
Starship Prototype Unveiled - childintime
https://www.space.com/elon-musk-unveils-spacex-starship-2019-update.html
======
hoorayimhelping
380s for ISP for the Raptor vacuum engine seems durn good, considering the
tradeoffs between hydrogen and methane.

The most efficient engines we've flown, the RL-10 [0] (used on the Delta IV
and Atlas rockets as part of the Centaur Upper Stage) and the RS-25 [1], (the
Space Shuttle Main Engine) get around 450-460s for their specific impulse.
These engines use liquid hydrogen and liquid oxygen. The issue with liquid
hydrogen is twofold: it is not very dense, and to keep it from boiling away in
liquid form, it needs to be _really_ cold. So you need huge, insulated tanks
to store it. Hydrogen is everywhere, but it's kind of a pain to use as rocket
fuel.

Merlin Vacuum [2], which is currently used on the Falcon vehicles gets 311s.
The RD-0110 [3], used on the Soyuz gets 326s. These use RP-1, which is highly
refined kerosene. It's super easy to work with. On earth. Where we have 200
years of infrastructure in place to support using hydrocarbons. It takes that
infrastructure to refine it into a form that rocket engines can use without
gunking up the works with unburnt carbon and other particulate crap.

Raptor uses methane, which is kind of like a jack of all trades between
density, efficiency, ease of processing, storage, and ease of use in engines.
This is basically how SpaceX seems to operate: rather than optimizing a single
part of the system (like trying to get the most efficient engine), they try to
optimize from a systems level. I don't really know much more than that,
because there hasn't really been a lot of stuff for civilians to read on
methane engines. This is kind of the cutting edge of the second golden age of
space exploration. This freaking rules, what a time to be alive.

[0] [https://en.wikipedia.org/wiki/RL10](https://en.wikipedia.org/wiki/RL10)

[1] [https://en.wikipedia.org/wiki/RS-25](https://en.wikipedia.org/wiki/RS-25)

[2]
[https://en.wikipedia.org/wiki/Merlin_(rocket_engine_family)](https://en.wikipedia.org/wiki/Merlin_\(rocket_engine_family\))

[3]
[https://en.wikipedia.org/wiki/RD-0110](https://en.wikipedia.org/wiki/RD-0110)

~~~
codeulike
Here's a Wired article about the raptor engine - it's "a full-flow staged
combustion engine, only the third engine in history to employ this technique
... The previous two attempts at such an engine, one in the Soviet Union in
the 1960s and another in the US in the early 2000s, never made it beyond
testing."

[https://www.wired.co.uk/article/spacex-raptor-engine-
starshi...](https://www.wired.co.uk/article/spacex-raptor-engine-starship)

~~~
Klathmon
And if you want to get a lot more detail on what makes a "full flow staged
combustion engine" so special, this article from Everyday Astronaut goes into
some amazing detail on this and many other engines.

[https://everydayastronaut.com/raptor-
engine/](https://everydayastronaut.com/raptor-engine/)

~~~
aaronblohowiak
This was AMaZING. Exactly the kind of content I want to consume on HN

~~~
oska
This guy is amazing. Look out for his interview with Elon Musk that should be
released in the next 24 hours on his YT channel [1].

[1]
[https://www.youtube.com/channel/UC6uKrU_WqJ1R2HMTY3LIx5Q/vid...](https://www.youtube.com/channel/UC6uKrU_WqJ1R2HMTY3LIx5Q/videos)

------
drchewbacca
I am so amazed by the genius of making it out of steel. It's just so
completely counter intuitive but has accelerated their progress so much.

If they told you the stats of the material, better strength at cryo
tempertures meaning mass reduction, higher melting point meaning minimal heat
shielding and great thermal conductivity it would be easy to imagine it was
some new super composite. Then your head explodes when they tell you it's 2%
the cost of what they were using before and it's so easy to work with they
don't even need a factory they can just weld it in a field.

Imo Elon is starting to get into contention for greatest engineer of all time.

~~~
elif
I know there are 1000 of them 100x smarter than me at all of this, but I have
my doubts that the specs for "cold rolled" stainless will hold up after tens
of re-entries, as it is effectively being tempered over and over.

~~~
strainer
From the sounds of it steel structure can basically handle much greater
temperatures routinely and also even more in rare situations that might mean
retiring the ship afterward but not losing everything. In his presentation
Elon says that aluminum alloy or carbon fiber structure is basically done for
at 300 to 400 Celsius, well that's the temperature at which stainless steel
can just begin to get conditioned by heat, it doesn't structurally 'melt'
until over 1000 Celsius.

Although its a curious topic, I would have no doubt that whatever temperature
cycling they design parts of the structure to go through in their "rapidly
reusable" regime, the effects of "heat fatigue" or whatever to call it will
have been rigorously assessed .

~~~
fluffything
What do you mean by Handle?

Steel won't melt at 300-400 Celsius but "handling" those temperatures for 10
minutes will change the properties of the material, possibly by a lot, so you
don't need "melting" for structural collapse (Twin Towers style).

As the GP says, if you put cold rolled steel, which has an elastic yield
strength of >1500 MPa, at 300-400 Celsius, then it is only a matter of time
(30-120 min) till the elastic yield strength sinks to 500 MPa or less.

So either this is a single use device, or the steel isn't reaching
temperatures over 250 Celsius, or the steel isn't cold rolled but is a low
strength steel instead (although that would have other problems).

