1,721,036 research outputs found
Dynamical Effects of Radar Reflectors Attached to the Small Expendable-Tether Deployer System (SEDS)
No full textWave Propagation in the Tether Elevator/Crawler System
No full textAbstract - This paper analyzes the propagation of disturbances along the upper-tether of the Tether Elevator/Crawler System. Both longitudinal and transverse waves are investigated as the waves propagate from the station to the elevator, and beyond to the upper-platform. The model takes into account the effects of gravity gradient and material damping. An estimate of the various damping mechanisms affecting transverse waves is also provided in the paper. The frequency response functions at the elevator and at the upper-platform are computed for either a longitudinal or a transverse perturbation of the tether attachment point to the station. Copyright © 1990 Published by Elsevier Ltd
Low Altitude Tethered Mars Probe
No full textAbstract - A long tether connects a Martian orbiter to a small probe orbiting in the dense atmosphere of the planet. The minimum altitude reachable by the probe is estimated based upon considerations of dynamic stability, tether temperature, resistance of the tether material, and propellant consumption required to maintain a constant orbital altitude. The results obtained by means of a static-force model are then verified by dynamics simulation carried out by using a lumped-mass computer code. The scientific applications of this tethered system include probing of the Martian upper atmosphere and gravity mapping of the planet carried out by collecting gradiometric data from the probe. Another application involves the release of Martian rovers and penetrators from the probe at low altitude. Copyright © 1990 Published by Elsevier Ltd
Cala Incina (Bari): un esempio tipico di ripristino naturale della vegetazione litoranea pugliese
No full text
- …
