Spacecraft Definition

Spacecraft are vehicles used for travel through space. They may be either manned or unmanned and carry scientific instruments. Their engineering must allow it to pass safely through both Earth’s atmosphere and space itself.

An onboard computer oversees all activities, interprets commands from Earth and gathers telemetry from other instruments on board the craft, while other subsystems may include:

A spacecraft is a vehicle that travels in space.

Spacecraft are any vehicles designed to leave Earth’s atmosphere and travel through space, from satellites orbiting Earth to robots that explore Mars or other planets and sleek spaceships that carry human astronauts into outer space.

Space can be an intensely hostile environment for vehicles. To survive in space, delicate spacecraft components must be protected against extreme thermal variations and micrometeoroid bombardment. Furthermore, spacecraft contain various sensors and instruments for collecting data – for instance an infrared radiometer measures intensity of infrared energy reflected or emitted by targets while an optical polarimeter records direction and extent of polarized light reflection.

An onboard computer of a spacecraft performs many important tasks, from receiving commands uplinked by ground controllers to recording and telemetering science data. A clock (which keeps track of time since launch) serves to synchronize all data acquisition. Telemetry systems relay back information back to Earth containing scientific findings from instruments as well as engineering or health data from within its orbiter itself.

A spacecraft is a manned or unmanned vehicle.

No matter if it is an unmanned Mars rover or sleek spaceships of our dreams, every spacecraft relies on computers to manage its functions – including switch panels, displays and telemetry systems that enable astronauts to control them from distant places.

A spacecraft’s main computer plays a critical role in maintaining timing and interpreting scientific data gathered by its onboard instruments – these cover every spectrum from radio waves to remote sensing devices – providing vital services.

Spacecraft are usually classified based on their purpose. Orbital spacecraft are further subdivided by method of reentry to Earth – non-winged capsules and winged spaceplanes being the two primary options – into non-winged space capsules and winged spaceplanes, respectively. Most orbital spacecraft are expendable; there has been an emerging trend towards reusable ones. When landing on planet or moon surfaces, some spacecraft are equipped with propulsion for powered descent or propulsion/parachute to slow free fall. Landers might also carry propulsion/parachutes/surface penetrators devices capable of surviving landing and sending back environmental data back home from landing on-planet surface penetratorss designed to survive landing and send information back about its surroundings to Earth about their environments after landing and send back information back.

A spacecraft is a vehicle that carries science instruments.

Spacecraft are equipped with science instruments designed to collect data about outer space. This may include cameras, telescopes, particle detectors and particle monitors. Furthermore, a spacecraft must include protective structures and propulsion and navigation subsystems that enable its flight path through space.

Based on its mission profile, spacecraft must withstand launch loads; and if its intended landing site is on planet or moon then subsystems that slow it down and enable safe landing will also be necessary. Such subsystems could include parachute(s), drogues(stored folded until deployed during descent), and descent engines.

Modern spacecraft require power for their subsystems, and this is typically provided through solar panels converting sunlight to electricity. However, long duration missions must ensure their spacecraft can survive periods when eclipses prevent solar arrays from producing power and thus have no influence over power production.

A spacecraft is a vehicle that carries cargo.

Spacecraft must be designed to carry payloads such as scientific instruments (cameras and telescopes), cargo or, for manned craft, astronauts. Furthermore, they must protect occupants against the harsh environment of space, including temperature fluctuations and micrometeoroid bombardment.

Structural subsystems of a spacecraft provide the primary attachment point for all other components, and must be capable of withstanding launch loads as well as, depending on its mission profile, surface impacts, powered descent to or landing on another planet’s atmosphere or body, deployment/detach/recovery of appendages as needed and recovery when required.

Orbiters spacecraft carry science instruments for studying planets and smaller Solar System bodies like asteroids and comets. These include spectrometers, cameras and radar, with some even capable of penetrating bodies like Rosetta’s Philae lander on comet 67P/Churyumov-Gerasimenko to collect data back to Earth via surface penetrators (such as Philae).

Spacecraft are vehicles specifically designed to travel into outer space. Their engineering must accommodate for launch loads from their rocket, as well as operate effectively in an extreme environment of thermal variation, radiation exposure and other variables found therein.