~~~
ricardobeat
Re-entry will take something on the order of 10m or less. Even the space
shuttle only took 30 minutes while flying like a plane. There will be no
circumstances where the ship is going to be subjected to that amount of heat
for 30-120 minutes.

> or the steel isn't reaching temperatures over 250 Celsius

That might be the case. The space shuttle had an aluminum structure that would
fail at 175C, and now we have 40 years of technology advancements for the heat
shield.

~~~
strainer
Also I notice Cr-Steel's elastic yield strength at 400C is about 87% of its
strength at room temp and I don't think it does alter significantly over these
timescales at that temperature. It will be interesting to see how high it can
be routinely cycled without losing its temper, but it seems to certainly
provide much more overhead for safety margins as well as routine operation.

[1] [https://www.engineeringtoolbox.com/young-modulus-
d_773.html](https://www.engineeringtoolbox.com/young-modulus-d_773.html)

------
codeulike
I totally understand why they've gone for that design but the welded together
steel plates really make me think of the sort of thing Wallace and Gromit
would build.

~~~
faead_
he addressed in presentation, from what i remember it had a lot to do with
cost. Like $130k/ton with carbon vs $3k/ton with steel. He mentioned a few
other factors. Also it allowed them to build outside, not sure if t that is
true in production.

~~~
allannienhuis
the material isn't the question, it's why they had to weld it together in a
patchwork quilt. Elon talked about the next version would simply have rolled
coils with a single seam weld (although the cylinders would have to be welded
together too), which would be better structurally and cosmetically, and likely
lower cost of production. Sounds like they just didn't have the rolling
machines to do the job, or perhaps there was an availability issue with the
specific alloy.

~~~
_Microft
It will reduce the length of the welds (for the hull) quite a bit.

The number of rings is roughly 35 for Starship, with about ten vertical seams
each.

For easier thinking, line the vertical seams up and you see that this gives
50m length per vertical seam from bottom to top of Starship. So there are a
total of 500m for that.

35 rings with ~28m circumference add up to about 1km of seams between them.

Now if they can use rolls twice as wide and only a single vertical weld each,
then that's 500m between the rings and 50m for a single vertical seam. 550m of
welds there instead of 1.5m before. This should speed things up quite a lot
and reduce the cost of labour.

Raptor production is the real bottleneck, though.

~~~
jcims
>Raptor production is the real bottleneck, though.

They are shooting for one per day, no? Based on the differences identified in
the three hanging under the Boca Chica vehicle now, it’s still in development.

~~~
JshWright
They just shipped he 12th one. Definitely still in the development/ramp up
process.

------
nickpp
What I loved the most was the optimistic outlook, the forward looking focus
and the implicit belief that any problem will be solved and we'll advance.

This is exceedingly rare in a pessimistic world drowning in the voice of
Luddites and backwards-looking preservationists.

Like always, technology solving real world problems versus politicians
(professional or amateurs) creating (and never really solving) self-serving
perpetual issues.

~~~
walkingolof
I suspect that having a sense of urgency and limited resources contributed to
this phenomenal pace of development, it's in stark contrast to the glacial
pace of the SLS project (Boeing/Nasa) which is much better funded.

~~~
abcd_f
As someone else aptly remarked - NASA is no longer a space exploration agency.
It's now an employment agency. Hence the glacial pace.

~~~
dragonwriter
NASA was never a space exploration agency; in its heyday, it was a combination
thinly veiled demonstration of military capacity and thinly veiled military
projects agency, but most of both of those functions were superfluous by the
last decade or so of the Cold War.

------
philwelch
I suspect that Starship will fly to space before SLS ever will. I also think
Starship has a significantly higher chance of flying _at all_ than SLS.

~~~
DanCarvajal
Starship could have Falcon Heavy level of delays (which I think it will) and
still beat SLS.

~~~
cryptoz
FH was 5 years+ behind schedule before it was built and launched. Starship
already has multiple constructions going on, with multiple prototypes to test
and multiple full-size vehicles planned quickly.

In 2011, FH was supposed to have "arrival at launch site" by 2H 2012. It first
launched in 2018 (after arriving at launch site in 2018 not 2012). The same
level of delay would mean the first Starship does not reach orbit until ~2025.
That seems crazy pessimistic and would be a dramatic departure from the
otherwise normal delays faced by SpaceX.

I think it's extremely unlikely that Starship would face FH-level delays. That
would cancel the Starlink constellation, cede the space-internet game to
others, hand the torch to BO or others working on large projects, and
absolutely destroy morale at SpaceX.

I just don't see it happening.

~~~
justapassenger
FH is "just" 3 F9 strapped together. Doing that took them more than 5 years
than planned.

