The Multi-specimen Variable-G Facility (MVF) is a single locker sized centrifuge facility for life and microgravity sciences research on the International Space Station. The MVF is a rear breather EXPRESS Rack payload that leverages many of the existing subsystems of flight proven (STS-108) Avian Development Facility (ADF) thereby reducing costs and time to flight for new scientific capability. Two centrifuge rotor platforms are capable of applying 02 g's to the modular specimen containers which can be modified to accommodate a wide variety of experiment samples. Curved cell culture specimen containers are designed to maintain a constant radius (within ? 1 mm) without inertial-gradient shearing or significant Coriolis acceleration. Each rotor can accommodate 10 generic modular experiment specimen holders which can be accessed in real-time on-orbit any time during an experiment. The centrifuge platforms include an active balancing system to ensure balanced rotation when the experiment sample modules contain slightly variable mass. The MVF will control g-levels, temperature, humidity, ethylene, CO2 and other gases, and provides video observation capability with its removable modular subsystem allowing on-orbit cleaning and/or replacement. The potential uses of the MVF are numerous, such as cell culture, aquatics, plants, algae, and invertebrate organisms. The modular multi-specimen holder can be utilized as a prokaryotic and eukaryotic cell culture vessel. It can be used to contain aquatic organisms such as Zebra fish, Medaka, tadpoles, and even developing amphibian eggs. Seedlings, small adult plants (Arabadopsis), and even fern spores could be located within the specimen holder. Other possibilities include Algae (Chara) and fungi (S. cerevisiae). During the Phase II project, Techshot will complete the MVF design, fabricate a flight-like prototype, and test the hardware by performing selected biological experiments to demonstrate its scientific utility.