MASCOT thermal design: how to deal with late and critical changes

Abstract

MASCOT is a lander built by DLR, embarqued on JAXA’s Hayabusa-2, a scientific mission to study the asteroid 162173 1999 JU3, launched on the 3rd of December 2014. As part of the project challenges, the short schedule for the whole development of the lander (2.5 years from PDR to launch), the strict and contrasting thermal requirements for different phases of the mission, mass&power/technology/volume limitations put the thermal design at the edge of the state of art technology solutions. As a result, the thermal system development has been on-going until the last phases of the project, on order to cope with late changes and technologies development. This presentation focusses on the thermal control system evolution during the last months before launch and just after it and the tight schedule available to cope with late system changes. It shows the design modifications and updates, together with thermal modelling changes following intensive testing phases, in particular for the lander battery pack and the heating/pre-heating strategy for different mission phases. Many thermal vacuum campaigns, modelling re-iterations, better understanding of the main S/C thermal behaviour, together with the great team determination helped reaching a succesfull launch followed by an on-flight system verification.