Bruce Yost

The O/OREOS Mission: First Science Data from the Space Environment Survivability of Living Organisms (SESLO) Payload

We report the first telemetered spaceflight science results from the orbiting Space Environment Survivability of Living Organisms (SESLO) experiment, executed by one of the two 10 cm cube-format payloads aboard the 5.5 kg Organism/Organic Exposure to Orbital Stresses (O/OREOS) free-flying nanosatellite. The O/OREOS spacecraft was launched successfully to a 72° inclination, 650 km Earth orbit on 19 November 2010. This satellite provides access to the radiation environment of space in relatively weak regions of Earths protective magnetosphere as it passes close to the north and south magnetic poles; the total dose rate is about 15 times that in the orbit of the International Space Station. The SESLO experiment measures the long-term survival, germination, and growth responses, including metabolic activity, of Bacillus subtilis spores exposed to the microgravity, ionizing radiation, and heavy-ion bombardment of its high-inclination orbit. Six microwells containing wild-type (168) and six more containing radiation-sensitive mutant (WN1087) strains of dried B. subtilis spores were rehydrated with nutrient medium after 14 days in space to allow the spores to germinate and grow. Similarly, the same distribution of organisms in a different set of microwells was rehydrated with nutrient medium after 97 days in space. The nutrient medium included the redox dye Alamar blue, which changes color in response to cellular metabolic activity. Three-color transmitted intensity measurements of all microwells were telemetered to Earth within days of each of the 48 h growth experiments. We report here on the evaluation and interpretation of these spaceflight data in comparison to delayed-synchronous laboratory ground control experiments.

The O/OREOS Mission: First Science Data from the Space Environment Viability of Organics (SEVO) Payload

We report the first science results from the Space Environment Viability of Organics (SEVO) payload aboard the Organism/Organic Exposure to Orbital Stresses (O/OREOS) free-flying nanosatellite, which completed its nominal spaceflight mission in May 2011 but continues to acquire data biweekly. The SEVO payload integrates a compact UV-visible-NIR spectrometer, utilizing the Sun as its light source, with a 24-cell sample carousel that houses four classes of vacuum-deposited organic thin films: polycyclic aromatic hydrocarbon (PAH), amino acid, metalloporphyrin, and quinone. The organic films are enclosed in hermetically sealed sample cells that contain one of four astrobiologically relevant microenvironments. Results are reported in this paper for the first 309 days of the mission, during which the samples were exposed for ∼2210 h to direct solar illumination (∼1080 kJ/cm(2) of solar energy over the 124-2600 nm range). Transmission spectra (200-1000 nm) were recorded for each film, at first daily and subsequently every 15 days, along with a solar spectrum and the dark response of the detector array. Results presented here include eight preflight and 16 in-flight spectra of eight SEVO sample cells. Spectra from the PAH thin film in a water-vapor-containing microenvironment indicate measurable change due to solar irradiation in orbit, while three other nominally water-free microenvironments show no appreciable change. The quinone anthrarufin showed high photostability and no significant spectroscopically measurable change in any of the four microenvironments during the same period. The SEVO experiment provides the first in situ real-time analysis of the photostability of organic compounds and biomarkers in orbit.

Small Spacecraft for Science and Exploration in NASA's Robotic Lunar Exploration Program

NASA’s Vision for Space Exploration (VSE) calls for returning humans to the Moon as preparation for the exploration of Mars and the solar system. Robotic precursor missions can and should play an important role in our plans for a permanent human presence on the Moon. Here we describe a rationale and methodology for the development of small, low-cost, high-heritage lunar orbiters capable of measurements relevant to both basic lunar science and VSE priorities. The use of small (<150 kg) spacecraft enables a multitude of primary and secondary launch opportunities, and many small satellite systems developed for terrestrial applications are also applicable to lunar exploration. We show an example of one such lunar mission, based on a medium-class explorer spacecraft bus, which has been fully studied and costed as a primary or secondary payload and is capable of carrying out high priority measurements of the lunar environment. In order for small spacecraft to work effectively as part of a larger lunar exploration architecture, their design would ideally evolve toward a common bus, thus enabling repeatable and reliable access to lunar orbit. We summarize these and other possibilities explored during a summer study program involving students and the NASA Ames Research Center small satellite program, where we show that important lunar science and exploration objectives can be obtained using small spacecraft and for under

The O/OREOS mission—Astrobiology in low Earth orbit

100M total cost.