I am so glad /r/spacex had the chance to host the AMA. Even this thread shows a pretty depressing lack of understanding (so far) of what Elon has claimed and what SpaceX has actually demonstrated. A bunch of tilting at windmills, virtue signalling and strawman construction efforts while the people who have a clue have a real discussion elsewhere.
As anonymous internet message boards go, /r/spacex is really impressive. They have a lot of highly informed space enthusiasts, both amateur and professional.
Here's one time Reddit was actually able to help SpaceX (!) by reconstructing a corrupt video stream:
I personally don't think that I have a lack of understanding of what Musk has claimed or SpaceX has demonstrated, and I'm incredibly skeptical of their ability to safely deliver on their promises within his proposed timeline.
I'd quite like to be proven wrong, spaceflight is an area very near and dear to my heart, but from my point of view Musk's reach appears to vastly exceed his grasp.
EDIT: I did enjoy the AMA though, as it provided some interesting insight into their plans for all of this.
thelambentonion, I can't help but notice your numerous posts expressing skepticism regarding SpaceX in this thread. I see a post in your comment history where you included a disclaimer, saying that you worked for a competitor to SpaceX.
Does the fact that you aren't including any disclaimers in your posts now mean you no longer work for a competitor to SpaceX?
Ah yes; I sold out not-too-long-ago to go work in commercial software :)
I suppose it might be worth it to keep including the disclaimer, as it'a possible I may be biased in some way that I'm not consciously aware of. Although it bears mentioning that if my former employer made half of SpaceX's promises, I'd be twice as skeptical! So a point in their favor.
I hope I'm not coming off as too much of an asshole in these threads; I really do want to see commercial space flight grow and succeed going forward. It's just that my experience and the conversations I've had with current and former SpaceX employees gives me an unhealthy dose of skepticism regarding a lot of their claims.
Totally fair to be skeptical; not very impressive though unless you have detailed cause. Not quite as fair, or impressive to make comments like these with no effort or backing:
>Glass domes and underground Martian tunnels make for some very interesting science fiction, but I'm concerned about the engineering challenges that he seems to be ignoring in favor of his grand statements of intent.
The AMA, and even that specific question was all about the engineering challenges...
>but the amount of press and attention that they get just by saying "we are going to mars" are crazy! Nothing practical to show, i would be more interested in a mission to build up a base at moon first.
But hey! This is show business, what we losers can possible know!?
He literally showed images and video of fuel tank and rocket tech that represent novel advances. He has also spilled gallons of ink justifying why Mars is the place to go next.
EDIT: To be clear, I don't think I am quoting lambentonion here, just giving examples of the stuff that made me comment initially
> The AMA, and even that specific question was all about the engineering challenges...
Re: that specific question, I may just have a different view of what constitutes a question on engineering challenges.
That AMA is of exceptional caliber, however, and there are definitely some gems to be found (see [0] and [1], in particular).
The fuel tank and rocket tech represent novel advances in rocket tech that are as-yet untested, afaik. A scaled-down test stand prototype and a prototype of a composite tank are certainly worthy of praise, but they still require an enormous amount of work to turn into a functioning product.
I'd also like to qualify some of my statements here: I don't think _any_ of these challenges are insurmountable. However I think that it would be impossible for all of them to be addressed on the time scale that Musk proposes, for the amount of money he has stated, with the manpower that SpaceX possesses.
Which has been the case in all of Elons endeavours. They usually take twice the time at double the cost, and probably cost some marriages along the way. But he does get publicity and funds it out of his own pocket as far as he can.
One serious danger I haven't heard anyone mention mention in regards to the Mars colonization project (though it was considered to some extent in Carl Sagan's "Contact" and probably some other science fiction) is the possibility of terrorism against either the fragile spacecraft or colony.
Musk has said there will be no screening of the Mars colonists, and that anyone could go. That means someone who's mentally unstable and/or wants to make a name for himself (ala Herostratus[1] or any number of modern publicity-seeking terrorists and murderers) could go and attempt to harm the spacecraft or colony, both of which would be incredibly vulnerable to such intentional attempts at destruction and are guaranteed to get massive publicity were they to be destroyed or even merely attacked.
