When engaging in discussions about space exploration, especially regarding the feasibility of human habitation in space, the dialogue often leads to the International Space Station (ISS). This is logical; the ISS stands as the largest and most ambitious crewed space station throughout the timeline of contemporary space science and has been operational since 2000, carrying out remarkable experiments and encountering the occasional near-disaster. Naturally, only a select group of extensively trained personnel have the privilege of boarding the ISS, making it somewhat challenging for those of us on the ground to envision the experience of being there. At first glance, it may be hard to tell, but the ISS is, in reality, larger than a six-bedroom house, with an internal structure reminiscent of the layout of a jumbo jet.
Though the ISS may not resemble a conventional house in space and certainly lacks the spaciousness of an average suburban residence, this doesn’t imply that all astronauts on board are crammed in like sardines. While much of the ISS comprises equipment such as solar arrays, the habitable section of the station is quite roomy enough to accommodate its sizable crew of astronauts. Arranged in a series of tubes and compartments, those residing in the ISS certainly have ample legroom.
The entire length of the ISS is approximately equivalent to that of a football field. The ISS can be observed through a telescope, depicted in an artist’s rendering, or, if we’re fortunate, captured in a photograph taken from the station itself. Nevertheless, none of these perspectives truly convey the vessel’s actual dimensions or clarity, unlike standing right in front of it. Based solely on such renderings, it could appear to be a straightforward satellite like the Hubble Space Telescope, which spans roughly 43 feet in length.
In reality, measuring the ISS from one end to the other reveals its length to be just under 360 feet, which is akin to the size of a professional U.S. football field from end zone to end zone. The entire station has a mass of 925,335 lbs., roughly comparable to the weight of two and a third empty Boeing 747 aircraft.
As documented by NASA, the assembly of the ISS required a total of 42 flights to deliver and construct the various sizable modules and components of the station. Some of the largest modules are similar in size to individual satellites like the Hubble. For example, the Russian Multi-Purpose Laboratory module measures about 42 feet wide. Therefore, instead of likening the ISS to a single satellite, it may be more accurate to compare it to a network of satellites interconnected.
The habitable area exceeds that of a six-bedroom house. While the ISS is enormous, significant portions of this size consist of uninhabitable equipment and modules, including solar panels located on both sides of the station. Although the entire structure isn’t fully habitable, this does not mean astronauts on board lack space to navigate. Approximately 218 feet of the station’s length is pressurized, providing a safe environment for humans to move around in its microgravity, although this same microgravity condition is why open flames are prohibited aboard the ISS.
The ISS includes a variety of interconnected modules, such as docking adapters for incoming and outgoing vessels, airlocks separating different modules, research modules for conducting experiments, and living quarters where residents sleep and engage in approved leisure activities. When you tally the total habitable space between the functional and living modules, ISS inhabitants enjoy more room to maneuver than what would typically be found in a six-bedroom house. The living areas alone consist of six sleeping quarters, two bathrooms, a gym, and a 360-degree cupola for observing Earth and the stars.
Some astronauts have drawn parallels between the interior of the ISS living quarters and the cabin of a Boeing 747. The key distinction is that, unlike in a passenger aircraft, there are no floors necessary due to the absence of gravity, making it resemble a series of tubes and tunnels instead of corridors.
