Tranquility Base here.
The Eagle has landed.
Those words, the first ever transmitted to Earth by a human being from the surface of the Moon, are testimony to the essential role played by the Mission Control Center at NASA’s Johnson Space Center in Houston.
Since 1965, the Mission Control Center (MCC) has been the nerve center for America’s manned space program.
The men and women who work in Building 30 at the Johnson Space Center have been vital to the success of every manned space flight since Gemini 4. These teams of experienced engineers and technicians monitor systems and activities aboard spacecraft 24 hours a day during missions, using some of the most sophisticated communication, computer, data reduction, and data display equipment available.
They watch every movement the crew and spacecraft make, double-check every number to be sure missions are proceeding as expected, and provide the expertise needed to deal with the unexpected.
During the Mercury project, when mission control was at Cape Canaveral, capsules were controlled almost entirely from the ground. The capsule’s manual control systems served in most cases as backups to the automated systems, and astronauts relied heavily on ground control for solutions to problems that arose.
As spacecraft became more complex in the Gemini years, dependence on the new MCC in Houston lessened slightly. During Apollo, when distance and communications breaks made it necessary, some onboard systems became prime while others retained their reliance on MCC direction.
Space Shuttle Mission Control
The frequent missions of the Space Shuttle program required a new approach to flight control. Because there is more data to monitor than the crew has time to manage, the flight control team’s main responsibility is evaluating the data to provide the crew with additional insight and aid it in managing the complex systems of the Orbiter.
From the moment the Solid Rocket Boosters ignite at liftoff to the moment the landing gear wheels roll to a stop at the end of a mission, the MCC is the hub of communication and support for the Shuttle.
The MCC’s focal point is the Flight Control Room, or FCR (pronounced “Ficker”), where flight controllers get information from console computer displays or from projected displays that fill the wall at the front of the room. Almost everyone has seen the television pictures of MCC flight controllers working feverishly at their consoles, headsets in place.
Flight controllers who work in the FCR represent only the tip of the staffing iceberg in the MCC. Each of the 15 to 20 flight controllers who sits at a console in the FCR has the help of many other engineers and flight controllers monitoring and analyzing data in nearby staff support rooms.
The Space Shuttle Mission Control Center (MCC) is essential to the success and safety of manned spaceflight operations, serving as the nerve center for monitoring and managing every aspect of a mission from launch to landing. The MCC is staffed by a highly skilled team of flight controllers, engineers, and specialists who work around the clock to ensure the shuttle and its crew are operating safely and efficiently. These professionals continuously monitor real-time data from the shuttle, including telemetry, communications, and environmental conditions, to detect any anomalies or potential issues that could jeopardize the mission. Their constant vigilance enables quick decision-making and immediate response to problems, ensuring that any unforeseen challenges are addressed promptly to maintain the safety of the astronauts.
In addition to real-time monitoring, MCC plays a critical role in mission planning and preparation. Before any shuttle launch, extensive simulations and rehearsals are conducted at the control center to practice various scenarios, including potential emergencies. These exercises allow flight controllers and astronauts to train together, building familiarity and trust while refining their responses to unexpected situations. The insights gained from these simulations contribute to the development of detailed contingency plans, which are vital for handling a wide range of issues, such as system malfunctions, navigation errors, or threats from space debris. By having a well-coordinated and thoroughly prepared team, MCC ensures that missions can adapt to dynamic conditions and maintain their objectives, even under duress.
Moreover, the Space Shuttle Mission Control Center serves as the central point of communication between the shuttle crew and ground-based support teams. Through the CAPCOM (Capsule Communicator), MCC relays critical information, instructions, and updates to the astronauts, keeping them informed and aligned with mission goals. This structured communication framework minimizes misunderstandings and ensures that decisions are based on the most accurate and up-to-date information available. MCC also coordinates with international partners, other NASA facilities, and external agencies, facilitating collaboration and resource sharing. The center’s ability to integrate complex data streams, manage resources, and provide decisive leadership is fundamental to the safety and success of every manned spaceflight operation, underscoring its indispensable role in human space exploration.
Mission Control: The Unsung Heroes of Apollo
The Cathedral of Manned Spaceflight
Flight Control Room Positions
The Space Shuttle Mission Control Center (MCC) is staffed by a variety of highly specialized flight control positions, each responsible for specific aspects of the mission’s operations. These positions use unique abbreviations or “call signs” to communicate efficiently and clearly during the critical moments of a spaceflight. If you visit the FCR, you’ll notice the initials or names of these Flight Controllers placed atop each console.
