The mission design process begins with stating the goals of the mission. What task, or set of tasks, is the mission to accomplish?

Mission constraints are those things that effect your mission. Sure, you would love to send a big spacecraft to the Moon. However, a mission constraint in this scenario is that a launcher big enough for what you need probably does not exists. Feul and payload mass are usually a big mission constraint because of the Rocket Equation. In manned missions, life-support and consumables are usually large constraints as to how large the crew will be.

Determining the crew, spacecraft, launcher, propulsion system, communications network backbone, etc. determines the mission elements. The mission elements are the things you need to accomplish the mission.

Mission analysis can involve many things, but the end result is the same. The mission design state that exists at this point in the design process needs to be looked at from an orbital mechanics, flight dynamics, dependability, etc. point of view. Given a desired mission to another planet, are the desired times of departure and arrival in line with the synodic periods of the two bodies? Is the satellite designed so that its mass-moment of inertia is properly arranged to prevent tumbling? These are the sorts of questions that the analysis process needs to answer.

At the end of a mission design iteration is a candidate mission. Do the characteristics of the candidate mission fit within the mission goals? Are the expectations of the mission designers met? Are the cost-benefit balances reached in a given design iteration "the best"? If not, then the mission design process repeats. However, if the candidate mission characteristics are acceptable, then the mission design phase has ended except in those instances when the mission's goals, constraints, scenarios, or elements change.