Exploring the Unknown: Selected Documents in ... - The Black Vault

Exploring the Unknown 565
c. lunar landing in earth reflected or direct sunlight and b.
d. mission design for immediate insertion checking by tracking
[2]
e. allowance for solar interference with deep space tracking and c.
f. adequate tracking immediately prior and subsequent to reentry
and follow-up to landing to ensure minimum recovery time.
The above rules have been investigated by the Operational Analysis Section
of the Mission Analysis Branch, FOD, to see how they affect the Apollo launch
window. These same mission rules will also influence the selection of possible
lunar landing sites.
3. Taking into account the mission rules stated in paragraph 2, the
following disadvantages for the selection of a single lunar landing site are noted:
a. Mission rule of a single lunar landing site imposes a severe
restraint on the launching day and time because of its dependency on
the lunar declination.
b. A single lunar landing site is not compatible with the variable
launch azimuth and parking orbit scheme which opens the launch
window and thus eliminates the need of major plane changes.
c. Without an extensive investigation this extra restraint might be
too restrictive because not knowing the final design weights the amount
of fuel needed to make a necessary plane change may be prohibitive. Any
plane changes in the vicinity of the moon must result in suitable earth
return trajectories compatible with 2f.
d. The photographic and geophysical data obtained from the
Ranger and Surveyor programs and the Apollo manned lunar missions
may drastically alter present day concepts of the lunar surface, the single
landing site selected now could therefore be worthless.
4. The present day thinking is to restrict the landing site to a belt
approximately 10 degrees on either side of the lunar equator and on the front side
of the moon. If this will be true a few years from now then the following suggestions
of obtaining lunar surface data prior to manned lunar landings could be followed.
a. Obtain USAF lunar charts 1:1,000,000 scale of the landing area
belt that are based on today’s state of the cartographic art using lunar
telescopic photography taken on earth.
[3]
b. Augment the JPL Ranger and Surveyor programs to include
several landing sites in the +10 degree latitude belt on the front side of
the moon.