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Comment by somenameforme | Hacker News Reader

Except SLS/Orion should be cancelled. The SLS is pejoratively called the Senate Launch System, because it has no real place in the market yet is continuing to consume tens of billions of dollars. It was mostly obsoleted by Falcon Heavy years ago (SLS has been a black hole of funding since 2011), and its costs are completely ridiculous. You're looking at billions of dollars per launch if it ever is confidently flight ready.

And mind you it's not some amazing technological marvel that's driving these ridiculous costs. It's essentially a really expensive refactoring of the Space Shuttle program to the point that it will be using the literally exact same rs-25 engines.

And you already hit exactly on why they're not being cancelled - there's going to be a very short degree of separation between Congressmen and the people charging absurd costs for simple tech that's being used in this project. To me, this is perhaps the purest embodiment (and reason) for governmental dysfunction, at all levels. It's simple pork and corruption.

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The real tragedy is that the administration withdrew Jared Isaacman's nomination to be NASA administrator. He had bold plans for modernizing NASA and the experience to lead. But he didn't kiss the ring and instead made comments suggesting NASA's budget shouldn't be eviscerated, so his appointment was torpedoed.

A tragedy avoided given his close ties to SpaceX and Musk, which would have been inappropriate at best and corruption at worst.

Just because Elon knows people doesn’t make it automatic corruption.

The space industry is still pretty small, insiders naturally know one another and have professional contacts.

RFK jr. is destroying all US public health institutions for less "insiderism" than that.

He is a paying customer of SpaceX. Where’s the corruption?

The administrator is definitely one of the weakest links in the system. Bridenstine was looking amazing for NASA then at one point he did a hard 180 and suddenly just became an unthinking Boeing cheerleader, and is largely responsible for the catastrophe that is Boeing's Starliner. And then as soon as he left office he suddenly is in a senior advisory role for some military industrial complex orgs, probably pulling 7 figures for a Zoom call now and then.

But Isaacman? Well he's already a billionaire, and highly ideological towards progress in space. Yeah 0 chance he gets appointed.

Starliner was a catastrophe long before Bridenstine was ever involved.

Absolutely but it never should have been greenlit, allowed to simply skip tests (in flight abort) after essentially failing the pad abort test where only 2 out of 3 parachutes deployed + propellant leak in beyond optimal conditions, and so on.

That craft was not even remotely fit for humans and there was far too high a chance that their 'test pilots' lost their lives in something that never should have been allowed to have a human in it to start with. And that all happened under Bridenstine.

Your point was stronger 6 months ago before SpaceX started regressing on their Starship test flights. The U.S. needs to have multiple horses in the race

I did not mention Starship, because I'm not comparing the SLS against future tech, but against tech that was finished 7 years ago and is commercially available at this very moment. And I'm contrasting this against SLS cost "projections", which invariably end up lowballing reality. I'm steel-manning the argument for the SLS as much as I can, but it's still just nonsensical.

The idea we need to compete against ourselves is something that came straight from Boeing after they lost their bid for commercial crew, leading to them to use their connections to Congress to force NASA to make an unprecedented decision to give bids to 2 different companies. SpaceX succeeded at commercial crew putting astronauts on the ISS in 2020. Boeing, by contrast, was allowed to skip parts of the testing phase (for Commercial Crew), failed others, and was still greenlit because of corruption. And that's precisely how you ended up with the two astronauts put on their first human launch stranded on the ISS for months, only to end up getting rescued by SpaceX.

It's a nonsensical argument - we didn't create two Apollo programs, because there's no justification. And in any case, Boeing is clearly incapable of producing anything resembling a "horse" for this race. Instead we get a 3-legged mule sold at 5-time Kentucky Derby winner thoroughbred prices.

>I did not mention Starship, because I'm not comparing the SLS against future tech, but against tech that was finished 7 years ago and is commercially available at this very moment.

You mentioned Falcon Heavy but that has less than half the payload of SLS.

It is enough payload.

According to whom?

In partial reuse mode, you get 57k kg from Falcon Heavy vs 95k kg from SLS, with the catch that you can launch 25 Falcon Heavies for the same cost as 1 SLS. And that's exclusively the recurring (and likely greatly low-balled) per-launch costs, ignoring the tens of billions of dollars that have (and are) being dumped into its development. In reality those also need to be aggregated into its cost per launch.

