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Fission power is a promising technology, and it has been proposed for several future space uses. It is being considered for high-power missions whose goal is to explore the solar system and even beyond. Space fission power has made great progress when NASA’s 1 kWe Kilowatt Reactor Using Stirling TechnologY (KRUSTY) prototype completed a full power scale nuclear test in 2018. Its success stimulated a new round of research competition among the major space countries. This article reviews the development of the Kilopower reactor and the KRUSTY system design. It summarizes the current missions that fission reactors are being considered as a power and/or propulsion source. These projects include visiting Jupiter and Saturn systems, Chiron, and Kuiper belt object; Neptune exploration missions; and lunar and Mars surface base missions. These studies suggest that the Fission Electric Propulsion (FEP)/Fission Power System (FPS) is better than the Radioisotope Electric Propulsion (REP)/Radioisotope Power System (RPS) in the aspect of cost for missions with a power level that reaches ~1 kWe, and when the power levels reaches ~8 kWe, it has the advantage of lower mass. For a mission that travels further than ~Saturn, REP with plutonium may not be cost acceptable, leaving FEP the only choice. Surface missions prefer the use of FPS because it satisfies the power level of 10’s kWe, and FPS vastly widens the choice of possible landing location. According to the current situation, we are expecting a flagship-level fission-powered space exploration mission in the next 1-2 decades.

Cosmic ray muon radiography is a new imaging technique that is being used to investigate the density structure of large objects and the shallow crust. For example, it has been used to investigate magma conduits of active volcanoes, cavities above tunnels and hidden chambers inside pyramids, and has proven to be effective and accurate. However, low cosmic muon flux has limited the development of muon radiography in many engineering applications. In this paper, the potential application of muon radiography to investigate density anomalies in tunnel overburden is discussed. Results show that in a typical 25-meter thick overburden, muon radiography can identify overburden anomalies of 10% in two hours with an inaccuracy probability of 30.8% by lack of enough statistics, and this inaccuracy will reduce to 2.2% if data are collected over a full day. The study also indicates that muon radiography can detect structure density anomalies above 1% with an inaccuracy probability of 2.2%. As a non-destructive, non-invasive and passive imaging method, cosmic ray muon radiography has its great potential in timely monitoring and imaging of overburden structures to discover potential structural defects.

The existing image block compression method does not reduce the amount of data after the image block processing. For the image with large amount of raw data, such as high-resolution remote sensing images, the image compression will consume more hardware resources and cause great pressure on the compression performance. Aiming at this situation, a method for block compressed of images based on data-hiding is proposed. The reference image block and similar image blocks are judged by the similarity of image blocks. The number of similar image blocks is hidden in the reference image block by data-hiding, and only the reference image blocks are subjected to JPEG2000 compression. The experimental results show that the method reduces the amount of data before image compression by 1/3 and increase the compression ratio of image compression by 1.5 times.