Many of these call signs originated during earlier space programs, such as Gemini and Apollo, and have been carried over to the Space Shuttle program, underscoring the legacy and continuity of NASA’s mission control operations. This continuity helps maintain consistent training and operational protocols, allowing flight controllers to draw on decades of experience and best practices. The careful coordination and specialization of these roles ensure that every aspect of the shuttle’s operations is monitored and managed with precision, contributing to the overall success and safety of human spaceflight.
Since my career as a Flight Dynamics Officer was during the height of the Space Shuttle Program, this MCC reference page will focus almost exclusively on the Shuttle Flight Control Team.
Shuttle Flight Control Positions
Flight Director (FLIGHT)
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Leads the flight control team. Flight has overall operational responsibility for missions and payload operations and for all decisions regarding safe, expedient mission operations. This person monitors the other Flight Controllers, remaining in constant verbal communication with them via intercom channels called “loops”.
The Space Shuttle Flight Director (callsign “FLIGHT”) held one of the most critical roles in a Shuttle mission, responsible for overseeing the entire mission’s operations and ensuring the safety and success of both the crew and the spacecraft. From the moment the countdown began until the Shuttle landed back on Earth, the Flight Director was at the helm, making real-time decisions based on the data received from various Flight Control teams. They coordinated with engineers, scientists, and astronauts, interpreting complex information and providing guidance on everything from launch trajectories and orbit insertion to re-entry and landing procedures. The Flight Director’s role requires a deep understanding of shuttle systems, mission objectives, and emergency protocols, as well as the ability to remain calm and decisive under pressure.
In addition to managing the Shuttle’s immediate operations, the Flight Director played a crucial role in long-term mission planning and preparation. They were also responsible for assessing and mitigating risks, ensuring all systems and backup plans are in place to handle unexpected situations. Ultimately, the Flight Director acted as the central point of command, synthesizing input from various experts and making the final call on critical decisions, thus playing a key role in the success and safety of each Space Shuttle mission.
Spacecraft (or “Capsule”) Communicator (CAPCOM)
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A Space Shuttle CAPCOM, short for Capsule Communicator, serves as the primary communication link between the astronauts in space and Mission Control on Earth. This role is crucial for ensuring clear, accurate, and efficient communication throughout the mission. The CAPCOM is the only person authorized to speak directly to the crew in orbit, which helps to streamline the flow of information and reduce the potential for miscommunication. They relay instructions, updates, and advice from flight directors and other mission control specialists, providing astronauts with the support and guidance needed to perform their tasks. CAPCOMs must be familiar with the mission details, shuttle systems, and emergency procedures to accurately convey messages and assist in decision-making.
In addition to real-time communication during the mission, CAPCOMs play an essential role in mission planning and training. They work closely with flight directors, engineers, and astronauts during the preparation phase, participating in simulations and rehearsals to practice scenarios that may arise during the flight. CAPCOMs are often astronauts themselves or have undergone extensive training to understand the nuances of space missions and the needs of the crew. Their experience and knowledge allow them to serve as a trusted voice, offering reassurance and clarity to astronauts navigating the challenges of spaceflight. By ensuring smooth and effective communication, CAPCOMs contribute significantly to the overall safety and success of Space Shuttle missions.
Even though, beginning with the Shuttle Program, spacecraft were no longer “capsules”, the name CAPCOM was retained for both continuity and a continued nod to the history of the program.
Flight Dynamics Officer (FDO)
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The FDO, call sign “Fido,” plans all maneuvers and is responsible for the overall trajectory from launch, on-orbit operations, deorbit, entry, and landing. FDO monitors vehicle performance during the powered flight Ascent phase and assesses abort modes, calculates orbital maneuvers and resulting trajectories, and monitors vehicle flight profile and energy levels during re-entry.
Read more about the Flight Dynamics Officer, including what the FDO was looking at during Space Shuttle Missions.
The Trajectory Officer, callsign “TRAJ”, assists the FDO during missions. A FDO is always certified as a TRAJ in various phases (Ascent, Orbit, Deploy, Rendezvous, and Entry) before ever beginning training towards certification as a FDO. Often times a senior FDO will be assigned as a TRAJ for a first-time FDO in a particular phase for experience and support.
