The station’s physical structure is also impressive: a suite of Russian living and research quarters, an American lab, a European lab, a Japanese lab, three connecting nodes, a Canadian robot arm, a multi-window cupola (with 360-degree views of Earth), and a football-field-sized truss structure, which holds four sets of solar arrays, batteries, and radiators. As you can imagine, all those additions ad up. The ISS weighs close to a million pounds (450,000 kilograms) and has a habitable volume greater than a six-bedroom house (13,700 cubic feet, or about 400 cubic meters).
Building, restocking, and crewing this colossal edifice in the sky has so far taken 37 Space Shuttle missions, 63 Soyuz flights, and even a
recent trip on SpaceX’s Crew Dragon. In addition, 73 Russian Progress freighters, 34 commercial Dragon and Cygnus cargo ships, nine Japanese H-II Transfer Vehicles (HTVs), and five European Automated Transfer Vehicles (ATVs) have delivered essentials such as food, water, clothes, experiments, fuel, tools, and spare parts.
However, these resupply missions aren’t only about restocking necessities. Their cargo has also contained birthday cards, holiday gifts, specific toothpaste, a 3D printer, and even an espresso machine. Recently, a Cygnus cargo ship dropped off a new toilet (which, admittedly, is a necessity), along with Estée Lauder skincare products for an in-space advertising campaign.
The past 20 years
Since the initial arrival of Shepherd, Gidzenko, and Krikalev to the space station, 63 additional expedition crews have lived and worked on the ISS for periods lasting from a few months to more than a year.
In the early days, rotating crews of three were dropped off and picked up by space shuttles. But because the shuttles didn’t usually linger for long, the crew needed an emergency escape option. Russia sent up regular Soyuz ‘taxi’ flights, whose crews spent a few days working with the expedition crew, dropped off a fresh ship, then returned home in the old one.
Those taxi flights permitted, for the first time, fare-paying visitors. In April 2001, engineer Dennis Tito paid $20 million to become the first commercial ‘spaceflight participant,’ spending a week aboard the ISS. His flight, however, would not be the last.