Why Would You Want to Live in an Orbital Habitat?

A Stanford Torus, the archetype for rotating deep space habitats.
A Stan­ford Torus, the arche­type for rotat­ing deep space habi­tats.

This post is part of an on-going series. See the oth­er posts here.

There is a great post over at SF Sig­nal by author Rob Bof­fard, about the fea­si­bil­i­ty of con­struct­ing a large-scale per­ma­nent habi­tat in orbit over Earth. It’s a neat thought exper­i­ment:

Get­ting stuff into space, and keep­ing it there, is hideous­ly expen­sive. Even some­thing as low-tech as send­ing an object weigh­ing no more than three pounds into the stratos­phere on a bal­loon (as my pub­lish­er and I did with my sec­ond book – for the lulz, OK?) costs a cou­ple of thou­sand dol­lars. The Inter­na­tion­al Space Sta­tion, which is a good deal high­er up, has cost the plan­et approx­i­mate­ly $150bn, which includes mate­ri­als, crew costs, labour and launch. This for an apart­ment-sized set of mod­ules that can house a max­i­mum of six peo­ple.

If any­thing, this under­es­ti­mates the actu­al costs of launch­ing huge chunks of met­al and thou­sands of peo­ple into orbit. Bof­fard uses a medi­um-sized city as an idea of a large-scale habi­tat, which would be around 60,000 peo­ple or so, with num­bers from NASA he sug­gests it would cost $75 tril­lion. (For some rea­son, Bof­fard says such a sum “is a good deal more, by an order of mag­ni­tude, than the total GDP of the entire plan­et” but he’s wrong: accord­ing to the World Bank, the glob­al GDP was around $77 tril­lion in 2014.)

The cost of a per­ma­nent space colony is not just the mass of every­thing you’re send­ing up divid­ed by the cost of oper­at­ing a rock­et. The research and devel­op­ment costs of, say, fig­ur­ing out how to cre­ate cen­trifu­gal grav­i­ty, or cre­at­ing enough shield­ing to keep can­cer rates to around what they are on earth are (sor­ry) astro­nom­i­cal — at least if you don’t want to sheath every­thing in a few inch­es of lead, which would be unfath­omably expen­sive to launch for a habi­tat big enough to house and feed 60,000 peo­ple. Sim­i­lar­ly, while Bof­fard hand-waves away the dif­fi­cul­ty of build­ing an ecosys­tem that can sus­tain human life, it is actu­al­ly an incred­i­bly com­plex, dif­fi­cult, expen­sive chal­lenge that we have not yet been able to mas­ter here (con­sid­er the utter fail­ure of Bios­phere 2 in Ari­zona).

But there is a deep­er ques­tion about the prospects of build­ing a mega-struc­ture in space to house tens of thou­sands of peo­ple, one that Bof­fard elides in the breezy attempt to por­tray it as a sim­ple mat­ter of scal­ing cur­rent engi­neer­ing: why?

To be pre­cise, why would you want to send 60,000 peo­ple — or hell, even 10,000 peo­ple — into space? What pos­si­ble eco­nom­ic gains do you get from such an endeav­or, to jus­ti­fy that exor­bi­tant cost?

The cost of space trav­el is eas­i­er to jus­ti­fy for small scale sci­ence research projects — the ISS, for exam­ple, or a small habi­tat on Mars where sci­en­tists can study the envi­ron­ment. There is even a case to be made for deep space sci­ence sta­tions (some­thing NASA is work­ing on right now, actu­al­ly). That is because the pur­pose of these small scale habi­tats is not gen­er­at­ing a func­tion­ing econ­o­my and soci­ety; their pur­pose is to advance knowl­edge, which is not always inher­ent­ly eco­nom­ic activ­i­ty.

Few advo­cates of space col­o­niza­tion can answer the basic ques­tion of why you would want to send 60,000 peo­ple into a frag­ile envi­ron­ment where irre­spon­si­bil­i­ty can kill thou­sands and doom the colony. There is — maybe! — a case to be made for build­ing a tourist hotel in low Earth orbit, using one of the many com­mer­cial space­flight sys­tems being built right now, whether SpaceX or Blue Ori­gin or Vir­gin Galac­tic. But even sub­or­bital flights on Richard Bran­son’s planes cost $250,000, which is about the aver­age cost of a home in the Unit­ed States (which few can afford and must mort­gage over 30 years). And that’s just for a quick squirt up to the edge of space and a few min­utes of weight­less­ness.

