Simulator 1

Docking with the space station

Your capsule is 60 m from the station. Null out lateral and vertical offsets, slow your closing rate as you get closer and meet the docking port with centimetre precision. There is no friction in space: every thrust changes your speed for good, and stopping takes a thrust the other way.

Success: less than 20 cm off the port centre, closing slower than 0.15 m/s and less than 6 cm/s lateral speed. Real vehicles such as Crew Dragon dock automatically; astronauts can take over by hand.

Simulator 2

Landing on Mars: seven minutes of terror

Perseverance hits the atmosphere at 19,000 km/h. Because of the signal delay between Mars and Earth, the landing must be fully automatic; this time you make the calls. Open the parachute at the right moment, leave the backshell at the right height and slow down on engines to touch down below 1 m/s.

Tips: open the parachute below Mach 2.2, at about 9–12 km (in reality around Mach 1.75). The heat shield releases by itself 20 seconds later. Leave the backshell at about 2,000 m. The model is simplified: Mars’ atmosphere uses an exponential density, and vehicle masses and parachute size are close to Perseverance’s.

Simulator 3

Interplanetary transfer planner

The lowest-fuel way from one planet to another is the Hohmann transfer: an ellipse around the Sun that touches both planets’ orbits. Choose your departure and arrival planets to see the travel time, the speed change (Δv) needed and the next launch window.

The calculation assumes circular, coplanar planetary orbits. Real missions use near-Hohmann paths, gravity assists and windows a few weeks wide, so dates can differ by several weeks.

Mission Simulators: Station Docking, Mars Landing and Hohmann Transfers