The Economist October 30th 2021 Science & technology 89months later, by a second and a third mod
ule. After a fourth and final module,
equipped to generate extra solar power, ar
rives in 2027, Axiom Station, as the whole
assembly will be known, will detach and
become a “free flyer” with nearly double
the usable volume of theiss.
The cost of doing all this will be about
$3bn, says Matt Ondler, Axiom’s top tech
nologist. Though no trifle, that is but a
small fraction of what the isshas cost. Ev
ery year, nasa spends roughly $3.5bn
merely to maintain and operate the sta
tion. And that covers only about three
quarters of the cost of doing so. The rest is
provided by Canada, Japan, Russia and par
ticipating European countries.
Axiom’s lower budget is partly ex
plained by elimination of the waste com
mon in government spending. But the firm
is also harnessing lessons from the issto
cut costs for things that range from block
ing radiation, via recycling urine to reco
vering water from rubbish. Beyond that,
much kit is cheaper and better now than
when the isswas designed in the 1990s. To
day’s solar panels generate, kilo for kilo, six
times more power. And lots of the compo
nents developed for smartphones and cars
will be used in Axiom Station. Mr Ondler
reckons it will cost, per unit of capability,
about a hundredth of the bill for the iss.
Axiom’s competitors, for their part,
have kept quiet about their stations’ ex
pected costs, but all the firms envisage a
range of ways to make money. Hosting as
tronauts, tourists and even marketing
campaigns will be one source of revenue.
Servicing and refuelling satellites could be
another. Many people also believe there
will be demand for pharmaceutical and
biotechnological work in microgravity, in
cluding the 3d-printing of human organs
for transplantation and the development
of stemcell therapies.
On Earth, gravity means that cells print
ed onto scaffolds intended to create struc
tures that are the same shape as natural or
gans have to be suspended in a viscous gel,
to stop them dripping off the scaffold. This
means high pressure is required to force
them through the nozzle of the printer that
sprays them onto the scaffold, a process
that damages a fair number of those cells.
In orbit, though, nothing drips, so the gel is
no longer needed. Cell cultures, mean
while, benefit from microgravity because
their components remain in suspension in
their nutrient fluids, rather than tending to
settle out, as happens in Earthbound fer
mentation tanks.
The firms also plan to host microgravity
manufacturing. Axiom, for example, says
one of its potential customers thinks it can
produce better eyesightrestoring retinal
implants in space than on Earth. Other
firms with which it is in talks hope to har
ness freefall to make purer fibre optics for
lasers and, more challengingly, to forge
stronger alloys for things like jet turbines.
At first blush, all this sounds a bit like
scifi. But the technology to achieve it ex
ists. For one thing, robots operating in
freefall can achieve extraordinary preci
sion. As Christian Maender, head of “in
space” manufacturing at Axiom, puts it,
“they need not fight the weight of their
own systems”. Launch costs have fallen
sharply too, especially since nasagave pri
vatisation a shot in the arm by ending its
staggeringly expensive Space Shuttle pro
gramme in 2011. Mr Maender reckons the
next decade will see them halved again. In
vestors, for their part, are enthused. Axiom
says it has had to turn some away.Who knows if the Moon’s a balloon?
Part of Blue Origin’s Orbital Reefis to be
provided by Sierra Space, a division of an
aerospace firm called Sierra Nevada Corpo
ration which already had a separate project
to make a space station out of big, inflat
able bladders. Once ejected into space from
a rocket’s fairing, such a bladder will ex
pand into a habitat 11 metres long and with
a diameter of eight metres, somewhat re
sembling a cylindrical paper lantern.
To stop its modules being punctured by
bits of highvelocity orbiting debris and
cosmic dust, Sierra has designed shielding
that incorporates layers of Kevlar and Vec
tran—fabrics used in things like bullet
proof jackets and the airbags that cushion
the fall of spacecraft dropped onto Mars.
The outer layers will break up these incom
ing objects. The smaller, and therefore less
energetic, fragments that result will then
be stopped by the underlying layers.
Sierra’s modules will be fitted out, by
astronaut handymen and women, with a
rigid internal structure that incorporates
avionics and control interfaces. Crew quarters, galley, toilet and facilities for re
search, manufacturing and satelliteser
vicing can be installed as required (see pic
ture below, of a groundbased mockup).
Connected together, three of these mod
ules will provide nearly as much pressur
ised volume as does the iss.
The iss, however, took about 40 launch
es to assemble. Sierra reckons it can loft
and equip three modules with just eight or
nine launches. The firm plans to shuttle
goods and crew between Earth and its orbi
tal facilities using a spaceplane called
Dream Chaserthat it is developing. (Orbital
Reefis to be supplied by Boeing’s Starliner
capsule, but Dream Chasermight pitch in
for that job, too.) Dream Chaserwill be able
to land on any long airport runway. That,
Sierra hopes, will provide a competitive
edge for the manufacture of fragile, urgent
ly needed goods, not to mention providing
a comfortable and convenient ride for rich
space tourists.
Sierra’s plan is for Dream Chaserto make
its muchdelayed maiden flight next year,
and to have its station operating in 2027, so
that its “anchor” tenant, nasa, can move in
before the iss’s demise. Others, it hopes,
will follow. Earlier this year, for example,
the firm said it was working with Redwire
Space, a company that is also part of the Or-
bital Reefproject, and which has been us
ing the issto test processes intended to
manufacture speciality ceramics, crystals
and fibre optics.
The second phase of nasa’s cldplan is
to award, in about 2025, big contracts for
specific orbital services. The agency hopes
that by the middle of the decade at least
two companies will be far enough along to
secure such contracts, and to begin offer
ing services in orbit shortly thereafter.
When the time comes to abandon the iss,
the agency is keen not to be left in the lurchAll mod cons available