Light Sources in Mars Simulation Chamber

Light Sources in Mars Simulation Chamber

Oriel® Light Sources in Mars Simulation Chamber

Scientists at the Kennedy Space Center, FL used Oriel® Light Sources in their Mars Simulation Chamber (MSC). The MSC was designed to accurately maintain the pressure (7 mb). temperature (-100 to +30 0C), atmospheric composition (pure CO2), and UV irradiation experienced at the Mars equator, under clear-sky conditions.1

Two Oriel 450 W Xenon Arc Lamp Systems delivered a simulated Mars environment to samples within the MSC via fiber optic cables, as shown in these figures.

two 450 W Xenon Sources used to stimulate the UV radiation experienced at the equator on Mars, under clear-sky conditions
Figure 1. Scientists at the Kennedy Space Center, FL used two Oriel® 450 W Xenon Sources to stimulate the UV radiation experienced at the equator on Mars, under clear-sky conditions. The sources are part of a Mars Simulation Chamber (MSC). This figure shows the two Oriel Sources (A) mounted on top of the Mars Simulation Chamber (MSC). Water filters (B) and 90° Beam Turning Assemblies (C) are mounted to the output of the sources.

The Experiment

The output from the Oriel® Sources first passed through 60 mm long Oriel Water Filters to remove the high-intensity mid-infrared (MIR) radiation; 1200 to 2500 nm radiation was attenuated. The reduction in MIR was required in order to prevent IR damage to the UV-transmitting fiber-optic bundles.

The Mars simulation chamber (MSC) was configured with a liquid-nitrogen cold-plate
Figure 2. The Mars simulation chamber (MSC) was configured with a liquid-nitrogen cold-plate. Carbon dioxide (CO2), N2, air, or Mars gas were supplied to the MSC via high-grade gas mixtures. Ozone produced by the Oriel Xenon Arc Sources was scrubbed by passing ozone-enriched cooling-air through charcoal filters (O3). A CCD camera mounted inside the MSC was used to view the UV-illuminated targets during each experiment. A water chiller supplied 15 °C water to Oriel Water Filters, mounted on the illuminator's output.

The attenuated radiation was then reflected off of an Oriel 90° Beam-turning Assembly, and focused onto the tops of two MSC bulkhead fittings. Each bulkhead fitting was configured with a 12.5 mm core UV-transmitting fiber optic bundle, which transmitted the simulated Mars spectrum across the pressure differential of the MSC. All optical elements in the Oriel Illumination Systems were fabricated from highly purified fused silica, to ensure UV transmittance down to 200 nm. Within the MSC, precisely aligned fiber-optic assemblies were used to deliver the simulated Mars-normal light spectrum onto biological specimens maintained within microbial holders.

This photograph shows the inside of the MSC; visible are eight microbial holders attached to the upper surface of the LN2 cold-plates
Figure 3. This photograph shows the inside of the MSC; visible are eight microbial holders attached to the upper surface of the LN2 cold-plates. The fiber optic bundles that distribute the Mars-normal UV irradiation are precisely held in place by aluminum scaffolding.
  1. Schuerger, A.C., Mancinelli, R.L., Kern, R.G., Rothschild, L.J., and McKay, C.P. 2003. Survival of endospores of Bacillus subtilis on spacecraft surfaces under simulated Martian environments: Implications for the forward contamination of Mars. Icarus 165:253-276.