QUESTION: 
I want to know about the difficulty of
the mission.  How hard has it been to plan this Mars mission and what
have some of your biggest problems been?

ANSWER from Donna Shirley on January 30, 1997:
It is VERY, VERY hard to send missions to other planets.  For
Pathfinder, the Mars lander, we had to figure out how to do everything that
the Viking Mission did in 1975 for 1/20 th of the money.  Everything has to
be designed to stand temperatures colder than anyplace on earth ever gets.
Everthing has to be able to work in space where there is no air and where
radiation from the sun is deadly because there is no atmosphere to block
it.  For Pathfinder, everything had to be able to stand forces up to 50
times the force of gravity - like falling off a tall building without
getting hurt.

The rover had to be designed to do all the things a spacecraft does, plus
be smart enough to stay out of trouble on the surface of Mars, a place we
know almost nothing about.

And finally, we had to convince the government to give us the money to do
the mission - a very hard job indeed.