A spacecraft flying through normal space for seven hours at 2-billion miles per hour travels 7*2=<<7*2=14>>14 billion miles.
A spacecraft flying through a black hole at 3*2=<<3*2=6>>6 billion miles per hour.
Thus, a spacecraft flying through a black hole for two hours travels 2*6=<<2*6=12>>12 billion miles.
Therefore, in total, the Zargon spacecraft will travel 14+12=<<14+12=26>>26 billion miles.
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