Mars Exploration Strategies

Design Refernce Mission

The recent increase in interest for the exploration of Mars, which has been marked by the launch of the Russian mission Mars 96 and by the successful landing of Pathfinder, has led mission designers to seriously look into a manned mission to Mars in the near future. Due to the high costs traditionally associated with a mission of these characteristics, alternative architectures are been studied to replace those normally used in space missions.

One of the alternative architectures that is currently under consideration for its live application is the design reference mission (DRM).

The goal of the DRM is

  To create a baseline strategy enabling the earliest and most     cost-effective program for the human and robotic exploration of Mars,     while addressing fundamental science questions and demonstrating the     ability for humans to inhabit Mars.

The focus of this exploration strategy is the use of the vast majority of available resources on the surface of Mars rather than on the transit time to and from the planet. Another of the objectives of this plan is to establish the highest possible degree of commonality between the Mars manned mission and the First Lunar Outpost.

To achieve all of the objectives of this design, the design team that worked on the project started on the assumption that the manned mission to Mars would occur before the First Lunar Outpost. Therefore all technologies and systems were designed to the more extreme conditions on Mars and once developed were examined for possible application on the Moon.

The DRM was developed around five central points that served as the guidelines during the duration of the project. These points were

  Define a robust planetary surface exploration capacity capable of     sustaining crews on the Martian surface for 500 to 600 days per     mission
  Limit the length of time the crew is exposed to the interplanetary      environment
  Provide an operationally simple mission approach that focuses on      common systems
  Provide a flexible application strategy
  Balance technical, programmatic, mission, and safety risks.

Out of the five fundamental points for the development of the project, the first was the basis of all the others. The robust surface capability called for in the DRM has the essential purpose of providing a comfortable, productive, reliable, and safe place for the crew. This allows the crew, unlike in many other designs, to carry out an abort to the Martian surface instead of a trajectory abort in case that a contingency may arise. By being able to abort to the planet, the crew is not exposed to unnecessary levels of radiation and are provided with a safe haven until the return trip of minimum exposure can be carried out.

The robust mission capability that allows for such operations is placed on the surface of Mars in separate units that are tested before committing crews to their mission. Each section of the outpost as well as the manned missions is carried in a FLO-class heavy-lift launch vehicle. This vehicle has a nuclear thermal propulsion (NTP) upper stage that injects the entire payload on a direct trajectory to Mars. The components of the outpost are taken on a minimum energy trajectory, while all crews are transported on more energy demanding and faster trajectories.

For the design of this mission, the Mars DRM assumes the use of Earth-Mars launch opportunities occurring in 2007 and 2009. 2009 was chosen, because it is the most difficult launch opportunity in the 15 year Earth-Mars cycle. By designing space systems that can function in this opportunity, mission designers have a high degree of confidence that these systems will function in all other launch opportunities. 2007 was chosen as the first date in the DRM, because it lies far enough into the future for the technology needed to commit humans to Mars to be developed.

In 2007, three cargo missions are launched on minimum energy trajectories. In 2008, the equipment on the surface of Mars is checked, and in 2009 the first crew is committed to the Red Planet.

For a description of the space transprtation systems of this mission:

     Space Transportation