This could become even more likely if living on Mars long-term actually becomes viable, and people wind up spending decades on there. Some people will likely go stir-crazy and attempt to harm themselves and/or others.
People who are allowed to go live in Antarctica or out in to space are currently screened very carefully to be compatible with each other and able to psychologically withstand the rigors of life there, and the relative isolation. But there will be no such screening for the Mars colonists, according to Musk, and the isolation and danger on Mars will be even worse than it is in Antarctica.
The isolation and danger will be hugely stressful and difficult to deal with over the decades people will live on Mars. I've read that even in Antarctica, people are rotated out within a year or so because of the psychological difficulties of living there, and no one's been in space for much more than a year.
Any claim that there will be no screening of colonists is highly dubious at best. All you need to make some form of screening mandatory is to have more applicants than open positions.
Even if all you do is accept applicants as they apply, that immediately biases the selection process to better informed and connected individuals.
It's one thing to have a fist-come-first-served system, where the more informed, connected, wealthy, or eager individuals get to go first. It's quite another to psychological screening, background checks, and perhaps even rigorous training to make sure they can withstand the great psychological pressure that will be present on the trip and on Mars. There are no plans to use these latter measures, as far as I know.
Even if there was such screening or training, that alone won't be enough if despite it someone onboard the spacecraft or in the colony decides to act out anyway.
I really hope someone at SpaceX is seriuously thinking about these issues and coming up with practical solutions, as that's the only hope of preventing some unhinged or politically motivated individuals from turning a promising colonization effort in to a tragedy.
That's a great comment. This is why I thought the one-way ticket trips to Mars were the most honest. I thought most or all of them were covertly or accidentally doing the same thing just with longer, life expectancy.
"Musk has said there will be no screening of the Mars colonists, and that anyone could go."
I suspect that will go out the door as soon as a major funding partner demands otherwise, to mitigate potential risk to their investment.
Eventually, sure, the screening will likely become less and less invasive; but at that point we'll have hundreds of people on Mars and the launch/voyage will be routine.
I'd encourage everyone reading the AMA to take a lot of what Musk is saying with a grain of salt. The Interplanetary Transport System (ITS) is a wildly ambitious project that is attempting to accomplish more things in a shorter period of time than the Apollo program (and on a substantially smaller budget to boot).
Check out Robert Zubrin's article, which presents a much more salient critique of SpaceX's current plans than I could [0].
Zubrin starts by misrepresenting the Spaceship as two inseparable stages, and overestimates the mass of the motors by a factor of three.
He then claims that ISRU is impractical due to hypothetical resource constraints.
Zubrin then claims that the Spaceship is a "habitat" that should only go one way. SpaceX has decided that the habitat should be built on Mars from indigenous materials. A one-way Spaceship is vastly more expensive than a reusable one.
Zubrin dismisses fast transit to Mars entirely on the basis of not being a free-return trajectory with a symmetric time span (6 months out, 6 months back). The free return is only if use if the spacecraft is not going to land. The number of failure modes where the Spaceship can't land on Mars but can still manoeuvre into Earth orbit are very small. The Spaceship is designed for aerobraking and landing, not orbital capture.
He then goes on to criticise the four-month express crew transfer as having no payload capacity, when the intent was only to show that rapid crew transfer is possible. The benefit of the shorter trip is less exposure to harmful radiation. The assumption is that sufficient resources already exist on Mars to house and feed the new arrivals.
A multi-component system as proposed by Zubrin with an Earth-Mars transport with separate craft for leaving Earth and landing on Mars adds far more complexity, more moving parts, more ways for things to fail.
The SpaceX monolithic approach us safer simply because there are fewer things that can go wrong.
Zubrin's supposed improvements are to split the Spaceship into propulsion and habitation modules, with the habitation module having its own vacuum engines for Mars intercept and landing, and then some way of splitting those motors away from the habitat upon landing so they can be cannibalised or returned to Earth.
Which is to say, Zubrin has spent so much time evangelising Mars Direct that he no longer considers any other option as valid.
SpaceX are pursuing the engineering goal of sending large payloads to Mars and back to Earth with best use of resources. They want the incremental cost of moving people and things around the solar system to be as low as possible. Zubrin wants a single transit to be as low cost as possible, meaning use of disposable spacecraft, meaning higher costs overall.
