© 2006 by Donald F. Robertson.
This article originally appeared somewhat different form in
the Institute of Engineering
and Technology's journal, Engineering and Technology.
Donald F. Robertson
On 19th September 2005, NASA Administrator Dr. Michael Griffin
the details of The United States’
$104 billion plan to send astronauts back to Earth's moon
by 2018 and
go on to Mars. Critics called the plan “Apollo
Redux.” Supporters called it a “go-as-you-can-pay,”
strategy to keep the United States a
new plan represents a painful accommodation with two conflicting
political constraints. The United States is unlikely to fully
retreat from human spaceflight -- especially with geopolitical
adversaries like China entering the fold. Congress will not let NASA
move beyond the Space Shuttle and Space Station if it costs much more
than the country already spends.
is giving up an almost four decade “push”
to lower the price of reaching orbit. The unsustainably fragile
Space Shuttle will be retired by 2010 or earlier. New reusable
rocket development and other long-term research with no immediate
application will be suspended. Instead, NASA is assembling the
technology and money it already has into a focused effort to
establish additional human outposts in space, beyond the
International Space Station. The market to supply those destinations
private efforts to create innovative launch vehicles and start the
earliest beginnings of trade on the new frontier.
this reversal of priorities work? Or, is the United States headed
down another blind alley on the elusive road to a spacefaring
ARE YOUR GRANDFATHER’S
the Space Shuttle program winds down, old bits from the Shuttle,
Apollo Saturn rockets, and the Centaur upper stage –
and a few carefully chosen new pieces –
will be assembled into two launch vehicles.
The Space Shuttle
reusable Solid Rocket Booster, using technology dating from the early
1970s, forms the core of NASA’s
architecture.” In spite of being the direct
cause of the Shuttle Challenger’s
loss two decades ago –
and impossible to shut down once it is ignited –
this redesigned and relatively inexpensive rocket is now considered
reasonably safe and reliable.
will be launched on a “single
four-segment Shuttle booster with a new cryogenic upper stage powered
by one Space Shuttle Main Engine. Retired Shuttle engines will be
flown one last time on the new vehicles; when those run out, a
simplified, non-reusable version will be deployed. NASA has
allocated approximately $3.2 billion to develop this “Crew
replacement will be the much smaller Crew Exploration Vehicle. This
is a modernized, reusable, scaled up Apollo spacecraft: a blunt cone
5.5 meters in diameter with a crew of four to six. An expendable
service module containing tankage, thrusters, and a main engine is
mounted behind. Development is underway and is expected to cost some
a series of automated test flights, trial missions to the Space
Station are planned for 2012. Ultimately, NASA hopes to off-load
this task to commercial operators, jump-starting a new industry
delivering bulk cargo to orbit. Future Crew Exploration Vehicles
will be dedicated to lunar missions.
the exploration vehicle and its rocket are safely flying, development
will begin on a second rocket. Able to life 125 metric tons –
more than the old Saturn-V moon rocket –
this behemoth also will be built from cast-off parts from the
Shuttle. Two five-segment Shuttle solid rocket boosters will be
attached to the sides of a lengthened Shuttle External Tank and five
Shuttle main engines will be mounted underneath.
everything can be pilfered from NASA’s
rubbish heap. A brand new methane-burning engine is under
development for use on the Crew Exploration Vehicle’s
service module and a newly designed lander. The relatively simple
engine will be pressure fed to avoid complex compressors and turbo
pumps that could go wrong on long missions to the planets.
is storable during flight and can be derived from Mars’
atmosphere. Oxygen, for the rocket’s
oxidizer (and for breathing by astronauts) is believed to be readily
available in the lunar regolith, as well as in Martian aquifers. “Living
off the land”
could dramatically reduce the mass that must be sent from Earth and
is a key feature of Dr. Griffin’s
ME TO THE MOON
first expedition to the moon since Apollo-17 in 1972 is to get
underway circa 2018 with the ignition of the heavy
vehicle first stage’s
five engines and twin solid boosters. A newly-developed Lunar
Transfer Stage will fire J-2 rockets –
derived from the Saturn upper stages –
to complete placing the lander into parking orbit, where it will be
thoroughly tested. Then, a Crew Exploration Vehicle with four
astronauts will be launched to dock with the lander. The transfer
rockets will re-ignite, sending both spacecraft toward the moon.
The combined Crew
Exploration Vehicle and lander will decelerate into lunar orbit with
methane engine. After checkout, the entire crew will pile into the
lander, leaving the exploration vehicle unattended in lunar orbit.
first stage RL-10 rockets, adopted from the venerable Centaur upper
stage, will fire to start the descent out of orbit. These powerful
engines can be re-started and throttled for a controlled landing
anywhere on the lunar surface, not just near the equator as with
The first crew
will spend one week testing equipment, experimenting with mining
oxygen from lunar soil, and doing some initial exploration and
science. Later missions will be launched approximately twice a year
to keep annual operations costs under $6 billion. They will quickly
expand into “Lewis
class scientific expeditions of up to six months, beginning as early
as 2022. Each crew will leave excess hardware in place so subsequent
missions can reuse it, gradually accumulating the material to
assemble a permanent base, probably at the lunar south pole.
it is time to leave, the lander's second stage will lift off with its
methane engine, and dock with the orbiting exploration vehicle. The
lander will be abandoned as the crew fires the service module engine
to head back toward Earth. The exploration vehicle will enter
atmosphere with the same blunt lifting shape used by Apollo, but will
use parachutes and small rockets or airbags to settle down onto dry
missions will remain undefined until the lunar architecture is in
place to avoid having to develop more than two or three new vehicles
at a time. However, two of the most critical developments -- the
heavy lift launch vehicle and the methane rocket -- should have years
of successful flight operations when they are needed for Mars.
plan that costs much more than NASA spends now can survive through
multiple administrations and congresses. Dr. Griffin did not propose
the lowest-cost options, or those most useful to the wider space
community (see the cutout box, What's Wrong with Air Force Rockets?).
