This paper proposes and develops a Mars Robotic Global Exploration Network(MARGEN) to explore Mars on a global range in the air and on the ground at low cost. MARGEN is composed of five robotic crafts that can fly in Martian atmosphere and vertically land/takeoff anywhere on Martian surface. The network is supported by a parent craft, Mars Aerial Nuclear Global Landing Explorer(MANGLE). The rest of the four crafts are the offspring craft, Mars Aerial and Surface Terrain Electric Robots(MASTER) powered by Li-ion batteries at low cost. The MANGLE powered by nuclear fission reactor is also a mobile power station to charge the batteries of the MASTER. The robotic network will move together on Martian atmosphere and land on any location of interest. Each robot will carry instrumentation for atmospheric survey, high resolution cameras for topographical survey, and deep drill for soil sample deeper than 1m. The whole mission period is four Martian years. MANGLE can work all seasons on Mars. However, due to the operating temperature limitation of the batteries, MASTER will only operate during the summer season of Mars, hibernate in the winter, and operate again in the next summer. For the whole mission, the MARGEN will survey a total area coverage of 13,210,675.808 km2 (9.12% of Mars surface). The cost of one MASTER is about 1/1000 of the MANGLE, but a MASTER can almost perform the same exploration missions as the MANGLE system. The MARGEN is hence a system that massively increases the Mars exploration scale at low cost.