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> There are still major risks with the Starship program

To expand on this: I think it's reasonable to assume that the stack will reach orbit just fine and be a functional rocket.

The big risks are related to recovery. Starship will require in-orbit refueling to go to the moon, so (rapid) reusability is somewhat of a hard requirement.

Superheavy (the first stage) is huge and will land directly on the launch tower instead of using landing legs - to reduce turnaround times. This is innovative and completely unproven. And a RUD would at the very least put the launch tower out of commission for a while.

Starship (the second stage) will also have to survive the high velocity reentry in a good condition and nail the crazy landing maneuver. SpaceX heat shield tiles and the general aerodynamic and thermal properties of the rocket are an unknown for now.

Musk recently said that Starship will probably require "many test flight" to achieve successful reentry and landing.

On top there have been quite a few reliability issues with their new Raptor engine, which need to be ironed out.

I'm sure SpaceX will figure it out, but there are a lot of risks lurking in the development program.

All this makes the choice to go for SpaceX more impressive for the usually so cautious NASA.

But the payoff would be enormous. If the re-usability works out, Starship can completely change the game for the launch market and lift capability.

I'm getting very nervous about manned propulsive landings. I know it's been done before, e.g. the LEM, but that at least had an abort option available and the flip manoeuvre seems to introduce a lot of unpredictability into the process. I wouldn't be surprised if they take up a Crew Dragon with them in a cargo bay to bring the crew back down separately for the first manned flights, until they've demonstrated a strong track record of successful propulsive landings.

As for Lunar Starship, it's massively overengineered for the Artemis requirements, capable of taking 100 tons to the Lunar surface. That's great for later missions to set up a base, but even then you'd likely need a crew version just for shuttling people back and forth. So I wouldn't be surprised to see the first version of that to be somewhat scaled down from the concept art. That should massively reduce the number of refuelling missions needed for the early Artemis flights.

I agree, Crew Dragon (and maybe Orion and Boeing Starliner) are going to be the people-carriers of choice for Earth launch and re-entry for at least the next decade.

I don't really have concerns about launching people on Starship, it's the landing process that gives me the willies.

I think people are really vastly underestimating how fast things are moving. I think you're completely wrong and Crew Dragon will be relegated to only fulling a remaining portion of a NASA contract after less than 5 years. Everyone else (private astronauts) will fly on Starship.

Yeah, I really can't help but wonder if SpaceX is going to go after the long distance travel market. Starship can do suborbital hops without Superheavy.

Only comparatively short ones, with limited payload. Getting to a ballistic trajectory from one side of the planet to the other takes almost as much dV as going to orbit.

A decade is a very long time. A decade ago, SpaceX only had 4 successful launches.

> I'm getting very nervous about manned propulsive landings.

Humans will land on earth in Orion capsule not Starship. So there will only be a tanker that has to do the flip.

On the moon, there is no flip.

The Appollo didn't have a abort option is parts of the flight, unless I am misinformed.

> So I wouldn't be surprised to see the first version of that to be somewhat scaled down from the concept art.

The problem is then about how you do the integration. All the tooling and processes are designed for one size of Starship, to change the whole design just to make it smaller is unlikely to be an efficient thing to do.

Instead they could just fly part of it empty and take far less then the full 100t to the moon, rather then design a smaller version.

If a LEM landing became untenable they could abort to Lunar orbit by launching the crew capsule. You know how after landing on the moon the way they got back to Lunar orbit was by launching the crew capsule, using the lower stage of the LEM as a launch platform? They could actually do that in flight. You're right of course though, I forgot that for Artemis they wont be landing people on Earth in Starship.

All they need to do to make a lighter Lunar starship is make it shorter. Just miss out some fuel tank and payload section segments. No need to make significant changes to the functional parts, it would just be stubbier.

I didn't know they could actually do the accent in flight. Do you have a source about that? Apollo is seriously insane, they thought of everything and pulled it off.

Check out the Apollo 10 mission; they in fact did that as a rehearsal for the landing.

