30 http://www.popularmechanics.co.za _ AUGUST 2017
How it works
Stratolaunch is designed to give rockets
a head start on their journey to orbit by
removing the need for a launchpad.
Payloads will be mounted at the very
centre of the aircraft, between the twin-
fuselages. Takeoff will be from a runway,
just like regular planes. The giant cargo-
carrier will shepherd the payload high into
the sky, where it will be released to travel
the last part of its journey into orbit unas-
sisted.
“Taking off from a runway, rather than
a logistically vulnerable fixed range, allows
us to avoid hazards such as inclement
weather, airborne traffic and heavy marine
activity,” the company said in a statement.
“Stratolaunch’s airborne launch platform
significantly reduces the risk of costly
delays or cancellations.”
Design
The Stratolaunch’s design is a throwback
to the twin-fuselage planes of the early
20th century. Although it’s true that even
in recent years twin-fuselage designs have
been produced, the concept was first pop-
ularised during the early 1900s. The pluses
were increased stability and potential for
long-range missions.
In the case of the Stratolaunch, its twin-
fuselages add to the aircraft’s stability.
That’s really useful in helping to distribute
weight when carrying a payload. The added
space of twin-fuselages also allows for,
well, more space for crew and the flight
data systems.
A distinctive feature of Stratolaunch
design is its ultra-long wing that not only
provides lift, but links the fuselages and
the payload connection point.
The wing spans a distance almost the
length of a rugby field.
Why Low Earth Orbit?
Space seems a very long way away, but
in conventional travel terms it’s pretty
close. The International Space Station
orbits Earth just 400 kilometres above
its surface. That’s almost the distance
between Cape Town and Mossel Bay, or
Johannesburg and Malelane. Outer space
is so close, it took the New Horizons probe
only 8 hours and 25 minutes to reach the
Moon, which is 384 400 kilometres away.
But why are we so fascinated with LEO?
Simply because it is the mathematical
sweet spot for satellites and spacecraft. It
is here where a satellite’s horizontal speed,
coupled with Earth’s gravitational pull,
eases it into a curved path that we know
as orbiting the planet.The future of Stratolaunch
The aircraft’s first rollout at the Mojave
Air and Space Port in Mojave, California,
in May, marked the completion of the ini-
tial aircraft construction phase and the
beginning of the aircraft ground and flight
testing phase.The reveal in May was the
first time Stratolaunch was removed from
the scaffolding supporting its weight. It
was also the first time the aircraft’s full
weight was put on its 28 wheels.
“This was a crucial step in preparing the
aircraft for ground testing, engine runs,
taxi tests, and ultimately first flight,” the
company says.The company hopes Stratolaunch will
be fully operational in 2020 and has even
concluded its first launch partnership
in anticipation of this. Aerospace and
defence company Orbital ATK has signed
the deal with Stratolaunch.
“Orbital ATK is excited by this collabo-
ration and sees it as a positive first step in
a long-term partnership,” said Scott Lehr,
president of Orbital ATK’s Flight Systems
Group. “The combination of our extensive
air-launch experience and the Stratolaunch
aircraft has the potential to provide
innovative and cost-effective options for
commercial launch customers.”Stratolaunch is the world’s
largest plane, beating the
wingspan of the previous
record holder, the Hughes H-4
Hercules aka the Spruce Goose
by 19 metres. It also takes the
prize for the heaviest, beating
the 245 847 kilogram North
American XB-70 Valkyrie.Stratolaunch is rolled out of its hangar for the first time.