SBIR-STTR Award

Payloads in a launch vehicle are mounted on standard payload attachment fittings which provide no vibration isolation, imposing severe requirements on payload design. There is a need for inexpensive and effective means to isolate the payload from vehicle vibration. Complications include conflicting requirements for compactness, high static strength, widely varying static load, secure tiedown, low dynamic spring rate and little or no interaction with launch vehicle control dynamics.OmniTek proposes to address this need with a passive/active hybrid (semi-active) system in which the mechanism of isolation is passive and parameters of the mechanical system are automatically adjusted for varying launch conditions. With the inclusion of a novel structural characteristic, the system can meet all the requirements without compromise.The objectives of Phase I are:1. Analyze and characterize the launch environment and equipment to develop design specifications, guides and priorities.2. Develop a number of alternative systems to the conceptual design stage for comparative evaluation.3. Compare and rate the design alternatives against specifications and select one concept for development to the prototype stage.

The objective of this Phase II effort is to design, construct and test a proof of concept prototype of a novel isolating Payload Adapter Fitting (IPAF) for launch vehicles. The main performance specification for the IPAF is vibration attenuation of 50% at 10Hz and higher frequencies. Furthermore, the proposed IPAF should not interfere with the vehicle attitude control system. During the Phase I effort, a set of design specifications and launch environmental conditions were assembled. Thereafter, a number of alternative isolation systems were proposed, compared, and contrasted and one concept with possible options was selected. The proposed IPAF will have the same mechanical envelope and the same attachments to the rocket and the payload as the present PAF so that an easy upgrade may be achieved. The proposed IPAF is equipped with both axial and lateral isolation elements. The rotational motion of the payload with respect to the rocket is constrained through a novel mechanical linkage mechanism built into the IPAF. In addition, the IPAF has a novel semi-active feature which provides the necessary adjustment to hold the desired compliance despite large quasi-static variations in the acceleration of the vehicle and the corresponding load on the IPAF. Simulation studies during the Phase I effort have shown the efficacy of the proposed system. It is intended that a small-scale and a full-scale IPAFs be built and tested during Phase II.