Research on Gas Dynamics in Relation to Performance of Sail-type Spacecraft for Exploration to Outer Planets and Interstellar Region

点击翻译按钮获取中文摘要

The methods to augment the ability of the sail type spacecraft by using the aerodynamic force during the atmospheric pass are investigated.1. The plasma flow of the solar wind around the magnetic sail is numerically analyzed by full-PIC method. The magnetic sail can generate the thrust, but it is much smaller than that obtained by the solar sail with the same size. Consequently, the solar sail should be chosen as the first generation's sail-type spacecraft.2. The secondary use of the sail as an aerodynamic decelerator for the spacecraft to be inserted into an orbit around a planet enables us to make the nearly fuel-free orbiter mission for planetary exploration. The low ballistic coefficient atmospheric entry widens the entry corridor, and reduces the aerodynamic heat and load.3. The aerodynamic performance of the hoop-supported membrane vehicle is investigated in the hypersonic wind tunnel It is demonstrated that the automatically deployed aeroshell can be realized by using the shape memory alloy for the hoop. This system is suitable for small atmospheric entry probes. Shape like delta wing can be obtained by the multi-hoop structure. High lift-to-drag ratio of about 5 is expected after shape optimization.4. The rarefied hydrogen plasma wind tunnel has been developed to simulate the aerodynamic heating environment at atmospheric entry to outer planets. The heating tests suggest that the multi-layer material made by the combination of high temperature membranes and high strength ones is promising.5. The combination of the solar sail and the aero-gravity-assist is investigated. The trajectory analysis shows that the membrane spacecraft with length 220 m and mass 410 kg will leave the solar system at velocity 30 km/s and reach the Kuiper belt in 30 years. The proposed vehicle seems promising as the first generations interstellar probe.