As a part of the “Membrane Aeroshell for Atmospheric-entry Capsule” (MAAC) project pursued by the University of Tokyo, JAXA and several other universities, a demonstration is planned to deploy an atmospheric-entry nano-satellite from International Space Station (ISS). The effect of aeroshell deployment timing on the orbital decay was evaluated and it was clarified that the orbital decay is significantly accelerated after aeroshell deployment due to the change in its ballistic coefficient. In order to keep the forward surface of the aeroshell in the direction of motion at the moment of aeroshell deployment, it is necessary to obtain the attitude of satellite with reference to the orbital direction. The applicability of the Faraday cup as an ion detector is discussed through experimental results at Inductively Coupled Plasma (ICP) wind tunnel and it was revealed to be promising for the estimation of the satellite direction.