How to become an Astronaut: One step at a time
I have Fitbit sense fitness watch that I wear consistently both for the purposes of tracking my daily walks and gym visits. Additionally, I am interested in the health data the watch collects such as heart rate and sleep data and what I can do to improve my wellbeing or in general to just explore what health data can for human wellbeing.
Recently I got a notification on my phone from the Fitbit app that I had achieved a badge, a sort of award for achieving certain fitness milestones such as number of steps in a day or how many floors you have climbed. Normally these sorts of notifications are dismissed without thought, as they are often aimed to bring attention away from life and to spend more time (money) on an app or website. Particularly the game-ification aspect of apps can be troubling such as the robin hood trading app and various sports gambling apps which aim to draw the user into fixating the app. However, I don’t mind this on the Fitbit app since this game-ification does not necessarily mean I will exponentially spend more money but rather take some time to focus on my health.
Anyway, the badge I received was the astronaut badge was the Astronaut badge, awarded for climbing over 28,000 floors over my lifetime, at least since I’ve had an account with Fitbit.
Fitbit Astronaut Badge
This sounded like a lot to me but then I realised I had only been using my watch for just about a year, though I admit I do live in a 5th floor apartment with no elevator. However, normally the badges are linked to a very tangible number. For the lifetime steps taken, there is a New Zealand badge for the amount of steps taken to walk all the coastlines of the north and south islands of New Zealand, accounting for the variation in step size, this is a fairly accurate number. However, the astronaut badge raised some questions:
- How high do you have to climb to be considered an astronaut?
- Is the number of floors climbed correct for being an astronaut?
How high do you have to climb to be considered an astronaut?
When I first thought of the astronaut badge, I thought that the common idea of an astronaut would be on the International Space Station which orbits above 400 km. However, I know that people who have gone above the Kármán line are considered astronauts, a line defined as the boundary of earth’s atmosphere and outer space is set at 100 km, today designated by the FAI, an international organisation that designates astronauts. The US Military has historically considered 80 km as the line at which people that have gone past received their astronaut wings, an award for becoming an astronaut. However for the purposes of the calculations I’ll make I will use the 100 km definition of space ( sorry Richard Branson). I checked the Fitbit website [1] for a list of all the possible badges and another badge designed the Satellite Badge is awarded at 38,000 lifetime floors. Therefore, I can consider the astronaut badge as the floors needed for reaching the Kármán line and the satellite badge for reaching a height of any orbiting satellite.
Is the number of floors climbed correct for being an astronaut?
So if the 100 km is the height and 28,000 floors are required to reach that height, is the height of the floors realistic? Assuming equal floor heights, it worked out to a floor height of 3.57 meters. Looking at a research paper examining floor heights for energy efficiency [2], a common floor height inside each floor is found to be 3.1 meters. However, since there floor itself takes up space, the distance to travel between floors was found to be 4.65 meters. This is for residential floors, tall buildings such as skyscrapers contain mechanical floors for building equipment such as air conditioners and elevator rooms that are much larger, found to be on average 4.65 meters for the interior height and 6.2 meters for the total height, assuming a mechanical floor is required for every 30 normal floors. The average of interior and total floor heights are found to be 3.15 meters and 4.7 meters respectively. Using the definitions of interior and total floor heights, this gives use a range for floor heights between 3.15 meters and 4.7 meters. It is reasonable to expect that what a floor is defined as by Fitbit should roughly fall between this range since what is defined as a floor is ambiguous for the purposes of Fitbit awards.
From the average floors heights found, we see that the 28,000 floors is correct to reach the Kármán line and become an astronaut. This means one could quite literally walk their way to being an astronaut given a tall enough staircase. What about the satellite badge?
Satellite Badge
The satellite badge requires walking 35,000 floors which given our calculated range of floor means a range of 110 km and 164.5 km. Typically most low earth orbit (LEO) satellite orbit above 350 km, the ISS orbiting above 400 km and all the way to geostationary satellites orbiting above 35,000 km. Most satellites don’t orbit below 300 km since the atmospheric drag would gradually re-enter earth and burn up or require frequent boosts to maintain that orbit. The lowest orbiting satellite I have found was the Super Low Altitude Test Satellite (SLATS) launched by the Japanese space agency JAXA launched in 2017. The lowest orbit it achieved was 167.4 km, requiring continual thrusters to keep it at this orbit due to the substantial atmospheric drag. Given that the Fitbit badges would need to end in round numbers, this seems plausible that the 35,000 steps could achieved to reach an orbit to be a satellite around Earth. This was assuming an lowest part of the orbit, a highly eccentric orbit may be able to reach a lower height above earth as it would undergo less atmospheric drag.
Pretty cool that Fitbit did their research for their badges!
Illustration of JAXA's Super Low Altitude Test Satellite