Such missions have included interplanetary missions to the outer limits of the Solar System, for which solar panels were not suitable as a source of electrical power because of the long duration of the mission at great distances from the Sun.
这些飞行任务包括飞往太阳系边缘的星际飞行任务，由于远离太阳长时间飞行，太阳能电池板不适合作为此种飞行任务的电力源。