EVALUATION OF CONTAMINATION CONTROL IN
HAYABUSAMISSION
BASEDON
INTIALDESCRIPTION DATA OF PARTICLES FROM ITSSAMPLE CATCHER.
T. Yada1, K. Kumagai1, M. Uesugi1, Y. Karouji1, Y. Ishibashi2,W. Satake3, A. Nakato1, T. Okada1, M. Abe1, and Hayabusa 2
Sampler Science Team. 1Inst. Space Astronaut. Sci., Japan
Aerosp. Explor. Agency. E-mail: yada@planeta.sci.isas.jaxa.jp.
2
Depart. Earth Planet. Sci., Grad. Sch. Sci., Kyushu Univ. 3
Nation. Museum Emerg. Sci. Innovat. , Japan.
Introduction: Hayabusa spacecraft returned its reentry
capsule from asteroid Itokawa in Jun. 2010 [1]. Particles fromasteroid Itokawa were identified in those recovered from its
sample catcher [e.g. 2], and initial description of particles
recovered from the sample catcher has been performed
continuously by Extraterrestrial Sample Curation Team(ESCuTe) of JAXA [3]. In order to understand the nature ofwhole the particles in the catcher and evaluate contamination
control of Hayabusa mission, we are now describing relatively
unbiased group of particles.
Samples and Methods: Hayabusa’s sample catcher consists
mainly of room A and B, and a rotational cylinder. The cover ofthe catcher room B can be separated from the catcher andobserved independently, thus we have developed a special holder
for field emission secondary electron microscope (FE-SEM) in
which the cover of room B can be set and introduced into FESEM to be observed directly. With this holder, we can map
whole the area of room B’s cover and describe all the particles on
it by energy dispersive X-ray spectrometer (EDS) equipped in
FE-SEM. With this method, we could expect relatively unbiaseddescriptions of particles in the sample catcher of Hayabusa.
Results: So far, one third of surface of the room B’s coverhas been mapped by the FE-SEM and a total number of theparticles larger than 15 µm reaches 990. 319 particles among
them are mainly composed of silicate, which are Itokawa origin.
Among the rest of them, 76 particles are mainly composed ofcarbon, and 459 are artificial materials whose sources areidentified. 136 of them are those whose origins are still unknown.
Discussion: Among two thirds of non-Itokawa particles, twothirds are artifitial materials whose sources are identified. For
example, half of them are flakes of aluminum which should havebeen come off from the inner surface of the sample catcher,because they are coated by pure aluminum. On the other hand,the origins of rest one third of them are still unknown. The
carbon-rich particles are now studied for their origins, still havenot been identified their origins [4]. Some particles are composed
only of metal like Ti, Zn and Fe, whose sources are still unknown,and others are only composed of NaCl or Ca phosphate, whichare not identified as terrestrial or extraterrestrial.
Actions taken by Hayabusa 2 mission: We took actions for
Hayabusa 2, the next sample return mission from asteroid. Inorder to exclude major contaminants, we avoided to coataluminum on inner surfaces of its sample catcher, just mirrorpolished them. And we have cleaned all the parts of its sample bycleaning procedures which had been checked its cleanliness level.
Additionally, we put contamination coupons all the environments
where its sampler had situated, and will analyze them for making
a list of possible contaminants to return samples.
References: [1] Abe M. et al. (2011) LPS XXXXII, #1638.
[2] Nakamura T. et al. (2011) Science 333, 1113. [3] Yada T. etal. (2013) Meteoritics Planet. Sci. 49, 135. [4] Uesugi M. et al.
(2014) Earth Planet Space, submitted