This post is for teachers in the 22 communities across the U.S. and Canada that just started SSEP Mission 9 to ISS. You are invited to use this Challenge with your students to get them thinking about the concept of microgravity (the technical name for the phenomenon of ‘weightlessness’). In the Challenge below, students are asked to post what they think is an answer to the Challenge in the comment section. Please encourage your students to do so, so that all students visiting this blog post can see what other Mission 9 students across the U.S. and Canada are thinking. Let’s use this blog post as a social media platform for sharing thoughts about microgravity. 

The solution to this Challenge will be posted Monday, September 21, 2015. 

Note that this Challenge is covered as part of the program start Skype for your community’s Local Team of Mission 9 educators. These Skypes for the Mission 9 communities are being conducted by SSEP National Program Director Dr. Jeff Goldstein through September 18, 2015.


I’ve heard a lot about this weightlessness stuff, with astronauts having a great time floating around in space. So I wanted to find out first hand what’s going on up there. Since they don’t have a spare seat on the next flight to low Earth orbit (at least not yet), I looked far and wide to find an amazingly tall mountain whose peak rises to the Space Station’s altitude in orbit so I could climb up and see for myself.

Station is currently orbiting the Earth about 250 miles (400 km) above sea level, and, by the way, crew and station are zipping along at 4.7 MILES PER SECOND (7.6 km/sec) relative to you sitting there at your computer. Bam. The Station just moved 4.7 miles. Really.

Hey! If you want to track station altitude, speed, and position over Earth, in REAL TIME, go to the SSEP home page http://ssep.ncesse.org, and in the Multimedia section at the top, open the toggle titled “ISS Current Location”. You’re invited to explore the other two toggles as well.

It took some Googling, but I found that really tall mountain! See my mountain in the picture? It accidentally got captured in an old Space Shuttle photo. Mt. Everest is only 5.5 miles (8.8 km) high. MY mountain (Jeff’s Peak) is 260 miles (420 km) high. I found it south of the Land of Make-Believe, down a not too well traveled path. Still, you’d think someone would have noticed it since it’s 47 times higher than Mt. Everest. (Have you ever heard of Jeff’s peak? No? See, nobody knows about it!)

So this week, I’m going to take the time to climb my mountain, and in my hand is my trusty bathroom scale, spring-loaded and guaranteed to be accurate at any altitude. I’ll camp out at the top, and I’ll wait until Space Station flies right by my mountain, so I can look in the windows and see if those lucky astronauts are weightless and floating around.

Here now the challenge—
As soon as I confirm they’re weightless in the Space Station, I’ll step on my bathroom scale to see my weight. If I weigh say 150 lbs (68 kg) when I’m standing on my scale in my bathroom at home, what will I weigh on top of my mountain?

Hint: You don’t actually need to calculate my weight. I’ll do that in the Solution to the Challenge. Your assignment—if you decide to accept it—is to guess what you think I’ll weigh and why. Hmmmm, lots of possibilities.

Post your guesses below, and remember to include why you think your guess is correct. Students of ALL ages are welcome to post a guess.

I’ll even give you a week to noodle on this in class, and at home with your parents, and then post your guesses. I’ll post the answer next Monday, September 21, 2015, right here at the SSEP National Blog. See you then, and good luck noodling!

Also – if you want to follow along with the latest news from the Student Spaceflight Experiments Program (SSEP), you are invited to subscribe to the SSEP National Blog at the bottom of the right column.


The Student Spaceflight Experiments Program (SSEP) is a program of the National Center for Earth and Space Science Education (NCESSE) in the U.S., and the Arthur C. Clarke Institute for Space Education internationally. It is enabled through a strategic partnership with NanoRacks LLC, working with NASA under a Space Act Agreement as part of the utilization of the International Space Station as a National Laboratory. SSEP is the first pre-college STEM education program that is both a U.S. national initiative and implemented as an on-orbit commercial space venture.

The Smithsonian National Air and Space MuseumCenter for the Advancement of Science in Space (CASIS), and Subaru of America, Inc., are U.S. National Partners on the Student Spaceflight Experiments Program. Magellan Aerospace is a Canadian National Partner on the Student Spaceflight Experiments Program.

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