QUESTION:
What kind of materials were used in the actual construction of the Mars
Pathfinder, and what did each material do to affect the performance?

ANSWER from Robert Manning on December 2, 1997:
To answer the first part of your question, we used everything from cork wood
filled with silca glass spheres (heatshield ablator) to titanium (separation
bolts & fuel tanks) to vectran fibers (airbag material) to plastic mylar
(thermal blanketing) to dacron cloth (parachute fabric) to rubber (a
component of the solid in the solid rocket motors) to phenolic honeycomb
(the white box with the US flag and JPL letters on it). So you can (nearly)
name it and we probably flew it! The actual structure of both the lander and
the cruise stage is made of "hogged out" aluminum (start with a big slab of
aluminum and whittle it down to desired shape in a milling machine).

I don't know how to answer the second part of your question just because
there were so many different types of materials that did different things.
It is really hard to say what each material did to affect the system
performance. That is kind of like asking an athlete how different cells in
her body helped her win the gold medal in the 100 meter. She is a complex
biological system with athletic characteristics that transcend the
characteristics of her individual cells. Likewise I can tell you that the
complex multi-material mechanical system that made up the lander impact
attenuation system (airbags and gas generators separation and retracation)
performed very well on July 4th. Even the bunching of the bags that delayed
rover egress for a day was within the design envelope we had specified. For
example, the ability of that system to limit the lander/rover impact
deceleration to less than 40 Earth G's was clearly demonstrated (only about
18 G's were experience by the lander). So all of the materials used just in
that (sub)system worked to perfection!

-Rob