Table of Contents (click to expand)
Whenever you hear or read anything related to the ongoing presence of humans in space, the term ‘ISS’ is almost sure to pop up. In fact, here on Science ABC itself, we have published a decent number of articles that relate in some way to the ISS. However, sure enough, many folks might not know much, or anything at all about the ISS. For example, you might use the term ‘ISS’ all the time in your space conversations, but when someone asks “So, what about this ‘ISS’ thing you’ve mentioned so many times? What is it really?”, you look something like this:
To avoid the occurrence of such a moment in future, let’s get this over with once and for all.
Recommended Video for you:
What Is The ‘ISS’?

The International Space Station, commonly abbreviated as the ISS, is the largest human-made object currently operating in space between 330 – 435 kilometers (205-270 miles) above Earth’s surface, and it is the epitome of the most advanced space engineering and technology that humans have acquired thus far. It is also, quite notably, the most expensive object (worth more than $100 billion) that humans have ever made collectively, i.e. it was built in parts from the combined efforts of the space agencies of many nations, including the United States, Russia, Japan, Canada and a few countries from Europe. (Source)

Simply put, it is basically a large spacecraft that revolves around the Earth and serves as a laboratory for performing a number of experiments related to the field of astronomy, meteorology, physics, human biology, space medicine, materials production, communications research etc., along with making important observations of Earth. It also serves as the habitat (akin to a 5-bedroom apartment with big bay window, a gym and two bathrooms) of astronauts currently on a long-term expedition in space.

Since the station’s orbital period is roughly 90 minutes, its crew members experience either a sunrise or a sunset every 45 minutes, which means that they witness 15 to 16 sunrises and sunsets every day! As one of the brightest objects in the sky, the ISS can be easily spotted from the ground anywhere on Earth if one knows when and where to look. In addition to that, you can also check out exactly where above Earth the ISS is currently located.
Also Read: If The ISS Is Not Stationary, How Are Rockets Launched To It?
Structure Of The ISS

Although now it is a single object in its entirety, the ISS is made of a number of separate parts that were attached to it progressively over a period of almost 11 years. The first component of the ISS, called Zarya, was launched into space in 1998 atop a Russian rocket. More parts were sent into space via space shuttles in the subsequent months and assembled by the crew members. It was not until November of 2000 that the ISS was ready to house Expedition 1 – its first guests, who would live there for four and a half months

Over the years, the ISS has been improved with a number of modules that dramatically increased the capabilities of the ISS, both as a space laboratory and a home. As of June 2011, the ISS consisted of 15 pressurized modules (that were assembled in space) and the Integrated Truss Structure (series of trusses on which unpressurized parts, such as solar arrays and radiators are mounted). Some of the larger components include Zarya, Zvezda, the Unity Module, the Columbus orbital facility, the Japanese experimental module and the Destiny Laboratory module.

As of now, the ISS will be operated at least until 2020, although there has been a request for its operational extension until 2024 by NASA.
Life On The ISS
The ISS currently houses 6 crew members (although it can support up to 7) who live and perform various duties pertaining to their mission objectives aboard the spaceship. According to protocol, they wake up at 06:00, perform some post-sleep activities and a routine morning inspection of various components and systems of the ISS. A typical day at the ISS consists of ten hours of work (five hours on Saturdays), three meals, and a great deal of exercise while strapped into the machinery.

You can read about life aboard the ISS in more detail in this article: How Does it Feel to Be Inside a Spaceship?
Also Read: How Do Astronauts Aboard The ISS Know When It’s Day Or Night?
Importance Of The ISS
ISS plays host to a great deal of experiments and scientific studies in the fields of technology, human biology, material sciences, communication, biotechnology, space medicine etc. that are carried out in space by astronauts. It has helped commercialize the low-Earth orbit, develop biologically-improved vaccines, understand and monitor natural disasters from space, and unravel the mechanism of many biological ailments, including breast cancer and osteoporosis. Furthermore, its perpetual presence in space has helped us gather a number of astronomical observations about outer space, which in turned have bettered our understanding of the galaxy (Read more about the importance of the ISS here).
These are just a few of the important things that you should know about the ISS, and this summary is just the tip of the iceberg that is the ISS. For more details about its history, components, functions and future plans, check out the following links:
Also Read: How Do People Communicate On The ISS?
How well do you understand the article above!

References (click to expand)
- (2015) International Space Station - NASA. The National Aeronautics and Space Administration
- NASA Missions A-Z. The National Aeronautics and Space Administration
- A Day in the Life Aboard the International Space Station - NASA. The National Aeronautics and Space Administration
- Current position of the ISS - AstroViewer.net. astroviewer.net
- International Space Station - Wikipedia. Wikipedia