Nov 15, 2023

【Research Highlights】 A curation for uncontaminated Hayabusa2-returned samples in the extraterrestrial curation center of JAXA: from the beginning to present day

　In Hayabusa2, different from first Hayabusa mission, we prepared a mechanism that allows some of the samples to be separated and stored in a vacuum to avoid exposure to the Earth's nitrogen, as we will be handling materials returning from an asteroid rich in carbonaceous matter (Fig. 1). The jigs used for removing the samples from the sample catcher after shifting from a vacuum to a nitrogen environment, the instruments for handling the samples and the containers for storing the samples were also designed to minimize the risk of sample destruction or leakage (Fig. 2). In terms of contamination control, the environment of both the clean room and clean chamber is monitored every six months before and after the sample return, and the environment is less contaminated than the glove box used for curation at NASA's Johnson Space Center (Fig. 3). As a consideration against magnetic contamination of the samples, the parts in direct contact with the samples were also demagnetized. Furthermore, for the initial description of the samples in the catalogue, we prepared the instruments and attached chambers for optical microscopy, weighing, infrared spectroscopy (two instruments) and visible spectroscopy, based on the principle of non-contamination and non-destruction of the returned samples, and proceeded with the initial description after sample return.

Fig. 1 Conceptual diagram of the clean chamber for the Hayabusa 2 return samples. The sample container was opened in vacuum at CC3-1 and CC3-2 and some of the samples were removed. The sample catcher was then transferred to CC3-3 and then to a nitrogen environment, followed by sample recovery, handling and initial description for catalogue. Fig. 2 Photograph of vacuum tweezers for handling mm-sized samples. When the aluminum cap on the tip is removed, a stainless-steel tube is attached, and by drawing back pressure, particles can be adsorbed and moved without grabbing them. Fig. 3 Monitor values for organic compounds in the clean room and clean chamber for Hayabusa 2 return samples. In addition to organic compounds, monitor values for anions, cations and metal elements are also measured.

＜From the primary author – Dr. Yada＞
Based on the experience of the first Hayabusa mission, the non-destructive and non-contaminating return sample curation techniques (acceptance, catalogue, storage and distribution) achieved with the Hayabusa2 return samples are a valuable asset of our research group. We intend to further refine these techniques and experiences, and to move forward with sample curation for future sample return missions such as NASA's OSIRIS-REx and MMX missions.

Original article:

Journal：  Earth, Planets and Space
Title：  A curation for uncontaminated Hayabusa2-returned samples in the extraterrestrial curation center of JAXA: from the beginning to present day
Author：  Yada, T. et al.
DOI：  10.1186/s40623-023-01924-2
URL：  https://earth-planets-space.springeropen.com/articles/10.1186/s40623-023-01924-2
Published：  November 15, 2023