Practical Design and Flight Test of a Yo-Yo Wire Boom Deployment System

Abstract

A yo-yo-type wire-boom deployment system has been developed and flight tested on a sounding rocket mission. The goal of the work has been to validate a new mechanism that rapidly deploys wire booms from a spinning spacecraft. This work takes a theoretical system design and implements it in practical hardware. The limitations inherent in practical hardware necessitated new theoretical developments. A modified stability analysis has been developed for the case of nonzero axial separation between the wire-boom base attachment points and the spacecraft's center of mass. This modified stability analysis dictates that a stable design is impractical for many missions because very large wire-boom tip masses are needed and because the three-dimensional deployment transients are very sensitive to small asymmetries. This problem has led to the development of design criteria and analysis techniques, which permit a short-duration mission to use a slightly unstable nutation mode. These techniques have been used to design a system that has been flown on two daughter spacecraft that were part of a formation of three sounding rocket subpayloads. Each daughter spacecraft deployed four 3-m-long wire booms in under 10 s and maintained a low level of spin instability for the remaining 700 s of the mission. The nutation oscillations showed a slow exponential growth, but the coning half-angles of both spacecraft never exceeded 16 deg.

SIERRA observations of Alfvénic processes in the topside auroral ionosphere

“…As the wire booms unwrap, the differential can rotation with respect to the subpayload body is controlled via a feedback loop controlling a damping system so that the correct amount of energy is extracted from the system to enable the booms to be radial without rewrapping. This entire operation to deploy the 6‐m tip‐to‐tip booms takes about 8 s. Details on this system's development can be found in the work of Psiaki et al [2000], and the details specific to the SIERRA design can be found in the work of Psiaki et al [2005]. The subpayloads, having a smaller payload body and smaller wires, measure less noise and see smaller shadowing effects than the MAIN payload.…”

Magnetometer-based Attitude and Rate Estimation for Spacecraft with Wire Booms

“…This is a good approximation for the SIERRA subpayloads. [2][3][4] Hence, the physical wire booms which are flexible all along their length are modeled as simple pendulums for purposes of simulation and estimation. In this work, both the physical booms and their model are described as flexible because their positions can deform with respect to spacecraft coordinates.…”

“…Due to the short duration of the flight, the unstable mode and consequent slow growth of the nutation angle were considered acceptable. 3 The rate of growth of the unstable mode and the decay time constants of the stable modes are functions of the energy dissipated by bending in the booms. A lumped dissipation parameter was calculated for the SIERRA subpayloads in pre-and post-launch empirical studies, predicting stable mode time constants of less than 300 seconds.…”

“…A lumped dissipation parameter was calculated for the SIERRA subpayloads in pre-and post-launch empirical studies, predicting stable mode time constants of less than 300 seconds. 2,3 Immediately following boom deployment, spacecraft motion may be expected to contain contributions from several different modes. Within a short interval the nutational mode dominates as the stable modes die out.…”

“…SIERRA designers ultimately satisfied the opposing broad baseline and compactness requirements via the Cornell Wire Boom Yo-Yo (COWBOY) system. 2,3 Probes were connected to flexible cables wound helically around an articulating drum, and then spun out during flight in a yo-yo-type deployment that was controlled by a damper.…”