QUESTION:
Who comes up with the designs and shapes for the Rovers?  What type of
training do these people have?
 
ANSWER from Tim Gallagher on May 1, 1997:
Even though I did not work on the Rover I will answer your question about
design and shapes from previous experience.

There are many factors in the design and shape of any small vehicle such as
the Rover:

1. What is the terrain?   Is it flat with a few small rocks or is it very
rocky?  A small rover type vehicle would not work in a place with many
large rocks.  However there are different type of robots which are better
for this such as one with legs not wheels.
2. What is the environment?  Is it very hot, very cold, or very windy? 
Different materials have to be used for different environments.  Sometimes
cooling systems are required (fans don't work without an atmosphere).
3. What is the cost?  As you find out when you buy a new computer anything
bigger, better, faster costs a lot more.  A system designed with very
expensive and exotic composites may save some weight but cost a lot more. 
Is the weight savings worth the cost?  Sometimes the development of a new
system costs more than an older system that may work just as well with a
few modifications but not have the same capability?  Is this a valid
tradeoff?
4. What is the maximum payload size and weight?  To launch any vehicle into
space is very expensive because of the cost of the launch booster such as a
Titan or Atlas rocket.  As the size and weight of the rover vehicle
increase then so does the cost to launch it.  Sometimes another experiment
would have to be cut out to decrease the weight.  Sometimes it is necessary
to spend many millions of dollars more to go to a bigger launch vehicle.
5. What experiments are attached to it?  Very tall experiments (i.e.
cameras, soil sample mechanisms, etc.)  would need much larger wheelbase to
be stable while many heavy experiments would require stronger motors.
6. How long to design the system?  The sooner the mission launch date the
faster the design has to be completed (such as the Mars Pathfinder).  This
may limit trying out new options to see if they work or not.  This may
force a less complex system to be designed.  
7. What type of power is available?  If batteries are used for simplicity
then do they need to be recharged to continue a long term mission?  If yes,
then solar arrays or another power source with its added weight, size, and
complexity has to be available.
8. How far does it need to go?  How many power is needed to go that far and
back.
9. How long does the mission last?  For long term and critical missions
then redundancy is added - that is, critical equipment is duplicated or
designed such that one failure would not cause a complete loss of the
mission.
10.  How does it communicate?  Any space system is worthless unless it can
transmit it's data back to earth or another satellite.  Does the vehicle
need to have a powerful comm system to communication with the base system
at greater distances?

The above are some but not all the tradeoffs in designing a rover type
vehicle.

An interesting part of designing anything for space is that as the system
is designed many of the above trade-offs are constantly changing.  For
example, if it was desired to add another camera to the vehicle then the
weight and size increase.  This will required more power and maybe more
batteries which also increases weight and size.  Maybe it needs to sit
higher up on the vehicle which will require structure modifications to
widen, lengthen, and strengthen the previous design which will also add
more weight.  Possibly the time and cost to add this extra feature (with
all the added problems) will cancel many of its benefits and the added
camera will be deleted.
 
There are many different specialists involved with a space system.  Most
seem to have physics, math, or engineering backgrounds.  I have found that
there are 2 essential skills that have greatly aided me - Math and English.
 Many things seems to involve some type of math calculation or logic and
good communication skills (written and oral) are essential in any team
project.