The international space station, launched in 1998 yet it still stands as one of humanities greatest achievements. A rare feed where 5 totally different regions work together to learn about the universe. This is why I find it fitting to write an article about the ISS. Here, we will go over the resupply procedure, the life of the astronauts on board, the uses, and finally some stats.
The resupply procedure
Since the retirement of the space shuttle in 2011 all astronauts travel to the ISS via the Soyuz module launched in Bakjonur, Kazachstan. The Soyuz consist of 3 modules: The reentry module, the spheroid orbital module and the service module, of which the latter 2 are destroyed when reentering the atmosphere. The reentry module lands down on earth after every launch by a combination of breaking engines and parachutes after it picked up the returning crew members if needed. Every Soyuz module can hold 3 crew members and are prepared for journeys up to 30 days. The astronauts at the ISS usually stay for about 6 months, and a module is usually launched every 3 months. SpaceX is also building their own crew Dragon module to bring astronauts to the ISS. This capsule is fully reusable and could limit the cost of human space travel. A recent successful explosion test with the Big falcon rocket brings the crew dragon capsule a little closer to becoming the go to crew launch module.
The ISS gets resupplied generally 8 to 9 times a year, by the commercial resupply services (CRS). The resupply is done by SpaceX using their Dragon 2 cargo capsule, Northrop Grumman Innovation Systems using their Cygnus flights, and Sierra Nevada Corporation with their Dream Chaser. Their contracts last till at least 2024 with NASA. The other space agencies use the Russian Federal Space Agency’s Progress spacecraft, the Japan Aerospace Exploration Agency’s H-II Transfer Vehicle and the China National Space Administrations Tianzhou spacecraft. On average a flight carries around 6000 kg of cargo and can return up to 3000 kg back to earth. Cargo ships can be connected to the ISS by the automated Kurs system which docks spacecraft automatically on to the ISS, or by being grappled with the Canadarm2 which docks the spacecraft.
The life of ISS crew members
There are always 3 to 6 members who normally stay for around 6 months. There are a few requirements to be an astronaut: First of all you have to have a bachelors degree in engineering, science or math; you also need to have 3 or more years of professional experience in a jet aircraft; and finally you have to pass the physical test. A knowledge of Russian is also a requirement that all astronauts have to learn. There have been 15 different nationalities on board, but many countries only submit 1 person.
Astronauts have to adapt to the microgravity on the ISS, this influences daily activities we ordinarily need gravity for like: flushing the toilet, showering, sleeping and so forth. The crew members need to exercise daily to prevent bone and muscle loss.
On board of the ISS the times is determined by the Greenwich Mean Time zone (GMT)/ ZULU time zone, this takes some time to get used to for the non European nationalities. A typical day on the ISS starts at 6 o’clock. They wash their hair with rinse less shampoo, and go to the toilet using straps to hold them, while the waste is being sucked in like a vacuum cleaner. In the morning the crew also participate in a planning conference with Mission Control in Houston. At 8:10 begins their first workout, and they start working. The work on board consist of constructing and working on the ISS, besides they also have to maintain the running experiments on board of the station. At 13:05 they take a hour long lunch break, their food consist of pre made meals that can be reheated or just be eaten without any preparation. The afternoon subsist of more exercising and working until 19:30. After which the crew eats another meal, and hold a crew conference discussing the work of the day. At 21:30 the crew proceeds to go to sleep. Every one has their own cabins where there is a big “body bag” which they can zip themselves in so they don’t float around in the microgravity environment. Their sleep isn’t very different like sleep on earth. Astronauts experience nightmares and dreams and also experience waking up in the middle of the night to go to the toilet, the sounds of snoring have unfortunately been reported. During their free time astronauts like to watch movies or series, practice their hobbies, read books and a common activity is looking through the big mirror overviewing our earth.
Uses of the ISS
In this microgravity environment space agencies can test how certain things behave when influenced by extremely low gravity. NASA found out that their astronauts were losing 1.5 procent of their total bone mass density every month, so to combat this problem they discovered that resistive exercises and vitamin D supplementation counteracts the loss. These results can help patients with osteoporosis (a condition which weakens the human bones). Furthermore, the robotic arms on the ISS can be used to treat inoperable tumor removals or for very precise surgical operations.
Besides the medical uses the ISS has also made it easier to respond to natural disasters, by capturing pictures of earth using the ISERV on board of the ISS. While the ISERV takes pictures of earth, the HICO detects water quality parameters that makes it easier to assess water quality. Instruments like these will keep on improving the observation of earth which will benefit every one here on our planet.
Finally we will look over some numbers about the ISS. The station moves at about 7.66 km/s, being 408 km away from earth. It completes a rotation every 1.5 hours. The station has a width of 109 m and a length of 73 m. The ISS was launched on the 20th of November in 1998, and costs around 150 billion dollars, making it the most expensive human made project to date. The ISS weighs about 419 725 kg and is mode of an aluminum alloy, and the outsides is reinforced with Kevlar and or Nextel.
The ISS is full of wonders and has tons of needs for humanity. I hope that I made everyone interested in one of humanities greatest achievements. If you want to read more about the space station, be sure to visit here or here