Ground Segment & Mission Operations

China's principal mission-control centre in Beijing, which directs the country's human-spaceflight, lunar (Chang'e), and planetary (Tianwen) missions.

ESA's mission-control centre in Darmstadt, Germany, from which the agency operates its scientific and interplanetary spacecraft through the Estrack network.

NASA's Goddard Space Flight Center in Maryland operates many Earth-orbiting and astrophysics missions and hosts the Near Space Network's control functions.

ISRO's network and operations organisation, headquartered in Bengaluru, which provides tracking and mission operations for India's Earth-orbiting and deep-space missions.

JAXA operates its science and deep-space missions from centres including the Sagamihara campus (ISAS) and the Tsukuba Space Center, working with the Usuda deep-space antenna.

NASA's iconic human-spaceflight control room at the Johnson Space Center in Houston, which has directed crewed missions from Gemini and Apollo to the International Space Station.

NASA's nerve centre for deep-space missions, at the Jet Propulsion Laboratory in Pasadena. From the SFOF, controllers command and monitor spacecraft across the Solar System through the Deep Space Network.

Roscosmos's Mission Control Center in Korolyov, near Moscow, which directs Russian human spaceflight and the Russian segment of the International Space Station.

The team and facility that command and monitor a spacecraft in real time — the heart of mission operations, staffed by controllers each responsible for a subsystem.

The discipline of determining and predicting a spacecraft's orbit and attitude, and computing the manoeuvres needed to keep it on its planned trajectory.

Estimating a spacecraft's precise position and velocity from tracking data (ranging, Doppler, and angles) — the input to every manoeuvre and every science observation.

The operational process of guiding a spacecraft to its target — combining orbit determination with manoeuvre design, using the deep-space network's radiometric tracking.

Receiving, decoding, and displaying the stream of engineering and science data a spacecraft downlinks, so controllers can assess its health and scientists can use its measurements.

Building and validating the time-ordered lists of commands a spacecraft executes, often days or weeks in advance, and uplinking them through the ground network.

Turning a mission's science and engineering goals into a detailed, resource-constrained plan of activities — what the spacecraft will do, when, and within its power, data, and pointing limits.

The pre-agreed decision rules that tell a control team how to respond to situations, so that time-critical calls are made consistently and safely rather than improvised.

Continuously watching a spacecraft's telemetry against expected limits to catch anomalies early — the routine vigilance that keeps a mission alive.

The onboard and ground logic that detects failures and responds automatically to keep a spacecraft safe when the ground cannot react in time — vital across the long light-time to deep space.

A protective state a spacecraft autonomously enters when it detects a serious problem — pointing its solar arrays at the Sun and its antenna toward Earth, and waiting for instructions.

Software that automates routine operations — from pass scheduling and telemetry screening to onboard sequence execution — reducing workload and enabling operations at deep-space distances.

The operations phase spanning launch and the critical early days — acquiring the spacecraft, checking it out, and getting it onto its planned trajectory (Launch and Early Orbit Phase, LEOP).

The long interplanetary-cruise phase — keeping the spacecraft healthy, performing trajectory-correction manoeuvres, and preparing for arrival.

The prime phase in which the spacecraft carries out its science — planning observations, commanding the instruments, and returning the data that is the point of the mission.

The final phase — safely disposing of a spacecraft (a controlled re-entry, a graveyard orbit, or a deliberate impact) and preserving its data — closing out the mission responsibly.