343 Development of a Low -Shock Payload Fairing Jettison System  

Boris Halter*, Josef Zeman n*, Simon Wieser*, Beatrice Burkhart*, Mathias Burkhalter* ,   Alberto Sánchez** and Oliver Kunz*  

Abstract  

Today’s robust and reliable separation and jettison systems safely actuate and execute the separation of  the payload fairing from the launcher . However, shock- loads are exported from the pyrotechnic separation  event . Further more, t he verification of new or adapted fairings is typically carried out by extensive and costly   test campaigns due to the installation of full- scale  components in vacuum chambers. I n recent years, there  is an increasing demand from the launcher primes and sate llite suppliers to improve the payload comfort  and to simplify the verification process.  Following this need, RUAG Space is developing within the ESA - funded Future Launcher Preparatory Program a low -shock separation and jettison system applicable to   currently used and future PLFs. The concept is based on a simple and reliable low -weight system for a  controlled  separation using  hinges and actuators to  rotate and jettison the PLF halves. This  paper describes   the developed concept  and the mechanisms for the rotation and jettison. The focus is on the event of  separation and jettison, excluding the method for fixation of the fairing during launch and the initial release.  The paper shows the advantages of the novel  design and explains the verification activities performed to  prove the system.  

Introduction  

RUAG Space is a leading supplier of products for the space industry in Europe and has  as well  a growing  presence in the United States. RUAG Space develops, designs and builds payload fairings for several  launch vehicles of different classes, having decades of experience in  reliable and robust technical solutions  with 100% mission success.  Furthermore, RUAG  Space  is developing and manufacturing high reliable  mechanisms for spacecrafts and launchers , as the herewith in this paper presented separation system.  

One of the key events in a satellite launch is the separation and jettison of the payload fairing (PLF) from  the launcher. In the following a short overview of the state- of-the-art separation system’s main  characteristics  is given.  

The central reasons for the use of  current fairing separation systems, based on pyrotechnic  solutions ,  include:   • High efficiency : the pyrotechnic separation system  provides a high ratio of separation force versus  system weight.   • After PLF separation only a small section of the interface ring remains  on the launcher as t he pyro  cords are typically encapsulated inside the PLF frame rings that are broken for  separation.  This  influenc es positively the fuel consumption of the mission.   • Simple and compact  design:  pyrotechnic systems are not only compact, but also have a simple  design compared to other mechanical systems ; less parts are included and no movable joints or  interfaces are needed, increasing the reliability of these systems.   • Flight -proven reliability and large heritage of the solutions: the large heritage of the pyrotechnic  solutions with thousands of successful separations makes them a safe and reliable system  consisting of only few components and fail -safe solutions.  

* RUAG Space Spacecraft, Zürich, Switzerland   ** RUAG Space Launchers, Zürich, Switzerland  

Proceedings of the 45th Aerospace Mechanisms Symposium, NASA Johnson Space Center, 20 20