Materials
Per group (~3 children):
- Egg
- Plastic cup
- Paper
- 3-4 balloons
- Scissors
Other materials:
- Cellophane
- Bubble wrap
- String
- Cotton wool
- Tape
Return to Earth: Build a Lander
Summary
Students will work in groups to design, test and build a model lander to safely transport their “astronaut” to Earth. This activity will provide your class with an exciting context within which to explore the effects of gravity, air resistance and friction on movement.
Goals
- Understand that unsupported objects fall towards the Earth because of the force of gravity,
- Explore and raise questions about the effects of gravity, air resistance and surface area by observing how their craft’s descent and landing is affected by features such as parachutes, balloons and padding.
- Work scientifically, designing and testing a variety of landers and carrying out fair tests to determine which designs are the most effective.
Planning
Background
All astronauts aboard the International Space Station today return to Earth via a Russian spacecraft called Soyuz TMA. The spacecraft takes less than 4 hours to return to Earth and land on a flat and remote steppe in Kazakhstan, a country in central Asia.
To safely return the astronauts to Earth the spacecraft has four main design features:
- Two out of three modules that make up the spacecraft are jettisons prior to entering the Earth’s atmosphere in order to lighten the load and slow the descent.
- Four parachutes are deployed 15 minutes before landing, dramatically slowing the vehicles rate of descent from 230 metres per second to just 7 metres per second.
- One second before touchdown three small engines on the bottom of the spacecraft fire-up to soften the landing further.
- Custom-fitted liners, made individually to fit the body of each astronaut, are used cushion the impact of landing.
Curriculum Links
- UK National Curriculum, KS2, Science: Forces
- UK National Curriculum, KS2, Science: Working Scientifically
Instructions
Begin the activity by asking students what happens when an object falls to the ground? (Two forces affect it: Gravity pulling it down and Air Resistance slowing its fall.
- Explain that this is an issue for scientist who need to transport astronauts safely from the International Space Station back to Earth.
- Open a discussion about how they could design a craft to safely transport an astronaut to Earth. Which features could they include and how would this help?
a. Parachutes use air resistance to oppose the force of gravity and slow down the rate at which their craft falls to Earth,
b. Padding can help absorb the impact,
c.Increasing the surface area of the craft to make it less streamline and thus, slow the descent.
d. Providing a context for an investigation always excites children's imagination and gives them a reason for their investigations. Split the class into groups of ~3 students. Provide each group with an uncooked egg; this will act as their astronaut.
Note: Ensure the first thing each group does is puts their “astronaut” in a “space suit” made of cling film, to avoid any sticky accidents!
3. Provide each student with the materials listed and give them around 45 minutes to explore the materials, using them to design and test a spacecraft that will be successful in transporting their astronaut to Earth safely.
4. When their time is up, invite the groups up to the front of the class one at a time. They will each explain the features of their design to the class.
5. You will then drop each lander from the top of a stepladder, asking the class to closely monitor the descent and impact.
Conclusion
By the end of this activity students should have an improved understanding of how the forces of gravity and air resistance affect a falling object, specifically the Soyuz spacecraft returning to Earth from the ISS, and the features built into the design of the spacecraft to slow the descent and soften the impact
Evaluation
Evaluate each group based on their design choices and the effectiveness of their lander. Was their lander successful in safely transporting their astronaut to the Earth? What affect did different aspects of their design have on the landing? What would they change if they were to make a second lander?
Age
- 7-11
- All ages
Duration
Medium (30-60 mins)