Pathfinder Mission to Mars—on a Shoestring
In 1976, NASA’s two Viking Mars-lander missions took six years and $3 billion (in 1992 dollars) to develop. Twenty-one years later, Mars Pathfinder and Sojourner Rover landed on Mars once again, but at a development cost of only $175 million, representing a whopping 94 percent cost reduction over the earlier mission. This amazing cost reduction was achieved through a variety of means but the most important was perhaps the philosophical one that this was a design-to-cost project rather than a design-to-performance project. Given this philosophy, the scope of the mission was intentionally limited and “scope-creep” was never an issue:
• to achieve a successful landing
• return of engineering telemetry
• acquisition and transmission of a single, partial panoramic image
• successful rover deployment and 7 sol (Martian day) operation on the surface
• completion of a 30 sol lander mission meeting all engineering, science, and technology objectives
• one successful alpha proton X-ray spectrometer measurement of a Martian rock and soil sample. The means of limiting the cost of the mission were multiple and creative:
• development was cost-capped, with no opportunity for more funds
• identifying a set of “de-scope” options which could be implemented in case the cost grew beyond the fixed budget
• mission, flight, and ground systems designs were driven by existing hardware and system capability
• a project cash reserve of 27 percent of the total budget was held back and carefully planned for time-phased release throughout the duration of the project
• mission designers/builders transitioned into the testers/operators to save documentation, time, labor cost, and chance of error
• existing NASA mission infrastructure was used rather than designing new systems
• instituting time-phased “what if” and lien lists for real or potential current and anticipated items of cost growth during the project
• choosing to use a “single-string” but higher risk design and offsetting the risk by using more reliable parts
• 70 percent of major procurements contracts were fi xed-price rather than cost-plus
• creative procurement, such as existing equipment spares, and accounting, such as lower burden rate personnel
On July 5, the Mars Sojourner Rover rolled down its deployment ramp and the resulting pictures made the headlines on newspapers around the world. The mission continued for almost three months and returned 2.6 Gigabytes of scientific and engineering data, 16,000 lander camera images, 550 rover camera images, 8.5 million environmental measurements, and the results of 16 chemical rock/soil experiments and 10 technology rover experiments.
1. How did a change in philosophy make such a drastic difference in project cost?
2. Why was the mission scope so limited? Why even spend the money to go to Mars with such limited objectives?
3. Describe their “de-scope,” “lien list,” and “cash reserve” approaches.
4. Recent design-to-cost interplanetary projects have also had some spectacular failures. Is this the natural result of this new philosophy?