The successful Orion test flight in
early December focused attention on the Orion capsule’s role in future NASA
missions beyond low earth orbit. Much of the discussion on the Internet has
dealt with the necessity of Orion at all, and whether it could be replaced by
one of the commercial crew vehicles NASA recently funded.
The on-line discussion is frequently
sidetracked by the all-too-common misunderstanding that Orion will be the sole habitat
for 4-6 astronauts on the 2-3 year Mars mission. I Googled “orion mars” and
found a comment to a Gizmodo article wondering how 5 or 6 astronauts could
spend months in such a tiny capsule heading for Mars—it was posted 2 days after
the Orion test flight!
The short answer is: nobody expects
anything of the sort. Orion is the astronauts’ taxicab from the launch pad in
Florida to the Mars transit vehicle in earth orbit at the start of the mission,
then again and most importantly for the high-speed entry into earth’s
atmosphere at the end of the mission (see figure 1). This
is well-established in the NASA Mars Design Reference Mission that describes the
general characteristics of the 100 thousand pound habitat (ref. 1).
Figure 1. Mars mission scenario. See Orion's major usage at steps 7, 9 and 14 |
However, the misunderstanding was a
central feature of the movie “Capricorn One” (1978) (ref. 2). This fictional story of a hoaxed Mars mission includes the image of the three
astronauts spending long months inside their cramped Apollo command module en
route to Mars.
The movie used accurate mockups of the Apollo
capsule, the lunar lander and the space suits, very familiar to TV viewers from
the moon landings only a few years earlier, but largely irrelevant to the Mars
mission being portrayed. The producers knew that such familiarity could enhance
the credibility of their story, encouraging the audience’s willing suspension
of disbelief. The bizarre tale of a faked
mission and a government cover-up that required the (spoiler alert!) murder of
the astronauts themselves would then have seemed even more thrilling.
But surely (I thought), no one could seriously
believe that NASA would send highly-trained astronauts in peak physical
condition on a multi-month trip to Mars in just an Apollo capsule, with no room
for exercise or privacy, any more than that they would land on Mars using an
unmodified, non-aerodynamic Apollo lunar module. After all, the movie was an action adventure,
not a documentary.
Apparently I was wrong. Now, over three decades later, when I lecture
on the medical aspects of NASA’s planned exploration-class missions to Mars, lay
and professional audiences alike still ask how the astronauts could really stay
in such a small capsule for such a long flight without going nuts. Of course, why should they know any better? The Apollo astronauts went to the moon inside
the command module, so why not all the way to Mars? If the Mars trip takes 60 to 100 times
longer, maybe it is just the price that the astronauts have to be willing to
pay. After I explain that the Mars transit
vehicle would be much larger and roomier, everyone seems relieved that NASA
wouldn’t be so inconsiderate of its high-value crewmembers.
What is more surprising is how many space
professionals also have that misunderstanding. Even NASA insiders were confused
in 2004 when the Crew Exploration Vehicle, or CEV, was announced, whether it
was the Mars transit craft that would house the six astronauts for the half-year
transits to and from Mars, or just the capsule they rode in from Earth to the
transit vehicle. This confusion was
exacerbated by the name: if it was just the taxicab, why was “exploration” part
of its name?
Back in October 2007, I lined up with
NASA Johnson Space Center workers who waited patiently for a chance to sit
inside the new, low-fidelity Orion mockup.
It was in the configuration with six seats, one of which was occupied by
mannequins and another left empty. When
four of us—all space professionals but not engineers—were seated inside it,
marveling at the close quarters, it quickly became clear that three of us
actually thought this was the condition in which the six-person crew would make
the six-month trip to Mars!
After a lecture at a space life sciences
conference in February 2008, a long-time NASA employee—also not an
engineer—confessed his relief that the crew wouldn’t be cooped up in the Orion
for the long trip to Mars. Other NASA science managers have wondered the same
thing, judging from comments I have frequently heard.
Not surprisingly, it is not just NASA
people that are confused. A well-informed
science writer asked me the question during an interview some years ago. About the same time, a retired astronaut
sheepishly admitted that he thought the same, but added that he hadn’t kept up
with the Mars vehicle design details. I
have also read a comment by a respected leader of a space advocacy organization
who wondered how Orion’s life support system would support a crew en route to
Mars.
