Epsilon rocket works on first try, Hisaki (SPRINT-A) telescope successfully deployed

Another reason to feel good in Japan just a few days after Tokyo won the 2020 Olympics - Japan's Epsilon rocket has worked on the first try, successfully launching the SPRINT-A (soon thereafter renamed Hisaki) telescope. Japan has been notorious for being plagued with launch failures, and this new rocket is very interesting, using a good deal of artificial intelligence which allows the number of crew at mission control to be reduced from 150 to just eight.



So what does the telescope do? It has a diameter of just 20 cm, and observes the atmospheres of planets in the Solar System in the ultraviolet spectrum, observations that cannot be conducted from the ground. Checking the Japanese Wikipedia on this telescope we see the reason why:

すでにアメリカのハッブル宇宙望遠鏡など、より高性能な宇宙望遠鏡が運用されているが、これらはさまざまな天体の観測に用いられるため惑星観測に充てられる時間は限られてしまう。特定の惑星専用の探査機を飛ばせば非常に高精度なデータが得られるものの、高額の費用がかかり、目的の惑星以外の観測は困難である。用途を太陽系内の惑星観測に限定すれば、ハッブル宇宙望遠鏡のような高い性能は必要ではなく、小型の安価な宇宙望遠鏡で、複数の惑星を継続的に観測できるという利点がある。

Hubble can do a better job of this already, but it is always tied up with more important observations, and thus long-term study of planets in the Solar System simply isn't possible. Launching a dedicated probe to a planet would also be nice, but costs are high and only one planet could be observed. With the launch of a telescope devoted to these objects, however, one can observe multiple planets in the long term at a relatively low cost.

The planets to be observed:

Jupiter and its aurora, the atmosphere of Io
The atmosphere (or rather, near-surface exosphere, magnetosphere) of Mercury
The interaction of the atmosphere of Venus and Mars with space
The aurora of Venus and Saturn, etc.