QUESTION:
Now that you are using the low gain antenna does that make the
pointing of Galileo less critical for staying in touch with Earth and
does this add flexability to camera and platform movement?  

ANSWER from Byron Yetter on March 29, 1997:
The Deep Space Networks largest antennas track the LGA S-Band signal. 
Since as you pointed out, the frequency being utilized is S-Band (2295 
Mhz) the spacecraft pointing to Earth is less critical. If Galileo was 
transmitting an X-Band signal they would need to hold their Earth 
angle pointing to within +/- 1 degree. An X-Band downlink, and more 
importantly the DSN antennas, have higher pointing constraints due to 
the narrow X-Band beam width. 
     
Galileo has realized a small benefit (we must look and the positive 
side) from the X-Band High Gain Antenna (HGA) non-deployment. By not 
having the very narrow X-Band pointing requirements, that not only (as 
you mentioned) provides a greater scan platform range, they also have 
saved quite a bit of fuel over the last 6-8 years. The saving in fuel, 
or attitude (thruster) propellant, comes from not having to routinely 
update the spacecraft's Earth pointing. 
     
The Project has been using (what I have come to call) the overshoot 
method. They force the S/C's pointing 5 or so degrees past the Earth's 
center. Then as time and celestial mechanics kicks in, the spacecraft 
drifts through the Earth's center point, and off another 5 degrees to 
the opposite side of the Earth. Then, commands are sent to fire the 
thrusters which swing the spacecraft back through the Earth boresight 
back to the starting 5 degree OEP (off Earth point). This whole 
process takes a few weeks. 
     
The savings in fuel will added to the fuel saved for the GEM program. 
That's the Galileo Europa Mission. This will be supported in the 1998 
time frame, and begins as soon as the Galileo Prime Mission is 
completed December 1997.