Title: OSIRIS-REx Contamination Control Strategy and Implementation,
Abstract: OSIRIS-REx will return pristine samples of carbonaceous asteroid Bennu. This
article describes how pristine was defined based on expectations of Bennu and
on a realistic understanding of what is achievable with a constrained schedule
and budget, and how that definition flowed to requirements and implementation.
To return a pristine sample, the OSIRIS- REx spacecraft sampling hardware was
maintained at level 100 A/2 and <180 ng/cm2 of amino acids and hydrazine on the
sampler head through precision cleaning, control of materials, and vigilance.
Contamination is further characterized via witness material exposed to the
spacecraft assembly and testing environment as well as in space. This
characterization provided knowledge of the expected background and will be used
in conjunction with archived spacecraft components for comparison with the
samples when they are delivered to Earth for analysis. Most of all, the
cleanliness of the OSIRIS-REx spacecraft was achieved through communication
among scientists, engineers, managers, and technicians.