>100 tons to the Lunar surface

the next morning after the first such delivery would feel like a new era because with Starships it will be just like a regular shipping line, less than $1B per 100ton cargo to the Moon taking just several days. The Moon will become more reachable than Philippines were at the time of Manilla Galleons (which would be more like the Mars flights).

Many of these risks don't apply to the lunar variant. The lunar variant won't be launching people from earth and won't be returning to earth. No re-entry, no landing flip, etc.

As far as descent, it will do final touchdown with smaller engines higher up to avoid kicking up rocks. During landing, I think pretty much any one of the 6 raptor engines can be used to abort.

They somewhat apply because the lunar variant still needs to be fueled up in LEO with ~ 6 additional launches , all in relatively quick succession.

This seems unfeasible without rapid reuse actually working.

True enough, they can't be throwing away tankers for each refuel.

At the price NASA is willing to pay, they can. The tankers are only a few million dollars in raw materials.

In my opinion the way to think about SuperHeavy+Starship is a scaled up stainless steel Falcon 9. Currently Falcon 9's first stage booster (usually) lands and is quickly/cheaply refurbished/reused, while the second stage is completely thrown away except for partially successful attempts at fairing recovery. They've used this partially reusable system to do a large number of launches quite cost effectively.

In SH+SS, the "Starship" part is the second stage, with the revolutionary goal that it can deliver a payload to orbit and then skydive back to earth and propulsively land itself. That has major risks and is unlikely to succeed the first number of attempts, with the loss of the stage and the 6 raptor engines.

The "Superheavy" portion is very much equivalent to a scaled-up F9 booster, and the risks to landing it should be much lower (Elon's crazy catch ideas notwithstanding).

tl;dr I think Starship system can mostly work if it's partially reusable to a similar extent as F9. Losing a half-dozen second stages to do a full orbital refueling for a Moon or Mars mission should still be a fraction of the cost of a single SLS launch, and they can continue working on full reusability while performing missions and cashing checks.

Fairing recovery has been abandoned.

Fairing recovery is not abandoned, they decided to fish them out of the water after a soft landing instead of catching them with a net.

Ah yes, right you are, it is the catching that they have abandoned. Thank you for the correction.

Why do you think they would need to do those launches in quick succession? If the lunar lander starship is parked in orbit without a crew it can be refuelled over any convenient period of time. Once it's fuelled just send up the crew in a dragon capsule and off you go. The dragon would probably make a good lifeboat if you brought it along for the ride somehow.

They may have solved the LOX boiloff problem, but perhaps not.

Even if they need to refuel quickly, why not launch 6 starships for that mission? They’re planning to build lots of them aren’t they?

As long as the crewed starship is fuelled in orbit not too long after the last tanker ship launched, then the amount of boiloff will be negligible.

I suspect Spacex will develop cooling systems to re-liquefy any gaseous propellants as this will be more of a concern for the ~6 month mission to Mars.

Wikipedia[1] cites a 2010 study that gives a boiloff rate of 0.1% per day for hydrolox. Not sure if it would be less for pure LOX. Methane would remain stable so I wonder if there's a way you could balance the fuel load so that you can deliver only methane on some of the trips and then all the LOX in one trip to avoid having it hang around in orbit.

[1] https://en.wikipedia.org/wiki/Propellant_depot#Feasibility_o...

Oxygen is the vast majority of the propellant mass, I'm afraid. Methalox is CH4+2O2->CO2+2H2O, so you need 4 Oxygen atoms for every Carbon atom (with Hydrogen being a rounding error).

Dragon is 4.4 meters (14.4 feet) tall and 3.66 meters (12 feet) in diameter. Starship fairing payload envelope is 22m tall and 8m in diameter. More than 3 dragons would comfortably fit inside.

I think the idea is that the fueled-up Starship in LEO would have already have most the payload inside since it launched. The only thing it would be lacking is the astronauts, so they can come in a much smaller vehicle.

That said, this contract has astronauts boarding Starship in lunar orbit, not Earth orbit.

This contract is to take astronauts from lunar orbit to the lunar surface. They get from Earth to lunar orbit with SLS/Orion.

Good one, you almost had me until 'SLS'.

As stupid as it is, that is the contract.

