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Nascap-2k is the updated version of the NASCAP/GEO spacecraft charging analysis code. In addition to packaging the physical content of NASCAP/GEO in a modern way, Nascap-2k incorporates other plasma analysis codes (in particular, the DynaPAC code) in order to extend its applicability to a wide variety of plasma environments. Nascap-2k also includes an interactive Object Toolkit for defining spacecraft surface models for analysis. In this paper we focus on the tenuous plasma charging capabilities of the code, with application to DSCS-III (geosynchronous environment), STEREO (solar wind environment) and MESSENGER (solar wind environment near 0.4 AU).

The new method of statistical studying of cosmic gamma-ray bursts is presented based on the averaging of time profiles. The comparison is done between bright and dim events: while no differences were found between average flux curves, the hardness ratios pointed out the effect of hardness/brightness correlation.

This catalogue includes 49 confirmed gamma-ray bursts recorded by the Signe-2M experiment over the period September 1978 – January 1980. This Soviet-French experiment was launched on the three Soviet spacecraft Venera-11, Venera-12, and PROGNOZ-7. The PROGNOZ-7 spacecraft recorded bursts from November 1978 to May 1979. The Venera interplanetary spacecraft operated with short interruptions. The catalogue gives the histories of selected bursts with a time resolution of 1/64 s, which have never appeared in the literature. These time histories demonstrate the difference between and temporal peculiarities of these events. Table 1 summarizes precise burst arrival times at the spacecraft and the coordinates of the spacecraft at those times.

The source location data analyzed by the first and second interplanetary gamma ray burst spacecraft networks are reviewed. The possibilities of additional networks and of related studies in other disciplines, and the prospects for real time optical transient observations and for the definition of gamma ray burst sources by optical transient astronomy are also reviewed.

Looking at the chance of the next apparition of the Halley comet in 1986, ISAS decided to send a first Japasanese interplanetary spacecraft for the study of cometary hydrogen coma and solar wind. The Planet-A spacecraft which carries VUV imaging camera and solar wind plasma analyser will be launched in August 1985 and flyby the Halley comet in early March 1986 with the distance of several million kilometers from the comet nucleus. This mission is not only self-consistent but collaborative with other space mission as well as earth-bound observations. In the present paper, the Planet-A mission to Halley is described with brief explanation of the spacecraft.