Zubrin thinks we can get to Mars with current tech. He has thought that for decades, and his outreach efforts was one of the things that inspired Musk in the first place. He disagrees with the timespan for colonization, yes, but his post here is mainly around optimizations for Musk's proposal, not an outright rejection:
>Still, with some corrections, a system using the core concepts Musk laid out could be made attractive — not just as an imaginative concept for the colonization of Mars, but as a means of meeting the nearer-at-hand challenge of enabling human expeditions to the planet.
It's good to see that the initial nearly religious fervor has worn off, and comments like yours can survive the voting process here. There are a number of issues with the "colony" concept, even beyond that excellent article, but until recently such a point was met with some version of fury. The general theme seems to have been that getting people excited, even with empty promises, was somehow virtuous and might lead to something good (for parties other than Musk's and SpaceX's bottom line).
I think people getting excited about space and space travel again is a good thing. It's the first step to getting people involved again, even if only to remember what we're capable of as a species, despite all our flaws and all the other problems we've yet to solve. Whether you agree with Musk's methods or not, I enjoy living in a time where we dream about the possibilities of new worlds, rather than reminiscing about a golden age of space travel long past.
I think that's a little sad, because it implicitly gives up on the notion of real progress in favor of PR and imagination. I'm excited about SpaceX, but not because of their "Mars Colony" PR. I don't think the situation is so dire that we need to suspend our skepticism and become mindless cheerleaders in the name of "dreams".
It's definitely a good idea to keep expectations grounded, but at the same time there's no reason why the current mind-numbingly slow crawl that space travel has come to should be taken as some kind of rule or requirement or inevitability. Musk's timeframes are overwhelmingly optimistic at best, but the current pace of development is also unacceptably slow.
I think that's a bit of a false dichotomy. I don't think some portion of the public being swayed by PR is going to stop SpaceX (or other entities) from making real progress. Musk is definitely not giving up on that notion.
If you just mean that it's sad that people need this kind of hyperbole to get excited about space, well, different strokes for different folks. You don't need it, they do.
The thing about false hope, is that it doesn't last, and in its wake you get cynicism and apathy. In the long run, lying to gin up excitement backfires.
Agreed, what's required is solid discourse, to fill in the endless details of a plan that will no doubt take longer than expected. However, the broad strokes are there, the goals have been set, and action is being taken. This is what makes me excited - not SpaceX, not Elon Musk, but that someone is trying to make commonplace space travel in my lifetime a possibility.
What I don't understand about people like you is how you can still talk this crap.
Musk has done incredible stuff already, he has shown multiple prototypes of what they are building. Sure, maybe they will fail, but I don't understand how you can call everything "empty promises".
He promised a orbital rocket landing, he delivered.
He promised a reusable rocket, this he is very close to as a used rocket was already did multiple full duration test fires.
He promised a new engine, he shows this new engine and its first tests.
He actually delivered a prototype of a carbon-fiber tank that literally nobody in the community was expecting.
Will people like you only be happy if there are 1 Million people living on Mars?
It seems to me that you have never read the actual communication and you are just going of on statements by third parties.
It seems to me that you've decided I fit some kind of preconceived archetype "people like you", which largely seems to consist of a lack of faith. "He's done X, why not Y?" Because when he promised X, he did so with a plan which accounted for the issues inherent in X. This is not the case for the orders-of-magnitude more ambitious Y.
"He's done incredible stuff, so take him at his word" is the kind of nearly religious suspension of logic I'm talking about, mixed with equally unfortunate hostility at the "unbelievers" (aka 'people like me'). That you end with a note of incredulity at the notion that I could have arrived at my viewpoints while fully informed walks the fine line between insulting me, and insulting yourself.
I would be most interested hearing exactly how many catastrophic launch failures the project is expecting to sustain whilst still going forward. SpaceX today has a somewhat above average launch success rate but the last two failures got the markets into a tizz, which is very significant here if this is meant to be at least a partially commercial venture.
The leaders of the most powerful nations on Earth are barely starting to talk about some small human missions to Mars and then there is Elon, casually discussing glass domes and tunneling drones creating underground networks on Mars. Truly incredible.
