computational
fluid
dynamics
analysis, and they did simulations
with it,” added Voss. ”They created
the control laws to be able to fly it
and had a lot of astronauts come
in to try it and fly it, so they did
thousands of hours of work on it.
“When our company (SNC)
decided to pick up a vehicle to be
in using we thought it was not very
smart to start with a clean sheet of
paper, but lets use something NASA
has already put a lot of effort and
research into. So we took the basic
design and we changed it only
slightly.”
The company hopes to launch
the first autonomous spaceflight in
2016 atop a United Launch Alliance
Atlas-V 402 rocket, with the first
crewed mission espected to launch
in the third quarter of 2017.
A fleet of Dream Chasers is
planned to be based out of
Florida’s historic launch sites at
Kennedy Space Center and Cape
Canaveral Air Force Station. No
abort blackout zones and a 3.5day free flight capability—with the
added benefit of deorbiting at any
time (since Dream Chaser can land
on any conventional runway)—
are a couple of the vehicle’s main
selling points.
The spacecraft will also be able
to stay at the International Space
Station for up to seven months at
a time, if needed, before having
to return to Earth. An expected
1.5 G nominal reentry will provide
ideal conditions for returning fragile
cargo and science experiments,
in addition to making the return to
gravity easier on the crew. SNC also
anticipates there to be immediate
access to crew and cargo upon
landing.
A quick turnaround and an
almost entirely reusable vehicle put
Dream Chaser in a class all its own.
“We had over 30 conditions that
we were testing for the flight, and
the vehicle either met or exceeded
– in a positive way – all 30 of those
conditions,” said Sirangelo. “The
flight was extraordinary.”
Sierra Nevada is one of several
companies currently competing
to develop commercial crew
transportation
capabilities
in
cooperation with NASA, with the
goal of achieving safe, reliable,
and cost-effective access to and
from low-Earth orbit (LEO) and the
International Space Station.
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