Dr. Alan Stern (SwRI), Principal Investigator and Flight Experimeter
Dr. David C. Slater (SwRI), Co-Investigator and Project Manager
Dr. Daniel D. Durda (SwRI), Co-Investigator and Flight Experimenter
Michael E. Epperly (SwRI), Electrical Engineer and Flight Experimenter
Kelly D. Smith (SwRI), Lead Engineer
Dr. William R. Ward (SwRI), Co-Investigator
Dr. John Marshall (NASA Ames Research Center), Co-Investigator
Dr. Faith Vilas (NASA Johnson Space Center), Research Flight Program Sponser
Linda Bjork (SwRI), Engineer
Joe Esquivel (SwRI), Experiment Technition
OASIS (Orbital Accretion Science In Space) is a microgravity research experiment that we have flown aboard NASA's KC-135 Reduced Gravity Aircraft (the "Vomit Comet") in order to develop the design for experiments in the physics of the early stages of planetary accretion suitable for flight on the Space Shuttle and the International Space Station. 
OASIS builds upon a series of Space Shuttle experiments conducted in the early 1990s by scientists at NASA's Ames Research Center that were intended to examine the dynamics of granular particles in microgravity. Instead of the freely flowing collection of sand grains expected, those early experiments produced instead "dust bunny"-like masses of sand grains clustered together by electrostatic forces that are completely masked in the 1-g environment on the ground. These dust bunnies closely resemble the fluffy aggregates that are expected to have accreted in the early solar nebula and that eventually accreted into larger, planet-forming planetesimals. With OASIS, we are developing the techniques to reliably grow dust bunnies and collide them together at low speeds to study in microgravity the accretion of the building blocks of the planets.
OASIS is a rack mounted experiment that allows study of the preparation and launch of centimeter-sized dust aggregates ("dust-bunnies") into a simulated target in a microgravity environment. A minimum of two (preferably three) individuals operate the experiment during the flight test. The experiment consists of an enclosure that houses the sample dust material (500-micron diameter silica sand inside the material hopper section), a small linear actuator (the "projectile launcher"), a target disk of aluminum, lexan (polycarbonate) window ports and a 20-inch lexan flight tube to allow the video recording (via a small CCD camera attached to a window port) of the sample prep and launch phases of the experiment. The above elements are all contained within the experiment housing. The housing itself is hard-mounted to a shelf that is attached to an AMCO Engineering instrument rack that also contains a small video recorder (data recorder), an LCD monitor, the launcher control electronics and power supply, a flashlight, and small AA battery packs for the CCD camera and LCD monitor. A hand-held camcorder is also used to record the impact of the dust-bunny into the simulated target.
On April 17 and 18, 2001, the OASIS flight team conducted experiments in a series of 80 zero-g research parabolas during two flights aboard NASA's KC-135 Reduced Gravity Aircraft. During the microgravity flights a series of pre-planned test runs were conducted with the OASIS experiment apparatus to verify the operation of the projectile launcher mechanism and to test the dust sample loading process. During the first series of test runs (one run per parabola), an OASIS operator loaded 1 and 2-cm styrofoam balls into the launcher cup and test fired the launcher mechanism at speeds ranging from 2-32 cm/s, in order to study the separation mechanics of projectiles from the launcher mechanism in zero-g. The second series of experiment runs involved testing the procedures for preparing and launching electrostatically-bound aggregates of sands grains with the launcher sample cup. Video images of the load and launch sequences are recorded via two CCD cameras: one CCD is attached to the experiment housing and peers through a lexan view port to image the loading of the launch cup; the second camera is a hand-held camcorder which is operated by one of the OASIS flight operators. In addition to the test runs with the OASIS experiment, the flight team also tested the electrostatic aggregation of a number of other materials, including small polystyrene spheres, mm-scale plastic chips, and a dusty lunar regolith simulant, during several hand-deployed, free-float experiments.
Dr. Alan Stern is the Principal Investigator of the OASIS team who led the two-flight series of zero-g experiments aboard the NASA KC-135 reduced gravity aircraft. Dan Durda and Mike Epperly rounded out the team of flight experimenters aboard the aircraft. OASIS Project Manager Dave Slater and Lead Engineer Kelly Smith also traveled to Ellington Field at NASA's Johnson Space Center in Houston to integrate the OASIS experiment rack into the KC-135 aircraft and to perform final checks of the experiment apparatus before flight. Additional members of the OASIS science and engineering team who contributed to the success of the flight experiments include Co-Investigator Bill Ward, Engineer Linda Bjork, and Experiment Tech Joe Esquivel.
A gallery of OASIS photographs. (Click here for a list of hi-res images.)
OASIS Test Equipment Data Package describing the OASIS experiment in more detail.
NASA's Reduced Gravity Program