Measurements of plasma are fundamental for space physics, especially for space weather. Recently, giant progress of the CubeSat technologies greatly lowers the barrier to insert a satellite into a lower earth orbit for space exploration. Satellite constellation missions consisting of tens of CubeSats is planned and launched. These missions provide multi-point measurements and make it possible to separate spatial and temporal effects regarding couplings between ionosphere, atmosphere and even lithosphere. And the altitude of these missions are rarely explored by conventional satellites because of large air drag and short mission lifetime. In addition to Cubesat missions, simultaneous multi-instrument measurements onboard sounding rockets aiming for the plasma characteristic investigations in the ionosphere D layers, which is the least-explored region in the ionosphere, is planned. In this presentation, the plasma diagnostic techniques onboard CubeSats and sounding rockets will be introduced. The design concepts of the solar EUV probe onboard the Phoenix CubeSat in QB50 mission and the “Mesosphere and Ionosphere Plasma Exploration complex (MIPEX)” instrument onboard the NCKU sounding rocket, which is planned to be launched in 2020, will be shown. These experiments can provide unique high-quality data of the plasma environment to explore the ion distribution and the electrodynamic processes in the Ionosphere D, E layers.