A flight spare is a copy of a spacecraft or spacecraft part which is held in reserve in case it is needed for the mission. Flight spares are built to the same specifications as the original equipment (the "flight model"), and can be substituted in the case of damage or other problems with the flight model, reducing launch delays. The extra cost of building a flight spare can be justified by the enormous cost of delaying a launch by even a short amount of time.
Flight spares are constructed as contingencies. As such, spare parts may be swapped onto a craft before launch, or completed spare spacecraft may be launched if the flight model is lost.
NASA has two basic types of spares, development spares and operational spares. NASA makes a determination about which parts need spares based on whether parts are custom built, and the lead-time for procurement. It also makes determinations about the quantities of spares, based on whether the part is critical to system operation, failure rate, and the expected life of the part. [2]
The flight spare can also be useful during a space mission if a change to the original plan is required, since the effect of changes can be safely tested on the ground.
Flight spares that go unused in their initial missions are still considered valuable. A 2017 NASA report on flight spare inventory control mentions hundreds of millions of dollars' worth of inventory, not all of it catalogued properly. [3]
Individual spare components manufactured for one mission may eventually fly on another. As a cost-saving measure, the Magellan spacecraft was made largely out of such parts: [4]
| Component | Origin |
|---|---|
| Attitude control computer | Galileo |
| Bus | Voyager program |
| Command and data subsystem | Galileo |
| High- and low-gain antenna | Voyager program |
| Medium-gain antenna | Mariner 9 |
| Power distribution unit | Galileo |
| Propellant tank | Space Shuttle auxiliary power unit |
| Pyrotechnic control | Galileo |
| Radio-frequency traveling-wave tube assemblies | Ulysses |
| Solid rocket motor | Space Shuttle Payload Assist Module |
| Star scanner | Inertial Upper Stage |
| Thrusters | Voyager program |
Since few space probes return to Earth intact, flight spares are useful for posterity, and may go to museums. The Mariner 10 flight spare is such an example. [1]
Interplanetary spaceflight or interplanetary travel is the crewed or uncrewed travel between stars and planets, usually within a single planetary system. In practice, spaceflights of this type are confined to travel between the planets of the Solar System. Uncrewed space probes have flown to all the observed planets in the Solar System as well as to dwarf planets Pluto and Ceres, and several asteroids. Orbiters and landers return more information than fly-by missions. Crewed flights have landed on the Moon and have been planned, from time to time, for Mars, Venus and Mercury. While many scientists appreciate the knowledge value that uncrewed flights provide, the value of crewed missions is more controversial. Science fiction writers propose a number of benefits, including the mining of asteroids, access to solar power, and room for colonization in the event of an Earth catastrophe.
The Mariner program was conducted by the American space agency NASA to explore other planets. Between 1962 and late 1973, NASA's Jet Propulsion Laboratory (JPL) designed and built 10 robotic interplanetary probes named Mariner to explore the inner Solar System - visiting the planets Venus, Mars and Mercury for the first time, and returning to Venus and Mars for additional close observations.
Space exploration is the use of astronomy and space technology to explore outer space. While the exploration of space is currently carried out mainly by astronomers with telescopes, its physical exploration is conducted both by uncrewed robotic space probes and human spaceflight. Space exploration, like its classical form astronomy, is one of the main sources for space science.
A spacecraft is a vehicle that is designed to fly in outer space and operate there. Spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, planetary exploration, and transportation of humans and cargo. All spacecraft except single-stage-to-orbit vehicles cannot get into space on their own, and require a launch vehicle.
The Space Shuttle program was the fourth human spaceflight program carried out by the U.S. National Aeronautics and Space Administration (NASA), which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. Its official name, Space Transportation System (STS), was taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development. It flew 135 missions and carried 355 astronauts from 16 countries, many on multiple trips.
Mariner 6 and Mariner 7 were two uncrewed NASA robotic spacecraft that completed the first dual mission to Mars in 1969 as part of NASA's wider Mariner program. Mariner 6 was launched from Launch Complex 36B at Cape Canaveral Air Force Station and Mariner 7 from Launch Complex 36A. The two craft flew over the equator and south polar regions, analyzing the atmosphere and the surface with remote sensors, and recording and relaying hundreds of pictures. The mission's goals were to study the surface and atmosphere of Mars during close flybys, in order to establish the basis for future investigations, particularly those relevant to the search for extraterrestrial life, and to demonstrate and develop technologies required for future Mars missions. Mariner 6 also had the objective of providing experience and data which would be useful in programming the Mariner 7 encounter five days later.
Mariner 10 was an American robotic space probe launched by NASA on 3 November 1973, to fly by the planets Mercury and Venus. It was the first spacecraft to perform flybys of multiple planets.
Uncrewed spacecraft or robotic spacecraft are spacecraft without people on board. Uncrewed spacecraft may have varying levels of autonomy from human input; they may be remote controlled, remote guided or autonomous: they have a pre-programmed list of operations, which they will execute unless otherwise instructed. A robotic spacecraft for scientific measurements is often called a space probe or space observatory.
