Aerospace OHD Quiz

Why do astronauts avoid bringing bread to space?

• It’s too crumbly

• Bread becomes rock-hard in space

• Zero gravity ruins the yeast

• Tortillas are more delicious

Answer explanation

Bread creates crumbs that float around in microgravity, risking damage to equipment or getting stuck in astronauts’ eyes. Instead, astronauts use tortillas—they’re crumb-free and perfect for space tacos!

As altitude increases, the amount of lift generated by an aircraft's wing:

• remains unchanged.

• increases.

• decreases.

• no idea!

Answer explanation

As we increase altitude, the air density decreases. This means that the pressure difference between the upper and lower surface of the wing is less dramatic, which means less lift!

What’s the real reason rockets have multiple stages?

• To improve aerodynamics during ascent.

• To enable reusability of rocket components.

• To distribute fuel more efficiently across the mission.

• To lose weight as fuel burns.

Answer explanation

Each stage carries its own fuel and engines, but once a stage burns through its fuel, it becomes dead weight. By dropping empty stages, the remaining rocket becomes lighter, allowing the next stage to fire more efficiently and continue accelerating toward space.

Pressing on an aircraft's rudder pedals will cause the aircraft to:

• pitch (nose moves up/down)

• yaw (nose moves side-to-side)

• roll

• accelerate

Answer explanation

The rudder pedals control the aircraft in yaw by moving the rudder control surface attached to the vertical 'fin' stabilizer - this creates an aerodyamic force on the fin, pushing the rear of the aircraft to the left or right.

Where is the farthest a human-made object has travelled to in space?

• We have sent spacecraft up to Pluto.

• The Moon.

• We passed the solar system boundaries and we’re still going.

• Mars has been the farthest we have gone.

Answer explanation

NASA’s Voyager 1 spacecraft is the farthest object from Earth. It left the solar system boundaries in 2012 entering interstellar space, or the space between stars.

The aircraft engine shown is a:

• turboprop engine

• turbofan engine

• turboshaft

• turbojet

Answer explanation

Large commercial airliners use turbofan engines. These have the same core components as a turbojet but a large portion of the the thrust is produced by the bypass flow through a front-mounted fan.

What is the minimum distance above the surface of Earth where you can have a spacecraft on a stable orbit?

• 2,000 km

• 15,000 km

• 180 km

• 35,786 km

Answer explanation

180 km! Like the distance between Edinburgh and Inverness (as the crow flies). Below 180 km a force known as atmospheric drag will cause any object to decelerate and eventually come back to Earth (if it doesn’t fully disintegrate on the way back).

A 1:16 scaled plane-model is tested in a wind tunnel. How can we get the same force as the full-scale plane?

• By using the same wind speed.

• By increasing wind speed by 2 times.

• By increasing wind speed by 4 times.

• By increasing wind speed by 16 times.

Answer explanation

It is possible to obtain same forces between a scaled- and full-scale model using the flow similarity principle i.e., keeping the Mach number and Reynolds numbers the same.

Which propulsion system would be best suited for a very long-duration mission?

• electric propulsion

• chemical propulsion but using liquid propellants

• chemical propulsion using solid propellants

• cold gas systems

Answer explanation

Electric propulsion (EP), when compared with chemical propulsion, is not limited in energy, but is only limited by the available electrical power on-board the spacecraft, which is used to accelerate a propellant to achieve thrust. Therefore, EP is suitable for low-thrust (micro and milli-newton levels) long-duration applications on board spacecrafts.

At normal atmospheric conditions, you would need approximately _____ litres of gaseous hydrogen to achieve the same amount of energy as one litre of kerosene jet fuel.

• 3

• 30

• 300

• 3000

Answer explanation

Clearly this is not feasible for aviation! One solution is to highly pressurise and cool the hydrogen to liquid form.. this would slash the 3000 litres to just 4. But this comes with massive technical challenges!