
erosion, while the wake samples and holders
were found to be uniformly covered with
molecular contamination and had numerous
colored spots. Surface analysis (X-ray
Photoelectron Spectroscopy [XPS] depth profiles) showed the contaminant thicknesses
depended on exposure duration.
PUBLICATION(S)
Kimoto Y, Ishizawa J, Shimamura H. Passive space environment effect measurement on
JEM/MPAC&SEED. Berlin: Protection of Materials and Structures From the Space Environment;
2013.
Miyazaki E, Kimoto Y, Yokota R. Flight experiment results of the polysiloxane-block-polyimide
BSF-30 on the JEM/MPAC&SEED mission on the ISS. Berlin: Protection of Materials and
Structures From the Space Environment; 2013.
Noguchi T, Nakamura T, Ushikubo T, et al. A chondrule-like object captured by space-exposed
aerogel on the international space station. Earth and Planetary Science Letters. 2011;309:198-
- doi: 10.1016/j.epsl.2011.06.032.
Edwards DL, Tighe AP, Van Eesbeck M, Kimoto Y, de Groh KK. Overview of the natural space
environment and ESA, JAXA, and NASA materials flight experiments. MRS Bulletin. January 31,
2010;35(1):25-34. doi: 10.1557/mrs2010.613.
Shimamura H, Nakamura T. Investigation of degradation mechanisms in mechanical properties
of polyimide films exposed to a low earth orbit environment. Polymer Degradation and
Stability. January 2010;95(1):21-33. doi: 10.1016/j.polymdegradstab.2009.10.017.
Kimoto Y, Ichikawa S, Miyazaki E, et al. Space environment effects on materials at different
positions and operational periods of ISS. Proceedings of the 9th International Conference:
Transmission electron microscope image (cross-
section) of Hoshi. JAXA image.