(Georgia Institute of Technology, 2006-05-01)
Thompson, Robert W.
The NASA Exploration Systems Architecture Study (ESAS) produced a transportation
architecture for returning humans to the moon affordably and safely. ESAS determined
that the best lunar exploration strategy was to separate the launch of crew from the launch
of cargo, thereby requiring two launches per lunar mission. An alternate concept for the
cargo launch vehicle is a side mounted Shuttle-derived heavy lift launch. This configuration
is similar to previously studied concepts, except engines and structure have been added to
the External Tank (ET), making it a complete first stage. The upper stage is mounted on the
side of the first stage, much like the Shuttle orbiter is mounted on the side of the ET. Like
the Shuttle, solid rocket boosters (SRBs) are also used. This configuration has several
performance and operational benefits over an in-line heavy lift launch vehicle.
According to the ESAS report, side mount configurations were not considered to be
among the most promising configurations, and were not carried forward for further
consideration within architectural options. The performance of this launch vehicle is
independently analyzed, using multidisciplinary analysis techniques. Methods and tools
used include launch trajectory optimization with POST, vehicle aerodynamic analysis using
APAS, and weights and sizing using historically based estimating relationships. Principal
trade studies performed include first and second stage propulsion (number of engines and
engine type), solid rocket booster size (four versus five segment), and staging ∆V. The
vehicle design that best meets the requirements for space exploration (lunar and future
missions) is presented.
(Georgia Institute of Technology, 2006-05-01)
Street, David
This paper describes the design and features of a Scalable Orbital Propellant Depot
Design tool. The purpose of the tool is to enable others to easily test the effectiveness of
adding a propellant depot to an exploration architecture. Several options are available
including zero boil-off technology, usable propellant and depot geometry. It is assumed that
the depot is refillable with a total service life of 10 years and resides in low earth orbit.
Examples of depots created with the tool are shown. Application to existing exploration
architectures is also discussed.