Innovative Mechanical Design Strategy for Actualizing 80 kg-Class X-Band Active SAR Small Satellite of S-STEP

Abstract

The Small SAR Technology Experimental Project (S-STEP) mission aims to develop a new (space-based 80 kg-class active X-band synthetic aperture radar (SAR)) satellite with a main imaging mode of 1 m resolution stripmap. In the S-STEP mission, to achieve the design goal of developing faster, cheaper, better, and lighter small SAR satellite systems, innovative thermo-mechanical design approaches have been proposed and investigated. The major design approaches are the bus-payload integrated flat plate-type structure, multifunctional transmit/receive (TR) module, and dedicated vibration-free orbit deployer (VFOD) with the function of whole spacecraft vibration isolation. To validate the feasibility of the innovative mechanical design of S-STEP, a structural analysis considering launch and on-orbit environments is performed. In addition, development test results are presented to confirm the effectiveness of the proposed design approach for VFOD.

High Damping Passive Launch Vibration Isolation System Using Superelastic SMA with Multilayered Viscous Lamina

“…In the test setup, to achieve a 28 Hz cut-off frequency for a 40 kg class satellite, four WSVIs with the Case (1) design were integrated with a mass simulating dummy satellite. The dummy satellite was configured as a flat plate-type to implement the design concept of a small synthetic aperture radar (SAR) technology experimental project (S-STEP) satellite [21]. The S-STEP satellite is an 80 kg class small SAR-satellite that provides a high resolution 1 m stripmap image.…”

New Thermal Design Strategy to Achieve an 80-kg-Class Lightweight X-Band Active SAR Small Satellite S-STEP

“…The S-STEP program has been started to develop an 80 kg class lightweight small SAR satellite for high-resolution SAR imagery for environmental investigation, surface mapping, and disaster monitoring. The mission operation concept of the S-STEP system is shown in Figure 1 [22]. The S-STEP system is operated at LEO and provides a 1 m resolution stripmap image, 4 m resolution ScanSAR image, and 1 m resolution VideoSAR for 10 s duration to capture the earth's targets of interest.…”

“…Therefore, the S-band intersatellite link (ISL) system is considered for immediate communication link between the satellites. Table 1 lists the basic system specifications of S-STEP [22]. Figure 2 shows the mechanical configurations of the S-STEP satellite.…”

“…These advantages make it attractive to be used for implementing the NewSpace small SAR satellite. The effectiveness of these mechanical design strategies has been investigated by Kwon et al [22]. However, this study did not perform the numerical or experimental verification of those thermal designs.…”

“…An 80 kg class high-resolution earth observation small satellite with X-band active phase array SAR, named the Small SAR Technology Experimental Project (S-STEP) [22], is under development. For developing an S-STEP system in accordance with a smaller, lighter, faster, better, and cheaper NewSpace paradigm, several mechanical design strategies are being adopted for the satellite [22]. The design strategies involve a bus-payload integrated flat panel-type satellite platform, a multifunctional TRM structure, and a vibration-free orbital deployer (VFOD).…”