Orion's mass far exceeds Heavy's payload to TLI. It simply can't be used for the Artemis manned lunar program unless you want to completely reengineer the entire thing.

This is incorrect. NASA even carried out an internal study on this exact topic. [1]

Everything NASA does is trying to shoehorn in Boeing one way or another because they have tremendous political influence, but there's really no reason for them to be involved at all from a technical point of view. And in fact if they weren't, then we indeed probably would have long since already put boots on the Moon again. But because they are involved, I suspect an appropriate timeline for success is: never, with a whole lot of money spent getting there.

[1] - https://arstechnica.com/science/2019/04/nasa-chief-says-a-fa...

Need some competition to commercial near-monopolization (in the pre-to-mid 2010s when it was funded), some other program, they already funded SLS (which was funded to carry way more payload than FH), let it play out, IMO.

Also, not to say it isn't a time to start acting, if we are another decade out still adding funding to SLS with the current balance sheet, we have major issues.

But $30B over 10Y isn't that crazy when we spend ~$900B a year (with much more in 2026) on defense.

This is the definition of throwing good money after bad. Even if SLS can be completed, it just has no purpose. The latest "estimates" (which means will likely be well below what actually happens) put the recurring per launch costs of SLS at $2.5 billion per launch, on top of the ongoing tens of billions in development costs.

That's for a system that is aiming for an initial payload of 95k kg (to LEO). By contrast the Falcon Heavy costs $0.097 billion per launch and can send 57k kg to orbit. So in other words, 1 SLS launch will costs more than 25 Falcon Heavy launches, with a payload capacity that's 67% greater.

How about as a backup in case all other current options are unavailable?

It's difficult to imagine any scenario where this happens. The only real possibilities are SpaceX going bankrupt or leaving the country. In either case, the government has substantial capacity to nationalize companies for the sake of national security during times of crises. It's also likely impossible for SpaceX to leave the US owing to ITAR and other regulations.

What about SpaceX deciding to raise the price 30 times because they no longer have any potential competition?

I don't believe that likely, but it does seem like something similar is a good reason to keep options open.

I'm sure SpaceX would be more than willing to sign a non-exclusive no-minimums fixed-price-per-launch (based on mass/orbit/etc) indefinite contract for any types of missions the SLS could hope to do. This type of contract isn't even new to NASA (or SpaceX), it's just the policy says "competition" like SLS has to exist and be funded too.

The two main stated aims of fostering competition are contingencies for any single provider and hopes that funding competition lowers cost in the long term (which is separate from preventing cost from going up). I used to be much more supportive of this policy... but nowadays I find myself on the fence. It's hard for me to believe however many billions of dollars we funnel into SLS per launch will ever result in cheap alternatives being developed. It may even have the opposite effect of "SLS got funded through all of its overruns on this policy, we should have no problems doing it again". On the contingency side it's a bit harder to navigate... but it's starting to feel like programs like SLS don't produce realistic alternatives anyways so how much of a contingency is it really providing to fund things like that.

Well, I mean it's unlikely but hear me out, what if SpaceX were actually run by a rogue trillionaire and the country were run by another rogue billionaire and they didn't get along?

At the stroke of a pen, a rogue billionaire could nationalize SpaceX citing some vague concerns about national security.

Money is powerful, but never under-estimate the power of having the coercive apparatus of state at someone's hand.

This is drastically under-appreciating the blowback nationalizing SpaceX would generate.

Both from the Republican base, to whom government is anathema and private industry the best.

And to corporate interests supporting the Republican Party.

Want to see where the real power is? Follow the political money.

Twenty years ago, would you have thought the religious right would accept a serial philanderer former Democrat from NYC whose favorite Bible verse is “Two Corinthians” as their idol?

The Republican base doesn’t actually care about the things they claim to.

Yes. Reagan got elected too.

What’s being said now is more important than what someone historically said, as long as the current messaging is consistent. (And opponents have been eliminated)

You just have to say something something national security and they will fall in line. Modeling politics on people or groups of people having principles is way outdated, and it’s questionable whether it ever was accurate.

Corporate interests are not a homogenous, a single block.

From time to time, it is very well known that a group of vultures organizes themselves to capture the State and royally fuck another vulture using the State's power and legitimacy.

