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

Exploring the Unknown 495
I. INTRODUCTION
In response to the request of the Associate Administrator on May 25,
1961, it has been undertaken to assess a wide variety of systems for accomplishing
a manned lunar landing in the 1967-1970 time period. This study has, as directed,
placed primary emphasis on the launch vehicle portions of the systems, including
vehicle sizes, types and staging. In addition a number of variations on the use
of rendezvous to add flexibility and improve energy management in the lunar
mission have been considered. The results of this study are the subject of the
present report, and they are discussed in the following order.
First, the use of rendezvous to achieve a manned lunar landing is discussed
in terms of rendezvous locations, vehicle types, and mission requirements, and the
more attractive types of rendezvous are rated in the light of these considerations.
Then a number of alter nate Nova’s for accomplishing the manned lunar mission
are discussed briefly, and some consideration is given to the attendant question
of launch sites, booster recovery, and the role of man in the system. Finally, the
various methods for achieving manned lunar landing are compared in terms of
time phasing, reliability, and approximate cost.
II. MISSION STAGING BY RENDEZVOUS
II.
1. General
Mission staging by rendezvous has been the subject of much investigation
at Marshall, Langley, Ames, Lewis, and JPL. The work has concerned itself with
analytical and simulator studies of orbital mechanics, and control and guidance
problems as applied to rendezvous. Such critical questions as launch timing,
and automatic and piloted guidance of the vehicles to a rendezvous have been
carefully analyzed. Orbital refueling as well as attachment of self-contained
modules have been considered.
Because the use of rendezvous permits the accomplishment of a given
mission in a number of different ways employing different launch vehicles, the
various groups working on rendezvous have arrived [2] at a number of different
concepts for accomplishing the lunar landing mission. The assumptions made
by the different groups with regard to such parameters as return weight, specific
impulse, etc., were, however, consistent to the extent that meaningful comparisons
can be made between the different concepts. In the discussion to follow, the more
attractive rendezvous concepts will be summarized, after which the advantages
and disadvantages of each will be indicated and a rating system developed.
II
1. a: Mission Types
The rendezvous concepts which will be considered for the lunar landing
are as follows:
1. Rendezvous in earth orbit;