The International Space Station is, to put it lightly, a miracle of modern technology. Even then, it has a finite amount of storage space and no way to produce a self-sustaining food supply. This means that, periodically, supply runs need to be made. Keep reading to find out exactly how supplies reach the International Space Station.
Hohmann Transfer 1
The astronauts begin by launching their rocket straight up to enter into orbit. Next, they should take a step back and close the distance to the ISS. You cannot, however, just turn your spaceship away from Earth and throw the engines because the spaceship would soon move away from the ISS and then into deep space. Instead, they go to a greater circular orbit by performing a Hohmann Transfer. The spacecraft uses its engines twice to carry out this maneuver; once to propel the spacecraft further into space and once again to hold it in that second orbit. The astronauts are unable to accurately determine the exact location of the circular orbit due to the differing characteristics of each ship and propulsion system.
Hohmann Transfer 2
Next, the astronauts shoot a number of short, speedy corrections to place them at the exact spot where one orbit around Earth takes 86 minutes, only 4 minutes slower than the ISS’s 90-minute time. This slight variation in timing is huge. The final phase will be to undertake a second Hohmann Transfer as the spacecraft approaches the ISS. That final transfer puts it 250 miles above the planet, right in front of the International Space Station. Once the spaceship gets back on its path, the astronauts turn it around and use the spacecraft’s thrusters to slow down, giving the ISS a chance to catch up. Then, it’s as simple as matching the ships up to each other.
Docking
Once the ships line up, they connect and create an airtight seal. The computer system will let the astronauts know once it’s safe for them to move between their ship and the station. Once it’s safe, it’s as easy as moving the supplies over. The zero-gravity environment of outer space makes this a pinch, as none of the supplies have any weight to them. Once the supplies have been transferred, the transportation crew can prepare to return home.
And that’s how supplies reach the International Space Station! Cargo transportation has always been an important part of society and while atmospheric transportation is at least a little bit more complex than ground or air, astronauts still need to find cargo securing solutions to keep the propulsion from sending everything flying around. Maybe it’s not so different after all!