Why are the LISA spacecraft sometimes called Sciencecraft?

The usual structural and thermal analysis of the spacecraft has therefore been extended to include gravitational effects as well to ensure that the requirements on gravity gradient at the position of the test masses is fully met. In addition, the payload controls the position of the spacecraft during science operations, rendering the spacecraft effectively a part of the instrument. The importance of the co-design and the co-operation of spacecraft and payload is captured in the term “sciencecraft”.