- White, Rowland.
Into the Black.
New York: Touchstone, 2016.
ISBN 978-1-5011-2362-7.
-
On April 12, 1981, coincidentally exactly twenty years after Yuri
Gagarin became the first man to orbit the Earth in
Vostok 1, the
United States launched one of the most ambitious and risky manned
space flights ever attempted. The flight of Space Shuttle Orbiter
Columbia
on its first mission,
STS-1,
would be the first time a manned spacecraft was launched with a crew
on its first flight. (All earlier spacecraft were tested in
unmanned flights before putting a crew at risk.) It would also be the first
manned spacecraft to be powered by
solid rocket boosters
which, once lit, could not be shut down but had to be allowed to burn
out. In addition, it would be the first flight test of the new
Space Shuttle Main Engines,
the most advanced and high performance rocket engines ever built,
which had a record of exploding when tested on the ground. The
shuttle would be the first space vehicle to fly back from space using
wings and control surfaces to steer to a pinpoint landing. Instead of
a one-shot
ablative heat shield,
the shuttle was covered by fragile silica tiles and reinforced
carbon-carbon composite to protect its aluminium structure from
reentry heating which, without thermal protection, would melt it in
seconds. When returning to Earth, the shuttle would have to maneuver
in a hypersonic flight regime in which no vehicle had ever flown
before, then transition to supersonic and finally subsonic flight
before landing. The crew would not control the shuttle directly, but
fly it through redundant flight control computers which had never been
tested in flight. Although the orbiter was equipped with ejection
seats for the first four test flights, they could only be used in a
small part of the flight envelope: for most of the mission everything
simply had to work correctly for the ship and crew to return safely. Main
engine start—ignition of the solid rocket boosters—and
liftoff!
Even before the goal of landing on the Moon had been accomplished, it
was apparent to NASA management that no national consensus existed to
continue funding a manned space program at the level of Apollo.
Indeed, in 1966,
NASA's budget
reached a peak which, as a fraction of the federal budget, has never
been equalled. The Saturn V rocket was ideal for lunar landing
missions, but expended each mission, was so expensive to build and
operate as to be unaffordable for suggested follow-on missions.
After building fifteen Saturn V flight vehicles, only thirteen of
which ever flew, Saturn V production was curtailed. With the
realisation that the “cost is no object” days of Apollo
were at an end, NASA turned its priorities to reducing the cost of
space flight, and returned to a concept envisioned by Wernher von
Braun in the 1950s: a reusable space ship.
You don't have to be a
rocket scientist
or rocket engineer to
appreciate the advantages of reusability. How much would an airline ticket
cost if they threw away the airliner at the end of every flight? If
space flight could move to an airline model, where after each mission
one simply refueled the ship, performed routine maintenance, and flew again,
it might be possible to reduce the cost of delivering payload into space by
a factor of ten or more. But flying into space is much more
difficult than atmospheric flight. With the technologies and fuels
available in the 1960s (and today), it appeared next to impossible to
build a launcher which could get to orbit with just a single stage (and
even if one managed to accomplish it, its payload
would be negligible). That meant any practical design would require a
large booster stage and a smaller
second stage which would go into orbit, perform the mission, then return.
Initial design concepts envisioned a very large (comparable to a Boeing 747)
winged booster to which the orbiter would be attached. At launch,
the booster would lift itself and the orbiter from the pad and accelerate to a
high velocity and altitude where the orbiter would separate and use its own
engines and fuel to continue to orbit. After separation, the booster would
fire its engines to boost back toward the launch site, where it would glide to
a landing on a runway. At the end of its mission, the orbiter would fire its
engines to de-orbit, then reenter the atmosphere and glide to a landing.
Everything would be reusable. For the next mission, the booster and orbiter
would be re-mated, refuelled, and readied for launch.
