This post gathers all the questions asked by participants during the webinar “Distributed Thermal Control System based on SMARTHEATERS,” presented by Juan Barbero. Topics discussed include sensor choices, system scalability, glueing validation, reliability, and temperature accuracy. Read on to learn more about the key considerations behind this innovative thermal control solution for space applications.
Q&A on Distributed Thermal Control
Q. Why don’t we use PT100 sensors? Thanks
A. We use PT1000 and digital sensors. PT1000 is very standard for space.
Q. How was the heater glued?
A. We used two-sided conductive tape. We are not experts on this, and mounting is a critical process to ensure proper heat dissipation. We are checking how the space integrators do it.
Q. Do you have an additional temperature control as part of the PT1000 fixed to the heater plate?
A. We are currently esting the Smart Heaters. And yes, we are placing an array of temp sensors to compare with.
Q. Is this thermal control system scalable? 100 sensors?
A. Each Smart Heater would control 14 heating lines (with 14 additional redundant lines). As the system works independently, it can be scaled up by adding more main boards to control other lines. So, the answer is yes; it can be scaled up to 100 or even more sensors.
Q. How do you proceed to validate the glueing of the heaters?
A. It is not our goal to do this. We understand that this is important for the tests we are conducting and have been informed by ESA on how to proceed.
Q. Thank you for the presentation. How is reliability affected compared to a traditional design, especially considering the sensors are daisy-chained?
A. We are evaluating the system. The heating lines have redundant lines. The fsystem’s initial reliability otill needs to be assessed.
Q. Is it necessary to shield the T° sensor harness to avoid noise, and if so, is more accuracy required?
A. We do not expect this to be necessary. Note that we do not have great accuracy as a target (±1ºc is the goal, but we expect to achieve around ±0.2ºc).
Q. Are all PCB components rad-hard? If not, how is it protected against latch-up?
A. We have selected the components to have a rad-hard version. The prototypes already manufactured have some rad-hard and some commercial devices, but we are now only validating the design.
Juan Barbero
Juan Barbero studied Physics at the Complutense University of Madrid. The first part of his working life was in the Failure Analysis laboratory of Alcatel, and in 2002 he joined the ALTER Technology team. Since then, he has been involved in testing components for space applications focusing mainly on optoelectronics, non-standard temperatures, and the development of non-standard test methods.
