90 Science & technology The Economist October 30th 2021
with no humansuitable habitat in orbit
around Earth. Experts caution, though,
that the ageing space station might not
make it to 2028. Some Russian officials,
noting spreading cracks and other signs of
senescence, have proposed that their
country jump ship by 2025.
It could, therefore, get dicey. If no
American firm is operating a space station
by the time the issis abandoned, America’s
leadership in space may suffer. To make
matters worse from an American point of
view, China’s new and expanding space
station, Tiangong, could become fully op
erational next year. Todd Harrison, a space
and defence expert at csis, an American
thinktank, says China’s goal of signing up
international partners for Tiangong in
volves “actively courting” America’s Euro
pean allies. Were America to find itself be
reft of a space station, Britain, France or
Germany might, he reckons, join Tiangong.
That seems a stretch, diplomatically
speaking, especially given other collabora
tions between nasaand Europe’s spacefar
ing powers. But even the raising of such
ideas shows that times are changing. Prog
nosticators would, however, be wise to fac
tor in the ambition and ingenuity of Amer
ica’s aerospace industry. For an inkling of
what might be achieved consider Nano
racks, a company based near Houston that
is one of Lockheed Martin’s Starlabpart
ners. In addition to Starlab, Nanoracks is at
work on a completely different type of
space station that is both more basic and
more technologically challenging. This in
volves converting, in orbit, discarded rock
et stages into stations it calls outposts.The lathes of heaven
The idea of converting rocket stages harks
back to Skylab, America’s first space sta
tion, which was built, on the ground, out of
the third stage of a surplus Saturn V rocket.
In this case, though, the conversion will be
of the upper stage of one of SpaceX’s Falcon
9s, or a similar rocket, and will be done in
space by a small robot affixed to the stage
in question.
After the stage achieves orbit, the robot
will cut metal and assemble parts to create
a docking port, windows and other fix
tures. When Jeffrey Manber, Nanoracks’
boss, pitched the idea a half decade ago, he
says, “my company laughed at me”. nasa,
however, was intrigued. The agency paid
for a study on the feasibility of using a ro
bot to convert the upper stage of an Atlas V.
The results were promising.
nasahas therefore coughed up more
than $12m for a test aloft, planned for Janu
ary. If all goes well, a robot will soften a
sample of metal in orbit by generating fric
tional heat with a spinning tool, and will
then cut that metal without, it is hoped,
creating scraps that could become projec
tiles dangerous to other satellites. This hasnever yet been done in space. A camera will
capture the action, which, for extra safety,
will take place inside a containment ves
sel. A welding test will be launched later,
says Robbie Harris, Nanoracks’ head of
technology for outposts.
If Mr Manber’s proposal works, build
ing private space stations could become (at
least by the standards of space flight) cheap
indeed. And the cheaper those stations get,
the more uses they may be put to. Orbitinggreenhouses intended to develop hardy
crops are one idea. Biopharmaceutical lab
oratories are another. A third, for the truly
adventurous, is honeymoon hotels in
space. How that will work out in practice
remains to be seen. The accommodation
will be cramped, for sure, and the cham
pagne may have an unnerving tendency to
float out of its glasses. But thereisnoques
tion that, viewed from out of theporthole
at least, the Earth will be moving.nF
ew animalshavecomecloserto
extinction, and yet survived, than the
Californian condor. Thousands died as a
result of flying into electrical cables or
being poisoned by lead shot from dis
carded gameanimal carcasses. By 1982,
there were only 22 left. These relicts were
rounded up and brought into a captive
breeding programme that proved an
astonishing success. Thanks to the ef
forts of a team of conservationists co
ordinated by the San Diego Zoo Wildlife
Alliance there are now 329 condors flying
freely in western North America, and 175
more in the care of various zoos.
As the precision of those numbers
suggests, these birds are among the most
closely monitored in the world. It there
fore came as a shock to Oliver Ryder, a
geneticist at the alliance, when he dis
covered that two of the females he was
scrutinising had laid eggs unfertilised by
males, which then went on to hatch.
As Dr Ryder and his colleagues report
this week in the Journal of Heredity, both
females had had ample opportunities to
mate, since each was housed with a male
with which she had successfully repro
duced in the past. One of them, indeed,
had raised a whopping 23 chicks before
laying the fertile unfertilised egg in
question. She and her mate then went on
to raise two more.
Parthenogenesis, as this form of
malefree reproduction is known, is
common in invertebrates and not un
heard of in vertebrates. Some snakes
indulge in it. So do Komodo dragons. But
it has rarely been recorded in birds, and
when seen (as it has been in domestic
turkeys) it has always been in circum
stances when no males were around and
it was therefore the only reproductive
option available.
In nature, it will hardly ever be the
case that there are no males around. On
the other hand, it is hard to say whether
parthenogenesis is happening in wildbirds,becausethatwould require in
tense genetic screening of nestlings of a
sort that is rarely conducted in ornitho
logical research projects.
In this instance, neither chick pros
pered. One, which was released into the
wild near Big Sur state park in California,
failed to thrive there and probably died
of starvation at the age of two—not an
uncommon fate for reintroductees,
unfortunately. The other, held in captiv
ity as part of a breeding programme,
nevertheless failed to breed, and died of
complications from a foot injury when it
was nearly eight years old.
At the moment, therefore, it is hard to
know whether Dr Ryder has stumbled on
an intriguing and previously unper
ceived mode of avian reproduction, or an
aberration of little wider significance.
But if condors, and possibly other bird
species, are routinely reproducing by
parthenogenesis, then some rewriting of
the textbooks will definitely be in order.AvianreproductionNo sex please, we’re condors
An endangered bird may sometimes reproduce without malesVery well, alone...