Description

The goal of this trade is to arrive at a definite list and ordering of the modules that will make up the satellite bus stack (stackup). A satellite’s bus is composed of any system that is not a payload. This trade assumes there are requirements in place that support a bus design that spans the Z axis of the satellite using the PC104 interconnect or similar. A secondary objective of this trade is to refine our volume allocations requirements. Exterior panel-mounted components are out of scope for this trade.

Specific attention is paid to the battery module, for which there has been discussion in the past about moving it out of the stack to be placed lengthwise along the radiator panel adjacent to the payload, under the premise that it will allow the batteries to absorb the heat directed to the radiator panel. A battery operates more efficiently when kept warm. This decision is reevaluated here.

The following systems make up the stack and are in need of finding a home (in no particular order):

Requirements

The following requirements are considered in determining a suitable stack order, listed in order of priority:

  1. The ADCS SHALL be located in the tuna can volume, according to previously established requirements
  2. The payload PCB SHALL be located at the bottom of the stack to allow for direct interface with the payload sensor
  3. The EPS SHALL be located next to the battery module to allow for custom interconnects in addition to the PC104 interconnect if deemed necessary
  4. The OBC SHOULD be located next to the EPS to allow for future opportunity to consolidate OBC and EPS onto single board if volume constraints demand it
  5. The OBC SHOULD be located next to the RF module to reduce the connector length between the OBC and the secondary (non-PC104) interfaces on the RF module
  6. The ADCS SHOULD be located next to the OBC to the reduce connector length between the OBC and the secondary (non-PC104) interfaces on the ADCS module
  7. The center of mass of the stack SHOULD be located as far as possible from the ADCS to make it easier for the module to control the spacecraft
  8. The center of mass of the stack SHOULD be as close as possible to the center of the spacecraft to avoid violating the center of mass deviation requirements from our launch service provider