Contributed by Teaching Science & Technology Inc.
Adapted from Chapter 15 of Understanding Space: An Introduction to Astronautics, 4th Edition, available on Inkline (www.inkling.com) starting Fall 2014.
The term “space operations” probably brings to mind engineers sitting at consoles looking at telemetry or sending commands to tell a satellite what to do. But space operations actually begins WAY before we get to that point. It requires the careful coordination of people, equipment, and facilities all over the world and even in space. Space operations involves a broad range of interrelated activities that encompass mission planning and analysis, flight control, training, and other actions aimed at ensuring well-trained operators are always on the job, vigilantly keeping mission data and services flowing to users. Figure-1 shows the key activities we’ll describe in this article.
Figure 1 Space Mission Operations Activities (Understanding Space: An Introduction to Astronautics Fig. 15-32)
To coordinate the efforts of everyone involved with space mission operation, we need a plan. Operations planning begins during the mission’s early formulation stage. Recall from our discussion of systems engineering in Chapter 11, the entire process begins with the scope—needs, goals, and objectives—and the concept of operations (ConOps).
Besides the big picture in Figure 15-33, systems engineers, operators, users, and other stakeholders need to put their heads together early in design to answer other questions that expand the concept of operations. Answers to these questions describe:
- Key mission events and their timelines
- Operational environments
- Operational interfaces with other systems and procedures we must use, along with any other constraints
- User and operator roles and responsibilities, along with the structure of organizations that will operate, support, and maintain the system
- Detailed operational performance requirements
That’s a lot of questions to answer! But if operators understand users’ expectations and spacecraft engineers understand operators’ expectations, the whole systems engineering process can better design, build, and deliver a system that will satisfy everyone.
Finally, everything is in place. The launch vehicle, with the spacecraft safely tucked inside the fairing, waits on the pad, and all that remains is to give the “go” for launch. At this point, flight control takes over. It focuses on monitoring and controlling every aspect of a mission in real or near-real time. By real time we mean as it happens (or as near as possible given communication lags due to the speed of light). Figure 2 shows attentive flight controllers in the European Space Agency Space Operations Centre (ESOC).
Figure 2: ESOC
Mission Data Receipt and Delivery
The first word spoken by humans from the Moon’s surface was “Houston.” Neil Armstrong was calling back to the Mission Control Center at Johnson Space Center in Houston, Texas, to let them know the Eagle had landed. To the anxious Flight Director and his operations team, that first transmission from the lunar surface was important “mission data.” Most space mission data is a bit less dramatic but still important. Without mission data, flight controllers are simply staring at blank screens. Ensuring all mission data gets to flight controllers, analysts, users, and customers, while sending commands as needed, is another critical mission operations activity.
Tracking and Navigation
Flight control activities depend on knowing where your satellite is! Tracking and navigation activities link closely to receiving and delivering data. If I don’t where the satellite is, I can’t point an antenna at it. If I can’t point the antenna, I won’t receive or be able to send data. Operators responsible for tracking and navigation use ground- and space-based mission operations systems to determine where the spacecraft is at all times and to predict where it will be. Either through ground tracking or onboard GPS, or a combination of both, operators start with an initial state vector. Then they use tools such as System Tool Kit (STKTM ) to generate ground track maps, like the one shown in Figure 3, and other planning products.
Figure 3. Satellite Ground Track
Spacecraft Support and Analysis
Even with intensive, specialized training, flight controllers can’t be experts on every aspect of the systems they fly. Occasionally, issues crop up that they’ve never seen crop up and their procedures checklists and flight rules don’t cover them. When that happens, they need to use their lifeline, calling in experts to help. These experts offer ongoing spacecraft support and analysis, answering questions about the bus and payload. They closely monitor telemetry and payload data looking for trends that could indicate imminent system failures.
Mission Data Processing
The only reason we fly space missions is to generate data or otherwise serve the users who pay the bills. For that reason, data processing is a critically important mission operations activity. In addition to time-critical payload data, operators also gather and analyze data about the system’s general behavior. This “engineering data” is important for spotting trends such as the solar arrays gradually losing efficiency. It’s also important to inform mission engineers about general system performance in case they need to tweak flight software or change designs for future missions.
User and Customer Support
Space missions exist to support users and customers. operators must focus on the daily needs of their users and customers and coordinate those needs with the mission planning and the other activities we’ve looked at. Even if all of the telemetry looks great, without happy users and customers, no mission is truly successful.
Typically, flight-control teams assemble months or even years before a flight. Until the launch, they focus on rehearsing for the mission using simulations. During a simulation (or “sim” for short), devious trainers feed simulated mission data and anomaly scenarios to operators at their consoles. Throughout this training, the operators see almost every problem that could conceivably occur during the mission. By learning to deal calmly and efficiently with “worst on
worst” cases, operators develop the skills and confidence to deal with the routine anomalies that inevitably occur.
Maintenance and Support
Behind the scenes at any operations center is a small army of engineers and technicians who ensure flight controllers and the rest of the operations team have the hardware and software tools they need. Maintenance and support activities include a wide range of tasks. They include everything from the huge efforts to bring a new launch complex or control center online to daily routine upgrades and keeping information technology (IT) systems running.
For More Information
Teaching Science & Technology Inc. (TSTI) (www.tsti.net) offers a range of technical training courses including our online Understanding Space that gives the you a broad overview of all aspects of space mission. We have also recently added Space Mission Operations to our catalog as an 3 day onsite course.