Teacher Background
Each NASA mission has its own statement of Goals. These may be science objectives: Determine the composition of Martian soil. Or they may be engineering goals: Develop a cheaper way to deliver payloads to Mars orbit. These goals may come with other requirements: Complete the mission before the end of this decade. But once the goals are set, it takes teams of people to carry them out. Here are some examples of careers required

Mission Planners Mission Planners compare different strategies for meeting goals and analyze the costs and benefits of each approach. One approach may be faster and cheaper-but more risky! Another may be very reliable but much more expensive. Yet another may be cheap and safe but take too long. Once a basic strategy has been chosen (such as the innovative new MGS aerobraking maneuver) more detailed planning begins. This includes schedules for design, construction, launch and operation of the spacecraft; detailed planning for the package of science instruments; discussions about the inevitable trade-offs between competing requirements. What will be required to make the best use of each instrument? What are the most important observations? The most difficult? How will information be returned to Earth and analyzed? Every aspect of the mission must be studied, understood and incorporated in a Mission Plan. Project Managers These specialists create budgets and schedules for the entire project. How many people are required for each task? How long will it take? Where will the spacecraft be built? (MPF is built at JPL, but MGS at Lockheed Martin Astronautics (in Denver). Who will be responsible for the launch vehicle? (McDonell Douglas builds the Delta IIs, the Air Force is responsible for launching them from Cape Canaveral, and then handing off control to JPL, which communicates with the spacecraft via the Deep Space Network, which has huge radio dishes in the Mojave desert, California, Spain and Australia.) How will components be tested? Who will monitor the "health and safety" of the spacecraft? Many of these are engineering questions, but all have cost and schedule implications and each issue is just a small part of a far larger puzzle that must ultimately fit together perfectly. Managers must choose particular people and personalities for each task, ensure that the required equipment is available at the right time, and monitor progress in each activity area. The Science Team This team will have specific detailed science objectives and a "wish list" for the types of instruments that will precisely answer their questions. Some will study radiation, the fields and particles that permeate space. Others will call for images of different wavelengths in the electromagnetic spectrum (visible light, infrared, ultraviolet, etc.)

Engineering Teams These teams will be concerned with how much power each instrument needs, and how much it weighs. Is the device sensitive to heat or cold? Will radiation affect the measurements? How precisely will the device need to be aimed? Does its operation affect other spacecraft systems? What if some component fails? Can there be a backup or alternative procedure? The Navigation Team This team must precisely calculate the position and movement of the spacecraft and its target, then specify changes in attitude via thruster firings. In the case of Pathfinder, navigation also includes remotely "driving" a roving vehicle that is millions of miles away and up to 19 minutes in the past! It takes that long for a radio signal, traveling at the speed of light, to get from Mars to Earth, so the "Nav" team has to be sure they're not going to drive over a cliff before they can order the rover to stop or turn. "OPS" Team Specialists responsible for Flight Operations and Spacecraft Systems formulate the coded electronic commands that tell the spacecraft exactly what to do and when to do it. They also monitor each subsystem: propulsion, power, communications, guidance and control. All operations are controlled by computers that may receive pre-programmed commands months in advance. But complex systems often behave in surprising ways and the "Ops" Team must be prepared to respond immediately to unexpected developments.

Only when all the spacecraft systems and ground systems are working properly can mission goals be met. The payoff is new data for scientists around the world to analyze, a process that may take years after the spacecraft finishes its part of the mission. And by then new missions are already on the drawing boards.

Objective

• Students will identify the various jobs of the Mars Mission Team.
• Students will organize these jobs into categories and write a formal application for a position on the Mars Mission Team.

Engage

Read aloud an excerpt of the most current Field Journal you have been able to find on-line ("Why, just yesterday Rob Manning wrote...") or one of the existing excerpts found on page 57 of this Guide. Review with students the position this individual holds on the Mars Mission Team.

Explore

Procedure

Mars Mission Logbook Entry: Ask students "What position on the Mars Mission Team interests you most? What qualities (of skills, or personality) do you think would be most important in a person applying for this position?"

Go on-line, and identify the various mission members who have volunteered to write Field Journals or answer student questions. Print out and add to Logbook some of the comments you find most interesting.

Compare the Viking mission to Mars Pathfinder and/or Mars Global Surveyor in terms of planning time, site, duration and cost.

Read on-line Field Journals

Language Arts: Write a formal application for a specific position at NASA or JPL. Include your educational background and state clearly your qualifications ("personal and professional") for the position.

Research and compare cost for the Viking Missions with the proposed budgets for Mars Pathfinder and Mars Global Surveyor.