Aura Mission. On July 15, 2004 NASA launched the Aura spacecraft to study the earth's climate and atmosphere. This satellite was injected into an orbit $705 \mathrm{~km}$ above the earth's surface. Assume a circular orbit. (a) How many hours does it take this satellite to make one orbit? (b) How fast (in $\mathrm{km} / \mathrm{s})$ is the Aura spacecraft moving?