Yeah, money have a lot of power, but a lot of money's power is contingent on the existence of the repressive apparatus of State. Don't discount the power of a charismatic populist leader (And I am not talking about Trump) or a political genius.

People thought that the oligarchs in Russia would overthrow Putin as soon as they felt the bite of sanctions on their backs. The only thing that got thrown were the oligarchs who didn't with the program, and didn't dance to the tune Mr. Putin was playing. And when I say thrown, I meant it literally, as in defenestrated from a high rise window.

Musk is having SpaceX give money to bankroll xAI.[1]

There is absolutely no company that is actually "too big to fail".

[1] https://www.wsj.com/tech/spacex-to-invest-2-billion-into-elo...

Just build a second Falcon Heavy.

If there was a genuine possibility of SLS being competitive, that's one thing. It's another when it's worse in basically every way.

Falcon Heavy as a TLI payload of 16,800kg. A fully decked Orion spacecraft weighs 33,446kg. Really the only alternative to SLS for Artemis would be Starship but that hasn't even achieved orbit yet (meanwhile SLS already did a successful lunar orbit and return).

I’m not happy with this argument because the Orion comes in two modules. It’s designed to go in SLS but each module separately can be launched by Falcon Heavy.

In view of the launch economics, this argument still doesn’t make sense of SLS.

[1]: https://en.m.wikipedia.org/wiki/Orion_(spacecraft)

>but each module separately can be launched by Falcon Heavy.

How do you know that they can feasibly be launched separately? Do you think NASA would have asked for a launch vehicle the size of SLS if could have done a manned lunar mission with something less then half its size?

Oh, they know it.

Saturn V was less powerful than SLS - but it could send an entire mission in a single launch. Capsule, lander and all.

A lot of what NASA has been doing with SLS is just trying to... rationalize its existence. This is what gave us NRHO, Gateway and others.

Reportedly, some of the people at NASA just believe that having an inefficient, wasteful and corrupt space program is better than not having it.

>Saturn V was less powerful than SLS - but it could send an entire mission in a single launch. Capsule, lander and all.

That's just not true. Saturn V had a paylod of 43,500kg to TLI. Only the largest configuration of SLS(Block 2) exceeds that with 46000kg. A Falcon Heavy is far below that.

Huh, I overestimated SLS? My bad - I think I must have used Block 2 numbers by accident. Thanks for the correction.

My point stands though: no Artemis mission has plans to launch a full Apollo style capsule + lander stack. Artemis HLS, SpaceX and Blue Origin versions both, flies entirely on its own. So what's required of both SLS and any would-be SLS replacement is a far less demanding mission than what Saturn V has done in the past.

Which calls into question: what SLS is even for? Does it add value to the mission, or is the mission subtracted from to justify adding SLS to it?

Add to that the fact that to my knowledge while falcon heavy claims it can achieve TLI it has never actually done so.

What?? It's launched multiple missions at energies significantly greater than TLI—Europa Clipper for one.

> put the recurring per launch costs of SLS at $2.5 billion per launch

I think the current administration puts it at $4B, but those estimates seem to include current and future development costs.

IMO, there are plenty of subsystems of SLS that weren't a waste to develop, and it surely fostered a generation of talented individuals, bolstered other companies, etc.

I doubt the Artemis program (as planned) survives a full four years of this administration anyway. The majority of "good work" for SLS seems to be completed, and hopefully, the talent, knowledge, resources, and so on will (has?) spread elsewhere.

Just to add to this, somehow the current plan for getting to the moon involves over 15 launches (or 25, the number does seem to vary). With Starship actually having a larger payload than the Saturn V at least to LEO, how 15 launches could possibly be required, and such a plan been approved to spend billions of dollars on, I just don't know.

So as much as I like the idea of NASA, something needs to be done there.

They got it down to 15 launches? Excellent news.

The starship refueling in LEO requiring multiple fuel starships is not advantages from a mass perspective...

Destin from Smarter Every Day put up a video of a talk he gave at NASA about this program, focusing on all the problems that nobody's talking about. It's a great watch and a good example of how to say the hard things to the people who need to hear them.

https://www.youtube.com/watch?v=OoJsPvmFixU

That's the one I watched and then fact checked after because I couldn't believe it.

