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IntroductionThe Solar Orbiter mission aims to produce images of the Sun and perform detailed measurements of the Sun’s properties.

Those involved in the mission hope that this will help us understand how the solar system works.

The sun has a temperature of almost 6000 ºC and to perform

Keeping it cool This activity has been designed for one session of approximately 40 minutes to an hour. If the extras are followed more sessions will be needed. You will need to allow time to prepare the materials used in the session.

This activity was inspired by and developed with Nikki Jahn, a STEM Ambassador. You can find Nikki’s profile on page three.During this activity you will introduce ideas about keeping materials and tools cool whilst in space and try to encourage the students to apply these ideas during a hands-on activity..

Warming cabinet, oven or hair dryer

Thermometer

Chocolate

Scissors

Adhesive (tape or glue)

Stopwatch

Ruler

its mission the orbiter will have to get very close to the sun’s surface. This means the orbiter needs a protective heatshield for the side which faces the sun. The instruments that look directly at the sun peer through this heatshield, which prevents the spacecraft from getting so hot that the materials melt and the electronics stop working.

This activity explores how materials and apparatus can be kept cool whilst in hot conditions.

A variety of materials: – thin metal foil– insulator (polystyrene)– plastics (e.g. milk bottles,

plastic pots)– cardboard, etc

Note for STEM Ambassadors: schools will have many of the items you need, so check with the teacher before your session. A risk assessment should be done before starting this activity.

What you needThe numbers needed will depend on the size of the group. Allow students to work in teams of two to four.

2 Keeping it cool

What to do Each team of students has to design, make, test and evaluate an appropriate heatshield to protect a square of chocolate from a heat source.

In this instance the chocolate represents the payload of important equipment and tools on the solar orbiter and the heat source represents the sun.

The students need to make a box to contain the chocolate square (the bottom of a polystyrene cup works well) and then think about which of the materials available will protect their chocolate from the heat.

Students should research the different properties of the materials they have available. Do they need the material to be a good conductor or a good insulator? (Remember students can use a mixture of materials in their design, but they should give reasons for each material used.)

If you wanted to expand this session you could ask the students to develop tests to determine the suitability of each different material in forming a heat shield for the chocolate.

Once they have researched the materials available, students then design and make their heatshield for their chocolate.

Remind the student they will need to observe whether the chocolate has melted so the box will need to be opened.

To test the heat shield, place the covered box into a warming cabinet or oven set at 50˚C for two minutes to see if it protects the payload. Chocolate melts at body temperature so the oven does not need to be too hot.

Alternatively you could heat the box using a hair dryer for a set time keeping the hair dryer a set distance from the box (e.g. 30cm away) during heating.

To ensure the experiment is reliable, make sure that the students have the same amount of chocolate, and the same heating method is used for the same amount of time.

Questions to think about:

How well do the designs work at keeping the chocolate cool and why?

How do the materials change over time?

How could the design be improved? [Reflective surfaces on layers facing the sun will reflect the heat more effectively]

It can sometimes be hard to distinguish between degrees of melting when inspecting chocolate, so make this exercise more quantitative by including a small thermometer or thermocouple in the box.

Curriculum links You may wish to discuss these areas when doing this activity:

England Science: Energy changes and transfers, Space physics

Scotland Science: Energy 3-04a, b

ExplanationThis activity looks at how the Solar Orbiter is being designed to protect its payload from energy transfer.

There are three ways that energy can be transferred:

Conduction – When a solid material is heated its particles gain energy, and this energy causes the particles to vibrate. The more energy that is transferred, the more vigorously the particles vibrate. The particles bump into nearby particles which causes them to vibrate, transferring energy from the hot part to the cold part of the material. If the substance allows the energy to move easily through it, it is a conductor. An insulator resists the flow of energy through a substance.

Convection – The particles in a liquid or gas move. When particles have a lot of energy they move more quickly, transferring energy to areas with less energy. The net energy transfer is from hot to cold areas.

Radiation – Radiation is energy transferred by electromagnetic waves. Electromagnetic waves (for example infrared) can pass through a vacuum. When they hit an object (for example the Solar Obiter) they can transfer their energy to the object.

Space is a vacuum (it has no particles) and so conduction and convection do not occur. (Remember conduction can occur between the materials of the spacecraft itself, but not between the craft and space).

Radiation from the sun would cause the exposed surfaces of the Orbiter to heat up very quickly. This energy could cause damage to the instrument payload so the heat shield is designed to reduce this energy transfer and keep the instruments at a stable temperature.

The heat shield also needs to be thermally isolated from the spacecraft itself to stop the conduction of heat from the shield to the Orbiter. It is designed to have gaps between the layers of protective material to allow heat to radiate into deep space, rather than conduct directly into the spacecraft. Can you incorporate these ideas into the activity?

Keeping it cool 3

Some extrasWhy not see how long the chocolate lasts in the student’s designs before it melts? Check at one minute intervals.

Look at the properties of different types of chocolate e.g. milk chocolate melts faster than dark chocolate due to the higher levels of fat compared to dark chocolate. Start with dark chocolate so that you have a larger temperature range to play with.

