• @Iliya Shofman: a company offered to make lens for us
  • asking to build a lens -40°C to 70°C is a big ask
  • mechanical aspect and and optical performance is stuff we need to deal with
  • thermal-induced defocus may be an issue
  • if we expose the payload unshielded, it will experience huge temperature fluctuations
  • need insulation
  • -40 to 70 is very expensive
  • clarification: we need to define the OPERATING temperature for the lens, which will be based on our simulations
    • would like to give a number that’s accurate to 10 degrees
• since we’re only imaging the ground for a short amount of time, would be good to thermally insulate the payload
  • aerogel weighs practically nothing
• concerns about heat sources (TEC)
  • TEC consumes 0.3 W under normal operating conditions. worst case is 2.5 W
  • how much heat can the satellite absorb safely?
• previous ideas on thermally isolating the payload:
  • from Noa and Ksenya, the idea was to place thermally isolating material between the payload and the brackets
  • @Iliya Shofman we need aluminum shielding and then just add aerogel in the spaces/gaps. since we already have the aluminum panels of the satellite, put aerogel around the payload cylinder. put an aluminum sheet around the camera and then add aerogel inside
  • HERON used aerogel, so would be good to look into it
  • @Iliya Shofman to document the decision to have aerogel as a requirement, add Thermal Opto-Mechanical as stakeholders
• FLIR Tau operates best at 20°C
  • TEC peak power is 2.5 W, actual power consumption varies with ambient temperature
  • if we keep it at room temp, it will only consume 0.3 W
• next steps:
  • taking model from STOP, look at temperatures for the payload and use that to inform the temperature we tell manufacturers
• note on requirements
  • @Carrie Ann Po: continue updating requirements and make sure to link the thermal budget. the thermal budget should be treated as source truth
  • for payload requirements, “withstand”: must be able to endure thermal stresses. for optics, a temperature change results in a change in refractive index, resulting in defocus.
  • ideal temperature for payload (when it’s operating in day time): room temp and fluctuate as little as possible (±5°C). we want to get as close as possible to this
    • when it’s operating in night time, we can afford it to be a bit cold as long as there aren’t gonna be any thermal stresses that break the opto-mechanical set-up