Quite frankly, 15 launches should have never been submitted let alone approved. That it was approved and billions burned already is an obvious sign that something is wrong at NASA.

>> Senate Launch System

A name also thrown around for shuttle. Do a little digging and a surprising number of shuttle crews had ties to the US congress, either as relatives or who themselves would later become representatives. They even flew a handful of serving reps (ie John Glenn, aged 77). Nasa has always known how to foster relations with political power families.

> or who themselves would later become representatives.

That's irrelevant. "Former astronaut" is buttercreme icing on any political resume.

Or they were from well-connected political families. The path for wealthy sons of academy ... elite military job ... politics, is well worn. Someone like John Maccain could easily be identified as a future political leader. He would have been a prime nasa candidate if not injured.

Go look at the resumes of astronauts, particularly before modern DEI stuff. For instance here [1] is Buzz Aldrin. A-student in school, varsity football center for a state championship team. Graduated third in his class at West Point with a degree of mechanical engineering while also competing in track and field. Enlisted in the Air Force as a combat fighter pilot where he saw plentiful [successful] combat including dog fighting. Enrolled at MIT and earned a doctorate in astronautics.

His thesis was "Line-of-Sight Guidance Techniques for Manned Orbital Rendezvous, the dedication of which read: "In the hopes that this work may in some way contribute to their exploration of space, this is dedicated to the crew members of this country's present and future manned space programs. If only I could join them in their exciting endeavors!"

He then began work as an engineer on Project Gemini. He then applied to become an astronaut and was rejected because he had not passed test pilot qualifications. He sought a waiver, and was rejected. Fortuitously for him, the next round of astronauts NASA sought required being a test pilot or having at least 1000 hours of flying time in a jet. He had more than 2,200 hours in jets alone. And at that point, he applied again, and was accepted.

---

McCain [2] - prep school (where he at least wrestled), graduated from the US Naval Academy ranked 894 of 899 students. Completed flight school where he was regarded as careless and reckless, having crashed his craft multiple times. He then requested a combat assignment. The first carrier he was on caught fire killing hundreds shortly after he arrived. He moved to another carrier and was shot down and captured a couple of months later. Not exactly "The Right Stuff."

[1] - https://en.wikipedia.org/wiki/Buzz_Aldrin#Early_life_and_edu...

[2] - https://en.wikipedia.org/wiki/John_McCain#Early_life_and_edu...

But with a father being very senior in the navy, and the war hero thing, he was destined for politics. He would have been a useful friend to have. The crashing thing isn't a big deal. Few astronauts ever actually put hands on the controls. Maccain would have been a perfectly adequate payload specialist.

The crashing thing was not the point - it was that McCain tended to fail at just about everything he did. I'd agree he'd be far more likely than average to end up in politics, but there's 0 chance he'd ever have been accepted as a working astronaut. Seriously, just look at the CV's of astronauts who aren't there because of DEI. They are the best of the best who excel, to an absurd degree, in just about everything that they do.

> It was mostly obsoleted by Falcon Heavy years ago (SLS has been a black hole of funding since 2011), and its costs are completely ridiculous

Falcon Heavy: Claimed payload to LEO (though it has never done anything like this): 63 tonnes.

SLS: 95t, 105t or 130t depending on version.

These are quite different capabilities.

The need for such large payloads is highly disputable, especially for propellant (which is most of the mass of any space mission).

This is why the congressional porkmeisters have been so adamant about NASA not developing in-space propellant storage and transfer.

> The need for such large payloads is highly disputable

Getting mass to orbit is one thing. The real game is "get masses into orbit and back to Earth", with the "mass" in question being either some sort of explosive, troops, ammunition or tanks.

When you don't need to have troops and vehicles distributed across the globe (which is very expensive to maintain) but can just go and ship them off with heavy rockets, the math on warfare shifts drastically.

Let me express great skepticism here as to the economics of this. Shipping things by air is expensive enough; shipping them by rocket will be even more expensive. And shipping troops by SLS? Utterly demented. So this cannot be an argument for SLS.

> Shipping things by air is expensive enough; shipping them by rocket will be even more expensive.

As if the US military would take care about costs. They transported fuel into Afghanistan and provided it to its military at insane costs, but a large amount of it got stolen because no one cared about auditing [1].

> And shipping troops by SLS? Utterly demented. So this cannot be an argument for SLS.