The Magellan spacecraft was a 1,035-kilogram (2,282 lb) robotic space probe launched by NASA of the United States, on May 4, 1989, to map the surface of Venus by using synthetic-aperture radar and to measure the planetary gravitational field.
A reusable launch vehicle has parts that can be recovered and reflown, while carrying payloads from the surface to outer space. Rocket stages are the most common launch vehicle parts aimed for reuse. Smaller parts such as rocket engines and boosters can also be reused, though reusable spacecraft may be launched on top of an expendable launch vehicle. Reusable launch vehicles do not need to make these parts for each launch, therefore reducing its launch cost significantly. However, these benefits are diminished by the cost of recovery and refurbishment.
A spaceplane is a vehicle that can fly and glide like an aircraft in Earth's atmosphere and maneuver like a spacecraft in outer space. To do so, spaceplanes must incorporate features of both aircraft and spacecraft. Orbital spaceplanes tend to be more similar to conventional spacecraft, while sub-orbital spaceplanes tend to be more similar to fixed-wing aircraft. All spaceplanes to date have been rocket-powered for takeoff and climb, but have then landed as unpowered gliders.
The National Aeronautics and Space Administration is an independent agency of the U.S. federal government responsible for the civil space program, aeronautics research, and space research. Established in 1958, NASA succeeded the National Advisory Committee for Aeronautics (NACA) to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968–1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA currently supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, the Commercial Crew spacecraft, and the planned Lunar Gateway space station.
The Boeing CST-100Starliner is a class of two partially reusable spacecraft designed to transport crew to the International Space Station (ISS) and other low-Earth-orbit destinations. It is manufactured by Boeing for its participation in NASA's Commercial Crew Program (CCP). The spacecraft consists of a reusable crew capsule and an expendable service module.
Development of the Commercial Crew Program began in the second round of the Commercial Crew Development (CCDev) program, which was rescoped from a technology development program for human spaceflight to a competitive development program that would produce the spacecraft to be used in the Commercial Crew Program to provide crew transportation services to and from the International Space Station (ISS). To implement the program NASA awarded a series of competitive fixed-price contracts to private vendors starting in 2011. Operational contracts to fly astronauts were awarded in September 2014 to SpaceX and Boeing, and NASA expected each company to complete development and achieve crew rating in 2017. Each company performed an uncrewed orbital test flight in 2019. SpaceX operational flights started in November 2020.
Orion is a partially reusable crewed spacecraft used in NASA's Artemis program. The spacecraft consists of a Crew Module (CM) space capsule designed by Lockheed Martin and the European Service Module (ESM) manufactured by Airbus Defence and Space. Capable of supporting a crew of four beyond low Earth orbit, Orion can last up to 21 days undocked and up to six months docked. It is equipped with solar panels, an automated docking system, and glass cockpit interfaces modeled after those used in the Boeing 787 Dreamliner. A single AJ10 engine provides the spacecraft's primary propulsion, while eight R-4D-11 engines, and six pods of custom reaction control system engines developed by Airbus, provide the spacecraft's secondary propulsion. Orion is intended to launch atop a Space Launch System (SLS) rocket, with a tower launch escape system.
Dragon 2 is a class of partially reusable spacecraft developed and manufactured by American aerospace manufacturer SpaceX, primarily for flights to the International Space Station (ISS). SpaceX also launches private missions, such as Inspiration4 and Axiom Mission 1. There are two variants of the Dragon spacecraft: Crew Dragon, a spacecraft capable of ferrying four crewmembers, and Cargo Dragon, a replacement for the original Dragon 1 used to carry freight to and from space. The spacecraft consists of a reusable space capsule and an expendable trunk module. The spacecraft launches atop a Falcon 9 Block 5 rocket and the capsule returns to Earth through splashdown.
Psyche is a NASA space mission launched on October 13, 2023 to explore the origin of planetary cores by orbiting and studying the metallic asteroid 16 Psyche beginning in 2029. NASA's Jet Propulsion Laboratory (JPL) manages the project.
The future of space exploration involves both telescopic exploration and the physical exploration of space by robotic spacecraft and human spaceflight.
The Commercial Crew Program (CCP) provides commercially operated crew transportation service to and from the International Space Station (ISS) under contract to NASA, conducting crew rotations between the expeditions of the International Space Station program. American space manufacturer SpaceX began providing service in 2020, using the Crew Dragon spacecraft, and NASA plans to add Boeing when its Boeing Starliner spacecraft becomes operational no earlier than 2025. NASA has contracted for six operational missions from Boeing and fourteen from SpaceX, ensuring sufficient support for ISS through 2030.
SpaceX CRS-25, also known as SpX-25, was a Commercial Resupply Service mission (CRS) to the International Space Station (ISS) that was launched on 15 July 2022. The mission was contracted by NASA and was flown by SpaceX using their reusable spacecraft, the Cargo Dragon. The vehicle delivered supplies to the crew aboard the ISS along with multiple pieces of equipment that will be used to conduct multiple research investigations aboard the ISS.
 | This spacecraft or satellite related article is a stub. You can help Wikipedia by expanding it. |