Such a design had the promise of dramatically reducing costs and increasing
flight rate. But it was evident from the start that such a concept would be
very expensive to develop. Two separate manned spacecraft would be required,
one (the booster) much larger than any built before, and the second (the
orbiter) having to operate in space and survive reentry without discarding
components. The orbiter's fuel tanks would be bulky, and make it difficult
to find room for the payload and, when empty during reentry,
hard to reinforce against the stresses they would encounter. Engineers
believed all these challenges could be met with an Apollo era
budget, but with no prospect of such funds becoming available, a
more modest design was the only alternative.
Over a multitude of design iterations, the now-familiar architecture
of the space shuttle emerged as the only one which could meet the
mission requirements and fit within the schedule and budget constraints.
Gone was the flyback booster, and with it full reusability. Two solid
rocket boosters would be used instead, jettisoned when they burned
out, to parachute into the ocean and be fished out by boats for
refurbishment and reuse. The orbiter would not carry the fuel for its
main engines. Instead, it was mounted on the side of a large
external fuel tank
which, upon reaching orbit, would be discarded and burn up
in the atmosphere. Only the orbiter, with its crew and payload, would
return to Earth for a runway landing. Each mission would require
either new or refurbished solid rocket boosters, a new external fuel
tank, and the orbiter.
The mission requirements which drove the design were not those NASA
would have chosen for the shuttle were the choice theirs alone. The
only way NASA could “sell” the shuttle to the president
and congress was to present it as a replacement for all existing
expendable launch vehicles. That would assure a flight rate
sufficient to achieve the economies of scale required to drive down
costs and reduce the cost of launch for military and commercial
satellite payloads as well as NASA missions. But that meant the
shuttle had to accommodate the large and heavy reconnaissance
satellites which had been launched on
Titan
rockets. This required a
huge payload bay (15 feet wide by 59 feet long) and a payload to low
Earth orbit of 60,000 pounds. Further Air Force requirements dictated
a large cross-range (ability to land at destinations far from the
orbital ground track), which in turn required a hot and fast reentry
very demanding on the thermal protection system.
The shuttle represented, in a way, the unification of NASA with the Air Force's
own manned space ambitions. Ever since the start of the space age, the Air
Force sought a way to develop its own manned military space capability. Every
time it managed to get a program approved: first
Dyna-Soar
and then the
Manned Orbiting Laboratory,
budget considerations and Pentagon politics resulted in its cancellation, orphaning
a corps of highly-qualified military astronauts with nothing to fly. Many of
these pilots would join the NASA astronaut corps in 1969 and become the backbone of
the early shuttle program when they finally began to fly more than a decade later.
All seemed well on board. The main engines shut down. The external
fuel tank was jettisoned. Columbia was in orbit. Now
weightless, commander John Young and pilot Bob Crippen immediately
turned to the flight plan, filled with tasks and tests of the
orbiter's systems. One of their first jobs was to open the payload
bay doors. The shuttle carried no payload on this first flight, but
only when the doors were open could the radiators that cooled the
shuttle's systems be deployed. Without the radiators, an emergency
return to Earth would be required lest electronics be damaged by
overheating. The doors and radiators functioned flawlessly, but with
the doors open Young and Crippen saw a disturbing sight. Several of
the thermal protection tiles on the pods containing the shuttle's
maneuvering engines were missing, apparently lost during the ascent to
orbit. Those tiles were there for a reason: without them the heat of
reentry could melt the aluminium structure they protected, leading to
disaster. They reported the missing tiles to mission control, adding
that none of the other tiles they could see from windows in the crew
compartment appeared to be missing.
The tiles had been a major headache during development of the
shuttle. They had to be custom fabricated, carefully applied by hand,
and were prone to falling off for no discernible reason. They were
extremely fragile, and could even be damaged by raindrops. Over the
years, NASA struggled with these problems, patiently finding and
testing solutions to each of them. When STS-1 launched, they were
confident the tile problems were behind them. What the crew saw when
those payload bay doors opened was the last thing NASA wanted to see.