Not for SLS... but for SpaceX with Starship. The USSF plans a demo flight for 2026 [2]. And militarily, this capacity is definitely worth it. 100 tons of cargo, delivered to any place in the world that has a suitable landing facility in one hour of flight time. There's absolutely nothing that can come close to this kind of logistic capability, and there is no competitor in sight. It would be an absolute edge over Russia, China or anyone else who thinks they can wage war against the US or whomever the US thinks is worthy enough of its protection.

[1] https://www.airandspaceforces.com/watchdog-report-blasts-us-...

[2] https://en.wikipedia.org/wiki/Rocket_Cargo

While I agree this will be a major boon for SpaceX because military gonna military, in realistic terms it's far from a game changer. ICBMs are tough to shoot down because of their high speed and small size. Starship, by contrast, is huge and will need to slow down much more when reentering the atmosphere. It would be a sitting duck.

For proxy and "we're not involved in this war, honest" type stuff, that might be acceptable so long as target is nowhere near peer. But in any war against a peer military power including Russia/China, they'd have about as much use as aircraft carriers - which is to say, basically none. This, btw, is the major problem with war logistics in general. It's not the speed, because throughput matters much more than latency anyhow, but vulnerability.

> As if the US military would take care about costs.

They constantly care about cost, even if it doesn't seem to you that they do.

Manned space flight in generally is a hugely wasteful money sink. It eats up about 50% of NASA's budget, and there's no real reason for it other than "we're putting people into space because we want to put people into space." People vigorously defend these boondoggles, then finally admit they were a huge waste years after the fact (as we've seen with the space shuttle, and as we're now starting to see with the SLS).

Idk, absolutely does fucking not at all look wasteful:

https://www.nasa.gov/missions/station/20-breakthroughs-from-...

> Idk, absolutely does fucking not at all look wasteful

It does if you actually look into at the facts instead of just taking a PR listicle at face value.

For instance, the very first thing mentioned on that list is Alzheimer's. Go ahead and look into what the ISS actually did with regards to Alzheimer's, and you see a lot of "this has the potential to teach us more about the disease," without any evidence that anything was ever learned. There's a reason why you don't hear researcher's working on these diseases go "well, we expect a huge breakthrough once this ISS experiment is done!"

This is the problem every time this gets discussed. People just run a Gish Gallop of copying and pasting a big list of vague claims from the NASA PR department, without bothering to look at the actual claims to see if they're accurate. When you do, they're invariably far less than they're made out to be.

So many of the things we use today on a daily basis came from having a manned space program.

It used to be that in the 1960s we were spending about 4.4% of the total federal budget on the space program.

Since the 1970s, it's gone down to around 0.71%.

Since the 2010s, it's gone down even further to 0.3% - 0.4%.

We've also not pushed much for talent in the federal government by way of salary and perks.

Despite these challenges, there are a whole host of technologies, medical treatments, navigational advancements, etc. we would not have without simply being in space. Even accounting for inflation adjusted dollars, the amount total spent in the history of NASA, across all programs, is absolutely miniscule to the technological and economic advancements that have come from it.

There are around 1,600 published papers with data from the ISS, and those have been collectively cited over 14,000 times by other papers.

That is a significant impact and can only be done by having people there.

We have ad-tech now I guess.

> So many of the things we use today on a daily basis came from having a manned space program.

What are these? If you say "integrated circuits" I'll point out that's largely a lie, unless by "space program" you mean "Minuteman II ICBMs".

"Comes from NASA" ends up meaning "NASA was tagentially involved early on". And really, how could it ever be concluded NASA was essential? You'd need to argue the counterfactual that a technology would not have been developed otherwise, and how can one do that?

Well, you have to quantify "waste" to make that claim.

There are many arguments that the space shuttle program's side effects helped win the cold war, foster modern communications, inspire generations to study science, ...

Those are good things, without stating its known direct accomplishments.

People debate whether the Human Brain Project was a failure, despite the fact that it generated a lot of new research.

In 2025 dollars, the cost for the Human Brain Project is just under $2 billion. In 2025 dollars, the Space Shuttle total cost is $311 billion. NASA spends about $3 billion every year on the ISS - more than the entire Human Brain Project.

