QUESTION:
Are there any plans for using Russian launch vehicle Energia for a Mars
mission? After all, it is the most powerful booster available on Earth and
it is capable of bringing about 100 tons to the Earth orbit.

ANSWER from Mark Adler on August 11, 1997:
No.  The Energia is no longer in production.  After the Russian space
shuttle was cancelled, there were no near-term users for a launch vehicle
that large.  Eventually to send people to Mars, we may have to design a new
launch vehicle in the same class as the Energia and the old Saturn V.

Mark Adler