Apparently the misunderstanding predates
even Capricorn One. In 1966, Eric John Bishop felt it necessary to describe his
work designing an underwater training mockup of what became the Skylab space
station as supporting the development of a large vehicle for planetary
missions, because the astronauts couldn’t be expected to stay in the Apollo for
such a long durations (ref. 3).
In 2006, NASA gave the name Orion to the
CEV, and in 2011 the acronym CEV was replaced by MPCV for Multi-Purpose Crew
Vehicle. Exploration was gone from the moniker but not from its mission; in
fact, Orion was specifically focused on atmospheric entry at interplanetary
speeds, and thus over-engineered and overpriced for anything less, as NASA
managers have publicly confirmed. But the confusion remains.
Why do so many people seriously think
that NASA would confine half a dozen astronauts in such a small space for six
months or longer? Why does that seem
even remotely possible, let alone acceptable, to anyone who has imagined the
effects of such confinement on the crew’s mental and physical health and on
mission success?
Part of the answer is probably
unfamiliarity with the realities of long-duration spaceflight, at least among
the general public. Another possibility became clear during the Orion flight
test. Orion was described by the press as the vehicle that will take astronauts
to the asteroids and Mars. Message boards were overflowing with confusion on
that point. The official Orion fact sheet describes it as “this new spacecraft
[that] will take us farther than we’ve gone before, including Mars” (ref. 4). And the Fall 2014 issue of Roundup (ref. 5), the self-described official publication of the Johnson Space Center, has a
cover image of what is clearly a late-model design for Orion with what is
clearly Mars in the background and with what is clearly no other vessel nearby
(see figure 2). This constitutes an official graphic statement that Orion will
at least operate near Mars alone, in direct contradiction to all NASA Mars DRM
planning! Thus, NASA’s own messaging is misleading.
Figure 2. NASA Johnson Space Center Roundup showing Orion spacecraft all alone in Mars orbit. |
That such a central feature of the NASA’s
exploration architecture is so poorly grasped is troubling as well as
surprising. NASA has released
high-quality animations of lunar and Mars mission scenarios, which are
available on agency websites and on YouTube.
Program officials and industry experts have described the architecture
in public presentations around the country. Still the misunderstanding
persists.
Space flight sometimes seems inherently
mystifying. For example, the physics of weightlessness are a mystery to many
people who have never experienced it, and are frequently misrepresented in
movies. But most people working
in space development venues do not require more than a passing knowledge of
such things. They understand enough to do their jobs well,
and they leave the rest to other specialists.
References.
- Drake, Bret G. (editor), Human Exploration of Mars Design Reference Architecture 5.0 (NASA/SP-2009-566), NASA, Washington, D.C., 2009, http://www.nasa.gov/pdf/373665main_NASA-SP-2009-566.pdf (accessed Dec. 23, 2014). See “bat chart” on page 5, and Mars Transit Vehicle description on p. 36.
- Capricorn One (http://www.imdb.com/title/tt0077294/, accessed Dec. 8, 2014).
- Bishop, E.J. Brooklyn, Buck Rogers and Me. iUniverse, Inc., 2003, http://bookstore.iuniverse.com/Products/SKU-000125340/Brooklyn-Buck-Rogers-and-Me.aspx (accessed Dec. 23, 2014).
- Orion spacecraft overview, NASA, 2012. (http://www.nasa.gov/sites/default/files/617409main_orion_overview_fs_33012.pdf, accessed Dec. 8, 2014).
- Roundup, Fall 2014, http://jscfeatures.jsc.nasa.gov/media/22_Fall_2014.pdf (accessed Dec. 23, 2014).
John -
ReplyDeleteIt might be a long shot, but perhaps some people think of Zubrin's Mars Direct. The Earth-Return Vehicle wasn't a whole lot bigger than Orion. Each crew member had about the volume of a phone booth for the six-month trip back to Earth. This was made necessary by desire to generate all propellants for return to Earth on Mars and to land the ERV with the fuel factory.
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