I would say that the leaders of the most powerful nations on Earth are a little more grounded in reality than Musk in this regard. Glass domes and underground Martian tunnels make for some very interesting science fiction, but I'm concerned about the engineering challenges that he seems to be ignoring in favor of his grand statements of intent.
To pick a specific example, he seems to have very little concern for radiation shielding both during the trip to Mars or on the Martian surface. Both of these present incredibly harsh radiation environments for humans, and we need to develop solutions before we even consider sending explorers, let alone colonists.
Most habitation would be underground (hence the mining drones) to reduce radiation exposure.
Overall radiation exposure would be higher, and life expectancy would take a hit, accordingly. This is a trade-off, not a non-starter. I too would like to see a bit more discussion of specifics, but I also don't see this as the Achilles' heel that many would make it.
> he seems to have very little concern for radiation shielding both during the trip to Mars or on the Martian surface.
I find it hard to believe his team have not considered something so obvious. This seems like one of those statements that assumed the experts are a bit stupid. Just because he hasn't specifically mentioned it doesn't mean it is not considered. And sure somethings are probably not considered, but something as obvious as this...
> "The radiation thing is often brought up, but I think it’s not too big of a deal"
AFAIK no one else within the community would think of saying that.
I'm sure that there are people within SpaceX studying this and taking it into consideration, but my concern is mostly with Musk's cavalier attitude towards individual safety.
I don't think you have looked very hard then. Here's Zubrin on the topic:
>However, we already have data that shows that the accumulation of slow rates of cosmic ray radiation received during long duration spaceflight is not a showstopper for human Mars exploration. GCR dose rates in low Earth orbit are about half those in interplanetary space. Thus, there is a growing number of cosmonauts and astronauts who have already received Mars mission equivalent GCR doses during extended space missions without any radiological casualties.
He mentions in a recent speech that the most deleterious effect of time spent in space is related to zero gravity, not radiation - and that can be fixed with resistance training.
How about one problem at the time. If we can actually go there with lots of stuff, stay for a long period and come back we will already have made more progress then most people thought possible.
We know most of the physics needed to deal with the situation, if we can get equipment to mars. Radiation is a problem, but its not Problem Nr. 1.
1) You imagine what's going on in Elon's head
2) You complain about it on HN
3) You expect other people to care about your fantasy
4) ...
5) ???
There are multiple hard-to-solve problems involved in sending humans to Mars. Complaining that Elon didn't give sufficient weight to your favorite problem in his executive summary is not that interesting.
That's a good point, but it is relevant that Elon Musk isn't just a "scientist" or "expert" but a businessman positioning himself to sell a product.
I'm willing to give him the benefit of the doubt on this one and wait for more details, but at the same time I concede that it's not unreasonable to be wary of claims that the radiation problem "isn't a big deal" from someone planning to sell tickets to Mars. Not everyone has the same notion of what an acceptable risk is.
I'm not very knowledgeable of radiation hazards in space, but from some casual wikipedia browsing, it appears that the primary hazard is from protons (and various charged particles) being spewed out from the sun.
How practical is it to use an electrically charged or magnetic object between the sun and the spacecraft to deflect particles? Presumably, the farther away it is the less deflection would be necessary, but at some point it would be too far away to effectively mask the whole disk of the sun.
Similarly, you could just use a physical screen. Apparently, things like aluminum don't work very well as shielding because the undesirable particles react with the aluminum and produce more undesirable particles. However, if it were far enough away from the ship, it wouldn't need to block the radiation, it would only need to deflect most of it in a slightly different direction. (Whether the "screen" is on a long tether or whether it's a separate drone-spaceship would be an implementation detail that's not particularly important.)
I assume there's some reason this is impractical, otherwise it would be a solved problem already...
(As for shielding on Mars itself, I'm okay with the idea that humans will spend most of their time underground.)
Well, glass dome, water, glass dome is a really old idea that would work, if water is readily accessible.
something like 50 feet of water would also work for the trip, but water is heavy and you need a lot of it. maybe they can catch a comet, or pull it from the moon. I think there are answers, they're all really expensive answers though.
