Luna-2 hit the moon in 1959 thanks to Soviet engineers/scientists using slide-rules & pencils & paper.
The Soviets had a crude main-frame computer available
for OKB-1 in those days; however, your wrist-watch electronic calculator has more calculating power than that machine.
But....the basic and foundational trajectory/time-table calculations
done for Luna-2 and its booster rocket were done by hand.
Jacob