space station - Past and present space stations, Types of space station

A long-lived crewed spacecraft in low Earth orbit; examples are the US Skylab and the Russian (formerly Soviet) Mir. It is used for the accumulation of long-duration flight experience and related biomedical research, for astronomy, for Earth observations, and for microgravity experiments. The US space station programme underwent a major redesign in 1993 to incorporate substantial participation by Russia. The first launches to begin the construction of this International Space Station were carried out in 1998 and the first crew arrived in 2000.

Space stations are used to study the effects of long-term space flight on the human body as well as to provide platforms for greater number and length of scientific studies than available on other space vehicles.

Past and present space stations

Salyut stations: Salyut 1, Salyut 2 (failed on-orbit, never occupied), Salyut 3, Salyut 4, Salyut 5, Salyut 6, Salyut 7 Skylab Mir International Space Station (ISS)

Following the controlled deorbiting of Mir in 2001, the International Space Station is the only one of these currently in orbit;

The International Space Station evolved from the American Space Station Freedom program, which - despite being under development for ten years - was never launched;

Currently, Bigelow Aerospace is commercially developing inflatable habitat modules, derived from the earlier Transhab concept, intended to be used for space station construction and for a space prize they are funding and operating, America's Space Prize.

Types of space station

Broadly speaking, the space stations so far launched have been of two types;

List of occupied space stations, with statistics

Space station	Image	Launched	Reentered	Days in use		Total crew and visitors	Visits		Mass (kg)
				In orbit	Occupied		Manned	Unmanned
Salyut 1		Apr 19, 1971 01:40:00 UTC	Oct 11, 1971	175	24	3	2	0	18,425
Skylab		May 14, 1973 17:30:00 UTC	Jul 11, 1979 16:37:00 UTC	2,249	171	9	3	0	77,088
Salyut 3		Jun 25, 1974 22:38:00 UTC	Jan 24, 1975	213	15	2	1	0	18,500
Salyut 4		Dec 26, 1974 04:15:00 UTC	Feb 3, 1977	770	92	4	2	1	18,500
Salyut 5		Jun 22, 1976 18:04:00 UTC	Aug 8, 1977	412	67	4	2	0	19,000
Salyut 6		Sep 29, 1977 06:50:00 UTC	Jul 29, 1982	1,764	683	33	16	14	19,000
Salyut 7		Apr 19, 1982 19:45:00 UTC	Feb 7, 1991	3,216	816	26	12	15	19,000
Mir		Feb 19, 1986 21:28:23 UTC	Mar 23, 2001 05:50:00 UTC	5,511	4,594	137	39	68	124,340
ISS		Nov 20, 1998	2025****	**2,898	**2,185	***153	***32	***25	**454,240 (206,040 kg)

Crew and visitors counting is non-distinct.