Based on their mission profile, spacecraft can either be used for human spaceflight or scientific research. Spacecraft that remain in orbit around planetary bodies are known as satellites.

Propulsion

Propulsion systems on spacecrafts provide them with the thrust needed to escape Earth’s gravity, using Newton’s Third Law of Motion which states that every action has an equal and opposite reaction. An engine on board fires gas out at high velocity from its rear engine compartment at high velocity generating this reaction force which propels upward.

Once the spacecraft has achieved sufficient velocity from its launch vehicle, it veers away and heads toward its final destination – perhaps entering orbit around an entire planet or travelling deeper into space on an exploration mission.

Be it unmanned or manned spacecraft, most spacecraft are designed to collect data about our universe. This has allowed us to gain an in-depth knowledge of stars, planets, and other objects within our solar system. Nations such as the United States, former Soviet Union (now Russia), and others continue to explore and develop new technologies for spacecraft as well as build, test, and operate satellites that comprise our space infrastructure.

Attitude and Orientation Control System

An accurately aligned satellite’s orientation in space is of critical importance, affecting how its sensors, antennas, and payloads work together. Communication satellites must maintain precise orientation to ensure antennas stay pointed toward ground stations for uninterrupted signal transmission; Earth observation satellites require stable orientation to capture high-resolution images of celestial objects; while deep space probes need accurate aiming of their magnetometers at specific targets.

The Attitude Control and Stabilization System (AOCS) is an arrangement of sensors, algorithms, and actuators used to maintain spacecraft orientation. Sensors like star trackers, sun sensors, inertial measurement units provide information about current spacecraft orientation. Once this feedback has been processed by an onboard computer running what’s known as a control algorithm it compares it with desired attitude; any discrepancies are then calculated into correcting techniques using actuators like reaction wheels, control moment gyros or thrusters which alter satellite orientation until finalization occurs or an additional stabilization strategy may be applied tethers may also help maintain alignment if required for increased stabilization.

Thermal Control System

Spacecraft must keep both its equipment and human crew members at an ideal temperature range to operate efficiently and reliably, and so rely on both passive and active thermal control systems such as insulation or radiators to accomplish this task.

Spacecraft require a thermal control system as both electronic and mechanical systems typically only function at certain temperatures. Furthermore, materials expand and contract at differing rates with changes in temperature which could alter equipment or even cause it to fail altogether.

Spacecraft designers rely on both passive and active methods to control temperatures aboard spacecraft. Heat pipes and thermal switches move heat from instruments, heaters and solar absorption towards radiators for dissipation away from the structure of modular satellites while in orbit; space robots use standard interfaces allowing space robots to easily install/disassemble components; Cao et al developed shape-stabilized phase change materials suitable for modular satellites that possess similar chemical stability, latent heat capacity and encapsulation qualities as traditional PCMs for easy integration into modular satellites in orbit; Cao et al developed shape-stabilized phase change materials suitable for incorporation into modular satellites as they possess similar chemical stability, latent heat capacity/encapsulation qualities as traditional PCMs.

Structure

Each spacecraft requires more than just propulsion to change its trajectory and control it; in addition to chemical rockets or solar panels and nuclear generators for propulsion and an attitude control system for keeping instruments oriented properly in all directions, every spacecraft requires power systems–from simple chemical rockets through solar panels and nuclear generators–that provide power. Every spacecraft must also contain communication systems capable of sending and receiving signals between Earth and space; an attitude control system to keep instruments facing in the right directions; an attitude control system for maintaining accurate instrument pointing; specific components required for its mission, such as Apollo capsules which transported NASA astronauts to and from space; specific components are required in order for any mission completion such as Apollo capsules which brought NASA astronauts from Earth to and back from Moon surface missions.

Spacecraft range widely in terms of size, complexity and purpose; those sharing common design features and functions are organized into spacecraft families (for instance Explorer, Galileo, Iridium Milstar Navstar Voyager in the United States; Astra Europestar Hotbird Meteosat SatView SatView in Europe and Anik Dragonfly Shenzhou Shenzhou Shenzhou from China). Spacecraft must be light in weight in order to meet mission speed/distance requirements while operating reliably in low gravity, rapid temperature changes, strong radiation environments among other demanding conditions.