The problem is that people are able to look at the Human Brain Project, and say that despite important research coming out of it, it might not have been a good idea (again, this gets debated). But people act as if some research coming out of NASA's endeavors entirely justifies them. When people refuse to look at things critically, resources almost invariably end up misallocated.

I am not saying that because good things happened that there was no waste. However, to say that nothing good came from (or can come from) something and it was a waste is stating something else entirely.

Not sure whats your problem, why can't we have both?

Those are definitely not money wasted - for waste look at things in ballpark of trillions like meaningless wars for made up reasons that destabilized whole parts of world and killed millions of civilians, look at various ways ultra rich and their companies avoid paying even bare minimum taxes and contributing back to societies form which they siphoned those vast amounts of cash.

These are peanuts which keep giving back to whole mankind and our future, instead of destroying it.

> Not sure whats your problem, why can't we have both?

Because resources are limited? Any money going to, say, SLS is money that can't go to another project. This would be true even if NASA's budget were 10x bigger.

I'm not sure what it is about NASA that leads people to pretending that we have infinite budgets. In just about any other area, we can have a discussion about whether or not this is a good allocation of resources (for instance, the Human Brain Project I mentioned before). But when NASA comes up, this goes out the window and we're supposed to believe projects like the SLS are tantamount to being free, and that they aren't diverting resources from other potential NASA projects.

Putting a man on the Moon is something many view as humanity's greatest achievement, ever. Even if we ignore absolutely everything else, I think this alone makes it worth it. People need to be inspired. It's the spice of life.

But if we look the future, the possibilities are even more enticing. Richard Nixon effectively cancelled human space flight after a series of Moon landings. Had he not, we could very well have a civilization on Mars today, industry in space, and who knows what else. I mean there's no realistic argument for why these things should be impossible given what we know today - they're certainly far less to strive for than putting a man on the Moon when starting from effectively nothing.

And these achievements are no longer just flag poling, but stand to genuinely revolutionize humanity - to say nothing how inspiring such achievements will be. Perhaps we might live in a world where our grandchildren will again want to be scientists and astronauts, instead of YouTubers.

> Putting a man on the Moon is something many view as humanity's greatest achievement, ever.

Because the Americans have such an amazing propaganda department and had to rub it in to the Soviets even after flunking every other “space race”.

As for canceling the space programs, if it wasn’t Nixon, it would’ve been done by any of the politicians following Hayek/Friedman economic policies - basically everyone after Nixon.

It has nothing to do with propaganda. It's such an inherently unbelievable achievement that many have indeed begun to doubt we ever actually even did it. And that doubt is very easy to understand because in modern times many have lost the ability to think big, let alone actually do big things. I mean can you believe we put a person on the Moon, let alone at a time when a "super computer" would have had a millionth of the processing power of that cheap phone in your pocket? It's nothing short of stupefying.

It's similar to how we still marvel at how people managed to build the pyramids. There, at least, there can be no doubt that they truly exist - but people have been debating, and aweing, at them for literally thousands of years. The Greeks, no amateurs to construction themselves, were debating how they such a thing could have been constructed all the way back in the 5th century BC!

These great achievements are what define humanity. In the blink of an eye on the scale of time, most of every company, person, and thing you know of today will be gone and completely forgotten. The very few things that will stay with us are these grand achievements that define not only an era of humanity, but humanity itself.

> Had he not, we could very well have a civilization on Mars today

Well, that's an interesting take. Fantasial, but interesting.

And how do you think putting a man on the Moon sounded at a time when we'd yet to put a single person into space?

Werner von Braun was the head architect of the Apollo Program and viewed the Moon as little more than a step on the way to his vision of colonizing Mars, for which he'd already been working on technical plans with the planned first landings to be in the early 1980s. In fact this is precisely where the Space Shuttle, and to a lesser degree the ISS, came from. They were meant to be tools, with the ISS a very small scale version of the supporting stations planned to come with the Space Shuttle working as a beast of burden during their construction.

He retired from NASA once it became clear the politicians were no longer interested in space after winning the space race. As an amusing anecdote, well before he was the head of Apollo, he also wrote a sci-fi book, "Project Mars: A Technical Tale." In it there was an advanced civilization living on Mars headed by a group of ten individuals who were, themselves, headed by "The Elon."

