本课题面向我国航天科技和空间科学的发展趋势，针对空天DTN网络中图像数据的回传问题，开展空天DTN网络的高效传输机理研究。以空天DTN网络星间链路特性建模与分析为切入点，基于极值理论方法对单跳链路的性能进行估计和预测，分析影响端到端性能的主要因素，并据此对端到端性能进行评估以优化配置相应的传输参数，提高图像数据在空间网络中的传输效率。在此基础上，基于前向纠删编码设计空天DTN网络的数据传输策略，探索高动态链路下数据的无反馈可靠传输理论，在保障可靠传输的条件下加快数据在网络中的传递，进一步提高空天网络节点存储资源的使用效率和网络吞吐量。拟提升空天DTN网络在数据传输时延和给定时间内投递成功概率两项指标上的图像回传能力，满足空天信息网络图像数据业务的可靠性和有效性需求。

With the trends of the globe developments on the scientific aerospace techniques and space communications, this project develops an elaborated theoretical fundamental on the image delivery for space disrupt tolerant networking, which fully exploits the capabilities of the collaborative earth-satellite relaying networks in order to get back the scientific returns rapidly and reliably. The work will put the highlights on the theoretical model of the EVT-based (Extreme Value Theory) estimation on the capabilities of each hop, which could be used to obtain the optimal parameters of the image delivery on the end-to-end path. Taking into the consideration the link quality characteristics and the aerial node’ kinetic characteristics, we attempt to establish the delivery time and packet loss probability models of the single hop link and introduce the erasure coding and bundle fragmentation into the image transport. These efforts will make systematic theoretical and technical breakthroughs on the applications of DTN into the earth-space network, by attentively addressing critical challenges in the way of prompting space communications. As a hopeful result, the proposed project expects to make the interesting improvements with the respects of the data delivery latency performance the data delivery successful probability for the image return over the space DTN.