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1. Why do spacecraft have thermal protection?
   
2. What does a shuttle tile look like up close?
   
3. Why are some parts of the Space Shuttle white but others are black?
   
4. Which space vehicle needs more thermal protection: the one that lands on Mars, or on Jupiter?
   
5. Is there grout between the tiles on the shuttle, like the tiles on my house?
   
6. What does its thermal protection system protect the space shuttle from?
   
7. Why does the Space Shuttle have wings?
   

1. Why do spacecraft have thermal protection?
   Because friction between a fast-moving spacecraft and the atmosphere generates enough heat to melt metal. That is why shooting stars glow: they are burning up from the heat.
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2. What does a shuttle tile look like up close?
   The original shuttle tile is made of silica fibers. They are very small (greater than ten times smaller than a human hair in diameter) and are very loosely packed. The majority of the volume is actually void space.
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3. Why are some parts of the Space Shuttle white but others are black?
   There are two reasons. First, white materials reflect a good percentage of incident solar/radiative heating. However, the equilibrium temperature increases with level of incident radiation. Eventually the reuse temperature of practical materials is exceeded. At some point it is more effective to switch to black material because it radiates heat back into space in proportion to T to 4th power. Second, convective heating from hot gas flow is concentrated on leading edges and windward (belly) locations. This type of heating is not effectively mitigated by white color, so in these locations it is better to use black materials.
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4. Which space vehicle needs more thermal protection: the one that lands on Mars, or on Jupiter?
   The larger the planet, the more severe the heating, and therefore the need for thermal protection, so therefore Jupiter would need more thermal protection.
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5. Is there grout between the tiles on the shuttle, like the tiles on my house?
   Well, not quite. There is a gap filler between the tiles and while it may have the consistency of grout, it is capable of handling pretty high temperatures (which house grout can't).
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6. What does its thermal protection system protect the space shuttle from?
   Too much heat (radiation) or too much cold.
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7. Why does the Space Shuttle have wings?
   So it has lift, much like an airplane, that allows it to change direction (within the atmosphere) and have sufficient crossrange capability if an alternate landing site is preferred. It also allows it to land like an airplane so that the TPS is not damaged on landing (as it would be if it came down on a parachute). This is an important consideration for TPS (and Shuttle) reusability.
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