SABL – An EXPRESS locker-sized incubator for performing biological experiments onboard the ISS

摘要

The Space Automated Bioproduct Lab (SABL) is an EXPRESS locker-sized incubatordeveloped by BioServe Space Technologies for use on the International Space Station (ISS).SABL provides a 41.9 x 27.9 x 19.4 cm (16.6'' x 11.1'' x 7.8'', DxWxH) sized science researchmodule (SRM) volume, which can be temperature-controlled from -5 to +43 °C. SABLimproves over the Commercial Generic Bioprocessing Apparatus (CGBA) in several aspectsincluding higher thermal ramp rate, lower thermal gradients, enhanced experiment control,software adaptability, and crew interaction. SABL is designed to accommodate a variety ofexisting legacy life sciences hardware that was previously used with CGBA, enabling SABLto function as a flexible lab for biological experiments in microgravity. This paper focuses onthe thermal design of the payload as well as on the verification testing of the engineeringunit. The design process for SABL focused on minimizing thermal gradients within the SRMvolume, improving thermal ramp rates between temperature set points, and eliminating theusage of forward facing cabin air exhaust systems that produce unacceptable acoustic noise.Temperature control of the SRM is accomplished using a total of four thermoelectric coolers(TECs) mounted to the top and bottom surfaces of the SRM. SABL utilizes the EXPRESSModerate Temperature Loop (MTL) as a thermal sink for the TECs and avionics. Thermalfeedback control and safety monitoring is implemented using a suite of sensors that interfaceto an NI sbRIO-9636 data acquisition and control computer. Performance of the engineeringunit was characterized to verify thermal models of operation, cooling/heating times, androbustness against uneven internal heat loads and off-nominal operation. After startingdevelopment in 2011, the first two SABL units are manifested to launch to the ISS onboardSpaceX CRS-8 in the fall of 2015.