- Zubrin, Robert.
The Case for Space.
Amherst, NY: Prometheus Books, 2019.
ISBN 978-1-63388-534-9.
-
Fifty years ago, with the successful landing of Apollo 11 on
the Moon, it appeared that the road to the expansion of human
activity from its cradle on Earth into the immensely larger
arena of the solar system was open. The infrastructure built
for Project Apollo, including that in the original 1963
development
plan for the Merritt Island area could support Saturn V
launches every two weeks. Equipped with nuclear-powered upper
stages (under active development by
Project NERVA, and
accommodated in plans for a Nuclear Assembly Building near
the Vehicle Assembly Building), the launchers and support
facilities were more than adequate to support construction of
a large space station in Earth orbit, a permanently-occupied
base on the Moon, exploration of near-Earth asteroids, and
manned landings on Mars in the 1980s.
But this was not to be. Those envisioning this optimistic future
fundamentally misunderstood the motivation for Project Apollo. It
was not about, and never was about, opening the space frontier.
Instead, it was a battle for prestige in the Cold War and, once
won (indeed, well before the Moon landing), the budget necessary to
support such an extravagant program (which threw away skyscraper-sized
rockets with every launch), began to evaporate. NASA was ready to
do the Buck Rogers stuff, but Washington wasn't about to come up
with the bucks to pay for it. In 1965 and 1966, the
NASA budget
peaked at over 4% of all federal government spending. By
calendar year 1969, when Apollo 11 landed on the Moon, it had
already fallen to 2.31% of the federal budget, and with
relatively small year to year variations, has settled at around
one half of one percent of the federal budget in recent years.
Apart from a small band of space enthusiasts, there is no public
clamour for increasing NASA's budget (which is consistently
over-estimated by the public as a much larger fraction of
federal spending than it actually receives), and there is no
prospect for a political consensus emerging to fund an increase.
Further, there is no evidence that dramatically increasing NASA's
budget would actually accomplish anything toward the goal of
expanding the human presence in space. While NASA has accomplished
great things in its robotic exploration of the solar system and
building space-based astronomical observatories, its human
space flight operations have been sclerotic, risk-averse, loath
to embrace new technologies, and seemingly more oriented toward
spending vast sums of money in the districts and states of powerful
representatives and senators than actually flying missions.
Fortunately, NASA is no longer the only game in town (if it can
even be considered to still be in the human spaceflight game,
having been unable to launch its own astronauts into space
without buying seats from Russia since the retirement of the
Space Shuttle in 2011). In 2009, the
commission
headed by Norman Augustine recommended cancellation of
NASA's
Constellation
Program, which aimed at a crewed Moon landing in 2020, because
they estimated that the heavy-lift booster it envisioned (although
based largely on decades-old Space Shuttle technology) would take
twelve years and US$36 billion to develop under
NASA's business-as-usual policies; Constellation was cancelled in
2010 (although its heavy-lift booster, renamed. de-scoped, re-scoped,
schedule-slipped, and cost-overrun, stumbles along, zombie-like,
in the guise of the
Space
Launch System [SLS] which has, to date, consumed around US$14 billion
in development costs without producing a single flight-ready
rocket, and will probably cost between one and two billion
dollars for each flight, every year or two—this farce
will probably continue as long as Richard Shelby, the Alabama
Senator who seems to believe NASA stands for “North
Alabama Spending Agency”, remains in the World's
Greatest Deliberative Body).
In February 2018, SpaceX launched its
Falcon Heavy
booster, which has a payload capacity to low Earth orbit
comparable to the initial version of the SLS, and was
developed with private funds in half the time at one thirtieth
the cost (so far) of NASA's Big Rocket to Nowhere. Further,
unlike the SLS, which on each flight will consign Space Shuttle
Main Engines and Solid Rocket Boosters (which were designed to
be reusable and re-flown many times on the Space Shuttle) to
a watery grave in the Atlantic, three of the four components of
the Falcon Heavy (excluding only its upper stage, with a single
engine) are reusable and can be re-flown as many as ten times.
Falcon Heavy customers will pay around US$90 million for
a launch on the reusable version of the rocket, less than a tenth
of what NASA estimates for an SLS flight, even after writing off
its enormous development costs.