That just confirms that they can launch and fuel the starship lander on their own schedule.

Also it does not need to be the same tanker to do the resupply. The plan is to make 2 starships per week. There should be plenty available to continue refuelling missions if one is not available.

Re-entry is required for the ship that will refuel the lunar lander. So yes the re-entry portion is required for the system to work.

> Starship will require in-orbit refueling to go to the moon, so (rapid) reusability is somewhat of a hard requirement.

Is it though? The lunar starship itself doesn't depend on reusability. If SpaceX cannot get reusability down, they'll have to expend a few boosters and tankers to get it working. That'll cost them their profit, but it would fulfil the contract.

If they have to expend them, I doubt SpaceX would have any profit at all and they'd reneg on the contract.

Second stage tanker build costs are estimated at around $30M. Expending a dozen would thus cost $360M, about 15% of the contract. I highly doubt that SpaceX set their profit margin lower than 15%.

Thry need to spend the R&D money anyway to get it working, why not let NASA subsidise it

> Superheavy (the first stage) is huge and will land directly on the launch tower instead of using landing legs - to reduce turnaround times. This is innovative and completely unproven. And a RUD would at the very least put the launch tower out of commission for a while.

I strongly suspect that they will be building many identical launch towers, it's pretty much their modus operandi and it makes sense. They've already had two Starships queued up at the launch pad for testing. Once they further improve the factory they'll probably need to build out more pads so they can keep the launch cadence up and free up space in the high bay. They're going to need to perfect that process if they are serious about eventually doing thousands of flights per year and sending hundreds of ships to Mars per conjunction. That's going to need a lot of Starships, a lot of launch pads, and probably several factories.

Well, they’ve got their two oil rigs, Phobos and Deimos, which I believe are to be the launch/catch facilities, so that’s two for starters. I don’t know if they’ll be doing it on land at all, or if the intent is to launch from one and catch with the other, allowing more downrange capability. We’ll see - it’s a blast (boom boom (boom boom!)) watching their development process.

SpaceX is asking the EPA for permission to build a second orbital pad and tower in Boca Chica, and I'd assume that we might hear something soon about the mothballed 39A Starship launch mount

If it was simply a matter of money, SpaceX could raise $15B in an IPO in a heartbeat given the incredible retail demand.

I'm glad that Elon is remaining "conservative" in his financing of SpaceX to avoid the quartly Wall Street song & dance.

Last I heard, SpaceX will IPO once there are regular trips to Mars with Starship. Looking forward to it to say the least.

Edit: Not sure why all the downvotes, so here is a citation. If someone has newer information about it, please post.

> SpaceX President and COO Gwynne Shotwell told CNBC in May that the company “can’t go public until we’re flying regularly to Mars.”

https://www.cnbc.com/2018/08/10/why-spacex-investors-arent-c...

I'm not down voting but I think there's a pretty big delta between "can't go IPO before X" and "will IPO once X"

In my head those mean the exact same thing, so I'm not sure why you say there's such a big delta. The only difference is the connotation.

To me they are pretty different.

"A will happen once X" to me means X is a necessary and sufficient condition for A happening.

"B can't happen before X" implies that X is a necessary condition, but it does not imply sufficiency to me.

If someone says: "I will give you a million dollars once you do a dance", I understand that as a commitment to provide me with a million dollars after I do a dance.

If someone says: "I can't give you a million dollars before you do a dance", I understand that dancing is a requirement for getting the million dollars, but I understand there may be other requirements as well (or they may not be willing to provide the money at all).

You are probably being downvoted because you seem to be saying you are looking forward to SpaceX's IPO, while trips to Mars are just the mechanism.

Sort of like the virgin galactic subreddit where everyone only talks about the stock. Spaceflight? Boring. A stock IPO? Can't wait! It's pretty depressing.

Oh? I didnt mean to do that.

I'm all about the Mars trips themselves and not the stock, for what it's worth. I look forward to both because both are signs of a strong future for the civilizations on Mars.

I believe Musk has mentioned that Starlink will IPO in order to fund SpaceX.

Next week he will probably announce that he’s already funded it via Dogecoin speculation.

