my email to a prominent astrophysicist

the gist: planned crewed Mars mission = hubris

17 July 2024

from: Mark Harris

to: Professor ———— ————

Dear Professor ————:

It wasn't all that long ago that I too would have counted myself a fan of 

director Ridley Scott's The Martian. The casting choices, I grant you, 

were spot on, with some of my favorite contemporary character actors 

in attendance, and how could one not root for uber-resourceful Mark 

Watney given Matt Damon's upbeat, charismatic performance (the very 

antithesis in most respects to his craven Interstellar persona)? 

But after the third (or was it the fourth?) time through, it dawned on me 

that the filmmakers had, up until then, gotten away (scot free!) with 

manipulating my emotions at the expense of percipient assessment. For one 

thing, the manner in which this man-left-to-his-own-devices-vanquishes-the-

elements angle plays out is just a bit too self-congratulatory for its own good, 

in sync with a tagline that could very well read: Science Personified confronts 

insuperable odds, but by hook and by crook flips Death the middle finger. 

Now I readily admit to an ingrained bias in favor of sic-fi stories about 

scientists overstepping moral boundaries (e.g., Mary Shelley's Frankenstein; 

Primer; Orphan Black), but that bent is consistent with my forty years of study 

and observation as an independent researcher, gadfly, and occasional 

participant in the field. (Not that my expectations of rank-and-file scientists 

adhering to the Method have been all that lofty since I stumbled upon 

Thomas Kuhn's myth-busting “The Structure of Scientific Revolutions” as a 

yet unworldly undergrad.)

In any event, my nagging misgivings led me to wondering whether or

not the widespread praise for The Martian's scientific fidelity was truly 

warranted. And so I started poking about. Since the entire plot hinges upon

a violent Martian dust storm forcing the team of astronauts to evacuate

the planet's surface, with the presumed-dead Watney left behind, I first 

checked into that well-studied phenomenon. According to nasa.com:

It is unlikely that even these dust storms could strand an astronaut on Mars, however. Even the wind in the largest dust storms likely could not tip or rip apart major mechanical equipment. The winds in the strongest Martian storms top out at about 60 miles per hour, less than half the speed of some hurricane-force winds on Earth.

Focusing on wind speed may be a little misleading, as well. The atmosphere on Mars is about 1 percent as dense as Earth’s atmosphere. That means to fly a kite on Mars, the wind would need to blow much faster than on Earth to get the kite in the air.

“The key difference between Earth and Mars is that Mars’ atmospheric pressure is a lot less,” said William Farrell, a plasma physicist who studies atmospheric breakdown in Mars dust storms at Goddard. “So things get blown, but it’s not with the same intensity.”

Discovering that this plot contrivance had in fact strayed so far afield  

from reality not only vindicated my suspicion that I'd been had, but it 

encouraged me to question the tacit premise, the given, charged with the  

task of anchoring The Martian to our collective consciousness, namely 

that crewed interplanetary expeditions planned for the near future are 

indeed feasible.

To estimate the probability of a safe and sound mission to the Red Planet, 

I considered the track records of two historic NASA crewed spaceflight 

programs comprising the total of 135 Space Shuttle missions plus the 7 

full-fledged Apollo voyages. The Space Shuttle missions ranged from 5 

to 16 days in duration. Of the 135 Space Shuttle flights, two ended in 

catastrophic failure, one during the launch phase and one during reentry, 

resulting in disintegration of the spacecraft and complete loss of crew. 

That's a failure rate of 1 in 62.5 or 1.6%. Of the 7 Apollo missions 

designated for trips to and from Luna's orbit sandwiching a stint on the 

surface, the average duration was about 10 days; one mission failed 

en route with its three astronauts barely surviving the harrowing trip 

home (Apollo 13; dramatized in the 1995 film of the same name). That's 

a 14.3% failure rate. 

I also took into account NASA's unmanned Mars missions. To date 13 

of 18 have been deemed successful yielding a 27.8% failure rate. 

Interestingly, of the 11 Mars missions launched by the USSR between 

1960 and its dissolution in 1989, none were successfully accomplished. 