But as all trav­el­ers know, there is a yuu­u­u­uge dif­fer­ence between vis­it­ing a place and actu­al­ly liv­ing there. Once peo­ple are liv­ing per­ma­nent­ly in an orbital habi­tat, what would they do that they can’t do on Earth? That isn’t clear at all, and there is cur­rent­ly no viable eco­nom­ic case for why any­one would spend the entire GDP of plan­et Earth for a year to get them there. There sim­ply isn’t a rea­son, beyond elite pres­tige rea­sons (as Bof­fard put it, “liv­ing in an enor­mous habi­tat which val­i­dates humanity’s awe­some­ness”), to plac­ing infor­ma­tion work­ers in orbit. And the hype about min­ing aster­oids aside, it isn’t at all clear that you can actu­al­ly send enough raw ores back down the grav­i­ty well to man­u­fac­tur­ing on Earth to jus­ti­fy the cost of launch­ing a space probe to las­so a giant hunk of rock such that it does­n’t acci­den­tal­ly burn up in the atmos­phere.

So orbital habi­tats don’t make any sense at all for per­ma­nent human habi­ta­tion, at least on a large scale, at least on any time frame that would make our chil­dren or grand­chil­dren want to build them. Orbital habi­tats do make a con­ve­nient place for research, for logis­tics hubs (say, as a refu­el­ing depot) and as a quick launch pad for a res­cue mis­sion or some­thing. But there’s no eco­nom­i­cal­ly jus­ti­fi­able rea­son to take tens of thou­sands of peo­ple into frag­ile rotat­ing tubes and just sit there, in space.

There is a bet­ter case to be made for a per­ma­nent colony some­where like the moon. For one, the engi­neer­ing is sim­pler, since you don’t have to wor­ry about the com­plex engi­neer­ing of bal­anc­ing cen­tripetal forces in a rotat­ing envi­ron­ment. Radi­a­tion shield­ing is eas­i­er, since you don’t need to launch it into orbit, you can just bury your habi­tats under lunar regolith. And the moon has water ice, which you can mine for water, so you won’t have to wor­ry about cre­at­ing a closed loop for water and oxy­gen recov­ery. The infra­struc­ture need­ed to keep it going is at least eas­i­er, because there are resources there, on the ground already, that you can exploit to make life hap­pen.

But logis­tics aside, you still run into the big ques­tion of why. A per­ma­nent research sta­tion on the moon makes sense, because there are lots of things we can learn from long-term habi­ta­tion in a low grav­i­ty envi­ron­ment, that will teach us about our abil­i­ty to live else­where in the uni­verse. A per­ma­nent colony, how­ev­er, with thou­sands of peo­ple, is a hard­er project to jus­ti­fy. It might be some­thing polit­i­cal pio­neers want to do, to form a com­mune or a Hein­lein-style Ayn Ran­darchy some­where, but there still isn’t a sol­id eco­nom­ic rea­son to do it. I can’t see a project like that scal­ing until peo­ple fig­ure out some sort of com­par­a­tive advan­tage that you get from such a place (this is some­thing I explore in my newest short sto­ry, “Blood Moon”).

Does this mean no one should try to build such a thing? No! But until the ques­tion of why any­one would invest in cre­at­ing a mas­sive space colony is answered con­vinc­ing­ly, I don’t see them hap­pen­ing. We need a rea­son to build out into space, one that can jus­ti­fy the extreme­ly high cost of doing so. If liv­ing per­ma­nent­ly in space had obvi­ous log­ic, then we’d be liv­ing per­ma­nent­ly in space. But the good­ness of liv­ing there is an assump­tion of space col­o­niza­tion advo­cates, some­thing they haven’t yet per­suad­ed any gov­ern­ment or cor­po­ra­tion to take on as a pri­ma­ry goal (again, this is besides the hype some entre­pre­neurs build up as a halo mar­ket­ing gim­mick). Sure, you can make the eggs-in-a-bas­ket case that peo­ple like Elon Musk and Stephen Hawk­ing do for liv­ing on oth­er plan­ets, but that does­n’t cre­ate a viable soci­ety; it’s just a state­ment of prin­ci­ples. In order to build a per­ma­nent human pres­ence in space, there needs to be a rea­son for it beyond cool­ness or abstract assump­tions of plan­e­tary cat­a­stro­phe. So far, in all the hul­la­baloo about reach­ing for the stars and plan­ets, that just does­n’t exist yet.

Joshua Foust used to be a foreign policy maven. Now he helps organizations communicate strategically and build audiences.