Elon could also keep it private and fund it himself "in a heartbeat" by selling a small portion of his Tesla stock.

Will SpaceX be as generous with its IP as NASA was in the 1960s and 1970s? The original moon landing yielded huge technological advances, many of which made their way into commercial applications. Tesla may instead hoard these advances to increase the networth of Elon Musk.

This is what I worry about with privatization of space technology in general; a free market with competition can in some ways be more efficient than a government agency, but then again if all the parties are incentivized to hoard their technology then you could end up with a lot of duplicate work and wonky suboptimal designs to work around patents.

I wonder if NASA has any technology sharing provisions in their contracts? Or at least agreements to make components available for sale to NASA or competitors, and to share as much data as necessary to allow parts from multiple vendors to interoperate.

There are very general Space Act agreements that try to make dissemination of information as wide as possible, but there is plenty of wiggle room for proprietary information.

https://www.nasa.gov/centers/johnson/pdf/189228main_setc_nnj...

You can possible expect them to do the same as with Tesla

https://www.tesla.com/blog/all-our-patent-are-belong-you

Well SpaceX doesn't patent stuff because patents have to be public and rocket technology can't be public.

some patents are actually classified: https://en.m.wikipedia.org/wiki/Invention_Secrecy_Act

why patent such things at all if they're classified? probably to keep other defense contractors from using your technology to compete on bids.

Yes, in fact, because it was part of the contract stipulation by NASA. And apparently Blue Origin/National Team's proposal scored poorly in part because they wanted to keep some of the data rights from NASA.

And this is just a sort of contractor arrangement. NASA didn't build the Apollo lunar module with civil servants, either, they hired contractors.

Also, this isn't a Tesla project.

The JFK quote still gives me (good) chills!

> The original Artemis plan never made much sense as a Mars "proof-of-concept", but it actually does now.

IIRC, in the Iliad Artemis helps out Ares (which is kinda the Greek version of Mars). Probably just a coincidence (I'm sure Artemis was chosen because she's Apollo's sister), but fun nonetheless.

Huh. I always just assumed they were copying the Andy Weir book of the same name. Guess I am going to have to add Greek mythology to the todo.

You thought NASA named a program after a random sci-fi book and not for a Greek god like the Apollo program?

To be fair, a lot of science is named after and even inspired from sci-fi works. The Alcubierre drive comes to mind, which was inspired by Star Trek.

But yeah, Andy Weir is far from a classic in that regard.

Artemis the goddess was associated with the moon.

Given the risks and delays with SLS, I’d say it’s pretty likely that SpaceX can outlift/out launch NASA to the moon and probably still will.

Going to be interesting

And it's winter for Gateway and SLS

A Lunar Gateway still sort-of-makes-sense, as an outpost near the moon, using ISS-derived hardware, makes it hard for Congress to argue cancelling something that is (a) new and (b) we know will work.

That being said, a few small LEO orbital depots makes more sense than Gateway. Or perhaps small LEO and Lunar gateways might make the safety-officer at NASA happier.

I don't think these stations really do make sense from an exploration perspective. If you are not saving much delta v then what is the point?

However, I think having permanent orbital stations is just as philosophically justified as going to the moon or mars etc. Living in space is amazing and we will learn a lot from it. So why not?

why is going to mars even remotely high on the list of humanities priorities? it seems like people think its cool and then try to have their cake and eat it to by claiming its somehow important. im pretty sure for at least a very long time its just cool.

Meteor impacts, caldera collapses, nuclear war. Every single one of these things could happen tomorrow, and we'd never see it coming. If we want any chance if humanity to survive, we need to get people onto other planets.

Earth after a meteor impact and a nuclear war happening at the same time would still be 100x more livable than anything we can do on Mars. Saving humanity by going to Mars is like saving yourself from the titanic by jumping into the ice-cold water.

We can barely make places like Antartica survivable! Huge chunks of "totally fine" places like Hawaii only exist thanks to massive shipping industries. If you have a way to build out a livable space on Mars, please give us Earthlings some of that technology cuz it would be pretty useful to a lot of people!