Thats not the reason. The reason is that the leaders of Earth have political constraints that does not allow them to do or change much. It has little to do with technical details.
Musk talks about it because he does not have those constraints.
As for radiation shielding, this has been a topic since the 60s. We know more or less what the risks are, we know the fundamental way to deal with the different type of radiation. The question is how to integrate it in your mission architecture.
He does not spend much talking about this because its not the fundamentally hardest problem that is to solve. The Core Problem to solve is the Transportation Problem. From what he has said about it, he proposed fundamentally the same basic ideas that people have been discussing for many years, and those should work.
Yeah, the Mars One project talks about burying their habitat five meters underground to get the same protection as the Earth's atmosphere; glass domes seem downright reckless in comparison.
All of our cereal crops are planted and harvested every year. They won't have time to accumulate the damage that we need to shield humans from. Also, plants seem to handle radiation very well - see the growth around Chernobyl[1].
(Note: The danger of eating Chernobyl's foliage is not that it has been irradiated, but that it has ingested radioactive material. That shouldn't happen with cosmic rays.)
Everyone's going to appreciate the opportunity to wander a green garden in a t-shirt. Do it at night and you're getting a lot less radiation, and I'll wager it'll be a hell of a sky too.
My impression was that once you're down on the surface of Mars the radiation that isn't blocked by the atmosphere is mostly cosmic rays which don't depend on day or night.
So you're saying that beyond everything else Musk is also making contributions to the marketing of greenhouses? Because "living space" is always related to humans, as far as I can tell.
Though some other comments I think mentioned that it probably wouldn't be too dangerous to allow the occasional stroll through the greenery. Doesn't sound too far fetched if you consider I can choose to hang out at the park without a hat in exchange for an extra dose of UV radiation for the day. Not saying UV is on the same level as cosmic radiation, it's just something to think about :)
I believe I recall talking about using water in the wall lining of the crewed area as shielding for radiation.
Also the radiation exposure during flight which would be the worse is equivalent to smoking for two years and dropping it. (I personally thought it was gonna be higher)
> ...the radiation exposure during flight which would be the worse is equivalent to smoking for two years and dropping it...
Please provide a citation for this. As far as I'm aware, we simply have no idea the kinds of effects that radiation encountered during the flight would have on humans.
The sample size for human exposure to space-based radiation is incredibly small (limited to just the astronauts on the ISS, and even then that is protected by much of the Earth's magnetosphere).
Radiation has been studied since the 60s. Multiple Mars mission had the equipment on board to do the measurements. Nothing to surprising was measured, the same results on Curiosity and Viking.
We know a lot about both type of radiation, cosmic and solar. Why know the basic physics, and we know how to prevent it. Both types of radiation have different properties and have different levels of danger, thus need different solutions.
This had been known for a while and solutions are possible. Thus, its not the most important problem in Humans to Mars architecture, as we know much less about reusable rockets and carbon cryo tanks.
Right!? Like, i have tons of respect for the guy, but the amount of press and attention that they get just by saying "we are going to mars" are crazy! Nothing practical to show, i would be more interested in a mission to build up a base at moon first.
But hey! This is show business, what we losers can possible know!?
"Nothing practical to show" ... I think you may be misinformed. There are a great deal of practical advancements (raptor engine, carbon fiber tanks, software and sensor suites that enable autonomous landing). There's tons of room for discussion around the mars architecture but to discount it because there's "nothing practical to show" is incorrect.
If you're not an expert in the field it might be worth it to do some research before immediately discounting an idea.
Well, TIL. Musk wins again, then. NASA with this huge budget, and I hear nothing. Then Dear Elon does ONE reddit AMA and I doubt I'll hear the end of it before 2023 ;)
Science Fiction writers have been discussing it for decades. Elon I think is A BIT out of touch when it comes to realistically coming up with timescales for this stuff. Obviously some day it will happen, but in the next ten years I think is ridiculous. I hope I'm wrong.
I am sure Elon Musk won't get the chance to answer my reddit question, since apparently the reddit mob downvoted me to death, so I am asking here, perhaps anyone knows.
1) What RTOS does SpaceX use for the embedded hardware on board? I know they use a lot of Linux, but not for hard real time stuff. What are they running on their microcontrollers?