By comparison,the Soviet Union's Venera program was a monumental 

consummation:

Launched between 1961 and 1983, the Venera ("Venus" in Russian) missions were focused on studying the second planet from our sun. Of the 28 spacecraft launched, 13 entered the Venusian atmosphere and eight successfully touched down on the surface.

The Soviet program set several firsts, including the first probe to descend into the atmosphere of a planet other than Earth; the first spacecraft to make a soft landing on another planet; and the first missions to return images and sounds from the surface of another planet. [space.com]

The varying cumulative failure rates of the U.S. space programs I reviewed -- 

Space Shuttle missions (126 near-earth orbits, 9 transports to the space station), 

Apollo (lunar round-trips + landings), and uncrewed Mars enterprises (one-way 

trips) -- increased with the distance from Terra of the target orbits or final 

destinations on the surface.

It's tempting to discount the uncrewed Mars missions because they were 

designed without the heightened safety requirements and other essential 

accommodations human occupancy entails, but the investments into each 

of those missions was substantial and necessitated years of careful preparation 

and execution. Indeed its preposterous to presume that even a single one of 

NASA's Mars missions to date were deemed frivolous or expendable by the

skilled ensembles tasked with pulling off a successful outcome. (Note: another 

website reports a total of 30 Mars uncrewed missions with the same number

of failures; if the failure ratio is instead calculated as 3/18 and not 5/18, that 

figure is still over forty times the ratio (1/250) stipulated by NASA as the 

maximum acceptable risk for human crews.) 

In fact, combining and coordinating the myriad systems necessary for sustaining

a human crew in spacecrafts capable of ferrying them to a suitable Martian orbit, 

then to that planet's surface for a fortnight or three, then back to the mother ship, 

and finally back to Terra will be more complicated and demanding than every  

uncrewed Mars mission by, I suspect, several orders of magnitude. And what is 

the estimated price tag for such a venture? According to Elon Musk, between $100 

billion and $10 trillion(!). 

The Space Shuttles each contained 70 components without fail-safes (including 

the O-rings and tiles constituting the external heat shield). Remember: the maximum 

duration for those Space Shuttle missions was just 16 days. The spacecraft for 

the crewed Mars mission would need to hold up for the approximately 18-month 

round-trip plus multiple weeks spent on the surface. I have asserted in one of my 

Substack posts that sending at least one additional spacecraft as a backup would 

be the best available method, if technocrats are bound and determined to go ahead 

with such a project (against my better judgement), to provide a safety net, so to 

speak, for the primary crew, because, if any critical system failure occurs during 

the voyage, in most instances there wouldn't be sufficient time to deploy a rescue 

mission even with a craft kept at the ready here on Terra. That proposal is almost 

certain to be rejected because of the enormous additional expense this backup 

expedition would entail.    

Apollo 11's sojourn was preceded by a practice run to lunar orbit and back by 

Apollo 10. The crewed mission to Mars by economic necessity would be a true 

maiden voyage.

Due to astronauts' undiluted exposure to galactic cosmic rays ("omnidirectional,

occurs continuously; shielding is not effective") in space -- lacking the protection 

afforded us by Terra's ionosphere -- in six months time one's level of exposure  

amounts to the equivalent of 1000 x-rays. In The Martian, the crew of the Hermes 

supposedly spends a total of 899 days in space, in the process greatly exceeding 

current allowable limits of GCR exposure. In that movie's coda, Michael Peña's 

character is seen returning to Mars for the subsequent mission, a blunder which 

indicates that the scriptwriter was either not cognizant of this very real attendant 

hazard or decided to pretend it away. 

Given the telltale precedents, the length of the planned mission, the lack of an 

opportunity to "get the bugs out" during a preliminary dry run, and the absence of 

supporting or backup spacecrafts, I estimate the probability of catastrophic mission 

failure for the inaugural crewed Mars expedition at >50% (= sheer hubris). (Note: 

were this estimate <1%, based strictly on a cost-benefit analysis I would argue 

against the grand folly of subsidizing such an endeavor.) 

Respectfully,

Mark Harris

mhbookish2@aol.com