---

Those who lack the ability to think big will, unsurprisingly, never have anything big. Because there's no technological point where colonizing another planet, much like landing on the Moon, will ever be easy or simple. Because you're doing something that's never been done before which means there are a basically infinite number of things that might go wrong, and you simply cannot account for all of them. And this always has and always will be the same story. Technology doesn't simply come to us - we make it happen, and without pushing forward we will stagnate.

You might consider checking out the Weinersmiths' book "A City on Mars." It goes into great detail of what still needs to be developed before we can seriously consider colonizing another world.

It's one of the reasons I support manned spaceflight - sending robots is easy but limited, sending people allows for way more flexibility but needs a lot more knowledge and engineering. We'll never develop that knowledge and engineering without actually sending people into space.

That book seemingly exclusively leans on misleading arguments. For instance, literally their very first effort is to try to 'debunk' the idea of having Mars as a sort of 'backup' to Earth by claiming that even in the case of a doomsday event Earth would still be far more hospitable than Mars. That statement is completely true but also completely irrelevant.

Take a typical doomsday event, an asteroid impact or a supervolcano. Both kill you the same way. It isn't the event itself, but rather the sun ending up getting blotted out for years by mass debris/ash not only causing an extreme freeze across the planet, but also ending photosynthesis rapidly killing all plant life which starts a mass extinction on up the food chain to animals that ate those plants then animals that ate those animals and so on.

This is the sort of event that could easily completely kill off humanity, but it's not because it'd make Earth a worse place than Mars. Even at the climax of mass extinction, Earth would still be dramatically more hospitable than Mars. The reason it will be so deadly is the same reason that more people die in the desert of drowning than of thirst. It's something you simply don't prepare for. An offworld colony in this case would help ensure humanity is perpetuated, Earth is recolonized, rescue survivors, ensure global order, and so on. In fact this is the case for most of all conceivable disasters.

If there's any argument you found particularly compelling from the book, please do share. I have a copy if you simply want to reference the page number or whatever.

Just FYI, my copy's 1500 miles away from me at the moment, so I can't give you page numbers and can only rely on my recollection of the book.

Your scenario would indeed be a "backup" for the species, but only in the very, very long term. It only works if we have a self-sustaining off-planet presence large enough to survive a complete separation from Earth. Most of the book goes into detail about what we still need to develop even to have a permanent presence in space (as in, you don't rotate people out every few months), much less a self-sustaining one.

We haven't done large-scale agriculture in space. We haven't developed methods of processing extra-terrestrial resources. We haven't seen what different gravity conditions does to children or pregnant women. We don't have solutions for the conditions people develop in zero-g, and we don't know if 1/3g or 1/6g causes those same conditions. We can't completely recycle our waste into food, water, and air without a steady supply of consumables from Earth. We don't know how to effectively deal with lunar regolith and we haven't done the engineering to keep the poisons in Martian soil out of the habitat. We haven't even developed the habitat!

The book speaks to me because I work for an engineering company and I know how much time and money it takes for even simple projects when there are lives on the line. The book doesn't say we can't colonize space, only that we have a lot of work ahead of us before we can successfully pull it off.

You're jumping from the start to the end. For instance you do not start with large scale agriculture on Mars - that will be a decades long project that will start with simple greenhouses. The first missions will be bringing 200% of the food they need with themselves, and then working to establish and ensure (as there will be unmanned deployments ahead of time) domestic life support systems. And the first habs will be exactly what we land in - the rockets themselves.

I think an important thing to consider is that in contemporary times most institutions are 100% risk averse outside of war. With Mars that will always be an impossible initial threshold. Because not only are there known unknowns, but also a practically infinite number of unknown unknowns. When we landed on the Moon internal estimates at NASA gave us about a 50% chance of success, which is why the public obituary for the astronauts was written before they'd even left Earth. Early on in the Apollo program NASA even ended up scrapping mathematical risk modeling because the numbers were always coming back so grim that they found it impossible to move forward with them.

Of course that doesn't been they were just suicidally YOLOing it. There was (and will be) extensive planning and preparation, but you have to strike a balance between achieving things and working to create an acceptable perceived risk factor. So for a practical example - the long-term effects of low g, as opposed to 0 g, can be relatively safely ignored. There's every reason to think that low g will be much closer to 'normal' gravity than 0g in terms of effects, and predictable bone/muscle deterioration can be mitigated with exercise or even weight suits much more easily than on the ISS.