Anything - including flight to and colonization off Mars - that moves humans closer to building mega scale space habitats is an important step forward. Thats where the road to immortality ultimately leads for humans as a species.

And possibly for individuals as well, given the potentially almost limitless resources available in Space.

One thing I've seen becoming a spacefaring civilization explained as is a "coming out of the cave" of sorts, which doesn't line up perfectly but it's not far off. The species' possibility space will be severely restricted so long as offplanet infrastructure is limited.

We can’t even not fck up our very own and livable planet, it’s just naive to think of colonization. We will kill ourselves much much earlier than that.

Nah, your imagination of the horrors that nature can (and did) unleash upon the Earth is pretty limited. A Theia impact would make Earth far less livable than Mars. Would sterilize the planet.

And you hit on a good point in your last sentence: Developing a self-sustaining civilization on Mars would PROVE we can easily be sustainable on Earth.

I'm happy to see people go to Mars for other reasons, but this one's (commonly-cited) BS. The odds of something happening that rendered Earth worse to live on than Mars but didn't also toast mars is incredibly small. Mars is really bad. Most plausible post-apocalypse Earths are way, way better. Yet I don't see anyone clambering to build apocalypse-survival shelters and pay people to live in them part-time, which is something we could do right now that's more effective than a Martian colony, and much cheaper.

I think the trouble is that people don't get just how bad Mars is. Take the peak of Everest, cross it with Antarctica, and dose it with radiation. Sounds bad? You're still nowhere near as bad as Mars. It's really, really bad.

> The odds of something happening that rendered Earth worse to live on than Mars but didn't also toast mars is incredibly small

Over a long enough time frame, the chance is nearly 100%.

A planetary extinction-level event has already happened where every land animal larger than 25kg died. Maybe it won't happen for another 65 million years. Maybe it will happen tomorrow. Maybe there will be a massive gamma ray burst that will sterilize the entire solar system. Who knows?

But just because we will eventually die out doesn't mean that we can't try to do what we can to survive. And anyway, say what you will about Elon's whole "thing", but a life where we're exploring the solar system is more exciting than one where we aren't.

> A planetary extinction-level event has already happened where every land animal larger than 25kg died. Maybe it won't happen for another 65 million years. Maybe it will happen tomorrow. Maybe there will be a massive gamma ray burst that will sterilize the entire solar system. Who knows?

Right, but... Mars is already worse for human life than Earth after every major extinction event. That's like "in case my house catches fire, I'm gonna build a backup house inside a working industrial furnace". If what we're worried about is surviving an event like the several that have affected Earth in the history of life on the planet, Mars is both more expensive and worse than a bunch of other options, including other space-based options (though I think that whole class of solutions is really wasteful compared to boring, Earthbound alternatives). That's a bad reason for going to Mars, is all I'm saying. I'll still be cheering along when the first boot-print is made, mind you.

OK, here: strip Earth of all oxygen and its ozone layer and turn all the land into parched deserts that can barely support even the hardiest of plants. You want to wake up in a sealed shelter on Earth, or on Mars, after that happens? The smart answer is "on Earth" because the list of horrible things about your situation on Mars is still 5x that long, plus all those things are already problems there. Mars is very, very, very bad.

Honestly, I think it’s not important, but the capabilities doing it will build are better than the ones we would get by spending the money elsewhere.

I think this because you can trick most programs into handing over money without giving results, but there isn’t a way to trick physics.

There is plenty of precedent for awarding contracts that get nixed due to changes in political winds before producing results though.

There could be substantial benefits in the long term, if we can get a self-sufficient colony going. In the short term, it's mostly working out the technology and being able to learn more about planetary science by studying something up close that isn't the Earth.

In the long term, Mars is a great refueling station because it has carbon dioxide and water that can be used to make methane, and it has much weaker gravity than Earth. That would make it much easier to access the asteroid belt, which may have a lot of valuable minerals.

There may also be some not-so-obvious benefits to living on Mars. For instance, people with mobility issues may be stuck in a wheelchair on Earth but be able to walk on Mars. (The optics of shipping all our old people to Mars isn't great, but it might actually be a pretty awesome spot for an old folks home.)

