The ISS, also known as the International Space Station, is a large spacecraft in low Earth orbit. The ISS orbits at an altitude of between 330 and 435 km (205 and 270 mi) with an orbital period of 92 minutes. It circles the Earth every 90 minutes. The station can be seen from the ground with binoculars or a telescope for up to about 30 seconds each time it passes overhead.
The station has been inhabited by crews continuously since November 2000, making it one of the longest-operating man-made satellites ever launched into space; this will end when its successor modules are completed no earlier than 2020 but may last much longer depending on what parts need replacement first. All crew members who visit must wear pressure suits like those on the Shuttle.
The first ISS module, called Zarya (Russian: Заря), was launched into orbit on 20 November 1998 and provided electrical power and propulsion to the nascent station through the Russian-built “Zvezda” service module for docked space shuttles. Several modules (service, scientific, and inhabited) were subsequently brought to orbit by a wide range of expendable launch vehicles. The first module of the ISS to be inhabited was a component eventually known as “Unity”, also known as Node 1. This initial part of the station included four docking ports with two habitable modules initially: a Russian-made living quarters named Zarya (“Sunrise”), a US command/service base named Unity, and a Russian-built propulsion/airlock module Zvezda (“Star”). In the years following 2000, an additional two modules were added to the station’s habitable section: ESA’s “Columbus” lab on 10 February 2008, and Japan Aerospace Exploration Agency’s conducted on 19 July 2012.
In 2011, Roscosmos initiated a plan to equip the ISS with a multipurpose laboratory known as “Nauka” (Russian: Нау́ка). A pair of docking ports will be used by Nauka; one port for attaching it to another module and another as an exit point for cargo spacecraft. Nauka is planned to replace Pirs and will become Russia’s primary means of researching orbit.
Soyuz-2 and Soyuz-U:
In 2011, the Roscosmos State Corporation announced that Russian rockets, namely Soyuz-2 and Soyuz-U will 2013 deliver cargo to the station. In 2012, a regular unmanned mission of Progress M was launched for this task.
Different Other Missions:
The ISS has been expanded by additional modules from several participating space agencies over time: Japanese Experiment Module “Kibō” (KIBO) in 2008; European Robotic Arm in 2009; “Canadarm 2”, a second robotic arm in 2001, which is currently stored onboard until needed for future assembly tasks. Since 2010, American companies have been able to contract with NASA to use cargo flights for their experiments. Other countries also supply additional components (Japan’s external experiment platform, the Russian Multipurpose Laboratory Module Nauka, etc.), as well as crews.
Provides a Unique Research:
The ISS provides a unique research environment because it is in a low Earth orbit. The low altitude and inclination (51.6 degrees) of the ISS allow for many types of research that would not be possible on other spacecraft, such as studying the effects of long-term spaceflight on the human body, microgravity research, materials science, and testing new technologies in space. With 16 laboratories, the ISS offers more living space and laboratory facilities than any other spacecraft. The ISS is also an important platform for Earth observation and weather monitoring.
Since its assembly began in 1998, the ISS has been visited by more than 190 astronauts representing 15 different countries. In October 2010 the crew of “Endeavour” delivered and installed the “Russian mini-research Module 1”. The total cost of the ISS was estimated in 2001 at about $100 billion over 30 years, or approximately $4 billion a year. More recent estimates suggest a combined cost to NASA alone of between $72 and $80 billion through 2015.
The ISS has been an important platform for Earth observation and weather monitoring. The low altitude and inclination of the ISS allow for many types of research that would not be possible on other spacecraft, such as studying the effects of long-term spaceflight on the human body, microgravity research, materials science, and testing new technologies in space.