On the heels of SpaceX, Jeff Bezos's Blue Origin is developing
its
New Glenn
orbital launcher, which will have comparable payload capacity and
a fully reusable first stage. With competition on the horizon,
SpaceX is developing the
Super Heavy/Starship
completely-reusable launcher with a payload of around 150 tonnes to
low Earth orbit: more than any past or present rocket. A
fully-reusable launcher with this capacity would also be capable
of delivering cargo or passengers between any two points on
Earth in less than an hour at a price to passengers no more than
a first class ticket on a present-day subsonic airliner. The
emergence of such a market could increase the demand for rocket
flights from its current hundred or so per year to hundreds or
thousands a day, like airline operations, with
consequent price reductions due to economies of scale and moving
all components of the transportation system down the technological
learning curve.
Competition-driven decreases in launch cost, compounded by
partially- or fully-reusable launchers, is already dramatically
decreasing the cost of getting to space.
A common metric of launch cost is the price to
launch one kilogram into low Earth orbit. This remained
stubbornly close to US$10,000/kg from the 1960s until the entry
of SpaceX's Falcon 9 into the market in 2010. Purely by the
more efficient design and operations of a profit-driven private
firm as opposed to a cost-plus government contractor, the first
version of the Falcon 9 cut launch costs to around US$6,000/kg.
By reusing the first stage of the Falcon 9 (which costs around
three times as much as the expendable second stage), this
was cut by another factor of two, to US$3,000/kg. The much larger
fully reusable Super Heavy/Starship is projected to reduce launch cost (if its
entire payload capacity can be used on every flight, which
probably isn't the way to bet) to the vicinity of US$250/kg,
and if the craft can be flown frequently, say
once
a day, as somebody or other envisioned more than a
quarter century ago, amortising fixed costs over a much larger
number of launches could reduce cost per kilogram by another
factor of ten, to something like US$25/kg.
Such cost reductions are an epochal change in the space
business. Ever since the first Earth satellites, launch costs
have dominated the industry and driven all other aspects of
spacecraft design. If you're paying US$10,000 per kilogram to
put your satellite in orbit, it makes sense to spend large sums
of money not only on reducing its mass, but also making it
extremely reliable, since launching a replacement would be so
hideously expensive (and with flight rates so low, could result
in a delay of a year or more before a launch opportunity became
available). But with a hundred-fold or more reduction in launch
cost and flights to orbit operating weekly or daily, satellites
need no longer be built like precision watches, but rather
industrial gear like that installed in telecom facilities on the
ground. The entire cost structure is slashed across the board,
and space becomes an arena accessible for a wide variety of
commercial and industrial activities where its unique
characteristics, such as access to free, uninterrupted solar
power, high vacuum, and weightlessness are an advantage.
But if humanity is truly to expand beyond the Earth, launching
satellites that go around and around the Earth providing
services to those on its surface is just the start. People must
begin to homestead in space: first hundreds, then thousands, and
eventually millions and more living, working, building, raising
families, with no more connection to the Earth than immigrants
to the New World in the 1800s had to the old country in Europe
or Asia. Where will they be living, and what will they be
doing?
In order to think about the human future in the solar system,
the first thing you need to do is recalibrate how you think
about the Earth and its neighbours orbiting the Sun. Many
people think of space as something like Antarctica: barren,
difficult and expensive to reach, unforgiving, and while
useful for some forms of scientific research, no place you'd
want to set up industry or build communities where humans would
spend their entire lives. But space is nothing like that.
Ninety-nine percent or more of the matter and energy
resources of the solar system—the raw material for human
prosperity—are found not on the Earth, but rather
elsewhere in the solar system, and they are free for the taking
by whoever gets there first and figures out how to exploit them.
Energy costs are a major input to most economic activity on the
Earth, and wars are regularly fought over access to scarce
energy resources on the home planet. But in space, at the
distance Earth orbits the Sun, 1.36 kilowatts of free
solar power are available for every square metre of collector
you set up. And, unlike on the Earth's surface, that power
is available 24 hours a day, every day of the year, and will
continue to flow for billions of years into the future.
