User:Hjpospie/Space system


 * This article is a common project of User:Hjpospie and User:Mdd to design a new article Space system

A space system is realized by one spacecraft or several co-operating spacecrafts.

Overview
A space system can have several objectives
 * Space exploration
 * Earth / space observation
 * Communications / navigation
 * Meteorology
 * Microgravity science
 * Space tourism
 * etc.

Depending on the mission and the functional / performance requirements a space system can embody one or more manned or unmanned spacecrafts or both categories together. The spacecrafts are newly developed or make use of existing spacecrafts.

A typical example for a comprehensive space system for on-orbit research by human beings is the International Space Station scenario including
 * ISS itself
 * TDRS
 * Supply vehicles:
 * Space Shuttle
 * Soyuz spacecraft
 * Progress spacecraft
 * Automated Transfer Vehicle.

Examples for space systems allowing navigation on earth by receiving signals from several spacecrafts are
 * GPS
 * GLONASS.

Each one of these spacecrafts is a dedicated spacecraft system.

A spacecraft is a vehicle or device designed for spaceflight. Depending on its system requirements it is a more or less complex spacecraft system. Though the Astronauts are necessary for execution of functions of a manned spacecraft they are not part of the spacecraft system but an interfacing, autonomous element.

History
Already in the first half of the twentieth century several people (e.g. Hermann Oberth, Robert Goddard) defined the basic solutions for building rockets and sending spacecrafts to space though they were considered as dreamers by many people. During World War II especially Germany developped rockets (V2) used as weapon to attack the enemy inland. During the Cold War the Americans and Russians started a competition who can bring the first spacecraft on orbit. The Russians, led by the ingenious systems engineer Sergey Korolyov, were the winner launching the first spacecraft Sputnik_1 into space in October 1957; this was the first "Space system" though consisting of only one spacecraft. The Americans followed with Explorer 1 in January 1958 after some unsuccesses.

The next step in this "Space Race" aimed for getting human beings on obit. Again the Russians were the first with Yuri Gagarin arounding the earth in April 1961. The Americans - after some smaller manned, missions as Mercury in 1961 and lateron Gemini - performed the Apollo program "sending Human beings to the Moon and back" during 1961 - 1975. All above missions consisted of only one spacecraft being only a rudimentary "space systems".

The next phase of Human spaceflight was getting more complex relying on several spacecrafts on orbit and are considered as real Space systems including Space stations as Skylab, Mir and supply vehicles.

Also the communications systems grew up from a single to several spacecrafts being developed as space system ensuring interface compatibility, growth cabability and failure recovery by "shifting" a spare spacecraft in the operational orbit position.-

The most complex space system presently in operation and still under development for some elements is the International Space Station.

Outlook
Many, very complex missions are in planing by [NASA]], ESA and other nations which can be only successfully implemented if they are developped under the systems engineering processes applicable to development, verification and operation of space systems.

Examples are Moon and Mars missions with unmanned and manned spacecrafts for exploration and possibly bring raw materials to earth.