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An even more general issue is that the best place to test things with relation to Mars is Mars itself, because Mars is far closer to the Earth in just about every way than it is to the Moon, let alone the ISS. So we have things like the Mars Desert Research Station in Utah, or AMADEE-18 that was carried out in Oman. But at the end of the day it's Earth - we know the conclusion of these simulations, and there's limitations on what we can simulate.

We might have issues with bone loss in low-g environments, we might not. The point is that we don't know. These are human beings we'll be sending. Taking a chance on "it'll probably be all right" just isn't acceptable.

And that's just one single issue out of thousands that needs to be resolved before we can start having people live off-Earth. Most of it is stuff we just don't know how to do. You're trying to build a rail network with iron-age know-how. We can't even get to the moon right now, much less build a Mars outpost.

And while it's true that testing stuff on Mars would be ideal, Mars is too far away. You can't respond to emergencies. You can't quickly iterate designs for systems. You can't easily commercialize tourism. If we build bases on the moon first, we can be much better prepared to take that larger step to Mars. Sure, send a couple Apollo-style "plant a flag, take pictures, hit a golf ball, go home" missions using professional astronauts, then maybe a few missions where you have a lab on the ground and you stay for a month. But if you're sending people to stay, you need to be very sure they aren't going to die on you. Dead astronauts are heroes. Dead colonists are a tragedy, and an excuse that will be used to justify never going there again. If we can keep a permanent settlement alive on the moon, Mars will be that much easier.

Either way, there's still a lot that needs figured out first. The book outlines just a small fraction of what needs to be done. A good chunk of that will happen here on Earth. Some will happen in orbit. Some will happen on the moon. And eventually, some will happen on Mars. And it'll be fucking cool! Seriously, space stuff is fun to geek out on. Lots of interesting problems to solve. If it was easy, it'd be boring.

Hitting on the most general issue first - you could spend the next million years trying to simulate every possible contingency and issue with Mars, but at the end of the day you're still going to have many things with a high level of uncertainty, let alone the unknown unknowns. This means that going with an acceptably high risk is simply a prerequisite - period. It worked during Apollo and it will work for Mars, simply because there is no other option. So yes, "it'll probably be alright" is absolutely going to be a norm.

And the Moon is a complete hell hole that shares essentially nothing in common with Mars. You're looking at 2 week long day/night cycles that oscillate between absurd extremes of temperature of something like -300f at night to +200f during the day. And there's also no atmosphere which is why the Moon's surface looks like a teen with chronic acne. Even the smallest pebble will pound into the surface and often at quite a high level of energy. Similarly this is a big part of the reason that Moon dust is some seriously nasty stuff. Mars has a similar issue, but orders of magnitude less severe owing to the nature of where its dust came from, which is more similar to terrestrial dust sans composition.

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As for the specific issue you mentioned - bone/muscle loss is not some unsolved mystery as the book implies. Your bones/muscles strengthen in accordance to the stresses they're under. In space there are 0 stresses so they deteriorate. The normal solution to this is weights, but in 0g that obviously doesn't work so astronauts are left doing largely ineffective and awkward elastic based exercises, which they have to spend 2+ hours a day doing. None of these are issues in low g where weights do work, and the bone/muscle loss will already be far less. These sort of arguments are like saying "Ok, we know this ship floats in 20 ft deep water, but how do we know it'll float in 50 ft deep?" Technically you don't, and you won't until you try it in 50ft of water, but ultimately there's no reason to think it won't.

> Perhaps we might live in a world where our grandchildren will again want to be scientists and astronauts, instead of YouTubers.

Sending a huge amount of your budget to send people into space because "people need to be inspired" leans a lot closer to YouTuber than science. You're sacrificing the scientific budget for the sake of giving people a spectacle. This comes at the cost of actual technological advancements. Look at the development costs for Falcon and Falcon Heavy, for example, or Starship, and then look at what NASA's spent on the Space Shuttle, SLS, ISS, etc.

The actual science, as I wrote in another reply, ends up being far less important than how NASA frames it (and often doesn't end up being used at all). And even in those cases, it's not at all clear that humans in space are actually needed to get the job done.

SLS is what keeps Elon from having American spaceflight in his own personal vice.

Senate Launch System sounds more appealing every day. All aboard!

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