Astronauts and the International Space Station are one of the best teaching gateways in all of science. They bring together biology, physics, engineering, health, forces, motion, and the sheer strangeness of life in microgravity. Students are usually hooked very quickly, but the real teaching win comes when that fascination turns into explanation.

That is why I like using surprising, evidence-rich facts when teaching this topic. A strong fact does more than entertain. It gives students something to explain, question, and connect to bigger science ideas.

A resource that fits this approach especially well is this one:

Astronauts & ISS | Space Strange But True Facts + 2 Truths & a Lie Activity Set

It is an easy way to turn curiosity into discussion, reasoning, and misconception-checking without needing a giant prep session first.

If you want to widen the topic into astronaut health and life in space, this paired reading resource also fits naturally:

How do Astronauts Stay Healthy? | Reading Comprehension 2 Passage & Questions 

Now let’s get into six facts that make astronauts and the ISS unforgettable for middle and high school science students.

A quick teaching playbook first

Before the facts themselves, here are three simple ways to use them in class.

Use them as a starter. Put one fact on the board and ask students to write, “Why might this happen in space?”

Use them as Two Truths & a Lie. Give students three statements, two true and one false, and ask them to justify which one is the lie.

Use them as Micro-CER tasks:

• Claim: What does this fact show about life in space?

• Evidence: Use the fact itself.

• Reasoning: Explain the science behind it.

That is exactly why the Astronauts & ISS Strange But True resource works so naturally here. It gives you a high-interest hook that still pushes students into proper science thinking.

1. Astronauts on the ISS see about 16 sunrises and 16 sunsets every day

The ISS circles Earth about 16 times every 24 hours, so astronauts on board pass through about 16 sunrises and 16 sunsets each day. NASA lists this directly in its ISS facts and figures. (NASA)

This is one of those perfect opening facts because it immediately makes students rethink what “day” means in orbit. It also helps you teach:

• orbit time

• motion around Earth

• relative movement

• why the ISS environment feels so different from life on the ground

A great classroom question is:“If astronauts see 16 sunrises a day, why does their sleep schedule not follow those sunrises?”

That opens the door to timekeeping, routines, circadian rhythms, and how human biology interacts with engineering.

2. Many astronauts get taller in space

NASA materials explain that astronaut height can increase by about 3% in the first few days of weightlessness because the spine stretches out in microgravity. (NASA)

This is a brilliant fact for showing students that gravity is affecting their bodies all the time, even when they are not noticing it. On Earth, gravity constantly compresses the spine slightly. In orbit, that load is reduced, so astronauts often become temporarily taller.

This fact connects beautifully to:

• the musculoskeletal system

• gravity and force

• body systems in space

• why exercise is essential on the ISS

If you want to develop that angle more fully, the How do Astronauts Stay Healthy? reading passage set is a natural next step because it directly addresses how microgravity affects bones, muscles, circulation, and health. (The Teaching Astrophysicist)

3. Space toilets use airflow, not gravity

On Earth, toilets rely on gravity. In orbit, they cannot. NASA explains that space toilets use airflow to pull urine and feces away from the body and into the correct waste collection systems. (NASA)

Students almost always remember this fact because it feels funny and strange, but it is actually a superb engineering example. It shows how even ordinary daily tasks have to be redesigned in space.

This is a wonderful point for asking:“What other everyday objects would completely fail if gravity disappeared?”

That question turns the lesson outward into engineering design and life-support systems.

It also helps students see that science in space is not only about rockets and stars. It is about solving practical problems under unfamiliar physical conditions.

4. Astronauts wear a maximum-absorbency garment during spacewalks

NASA documentation on the spacesuit and EVA systems explains that astronauts wear a maximum absorbency garment, essentially a specialized absorbent undergarment, during spacewalks because they cannot simply take the spacesuit off when needed. (NASA)

This is another fact students remember immediately, but it also has real teaching value. It shows that long-duration tasks in space must be planned in detail, including hydration, waste, comfort, time limits, and safety.

It is a useful reminder that:

• a spacesuit is really a small spacecraft

• spacewalks are physically demanding

• astronaut systems must support the body in many ways at once

A good question here is: “Why is a spacesuit more than just protective clothing?”

That moves students toward thinking about temperature control, oxygen, carbon dioxide removal, pressure, communication, and mobility.

5. Long missions can change astronauts’ eyes and brains

NASA now refers to a collection of spaceflight-related eye and vision changes as SANS, or Spaceflight Associated Neuro-ocular Syndrome. NASA sources describe findings such as optic disc edema, flattening at the back of the eye, and shifts in vision during or after long-duration spaceflight. (NASA)

This is one of the most important facts in the topic because it helps students see that long-term spaceflight is not just “cool.” It is also a medical challenge.

It gives you a strong way into:

• body systems in microgravity

• fluid shifts in the body

• why astronaut health is a real science field

• the challenges of future Moon and Mars missions

If you are building a deeper astronaut-health sequence, again, the How do Astronauts Stay Healthy? passage set fits perfectly because it connects those human-body changes to engineering and prevention strategies. (The Teaching Astrophysicist)

6. There is basically no laundry on the ISS

Because water, mass, and system complexity are such big constraints in orbit, astronauts do not run ordinary laundry on the ISS. NASA life-support and mission-design documents discuss clothing being discarded rather than routinely washed, and trash cargo is often packed into vehicles that burn up on re-entry. (NASA Technical Reports Server)

Students usually find this both funny and surprising, but it is a great systems-thinking example. It shows that:

• water is precious in space

• every system has a mass and energy cost

• “simple” conveniences on Earth are not simple in orbit

• waste management is part of mission design

This fact leads nicely into:“If you had to redesign clothes for space, what would matter most?”

Students often come up with excellent ideas about durability, odor control, lightweight materials, and reusability.

A simple 3-lesson mini-sequence you can actually use

Lesson 1: Hook and misconceptions

Start with a Two Truths & a Lie activity using astronaut and ISS facts. This gives you immediate engagement and reveals what students think they already know.

Best fit: Astronauts & ISS | Space Strange But True Facts + 2 Truths & a Lie Activity Set

Lesson 2: Read the science of astronaut health

Use a structured reading passage to move from “weird facts” into actual explanation: How do Astronauts Stay Healthy? | Reading Comprehension 2 Passage & Questions (The Teaching Astrophysicist)

That works especially well because it is differentiated with two reading levels and connects biology, health, and space science.

Lesson 3: Extend into wider space exploration

If you want to stretch the topic into a bigger unit, a research template can help students move from comprehension into inquiry. A good next step is: The Space Race | Astro Science Research Project Template (The Teaching Astrophysicist)

That gives students a broader context for why human spaceflight matters and how astronaut technology developed over time.

You could also branch into space hazards and engineering with: Space Junk | Space Science Research Project Template (The Teaching Astrophysicist)

Why these facts work so well

The best astronaut and ISS facts do more than sound surprising. They reveal the deeper science of life in orbit:

• how gravity shapes the body

• how engineering replaces everyday Earth systems

• how health, physics, and design all connect

• why human spaceflight is both inspiring and difficult

That is why this topic is so useful in middle and high school science. It naturally blends wonder with explanation.

And because strange-facts formats are flexible, they can work as:

• starters

• station activities

• review tasks

• sub plans

• quick writing prompts

• or full discussion lessons

If you want a straightforward way to make astronauts and the ISS instantly more engaging, the Astronauts & ISS Strange But True + 2 Truths & a Lie resource is a very natural entry point.

Thanks for reading

Cheers and stay curious

Oliver - The Teaching Astrophysicist