A team was set to analysing the consequences of the missing tiles on
the engine pods, and quickly reported back that they should pose no
problem to a safe return. The pods were protected from the most
severe heating during reentry by the belly of the orbiter, and the
small number of missing tiles would not affect the aerodynamics of the
orbiter in flight.
But if those tiles were missing, mightn't other tiles also have been lost? In
particular, what about those tiles on the underside of the orbiter which
bore the brunt of the heating? If some of them were missing, the structure of
the shuttle might burn through and the vehicle and crew would be lost. There
was no way for the crew to inspect the underside of the orbiter. It couldn't
be seen from the crew cabin, and there was no way to conduct an EVA
to examine it. Might there be other, shall we say,
national technical means,
of inspecting the shuttle in orbit? Now STS-1 truly ventured into the black,
a story never told until many years after the mission and documented
thoroughly for a popular audience here for the first time.
In 1981, ground-based surveillance of satellites in orbit was
rudimentary. Two Department of Defense facilities, in
Hawaii
and Florida, normally used to image Soviet and Chinese satellites,
were now tasked to try to image Columbia in orbit. This
was a daunting task: the shuttle was in a low orbit, which meant
waiting until an orbital pass would cause it to pass above one of the
telescopes. It would be moving rapidly so there would be only seconds
to lock on and track the target. The shuttle would have to be
oriented so its belly was aimed toward the telescope. Complicating
the problem, the belly tiles were black, so there was little contrast
against the black of space. And finally, the weather had to
cooperate: without a perfectly clear sky, there was no hope of
obtaining a usable image. Several attempts were made, all
unsuccessful.
But there were even deeper black assets. The
National Reconnaissance Office
(whose very existence was a secret at the time) had begun to operate the
KH-11 KENNEN
digital imaging satellites in the 1970s. Unlike earlier spysats, which
exposed film and returned it to the Earth for processing and interpretation,
the KH-11 had a digital camera and the ability to transmit imagery to
ground stations shortly after it was captured. There were few things so secret
in 1981 as the existence and capabilities of the KH-11. Among the people
briefed in on this above top secret program were the NASA astronauts who had
previously been assigned to the Manned Orbiting Laboratory program which was,
in fact, a manned reconnaissance satellite with capabilities comparable to
the KH-11.
Dancing around classification, compartmentalisation, bureaucratic
silos, need to know, and other barriers, people who understood what
was at stake made it happen. The flight plan was rewritten
so that Columbia was pointed in the right direction at
the right time, the KH-11 was programmed for the extraordinarily
difficult task of taking a photo of one satellite from another, when
their closing velocities are kilometres per second, relaying the
imagery to the ground and getting it to the NASA people who needed it
without the months of security clearance that would normally entail.
The shuttle was a key national security asset. It was to launch all
reconnaissance satellites in the future. Reagan was in the White
House. They made it happen. When the time came for
Columbia to come home, the very few people who mattered
in NASA knew that, however many other things they had to worry about,
the tiles on the belly were not among them.
(How different it was in 2003 when the same Columbia
suffered a strike on its left wing from foam shed from the external
fuel tank. A thoroughly feckless and bureaucratised NASA rejected
requests to ask for reconnaissance satellite imagery which, with two
decades of technological improvement, would have almost certainly
revealed the damage to the leading edge which doomed the orbiter and
crew. Their reason: “We can't do anything about it
anyway.” This is incorrect. For a fictional account of a
rescue, based upon the
report
[PDF, scroll to page 173]
of the
Columbia Accident Investigation Board, see
Launch on Need [February 2012].)
This is a masterful telling of a gripping story by one of the most
accomplished of aerospace journalists. Rowan White is the author of
Vulcan 607 (May 2010), the
definitive account of the Royal Air Force raid on the airport in the
Falkland Islands in 1982. Incorporating extensive interviews with
people who were there, then, and sources which were classified until
long after the completion of the mission, this is a detailed account
of one of the most consequential and least appreciated missions in
U.S. manned space history which reads like a techno-thriller.
September 2016 