For space exploration, "light travel" is the most basic requirement. To save fuel consumption, weight loss becomes a priority. In order to improve the efficiency of space launch, it is necessary to carry the necessary scientific equipment and other payloads. So it's a good idea to start with the launch vehicle. Carrier rocket weight reduction is not to carry less fuel, but to start from the fuel tank and oxidizer tank weight reduction. If the traditional aluminum alloy tank is replaced b...