Flight Dynamics MPSR positions
- Abort Support (ascent only) – provided expert support during the powered flight portion of an RTLS or TAL
- ARD Support (ascent only) – maintained the Abort Region Determinator processor which is used to predict trajectory capabilities during powered flight
- Ascent Support team (ascent only) – monitored the winds and weather at the launch site, help compute day-of-launch updates
- Dynamics – maintained the inputs to the Mission Operation Computer for all processors
- Entry Console – provided expert support for entry, approach, and landing
- Entry Support team (ascent and entry) – monitored the winds and weather at the various potential landing sites, prepare trajectory adjustments
- Landing Support Officer (LSO) team – maintained the airspace at any landing site, dispatch Search and Rescue teams if needed, act as first liaison in case of a landing outside the US
- Nav Support team – responsible for maintaining the on-board navigation (telemetry) and the ground navigation (tracking)
- Profile Support (rendezvous only) – assisted the FDO with rendezvous profile evaluation and determination
- Range Safety team (ascent only) – tracked the falling External Tank and Solid Rocket Boosters
- Targeting (ascent only) – provided expert support for Abort to Orbit (ATO) or Abort Once Around (AOA) trajectories
- Track – coordinated tracking site data flow and data requests
- Weather – a member of the Spaceflight Meteorology Group who provided worldwide weather data
Guidance Procedures Officer (GPO) / Rendezvous (RNDZ)
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Depending on the phase of flight the mission is in, this console is either staffed by the Guidance and Procedures Officer (GPO), a specialist in the procedures related to flight, or the Rendezvous Procedures Officer (RNDZ), a specialist in orbital rendezvous procedures.
- GPO is responsible for monitoring the Shuttle guidance and navigation as well as execution of crew procedures, particularly for ascent abort situations.
- RNDZ is responsible for activities such as trajectory operations (in coordination with FDO) related to the rendezvous and docking/capture with another spacecraft, including the Mir space station, ISS, and satellites such as the Hubble Space Telescope.
Propulsion Engineer (PROP)
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PROP monitors and evaluates reaction control thrusters and orbital maneuvering engines during all phases of flight, monitored fuel usage and propellant tank status and other consumables available for maneuvers, and calculated optimal sequences for thruster firings.
Guidance, Navigation, and Controls Systems Engineer (GNC)
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GNC monitors all vehicle guidance, navigation and control systems and was responsible for operating and monitoring the sensor system, which includes navigation sensors and associated software. GNC was also responsible for flight control system hardware and software, which includes aero and reaction control system controls, digital autopilots, main engines, solid rocket boosters, and orbital maneuvering system thrust vector control with associated software.
Ground Controller (GC)
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GC ensures the MCC is functioning properly and coordinates outside data and communications traffic. GC also directs all maintenance and operation activities affecting Mission Control hardware, software, and support facilities. GC coordinates space flight tracking and data network, and Tracking and Data Relay Satellite system with Goddard Space Flight Center.
Data Processing System Engineer (DPS)
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DPS is responsible for the Space Shuttle data processing systems. This included monitoring the onboard General Purpose Computers (GPCs), flight-critical, launch and payload data buses, the Multi-function Electronic Display System (MEDS), Solid-State Mass Memory (SSMM) units, flight critical and payload Multiplexer/De-multiplexer (MDM) units, Master Timing Unit (MTU), Backup Flight Control (BFC) units and system-level software.
Payloads Officer (PAYLOADS)
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PAYLOADS coordinates onboard and ground system interfaces between the flight control team and payload user.
Electrical, Environmental, Consumables Manager (EECOM)
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EECOM is responsible for the atmospheric pressure control and revitalization systems, the cooling systems (air, water, and freon), and the supply/waste water system. EECOM’s critical function was to maintain the systems, such as atmosphere and thermal control, that keep the crew alive.
EECOM MPSR positions
- Life Support – monitored atmospheric pressure control systems, O2/N2/CO2 maintenance and management, air cooling equipment, waste water systems,
- Thermal – monitored water and refrigerant coolant loop systems, supply water maintenance
Electrical Generation and Illumination Engineer (EGIL)
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EGIL monitors cryogenic levels for the fuel cells, electrical generation and distribution systems on the spacecraft, and vehicle lighting.
