Spacecraft Architecture and Subsystems

spacecraft architecture

At launch sites, the physical structures that garner the most interest are assembly buildings. Cape Canaveral’s VAB, for instance, was specifically designed to assemble Saturn V rockets vertically while they traveled down an overhead gantry track toward their pads.

Aerospace is focused on designing architectures with greater resilience and the capacity to reassemble quickly, necessitating faster acquisition and design processes and greater innovation on the factory floor.

Spacecraft Subsystems

Subsystems on board spacecraft include structural, thermal, electrical and data handling components. The structural subsystem ensures mechanical integrity of the satellite by supporting its components while withstanding handling loads during launch and freefall flight or the operation of propulsion devices.

The thermal control subsystem serves to protect spacecraft from the harsh environment of space, employing both passive elements such as thermal blankets and radiators and active ones like electric heaters for temperature regulation across its electronics and mechanical components.

The Command and Data Subsystem allows telecommands to be uplinked to the spacecraft and downlinked back to Earth, with telemetry information including scientific experiment data as well as engineering parameters like switch positions, voltages and temperatures from Earth. Telemetry information includes both science data from experiments as well as engineering parameters like switch positions voltages and temperatures. This system also maintains a spacecraft clock as well as performing fault protection by keeping records either on tape recorder or RAM until downlinking becomes feasible. Finally, Attitude and Orbit Control subsystem ensures that spacecraft can point towards target locations using electronic “eyes” that sense Sun or starlight to calculate position and orientation calculations of Earth-bound spacecraft in relation to its target location on Earth.

Propulsion Subsystem

Propulsion subsystems oversee a satellite’s movement in space, controlling both its direction and position. To accomplish this task, engines or thrusters emitting fuel can alter a satellite’s path; orbit insertion and station-keeping maneuvers may also be implemented as necessary.

Control systems determine how much thrust is needed to reach desired positions, with actuators using feedback from sensors such as star trackers, gyroscopes and magnetometers as a feedback system to implement these orders. Furthermore, propulsion subsystems produce and store their own fuel supplies.

This subsystem serves as the mechanical framework to house all other components, including the payload. Its design must take into account mechanical stressors associated with launch and in-space operation as well as being constructed from materials with superior strength-to-weight ratios. Furthermore, it must meet stringent safety and reliability criteria using redundancies and fault-tolerance measures.

Thermal Control Subsystem

The thermal control subsystem is responsible for maintaining an ideal temperature range in spacecraft by conserving heat, providing heat when necessary and rejecting excess heat as required for each mission profile and operational mode.

Most of the energy entering a spacecraft comes in the form of radiant heat from the sun; however, internal processes within it may create additional sources of warmth that vary between very hot areas and cold ones.

To address this challenge, designers use software like Thermal Desktop to determine allowable flight temperatures under various orbital conditions and design methods that keep all hardware at its appropriate temperature ranges. Once thermal requirements have been determined, hardware design begins. Common examples include radiators, multi-layer insulation blankets, two phase devices (such as loop heat pipes and capillary pumped loops), thermal straps, Radioisotope heater units, mechanical louvers temperature sensors as well as pumps used to circulate heat transfer liquids.

Communications Subsystem

The communications subsystem transfers information between satellites and other systems using electromagnetic pulses that contain data for transmission. Signals exchanged using radio antennas or lasers.

For instance, the AOCS uses sensors such as star trackers and gyroscopes to determine a spacecraft’s current orientation (attitude) while actuators such as reaction wheels and gyroscopes help change it. Finally, this system transmits commands to other subsystems.

Another example is the Telemetry and Command Subsystem (TT&C), which monitors and relays telemetry and command data between satellites and ground control stations. Radios using various frequency bands and modulation/coding schemes are used, with some satellites using software defined radios which rely on computer processors rather than physical parts for this task.

Architecture for Mars habitats will become increasingly essential as more stations and habitats are established in LEO and on Mars. For success, such structures must provide constant electricity supply as well as food and water services. Furthermore, their design must ensure psychological well-being for their occupants.

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