Design and development of steel riser assembly for the Orion space capsule
After the retirement of the Space Shuttle program, NASA intends to use the Orion Capsule for future space exploration. The new Orion Capsule is similar in design to Apollo except for the higher payload capacity and of course newer technology utilised in all aspects of its design and construction. NASA wanted a steel riser cable with improved properties compared to the Apollo·s standard 7"19 aircraft control cable used in the 1960's. The chosen steel riser cable had to pass a series of stringent tests devised to simulale the dynamic interaction with the inverted capsule during reentry into earth's atmosphere. Resistance to high temperature, abrasion-resistance, crush-resistance, retention of strength while bent over small radii, rotation-resistance while under tension, shock load resistance as well as high-stren9th-to-weight ratio were among the desired dynamic and mechanical properties. Since the steel riser is the tension member link between the Orion capsule and the Kevlar strength members connected to the parachutes, a specialised end attachment had to be designed and optimised for this application. This paper will provide a summary of design parameters for the chosen steel wire rope and its specialised end attachments. A summary of results for stringent testing performed will also be provided. A recently developed hybrid version of this cable bearing a higher strength to-weight ratio will also be presented.
Author(s): B. Pourladian, K. Bowland and M. Janda