The Refueling Craft itself is almost ex-
ternally identical to the Interplanetary
Spacecraft, sharing the same superstruc-
ture which cuts down on development
costs. At the base are six vacuum-opti-
mized Raptor engines set around a set of
three gimbled engines (each engine sits
on controllable hydraulics to control the
direction of the thrust). Before departing
to Mars, the spacecraft will take on fuel
from three to eight times, depending
upon the mass of the payload.
Once the craft has begun its journey,
two solar panels will be deployed and
supply the craft with 200 kilowatts of
electricity. It will coast away from Earth
at 100,800 kilometers an hour towards
Mars, before aerobraking in the Martian
air as it prepares for landing. The craft
is designed as a “lifting-body”, echoing
that of the now retired Space Shuttle,
providing the lifting force during atmo-
spheric entry to slow down the craft to
48
48
launch
The Refueling Craft is the key to the
system, compared to a Saturn V, for
example, which used a three-stage
rocket that maximized the payload, but
increased both the cost and complexity
of the mission. Refueling means that you
don’t have to bring as much mass with
you in the first place, as you can simply
launch the craft multiple times, which
reduces mission complexity and vehicle
size. Not refueling in orbit would require
building a three-stage rocket at five to 10
times the size and cost.
Once the Booster has delivered the
Interplanetary Spacecraft to low Earth
orbit, it will turn around and begin its de-
scent back to Earth. Utilizing the method
that SpaceX has become so famous
for, the Booster will use its grid fins and
engines to land back near the launch
platform. At this point, the Booster can
be refueled and the Refueling Craft is
loaded on top for its next departure.
draw any connections. The launch
height of the ITS is 122 meters, compared
to the 111 meters of the Saturn V. Addi-
tionally, the Saturn V was designed as a
single use vehicle, delivering it’s payload
into orbit using an expendable three
stage setup, meaning that after each
use the hardware is simply dropped into
the ocean. On the other hand, the Inter-
planetary Transportation System is a two
stage vehicle and is designed to be fully
reusable.
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