OSIRIS-REx Contamination Control Strategy and Implementation

TL;DR

This paper details OSIRIS-REx's contamination control strategy to ensure pristine asteroid samples, emphasizing cleanliness standards, contamination characterization, and collaborative implementation within schedule and budget constraints.

Contribution

It presents a comprehensive contamination control approach for OSIRIS-REx, linking cleanliness requirements to mission goals and operational practices.

Findings

Maintained sampler cleanliness at <180 ng/cm2 of amino acids and hydrazine.

Used witness materials to characterize contamination levels.

Achieved spacecraft cleanliness through interdisciplinary communication.

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.