Settling space will require using the resources available in
space, not just energy but material. Trying to make a space-based
economy work by launching everything from Earth is
futile and foredoomed. Regardless of how much you reduce
launch costs (even with exotic technologies which may not even be
possible given the properties of materials, such as space
elevators or launch loops), the vast majority of the mass
needed by a space-based civilisation will be dumb bulk materials,
not high-tech products such as microchips. Water; hydrogen
and oxygen for rocket fuel (which are easily made from water
using electricity from solar power); aluminium, titanium, and
steel for structural components; glass and silicon; rocks and
minerals for agriculture and bulk mass for radiation shielding;
these will account for the overwhelming majority of the mass of
any settlement in space, whether in Earth orbit, on the Moon or
Mars, asteroid mining camps, or habitats in orbit around the
Sun. People and low-mass, high-value added material such as
electronics, scientific instruments, and the like will launch
from the Earth, but their destinations will be built in space
from materials found there.
Why? As with most things in space, it comes down to
delta-v
(pronounced delta-vee), the change in velocity needed to get from
one location to another. This, not distance, determines the
cost of transportation in space. The Earth's mass creates a
deep gravity well which requires around 9.8 km/sec of
delta-v to get from the surface to low Earth orbit.
It is providing this boost which makes launching payloads from
the Earth so expensive. If you want to get to geostationary
Earth orbit, where most communication satellites operate,
you need another 3.8 km/sec, for a total of 13.6 km/sec
launching from the Earth. By comparison, delivering a payload
from the surface of the Moon to geostationary Earth orbit
requires only 4 km/sec, which can be provided by a simple
single-stage rocket. Delivering material from lunar orbit
(placed there, for example, by a solar powered electromagnetic
mass driver
on the lunar surface) to geostationary orbit needs just 2.4
km/sec. Given that just about all of the materials from which
geostationary satellites are built are available on the Moon
(if you exploit free solar power to extract and refine them),
it's clear a mature spacefaring economy will not be launching
them from the Earth, and will create large numbers of jobs on
the Moon, in lunar orbit, and in ferrying cargos among
various destinations in Earth-Moon space.
The author surveys the resources available on the Moon, Mars,
near-Earth and main belt asteroids, and, looking farther
into the future, the outer solar system where, once humans have
mastered controlled nuclear fusion, sufficient
Helium-3 is
available for the taking to power a solar system wide human
civilisation of trillions of people for billions of years and,
eventually, the interstellar ships they will use to expand out
into the galaxy. Detailed plans are presented for near-term
human missions to the Moon and Mars, both achievable within the
decade of the 2020s, which will begin the process of surveying
the resources available there and building the infrastructure
for permanent settlement. These mission plans, unlike those of
NASA, do not rely on paper rockets which have yet to fly,
costly expendable boosters, or detours to “gateways”
and other diversions which seem a prime example of (to
paraphrase the author in chapter 14), “doing things in order
to spend money as opposed to spending money in order to do
things.”
This is an optimistic and hopeful view of the future, one in
which the human adventure which began when our ancestors left
Africa to explore and settle the far reaches of their home
planet continues outward into its neighbourhood around the
Sun and eventually to the stars. In contrast to the grim
Malthusian vision of mountebanks selling nostrums like a
“Green New Deal”, which would have humans huddled
on an increasingly crowded planet, shivering in the cold and
dark when the Sun and wind did not cooperate, docile and
bowed to their enlightened betters who instruct them how to
reduce their expectations and hopes for the future again and
again as they wait for the asteroid impact to put an end
to their misery, Zubrin sketches millions of diverse human
(and eventually post-human, evolving in different directions)
societies, exploring and filling niches on a grand scale that dwarfs
that of the Earth, inventing, building, experimenting, stumbling,
and then creating ever greater things just as humans have for
millennia. This is a future not just worth dreaming of, but
working to make a reality. We have the enormous privilege
of living in the time when, with imagination, courage, the
willingness to take risks and to discard the poisonous doctrines
of those who preach “sustainability” but whose
policies always end in resource wars and genocide, we can
actually make it happen and see the first steps taken in our
lifetimes.
Here is an
interview with the author
about the topics discussed in the book.
This is a one hour and forty-two minute
interview
(audio only) from “The Space Show” which goes
into the book in detail.
June 2019 