← Back to Spaceflight
All 9 questions. After you submit, each question shows the right answer and why. Back to the quick check
What makes a rocket move upwards?
A rocket engine can still work in space, where there is no air.
What was Sputnik 1?
The International Space Station goes once around Earth about every 90 minutes. About how many orbits does it make in 24 hours?
Astronauts on the space station float because there is no gravity up there.
Which speeds are about right for low Earth orbit and for escaping Earth altogether?
Using the ideal rocket equation, Δu = (effective exhaust velocity) × ln(full mass ÷ empty mass), what velocity change in km/s (one decimal place) does a rocket with an effective exhaust velocity of 3 km/s and a mass ratio of 4 achieve, ignoring drag and gravity?
Inverting the rocket equation gives mass ratio = e raised to the power (Δu ÷ exhaust velocity). What mass ratio (one decimal place) would a single-stage rocket with an effective exhaust velocity of 3 km/s need to gain 8 km/s, ignoring drag and gravity?
Using the rocket equation, explain why a rocket reaching orbit carries a payload of only about 1% of its launch weight, and what the ideal equation leaves out.
