';

Mission Statement

The purpose of the MidSTAR power system is to collect, store, and distribute power to the satellite vital systems and experimental payloads.

The primary mission of the power system for MidSTAR-1 is to support the vital satellite systems (CD&H and Main Comms), ICSat, and CFTP for two years. The secondary mission is to support additional USNA and Goddard Space Flight Center experiments for two years.

The MidSTAR power system is a general-purpose satellite power bus capable of supporting a variety of space missions by easily accommodating a wide variety of space experiments and instruments. The integration of the experiments with the satellite power bus must be accomplished with minimal changes to the overall power system and necessary changes to the power distribution bus (to meet payload specific voltage and power requirements). The power system is intended to be a relatively low-cost, quick response system accommodating the satellite's vital systems and small payloads approved by the DoD Space Experiments Review Board (SERB) and awaiting launch through STP.

Mission Power Requirements

Power Requirements

To meet the Primary mission requirements, the EPS must deliver at a minimum, 27 W average power during normal operations. The maximum power used is 57 W during communication transmissions but when averaged over the course of the orbit, it falls within 27 W. To incorporate a safety factor, the power system is required to provide 30 W of power. This covers the most stringent power demands.

  1. Provide vital systems (CD&H, Main Comms, and ICSat (receivers only)) 20 W in a standby mode and 27 W average power in a transmit mode to fulfill basic life requirements.
  2. Provide the CFTP payload with 5 W in a normal operational mode and 0.5 W in standby mode.
  3. Provide experimental payloads power as available during normal satellite operations.
  4. Power system must have an end-of-life permanent kill switch to disconnect the batteries from the solar array.

A detailed breakdown of the power requirements for each payload and subsystem is found under the Power Details/Operations Page.

ESPA Ring Requirements

MidSTAR-1 will be mounted on an ESPA ring, which dictates the power constraints while the satellite is attached to the launch vehicle. The power system will be provided while on the ground with:

  1. A +48 V and ground line that will allow charging of the batteries for 4 hours cumulative during a 24-hour period, at least once every 14 days. 
    2. One thermistor will be installed in each battery box to monitor the temperature during charging.
  2. No payload may become operational until after the satellite deploys from the launch vehicle.

Mission Architecture

Return to EPS Table of Contents