  The Weak Equivalence Principle is the founding pillar of General Relativity
and as such should be verified as precisely as possible. The Microscope
experiment tested it in low Earth orbit, finding that Pt and Ti test masses
fall toward Earth with the same acceleration to about 1e-15, an improvement of
about two orders of magnitude over ground tests. Space missions, even if small,
are expensive and hard to replicate; yet, the essence of physics is
repeatability. This work is an assessment of the Microscope results based on
the laws of physics and knowledge from previous experiments, focusing on the
limiting thermal noise and the treatment of acceleration outliers. Thermal
noise reveals anomalies that we explain by stray sub-microVolt potentials
caused by patch charges, giving rise to an unstable zero. The measurements were
affected by numerous acceleration spikes occurring at the synodic frequencies
relative to the Earth (the signal frequency) and the Sun, which we interpret as
evidence of a thermal origin. In Microscope authors' analysis, the spikes were
removed and the resulting gaps replaced with artificial data (up to 35, 40 per
cent of the sessions data), which retain memory of the gaps and may simulate or
cancel an effect (signal or systematic). An alternative approach based
exclusively on real measured data would avoid any ambiguity. The lessons of
Microscope are crucial to any futures improved mission.