2) Is it programmed in C, or some other language?
3) Is the embedded equipment on board running on a switched network? If so, does it use TCP/IP or some other protocol?
As far as the RTOS, it sounds like they use Linux:
> Linux is used for everything at SpaceX. The Falcon, Dragon, and Grasshopper vehicles use it for flight control, the ground stations run Linux, as do the developers' desktops. SpaceX is "Linux, Linux, Linux", he said.
former SpaceX employee:
There are a couple of YouTube videos around where they talk about the nature of the systems. I'm pretty sure I can't talk about it but I'll try to find the videos.
The IT stack was the cause of over a billion dollars of lost missions from leaving Earth all the way to Mars missions. It also is what will or won't get the rocket to Mars. So, it was worth an answer given that by itself has killed so many missions with the Moon missions themselves taking a huge team & cost to do right despite failures [which showed up].
There's a lot of hand-waving about how a base on Mars would operate. Remember the Biosphere II debacle, an attempt to build a closed ecosystem in a big dome. That was intended partly as a test for a Mars colony. They had a terrible time trying to stabilize their little ecosystem. They had far more resources at start than a Mars mission could carry, and were only trying to support eight people.
The one difference is that for Biosphere II they tried to be cut out of the Earth atmosphere. They tried to be totally autonomous. For Mars, they will mine the local resources so they will not be "sustainable" at first.
Mining will be tough. Water, if it can be found, will be in the form of brine ice mixed with perchlorate. It's going to take a lot of energy and equipment to get usable water out of that. Reverse osmosis and ion-exchange resins will work, but they have consumables which must be brought from Earth.
The atmosphere of Mars, such as it is, is mostly CO2. It takes a lot of effort to get oxygen out of that. Sunlight intensity on Mars is about a quarter of what it is on Earth, so solar panels and plants will have about a quarter of the effectiveness.
There are no easily exploitable resources on Mars. It's going to be more like an Arctic base - you have to bring almost everything.
He has also, you know, achieved stuff. Actual rockets, actually going up. There's a tendency of people to devalue the successes of others by attributing it to marketing. But for the life of me I can't find a way that would work to sell rockets to governments. Musk has also started at least three somewhat successful businesses, and at this point I don't think either marketing or luck are sufficient explanations.
It reminds me of someone else. I hope Musk gets his pancreas checked often enough.
Curious, is reddit penalized by the hackernews algorithm (I don't see reddit links here often); this post is quite a bit lower on the main-page than older posts with fewer votes?
Are Elon's mining/tunneling droids discussed anywhere? He's said in the past the Earth cities need to "go 3D", putting cars in tunnels underground. Something needs to be done to cut the cost of tunneling, so I'm interested to learn more.
> Initially, glass panes with carbon fiber frames to build geodesic domes on the surface, plus a lot of miner/tunneling droids. With the latter, you can build out a huge amount of pressurized space for industrial operations and leave the glass domes for green living space
For me, mining robots were the biggest handwave of the session. They'd need to operate on Mars, at least semi-autonomously, and the current state of the art needs a fair bit of nursemaiding (and a local machine shop) to keep running.
Still, nothing spurs development like the prospect of a juicy colony contract!
Right now, it still feels like the "brainstorming" phase of the project. I guess it's OK to criticize various ideas, but it would be more interesting if alternatives were offered, then have a discussion of pros and cons. That is, assuming the goal is to make it happen, vs. prove it's infeasible.
Since it's such a blue-sky project, I'm hoping more to enjoy the design process -- the discussion of science and ideas. I wonder if that process will bring engineers together... or drive them apart?
They have showed actual prototypes of multiple different aspects. Usually you start rocket design with a engine, and build the rocket on top. The engine in testing already and they seem to have nailed down the basic specs and all the important parts.
That's more then brainstorming, thats actually prototype testing of specific sub-components.
I missed the AMA but I'll ask this here since people seem to be in the know. In the beginning, Spacex and the original merlin seemed to be all low tech, get it done (ie the merlin was ablative cooled chamber and nozzle). Now the ITS engine is super advanced.
I always wondered, why the turn around, and has Musk ever written or said anything about Truax's Sea Dragon[1] concept?
