Initial Design and Simulation of the Attitude Determination and Control System for LightSail-1

This paper discusses the design and simulation of LightSail-1’s attitude determination and control system. LightSail-1 will launch in 2011 and deploy a 32 m2 mylar sail from a 3U CubeSat with the intent of measuring thrust from solar pressure and raising the orbit. The spacecraft will be actively controlled with magnetorquers and a momentum wheel. The various control modes throughout the short mission lifetime include detumble, sun-pointing, and orbit raising. Each one of these modes is simulated in MatLab, and the assumptions and limitations of the MatLab model are discussed. The simulations show that the spacecraft will detumble in 90 minutes after ejection from the P-POD and demonstrate successful sun-pointing within two orbit periods. Orbit raising will require two rapid 90° slew maneuvers every orbit which are accomplished with the momentum wheel

BioSentinel: Monitoring DNA Damage Repair Beyond Low Earth Orbit on a 6U Nanosatellite

We are designing and developing a 6U nanosatellite as a secondary payload to fly aboard NASAs Space Launch System (SLS) Exploration Mission (EM) 1, scheduled for launch in late 2017. For the first time in over forty years, direct experimental data from biological studies beyond low Earth orbit (LEO) will be obtained during BioSentinels 12- to 18-month mission. BioSentinel will measure the damage and repair of DNA in a biological organism and allow us to compare that to information from onboard physical radiation sensors. This data will be available for validation of existing models and for extrapolation to humans.The BioSentinel experiment will use the organism Saccharomyces cerevisiae (yeast) to report DNA double-strand-break (DSB) events that result from space radiation. DSB repair exhibits striking conservation of repair proteins from yeast to humans. The flight strain will include engineered genetic defects that prevent growth and division until a radiation-induced DSB activates the yeasts DNA repair mechanisms. The triggered culture growth and metabolic activity directly indicate a DSB and its repair. The yeast will be carried in the dry state in independent microwells with support electronics. The measurement subsystem will sequentially activate and monitor wells, optically tracking cell growth and metabolism. BioSentinel will also include TimePix radiation sensors implemented by JSCs RadWorks group. Dose and Linear Energy Transfer (LET) data will be compared directly to the rate of DSB-and-repair events measured by the S. cerevisiae biosentinels. BioSentinel will mature nanosatellite technologies to include: deep space communications and navigation, autonomous attitude control and momentum management, and micropropulsion systems to provide an adaptable nanosatellite platform for deep space uses

BioSentinel: DNA Damage-and-Repair Experiment Beyond Low Earth Orbit

No abstract availabl