Another reason people have for going to Mars is the same as people who migrated from Europe to the Americas: to get away from a political situation they don't like and start a new life. If the optics of sending old people to Mars is bad, the optics of sending, say, Syrian refugees to Mars is even worse, but if someone wants a fresh start that's one way to do it. At least until Mars becomes as dysfunctionally political and tribal as Earth.

In the very short term, sending people to Mars may have a big impact on children being interested in science. I don't know if it's still the case that if you ask an elementary-aged child what they want to be when they grow up, it'll probably either be "an astronaut" or "president of the United States", but I think it was when I was that age.

as someone who occasionally needs a wheelchair, I'd miss my friends if I got shipped off to Mars! I'm also pretty sure that the gees wouldn't be good for my condition. there's also the small matter of radiation exposure, since Mars doesn't have much of an ionosphere.

I'm waiting on powered exoskeletons as my sci-fi mobility aid of choice.

Yeah, shipping off to Mars would be a hard sell for most people in that situation. I find it easier to imagine older couples or groups of friends who are all facing similar mobility issues going together rather than a solitary person going by themselves and leaving everyone they know behind. It would also be a long, rough trip. Which implies that maybe having a senior center on the moon or even in a rotating space station orbiting the Earth is a more attractive option.

I would prefer fixing our own planet before.

We absolutely should be doing a lot more about climate change, but this is something we can do in parallel. (There is some climate cost to rocket launches, but compared to our total economy it's very small.)

Based on the history of humanity, is there evidence we can fix our planet?

Following this logic, let's assume we can't. Then what are the chances we can plant a self-sufficient colony on a barren lifeless planet, all from a dying civilization on our still infinitely more hospitable homeworld?

Depends on whether the explorers self select for survival traits.

You mean like self selecting billionaires?

How can one be so deeply pessimistic about survival on a planet whose atmosphere we can safely breath and whose climate will likely be more amenable to us than Mars' even in a worst-case global heating scenario, and yet remain optimistic about an independently viable Mars colony?

We will fix on our own planet faster and better by also learning how to go beyond it. The lessons we learn and the technology we develop by doing so will help those on Earth. For this reason, it makes sense to allocate a small percentage of our resources each year towards these efforts.

It would create a ton of jobs. We would learn a lot. The world is awash in cash. This doesn't seem like a terrible use of it.

If I could pick, I'd pick planetary health, and improving human health and lifespan as my two top priorities. It's probably still good to not be too myopic and have researchers and companies working on ancillary topics they're interested in. Not only because you can't make people focus on things they aren't interested in, but because you probably can't make more progress faster just by having every single resource allocated in the same place, and you could get benefits that weren't anticipated.

Like football. It is used for state propaganda, to make populations dream and look forward to the same direction.

Sports are a branch of the entertainment industry. You don’t get paid to run fast, you get paid to gather crowds. Same for Mars, and it only impacts ideas and hope, not actual well-being. But it’s still required, otherwise people err in Brownian directions.

I hope very much that the new Mars funding will be taken off the football spendings.

It's not anywhere near remotely high on humanity priorities.

It's somewhere around lipstick market worth of ~10B dollar per year.

My biggest worry is whether SpaceX can keep up its momentum without Musk driving it. It's not unreasonable to think he could behave badly enough to end up in jail or removed from a leadership position.

SpaceX is not a public company and he has a majority stake and controls 78% of the voting rights. He can even still manage it from jail, if he wants.

Almost every prison facility prohibits inmates from managing a business from inside. Even if he was allowed to, he couldn't be the kind of energizing and driving force he is now.

Worked for the mafia.

“If at some point say 2025, NASA says to the President "we can get the first human on Mars in 4 years for $15 billion" I have to imagine any American president being eager to sign their name on that accomplishment“

Howard Stern had a great line in the 90’s about marijuana - “Every time you speak to these guys who dedicate their lives to legalizing marijuana, they go, “Hey dude, you can make rope out of marijuana.” I go, “Dude, don’t we have enough rope in this country?”

——

Every time I hear talk of spending billions on Mars, I ask “Dude, don’t we have enough red dirt in this country?”