| Person | Time | Accomplishments |
| Tsilokovsky | L 1800's | -Solid fuel rockets can't go to space. -Idea to use multistage rockets. -How much thrust needed for escape velocity. |
| Goddard | E 1900's | Liquid fuel can provide thrust throughout their whole flight |
| Astronomer | Time | Accomplishments |
| Ptolemy | 140 A.D. | -Idea of orbits -Geocentric model (things orbit Earth in perfect circles) |
| Copernicus | E 1500's | Orbit sun - Heliocentric model (things orbit sun in perfect circles) |
| Galileo | E 1600's | -Found evidence that supports heliocentric model -moons of Jupiter -Venus' phases |
| Brahe | L 1500's | Good observations of planet positions |
| Kepler | E 1600's | -All orbits are elipses -Kepler's Laws of Planetary Motion |
| Newton | E 1700's | -Inertia and Gravity keep things in orbit -Laws of Motion |