The ideas can be taken further. Although the side of the orbiter facing the sun will be hot, the other side looks at deep space, which is extremely cold.

Can the students improve their heatshield design to take account of this? It may be best to test your designs using a hairdryer in this instance.

Spacecraft can be fitted with devices to carry heat from hot locations to cold ones. These are called heat pipes. Some good, but rather technical explanations of the technology can be found here www.thermacore.com/thermal-basics/heat-pipe-technology.aspx

Most space missions use heat pipes to transfer heat away from a hot place to a cooler one, however on the Solar Orbiter, the temperatures are so high the spacecraft is being designed to work without heat pipes!

There are lots of ideas we can use when thinking about ‘designing for the space environment’.

Set the students another ‘Testing for Space’ scenario for example spacecraft have to survive a number of extreme environments like the forces on the craft when it is launched. Ask your students to build a spacecraft which has to protect their instrument payload (you could use an egg for this) from getting destroyed or damaged. You can use clean, recycled plastics and card. Use a plastic storage crate being shaken side to side to test their designs.

Nikki is part of a team who liaise with the instrument builders who are providing the

10 payloads for the Solar Orbiter mission.

Industry sector: Aerospace

How I got here: I studied for a degree in Physics at Imperial College. I was always very interested in space when I was younger, but didn’t realise the size or extent of the space industry in the UK until I started searching for graduate jobs. I got accepted onto the Astrium Graduate Development Programme in 2006, and spent the next two years getting a good overview of spacecraft engineering and design.

My favourite part of my job: I travel quite regularly in Europe to see the instrument teams, the European Space Agency and NASA representatives that we work closely with. It’s a really interesting job for meeting fascinating, dedicated engineers from all across the world.

Likes: Thames /South Bank festivals, Glastonbury, New York and Secret Cinema.

Dislikes: I really can’t stand seafood!

The future: Like any space engineer, working abroad is a career goal! It’s a great industry for stepping outside of your comfort zone and into another culture for work.

What is engineering? Engineering is applying an understanding of physical principles to the design and manufacture of real-world things.

Profile: who uses these ideas?Nikki JahnSolar Orbiter Payload Interface Engineer, Astrium

Handy hints Designing for space has many challenges, for example you might encounter extreme heat, extreme cold, high radiation environments, dust storms on Mars, and much more.

Start your session by asking what the students think it would be like in space, for example do they think it would be hot or cold? Then introduce the Solar Orbiter and the problems it may encounter (like the extreme heat as a result of being so close to the sun).

Remember any materials available like recycled plastics, foil or foam could be used for this session.

Why not limit the amount of materials available to the students and see what ideas they can come up with?

Do not eat the chocolate once it has been used in the test!

Royal Academy of EngineeringPrince Philip House, 3 Carlton House Terrace, London SW1Y 5DG

Tel: +44 (0)20 7766 0600www.raeng.org.ukRegistered charity number 293074

Generously supported by

www.baesystems.com/education

This is engineeringMany of the ideas and skills demonstrated in this activity are essential for engineering, in particular Aerospace Engineering.

Aerospace engineers look at the design, construction and science of aircraft and spacecraft. Generally you will need STEM A-levels (Advanced Highers in Scotland) including mathematics and preferably physics too. Alternatives include STEM related Advanced Diplomas or BTEC National Extended Diplomas, plus appropriate qualifications in mathematics and possibly physics. See www.ucas.com for more information.

Related subjects: Materials engineering

If students found the ideas presented in this session interesting then an apprenticeship in Heating, Ventilating, Air Conditioning and Refrigeration may be of interest. This is a broad industry with many occupations available to apprentices at the intermediate and advanced level. Visit www.apprenticeships.org.uk for more details. Apprenticeships can start at age 16 and students will need GCSEs including English and Maths.

In Scotland visit www.apprenticeships inscotland.com and in Wales wales.gov.uk/apprenticeships

Extra mathsKelvin, (K) is a unit of temperature which Scientists and Engineers use.

We can use the following equation to convert from degrees Celsius to Kelvin: [K] = [°C] + 273.15

Can you calculate the following in Kelvin?

The temperature of the Sun

Room temperature

Body temperature

Next stepsVisit the European Space Agency website for more details on the Solar Orbiter Mission https://sci.esa.int/solar-orbiter

Remember there are more resources at networking.stemnet.org.uk

For more on STEM Clubs visit www.stemclubs.net

For more information on Engineering: www.raeng.org.uk

For even more space resources visit www.esero.org.uk the European Space Education Resource Office

The STEREO website http://stereo.gsfc.nasa.gov describes another mission looking at the sun, this time working towards being able to see the structure and evolution of solar storms as they blast from the Sun and move out through space.

You may also find the NASA Sun-Earth system web page useful www.nasa.gov/topics/solarsystem/sunearthsystem/main/index.html

CREST Awards are easy-to-run, encourage students to continue with STEM subjects, and add real value to UCAS applications. To link this activity to CREST Bronze Awards, contact your CREST Local Coordinator: www.britishscienceassociation. org/crestcontacts

Finally, www.our-space.org has lots of useful videos and materials for further work on space.

Accredited Scheme