NASA’s Europa Clipper mission will conduct a detailed reconnaissance of Jupiter’s moon Europa and investigate whether the icy moon could host conditions suitable for life. To perform these tasks, the spacecraft will carry several scientific instruments, including cameras, mass spectrometers, radars, magnetometers, plasma sensors and dust analyzer. These state-of-the-art instruments are very sensitive to molecular contamination; hence it is important to properly design preferential venting paths that minimize the transport of contaminants to the instruments sensitive surfaces. The JPL Contamination Control Group developed a physics-based approach to quantify the amount of contaminants escaping from the thermal blankets vents. This approach includes a thorough design of the thermal blankets and vents in the Europa Clipper geometrical model and a detailed analysis of the transport of contaminants from outgassing components underneath the thermal blankets to the vents. The physics-based thermal blankets venting model enhances the ability to assess and control outgassing contamination on Europa Clipper, and subsequently to properly design venting locations that provide a preferential escape path for outgassed molecules. The model also provides more accurate results compared to the historic approach (area ratio) widely used in literature to estimate outgassing from thermal blankets vents.
The Mars Helicopter, developed by the Jet Propulsion Laboratory and attached to the M2020 rover, aims to be the first aircraft to fly on another planet. It is a high-risk, high-reward project with the objective to prove that autonomous, controlled flight can be executed in the extremely thin Martian atmosphere. Testing the Helicopter on Earth required a vacuum chamber both capable of reaching Mars atmosphere conditions and large enough to accommodate the Helicopter’s test flights. The only available option was the JPL solar simulator, a 47’ tall, 25’ diameter vacuum chamber meant to provide environmental testing for JPL’s largest spacecraft. The solar simulator includes a 23’ diameter focusing mirror suspended 4 stories above ground level to direct energy onto spacecraft in the chamber. If this mirror is contaminated, JPL loses its capability to provide solar simulating capability to its largest spacecraft until the mirror is pulled down and carefully cleaned. The sensitivity of the solar simulator at JPL necessitates careful vetting of materials entering into the chamber. For most flight projects, the major assemblies entering the chamber are made of vacuum-compatible materials. The Mars Helicopter project constructed a wind tunnel in the solar simulator to provide airflow over the Helicopter engineering model in a Mars pressure environment. The wind-tunnel assembly was constructed from Commercial Off The Shelf (COTS) components without clear material documentation. The JPL Contamination Control group analyzed all major materials with Direct Analysis Real Time Mass Spectrometer (DART-MS), measured component outgassing after bakeout with a quartz crystal microbalance (QCMs), and estimated contamination impact to the solar simulator from the wind tunnel assembly. Contamination Control also implemented mitigation steps for COTS components, including material substitution, bakeouts, and cleaning. This approach overcame long-standing rules of thumb about the type of components that can enter the solar simulator, and can be used as an example when vetting COTS components for use in a vacuum environment with contamination sensitive surfaces.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.