EGIL MPSR positions
- EPS – provided expert support monitoring of the fuel cells, cryo system, and electrical bus system
Flight Activities Officer (FAO)
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FAO plans and supports crew activities, checklists, procedures, schedules, attitude maneuvers, and timelines. Coordinates implementation of the flight plan and develops alternate and flight plans, as required. Provides the capability to transfer data (text, graphics, and video) between a ground PC network and the orbiter laptops.
FAO MPSR positions
- Attitude and Pointing Officer (Pointing) – Generated and maintained the Attitude Timeline, monitored the executions of all attitude maneuvers, provided attitude maneuver inputs for the crew, generated star pairs and attitudes for IMU aligns
- Message and Timeline Support (MATS) – Created messages based on MCC inputs, created the Execute Package, monitored crew activities and assessed impacts to the Timeline
- Orbital Communications Officer (OCA) – Transferred electronic messages to the crew, synced the crews E-Mail, uplinked and downlinked files for the crew
- Timeline – Generated the pre-flight timelines for the Flight Plan, monitored in-flight crew activities, coordinated activities with other flight controllers
Maintenance, Mechanical, Arm, and Crew Systems (MMACS)
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MMACS, call sign “Max”, monitors operation of the orbiter’s structural and mechanical system, monitoring auxiliary power units and hydraulic systems, managing payload bay door, external tank umbilical door, vent door, radiator deploy/stow, Ku-band antenna deploy/stow, and payload retention latch operations, landing gear/deceleration systems (landing gear deploy, tires, brakes/antiskid, and drag chute deploy), and monitoring the orbiter docking system. MMACS also followed use of onboard crew hardware and in-flight equipment maintenance.
MMACS MPSR positions
- MECH – provided expert support monitoring of mechanical, hydraulic, and landing gear systems
- MECH 2 – provided extra support during the dynamic ascent and entry phases of flight
- IFM – In-Flight Maintenance support
- Crew Systems/Escape – responsible for operations of onboard crew hardware and the crew’s Launch and Entry Suits
- Photo/TV – responsible for the “loose” camera operation and maintenance, such as still cameras and camcorders, and the integration of video into and out of the orbiter’s TV monitors
Integrated Communications Officer (INCO)
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INCO is responsible for all data, voice and video communications systems, including monitoring the configuration of in-flight communications and instrumentation systems. INCO monitors the telemetry link between the vehicle and the ground, and oversees the uplink command and control processes.
INCO MPSR positions
- RF COMM: MPSR lead and responsible for the Ku-Band and S-Band communication systems.
- INST: Responsible for uplinking commands and telemetry flows.
- DATA COMM: Responsible for recording and downlinking telemetry that wasn’t streamed live and the FM communication system.
Booster Engineer (BOOSTER)
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BOOSTER monitors and evaluates Space Shuttle Main Engine, Solid Rocket Booster, and External Tank performance during pre-launch and ascent phases of missions.
Extravehicular Activity Officer (EVA)
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EVA is responsible for all spacesuit and spacewalking-related tasks, equipment and plans when the EVA took place from the Shuttle.
Payload Deploy Retrieval (PDRS)
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PDRS monitors operation of the Remote Manipulator System (RMS), aka the “robot arm” used for satellite and cargo deployment and retrieval.
Russian Interface Operator (RIO)
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RIO serves as the primary interface between the U.S. and Russian control teams.
Public Affairs Officer (PAO)
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PAO provides mission commentary to supplement and explain air-to-ground transmissions and flight control operations to the news media and the public. The individual filling this role is often referred to colloquially as The Voice of Mission Control.
Flight Surgeon (SURGEON)
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SURGEON directs all medical activities during the mission. Monitors crew health via telemetry, provides crew consultation, and advises the flight director. A private communication channel can be established between astronauts and the flight surgeon, to provide doctor-patient confidentiality.
Mission Operations Directorate Manager (MOD)
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MOD is a representative of the senior management chain at JSC, and is there to help FLIGHT make those decisions that have no safety-of-flight consequences, but may have cost or public perception consequences. The MOD cannot overrule the Flight Director during a mission.


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This is a great resource! Thank you for providing it, and thank you for everyone who works or worked in the Mission Control Center!
Good site
Was looking for information on Apollo 8 and found this great site. You’ve created an amazing resource here, thanks!
Love this entire website!
This is inspiring to my young son who wants to work at NASA when he grows up. Thank you from a fellow dad,
You guys were heroes as much as the astronauts.
Thanks for all that you did! I love everything about space!
Everything is super information thank you so much
Cool