  The Space Time Explorer and QUantum Equivalence principle Space Test
(STE-QUEST) recently proposed, aims at performing a precision test of the weak
equivalence principle (WEP), a fundamental cornerstone of General Relativity.
Taking advantage of the ideal operation conditions for high-precision quantum
sensing on board of a satellite, it aims to detect possible violations of WEP
down to the $10^{-17}$ level. This level of performance leads to stringent
environmental requirements on the control of the spacecraft. We assume an
operation of a dual-species atom interferometer of rubidium and potassium
isotopes in a double-diffraction configuration and derive the constraints to
achieve an E\"otv\"os parameter $\eta=10^{-17}$ in statistical and systematic
uncertainties. We show that technical heritage of previous satellite missions,
such as MICROSCOPE, satisfies the platform requirements to achieve the proposed
objectives underlying the technical readiness of the STE-QUEST mission
proposal.
