Conceptual Structural Design

Transcription

1 Conceptual Structural Design Description: This document contains information about the conceptual structural design in order to let the other participants in the CubeSat project get an idea of the structural design and its limitations e.g. mass, volume. We have listed some questions in the text so please comment on these subjects. Responsible group: MK9 P22A - pon101, LcTo@mail1.stofanet.dk, s02marl@msektor.auc.dk Subsystem: The mechanical subsystem Date: Rev.: 1.0 File name: Conceptual-Structural-Design rev1-0-pdf Path: Literature: Non

2 Subsystem Preferred Location Mounting Type Masse [g] MECH Mechanical structure Max 240 Centroide (Ref: Geometric) [mm] Max. Dimension [mm] Technical Drawing Available 3D Model Available Frame - - ~190? 113.5x100x100 No PreModel Side panels Frame Adhesive bonding ~20? 100x83x2 No PreModel Top, Bottom panel Frame Adhesive bonding ~10? 100x100x2 No No Radiation shield Panels Adhesive bonding ~1?? No No Adhesive bonding mat. - - ~19?? No No COM Communication system Max 190 Antenna Bottom panel Fasteners ~50?? No No COM CPB Non Mounting type A ~30? 95x95x? No No Wiring - Mounting type C ~1 - - No No Radio COM CPB? ~70?? No No Modem COM CPB? ~30?? No No PL Payload Max 90 CCD camera Frame/top panel Adhesive bonding ~30? 40 x 50 x15 No No Lens CCD camera Adhesive bonding ~10? Ø30 / 36.8 No No Frame Top panel Adhesive bonding ~10?? No No CCD PCB Non Mounting type B ~30?? No No Wiring - Mounting type C ~1 - - No No PSU Power supply unit Max 290 Solar cells Side panels Adhesive bonding 10 (9) x 2.43? x x Yes PSU PCB Non Mounting type B ~30?? No No Batteries Shadow Side Frame/Thermal subsystem 4 (8) x 22? 83.3 x 38.8 x Yes Wiring - Mounting type C ~2 - No No COMP Computer system Max 40 COMP PCB Non Mounting type B ~30?? No No Wiring - Mounting type C ~1 - ACS Altitude control system Max 90 Electromagnetic coils Side panels Adhesive bonding ~20?? No No ACS PCB Non Mounting type B ~30?? No No Wiring - Mounting type C ~1 - - No No

3 1. COMMENTS ON THE TABLE ABOVE Subsystem Each subsystem is divided into main parts, please check if your subsystem fits the description. Preferred Location The preferred location is how each subsystem is preferred located relatively to each other. This is based upon an early request posted on the newsgroup; so far only two groups replied to this request. Therefore we have suggested some location parameters, sow please check if they are acceptable. Mounting Type The adhesive bonding process is must likely made with epoxy. Mounting type A is dependent on the communication system, which is supplied by OSSS. Mounting type B is not determined yet but all PCB will probably be mounted by the same method. This also includes mounting type C. Mass The mase is only a preliminary suggestion. Each system has a safety margin of 10 g. Hence the total mass safety margin is 60 g. Please comment on this if you think that your subsystem mass budget is wrong, whether it is too low or high. If the mass of your system is estimated too low, let us know how much you think you will need. If you think the mass is lower than stated in the above, the extra mass available could be helpful other subsystems that might be in need for it. Centroid This is our job, don t worry about it. Max. Dimensions If you have some dimensions on your subsystem please send them right away. A picture and some few dimensions are always helpful. Technical Drawing Available See Max. Dimensions above. 3D Model Available If you use a CAD program for constructing 3D models please contact us.

4 2. CONCEPTUAL STRUCTURAL DESIGN OF CUBESAT The terminology below describes the individual main parts in each subsystem. Terminology 1. MECH: Frame structure 2. MECH: Side panels 3. MECH: Top or bottom panel 4. COM: Antenna 5. COM: Com CPB. Radio and modem included 6. PL: CCD camera, lens and frame included 7. PL: PL PCB 8. PSU: Photovoltaic solar cells 9. PSU: PSU PCB 10. PSU: Batteries 11. COMP: COMP PCB 12. ACS: Electromagnetic coils 13. ACS: ACS PCB 14. CSR: Kill switch (CSR, CubeSat Requirements) 15. CSR: Optional data port access area 16. CSR: Flight pin access area The next three pages show a preliminary conceptual design of the CubeSat.

5 2.1 VIEW OF CUBES AT

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8 3. COMMENTS ON DESIGN IN RELATION TO OTHER SUBSYSTEMS 3.1 PAYLOAD We will try to place the COMP PCB above the CCD camera chip as requested. 3.2 POWER SUPPLY UNIT The shown configuration of the CubeSat contains eight batteries. We cannot guarantee that this configuration will be successful, but we will not rule it out before we are 100% sure. For the time being we see 2 possible configurations of the batteries, namely Configuration 1: Eight batteries with some sort of thin film material as thermal protected Configuration 2: Four batteries with some sort of a larger thermal subsystem e.g. foam. 3.3 ATTITUDE CONTROL SYSTEM The preferred ACS with reference to mass and volume is the magnet torques (electromagnetic coils). Maybe it is a more feasible solution for the ACS team to use momentum wheels regarding the location precision of the satellite, but we just want to point out that the precision may not be the design criteria since mass and volume is a critical aspect of the CubeSat design. 3.4 COMMUNICATION SYSTEM AND PAYLOAD There have been some discussions regarding the location of the antenna system and the CCD camera e.g. some wants to place these main parts at the same panel. This is highly dependent on the configuration of the antenna system (secondary structure), which is supplied by OSSS. If the antenna is as displayed at the previous 3D models then it is not possible to locate them on the same side. Besides, if it is true what Fleming Hansen from Terma says regarding the communication system this should not be any problem. E.g. the communication signal will not be contaminated if the CubeSat is shorter than one quarter of a wavelength.