Impact Attenuator for Ground Landing of Space Capsules
- Paper number
IAC-06-C2.5.06
- Author
Dr. Paulo Moraes Jr., CTA/ Institute of Aeronautics and Space, Brazil
- Coauthor
Mr. Odilon Costa Franco Jr., CTA/ Institute of Aeronautics and Space, Brazil
- Year
2006
- Abstract
The retrievable space capsule SARA has been designed to be recovered at ground after accomplishment of its orbital mission. Develop to conduct microgravity scientific and technological experiments of medium duration, the capsule shaped orbital platform re-enters the Earth atmosphere and makes use of a cluster type of parachutes to reduce the velocity and touch the ground with a velocity around 8 m/s. The structural design, the on board equipment and samples of the conducted experiments impose the requirement for a ground impact that not exceeds a deceleration higher then 10 g in any direction. In order to attend this restriction an efficient ground impact attenuator should be designed, qualified and applied. Several concepts of ground attenuators have been considered and analyzed. Crash structured and inflatable impact attenuators represent the most variant types of attenuators. In the present study an inflatable impact attenuator (airbag) was considered for development, which should be assembled in the front part of the capsule. The proposed system, accommodated inside the nose part of the capsule should be activated by two events: ejection of nose cap and air filling of the airbag. Preliminary studies of systems using airbags show particularities involving different geometries and different ways of ejecting the nose cap and inflating the airbag as for instance: a) nose cap ejection by a pneumatic actuator and airbag filling making use of the aerodynamic oncoming flow; b) nose cap ejection using a pneumatic actuator and airbag filling with a gas generator; c) nose cap ejection by a pneumatic actuator and filling of the airbag by means of pressurized air. An analysis of all the different concepts has allowed to make the most available choice which is based on an aerodynamically self-inflatable system that uses the oncoming aerodynamic flow after ejection of the nose cap with a pneumatic actuator. In this case the nose cap should be ejected after initiating the deployment of recovery system. The recovery system is based on high performance parachutes which begin to be deployed at an altitude of 6000 m. The estimated capsule velocity at this point is approximately 150 m/s. This concept uses a device to generate gas in quantity and pressure necessaries to put in action the actuator of the nose cap ejector and to fullfill the airbag. This solution also considers the use of complementary airbags that allows a protection of the capsule impacting with high lateral velocities, high lateral inclination or in inclined grounds. The present article describes the work done with respect to the development of an efficient ground impact attenuator for small retrievable space capsules.
- Abstract document
- Manuscript document
IAC-06-C2.5.06.pdf (🔒 authorized access only).
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