EFFECTS OF SEVERED TETHERS IN-SPACE

Experimental results and mathematical analyses are compared for determ ining the velocity of a severed tether and, consequently, its effects on the orbiter. Experimental analysis consists of measuring tether end velocity at the cut point, using both a reflex and a video camera wit h stroboscope. The mathematical models are based on a classical spring -mass-dashpot scheme, an elastic continuum, and a simplified energy mo del. Agreement between theoretical and experimental results is very go od because it is within the uncertainty band and all of the results di ffer by less than 10 %. In the cases of interest, tether end velocity may be considered independent of tether length (neglecting orbital eff ects). In the case of the tethered subsatellite system mission, there are no problems for orbiter integrity because, in the worst case, if a cut occurs 20 km from the Shuttle, the whole tether, with a stored en ergy of about 350 J, can return to the orbiter in about 2 h.