QUESTION:
My assignment for science class is a tough one! First I must research
a planet of our choice. I chose Mars. After using search engines on my
computer this site came up, I thought I might try it. After finding basic
information I had to design a space vehical to travle to the planet I chose,
weight, mass, measurements, and design must be included. Thirdly, we are to
find how long it would take to travel to the planet considering velocity,
acceleration, and the most difficult - orbits of our plannets.

For the second and third tasks I don't konw where to begin. I have
researched  in many places but it is hard to find. If you cannot provide me
with the answers I would like to know where I should start. Any clues to
where to begin would be helpful.

Thank you very much for taking your time to read my letter. It is
greatly apperciated! I admire your taking time to answering questions.

ANSWER from Rich Hogen on January 5, 2000:
There is a college textbook that I believe you can handle and I believe will
help you greatly.  It's full of neat cartoons to help understand basic
concepts, yet it addresses real problems with real math.

The book is

Understanding Space, Sellers, ed. Wiley Larson
Paperback (June 1994)
McGraw Hill College Div; ISBN: 0070570272

I found it on Amazon.com, so it's still available.  First see if your local
college bookstores might sell it -- look through it and see if it can help
you.  I feel sure it can, and that goes for other people in your situation.
Start with this book.  It's fun and has lots of tidbits about past space
missions, too.