The plan appears to exceed NASA’s
projected long-term budget by some $18 billion over thirteen years.
near-term threat remains the ever-escalating cost of keeping the
Shuttle alive long enough to launch Europe’s
components for the International Space Station. So far, Dr. Griffin
plans to delay milestones to keep the Shuttle flying and develop the
new hardware –
all while staying within the available funding.
spite of multiple natural disasters and wars, legislative
support remains strong. For the second year, NASA’s
budget endorses the early stages of the project.
weather may be helping NASA’s
case: the space agency is one of Louisiana’s
largest employers. The new upper stage and the body of the heavy
lift vehicle derived from the old Shuttle External Tank are likely to
be built at Lockheed-Martin’s
factory just outside of New Orleans. Dr. Griffin is carefully
spreading the work: most of the Shuttle workforce will not be sacked
and NASA announced that automated precursor missions to Earth’s
moon will be managed from NASA’s
Ames Research Center, politically liberal territory outside of San
it possible that devastating storms are helping to pave humanity’s
road to the planets? If so, it would not be the first time weather
and politics combined to change history.
WRONG WITH AIR FORCE ROCKETS?
Air Force has already developed two state-of-the-art Evolved
Expendable Launch Vehicles capable of launching twenty tons. Every
dollar NASA spends developing and maintaining the new Shuttle-derived
launchers is a dollar not spent flying to the moon. Moreover, these
vehicles were carefully designed to take advantage of economies of
scale. Flying them more often benefits everyone, weather satellites
and lunar missions alike.
NASA Administrator Sean O’Keefe’s
original idea was to develop a smaller exploration vehicle that would
seat fewer astronauts but would fit on any medium-class rocket,
Ariane. Using smaller launchers means breaking lunar missions into
smaller pieces, which complicates logistics and may incur more risk
and long-term expense. However, it reduces up-front costs and would
allow the first lunar missions to fly sooner. Smaller vehicles force
learning to make do with less, which is no bad thing if you plan to
explore the Solar System with a highly constrained budget.
congressional staffer and spaceflight analyst Tim Kyger suggests an
even cheaper plan he calls “Luna
again in 2010!” He would attach an upgraded
Russian Soyuz –
an early version of which was designed for lunar missions -- to upper
stages separately launched by the Air Force rockets. A lander would
be sent to the moon using the same technique, then dock with the
orbiting Soyuz to transfer the crew for landing. If Dr. Griffin’s
plan goes seriously over budget, something like Mr. Kyger’s
quick-and-dirty solution may yet see the light of day.
BOX: BUT WHY ASTRONAUTS?
spend money sending astronauts to Earth’s
moon? NASA Administrator Dr. Michael Griffin paraphrases jazz
musician Louis Armstrong, “If
you have to ask why we should explore space, you’ll
never understand the answer.”
are more practical reasons. Scientists frustrated at the costs of
human spaceflight tend to ignore its advantages and the ultimate
limits to robotics.
his seminal history of the Soviet lunar programs, Challenge
Apollo, Asif A. Siddiqi attempts to compare the scientific
of the Luna landers with the Apollo flights of the same era. While a
direct comparison is difficult, he argues it is not clear the 105
gram sample of regolith randomly collected by Luna-16 was more
scientifically cost effective than the sixty kilograms carefully
selected over wide areas by the first two Apollo crews. “Luna-16
was certainly a remarkable technological accomplishment,”
wrote Siddiqi, “but
it was probably not, as Soviet officials of the day touted, a
alternative to Apollo.”
the Mars Exploration Rovers are among the greatest achievements of
our time, but that project has spent well over a billion dollars and
more than two years achieving the initial reconnaissance a human
geologist could do in a couple of afternoons.
robot will rule out life on Mars, determine the widespread
distribution of any microfossils, detail the stratigraphic history of
Martian volcanic flows and flooding, or provide absolute lunar
cratering dates over wide areas. We cannot understand the accessible
bodies of the Solar System as we understand our own Earth without
experiencing them for ourselves.
FLY ME PERSONALLY TO THE MOON
Adventures, the United States firm marketing tourist flights to the
Space Station, has signed up Russian aerospace giant Energia
Corporation to offer excursions around the moon. In a plan that
sounds remarkably like Tim Kyger’s
(see the box, What’s
Wrong with Air Force Rockets), an upgraded Soyuz would be launched
with a pilot and two tourists. It would dock with a
separately-launched Energia Block-DM upper stage, which would place
the Soyuz into a free-return lunar trajectory. After sailing around
the far side of the moon, it would fall back toward a high-speed
entry into Earth’s
cost? $100 million per tourist. Space Adventures believes
approximately one-thousand people worldwide have the resources to
afford this adventure. For your money, you’ll
take on a great deal of personal risk, spend close to a week with two
other unwashed bodies in an enclosed space the size of a Volkswagen
Bug -- and see close up a world few have ever explored.