ROOM
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Astronautics
than suborbital spaceplanes and will cost roughly
ten times more to develop.
It is very likely that Virgin Galactic or some
competitor will eventually make a commercial
success of suborbital passenger spaceflight.
There have already been setbacks, and more
may follow, but the technology and passenger
demand are already in place and there are no
likely showstoppers. The advantages of aeroplanes
over missiles will then become obvious to all and
space agencies will no doubt eventually embrace
development of orbital spaceplanes.
The first orbital spaceplane will be able to
undercut any expendable launcher of comparable
payload capacity. Lower costs and improved
safety will increase traffic levels, which will in turn
release funding to enlarge and mature the design.
This will further reduce costs and increase traffic
levels, thereby releasing even more funding for
design improvement.
The result will be a virtuous downward cost
spiral until Spacebus, or something like it, is built
and the lower cost limit of spaceplanes based on
existing technology is approached. This cost can
be estimated by comparison with airliners and
works out at a few tens of thousands of dollars for
a few days in a space hotel.
This would be affordable for wealthy middle-
income people prepared to save for the holiday
of a lifetime, and market research indicates that
about one million tourists per year could visit
space at this cost, although such a figure cannot
be precise at this stage.
Development of reusable spaceplanes is very
likely to happen in the long term but the process
could be speeded up considerably if major players
start planning for it now. Given that advanced
technology is not needed, operational prototypes
of Spacebus could be flying in about seven years,
which is a typical time from go-ahead to early
operations for an advanced aeroplane.
either design would have passed muster with any of
the 1960s spaceplane design teams.
The history of spaceflight has created
institutions and concepts that repeatedly reinforce
the habit of throwing away one launcher per flight.
Even today, space agencies are promoting new
single-use launch vehicles.
During the heady days when orbital
spaceplanes were seen as the future of
spaceflight, the X-15 suborbital research
aeroplane made several successful flights to
space height. There was then a gap of 36 years
between the last flight of the X-15 (in 1968) and
the first flight into space (in 2004) of the only
other suborbital spaceplane to have flown - the
Scaled Composites SpaceShipOne. This hiatus
is an indication of the lack of priority given to
reducing the cost of access to space.
The way ahead
A spaceflight revolution has already started,
although this is not yet widely appreciated. In
the USA, the Federal Aviation Administration is
encouraging entrepreneurial passenger suborbital
spaceflights and the UK’s Civil Aviation Authority
recently published a ground-breaking report, ‘UK
Government Review of Commercial Spaceplane
Certification and Operations’.
Several companies are developing suborbital
vehicles for carrying passengers on brief space
experience flights. The activities of Richard
Branson’s Virgin Galactic in particular have been
influential in shifting the mind set around space
tourism from dream to a realistic prospect.
However, its spaceplane - an enlarged
development of SpaceShipOne - and others under
construction, provide just a few minutes of zero
gravity on top of a very steep flight. As such they
are useful lead-ins but to launch satellites and
visit space stations fully orbital spaceplanes are
needed, which have to fly about eight times faster
The revolution
in spaceflight
will be one of
perception as
much as one of
engineering
The North American
X-15 (above) and
SpaceShipOne (SS1) - the
only fully reusable
spacefaring vehicles to
date. There was a 36-year
gap between the last flight
of the X-15 and the first
flight to space of SS1.
