How was the Mars Express design adapted to the environment of Venus?
Venus Express and Mars Express are very similar in design but some modifications had to be introduced on the spacecraft as the environment near Venus is harsher than the Martian environment. The solar flux is twice as powerful as it is in Earth orbit and four times as much as it is at Mars. As a consequence, thermal control has been changed dramatically. Where Mars Express had about 10 thermal control zones, Venus Express has four times more to ensure the best working environment for the instruments. While Mars Express was wrapped into a black thermal insulation to retain some heat in the coldness of the outer Solar System, Venus Express bears 27 layers of kapton insulation with a shiny golden upper cover to evacuate as much thermal radiation as possible. The solar arrays had to be redesigned too. They extend only half of the span of those on Mars Express despite the fact that their size was actually not dictated by the conditions upon arrival at Venus but at departure from Earth, wher
