6,197 research outputs found
Biospheres and solar system exploration
The implications of biosphere technology is briefly examined. The exploration status and prospects of each world in the solar system is briefly reviewed, including the asteroid belt, the moon, and comets. Five program elements are listed as particularly critical for future interplanetary operations during the coming extraterrestrial century. They include the following: (1) a highway to Space (earth orbits); (2) Orbital Spaceports to support spacecraft assembly, storage, repair, maintenance, refueling, launch, and recovery; (3) a Bridge Between Worlds to transport cargo and crews to the moon and beyond to Mars; (4) Prospecting and Resource Utilization Systems to map and characterize the resources of planets, moons, and asteroids; and (5) Closed Ecology Biospheres. The progress in these five field is reviewed
Magnetostrictive direct drive motor
Highly magnetostrictive materials such as Tb.3Dy.7Fe2, commercially known as TERFENOL-D, have been used to date in a variety of devices such as high power actuators and linear motors. The larger magnetostriction available in twinned single crystal TERFENOL-D, approx. 2000 ppm at moderate magnetic field strengths, makes possible a new generation of magnetomechanical devices. NASA researchers are studying the potential of this material as the basis for a direct microstepping rotary motor with torque densities on the order of industrial hydraulics and five times greater than that of the most efficient, high power electric motors. Such a motor would be a micro-radian stepper, capable of precision movements and self-braking in the power-off state. Innovative mechanical engineering techniques are juxtaposed on proper magnetic circuit design to reduce losses in structural flexures, inertias, thermal expansions, eddy currents, and magneto-mechanical coupling, thus optimizing motor performance and efficiency. Mathematical models are presented, including magnetic, structural, and both linear and nonlinear dynamic calculations and simulations. In addition, test results on prototypes are presented
Development of the opto-mechanical design for ICE-T
ICE-T (International Concordia Explorer Telescope) is a double 60 cm f/1.1
photometric robotic telescope, on a parallactic mount, which will operate at
Dome C, in the long Antarctic night, aiming to investigate exoplanets and
activity of the hosting stars. Antarctic Plateau site is well known to be one
of the best in the world for observations because of sky transparency in all
wavelengths and low scintillation noise. Due to the extremely harsh
environmental conditions (the lowest average temperature is -80C) the
criteria adopted for an optimal design are really challenging. Here we present
the strategies we have adopted so far to fulfill the mechanical and optical
requirements.Comment: 7 pages, 2 figures, contributed talk at 'An astronomical Observatory
at Concordia (Dome C, Antarctica) for the next decade', 11-15 May, Rome
(Italy
The Impact of Science on Society
Four speeches delivered as part of a public lecture series to assess the impact of science on society are presented. The computerization of society, space exploration and habitation, the mechanisms of technological change, and cultural responses are addressed
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