Keeping that in mind, having 5 year delay on brand new design, using totally
different materials, new engine, etc isn't far fetched.

~~~
cryptoz
There is a quote somewhere (by Elon?) saying that FH is _not_ "just" 3 F9s
strapped together. A significant source of the slowdown for FH was the desire
to not launch it without full reusability of all 3 stages and not to launch it
without significant improvements (block 5 etc).

Starship has none of those potential delays and has already solved most of the
hard problems (as evidenced by the Hopper hopping already). Starship has all
of the learnings and experience that FH and F9 didn't have.

There will be delays, sure. But we won't be waiting 5+ years again for a
single launch. Those days are over, and SpaceX is proving it.

Some context, I haven't read this yet: [https://www.quora.com/What-makes-
SpaceXs-Falcon-Heavy-more-t...](https://www.quora.com/What-makes-SpaceXs-
Falcon-Heavy-more-than-just-three-Falcon-9-rockets-strapped-together)

Edit:

> Keeping that in mind, having 5 year delay on brand new design, using totally
> different materials, new engine, etc isn't far fetched.

The first full size Starship prototype is _already built_ though (within ~2
years of initial announcement? Not behind schedule basically at all, so far?).
IIRC for FH it was a ~5 year delay before SpaceX even starting construction on
the first parts. The difference with Starship is staggering. The pace is
_dramatically_ faster, the risks are reduced up-front, and the tests are
planned on a much shorter timeframe.

We would frequently go 6 months to a year and hear no news at all about FH.
There is news, updates and progress available to the public on an hourly or
daily basis about the Starship progress. Night and day.

~~~
justapassenger
Hopper shows that engine works outside of test lab. That's great, but it's far
far away from showing that they solved most of the hard problems.

Experience from FH and F9 is useful, but it's a totally different type of
spacecraft, with different use-cases, different materials, engines, cooling,
etc. There's TONS of new stuff that they have to research, experiment, fail,
try again, etc, until it's doing even 50% of what Elon promised.

~~~
cryptoz
Perhaps I'm misunderstanding something. I thought Hopper was not about Raptor
tests but about VTOL as well. The FH had to wait while F9 got down the
vertical landing science and engineering (though a lot of tests, explosions,
delays).

StarHopper seems like it can use those learnings, and that was tested
recently. The engine was already functioning on a test stand and mated to
Hopper for static fires; the Hopper _hop_ itself is testing the engine, sure,
but also the complex math of doing a vertical landing with a gimballing
engine, etc.

The general space industry considered reusabable spacecraft that land
vertically to be pretty much impossible until F9 and FH did it. But Hopper
just does that casually, you don't bat an eye, you don't even comment that
Hopper was testing a new rocket dynamics/physics for the math that (almost)
only SpaceX has figured out.

I just don't see the pessimism here. I've been watching SpaceX for 12+ years
and I don't see _any_ of the same issues plaguing them today as did in the
past.

New issues, but not the same ones. The new issues have dramatically smaller
turnaround time to resolve.

The days of 5-year SpaceX delays are over.

~~~
justapassenger
> The general space industry considered reusabable spacecraft that land
> vertically to be pretty much impossible until F9 and FH did it. But Hopper
> just does that casually, you don't bat an eye, you don't even comment that
> Hopper was testing a new rocket dynamics/physics for the math that (almost)
> only SpaceX has figured out.

VTVL isn't new. To do it you need ability to throttle engine and do trust
vectoring - once you have that, it's "fairly" simple math and physics.

SpaceX is first company that commercialized it, and huge props for that. No
one cracked economy of it before (and it's not 100% sure that spacex did - no
one saw their financials).

> New issues, but not the same ones. The new issues have dramatically smaller
> turnaround time to resolve.

We'll see, but I'm extremely sceptic about it. With F9/FH SpaceX did amazing
but incremental improvements to current rocket technology. Starship has tons
of uncharted territories.

~~~
greglindahl
So that quote by the CNES director of launchers praising SpaceX for pioneering
supersonic retropropulsion... he's confused and SpaceX didn't do anything new?

------
nerdponx
_NASA is still waiting for SpaceX to complete the Crew Dragon spacecraft that
will fly astronauts to and from the International Space Station. The space
agency has picked SpaceX (and another company, Boeing) to provide commercial
crew flights to the station._

 _While SpaceX did launch an unpiloted Crew Dragon test flight to the space
station this year, a subsequent abort system test failed, leading to the
destruction of the vehicle. SpaceX aims to resume abort system tests later
this year ahead of the first crewed test flight._

 _NASA Administrator Jim Bridenstine, it seems, is not happy with the years-
long delays of Crew Dragon, as well as Boeing 's Starliner spacecraft,
especially after seeing SpaceX build Starship Mk1 this year ahead of its own
test flight._

 _" I am looking forward to the SpaceX announcement tomorrow," Bridenstine
wrote on Twitter Friday. "In the meantime, Commercial Crew is years behind
schedule. NASA expects to see the same level of enthusiasm focused on the
investments of the taxpayer. It's time to deliver."_

Interesting.

~~~
Tepix
Here's Elons response given in a CNN interview yesterday:
[https://edition.cnn.com/2019/09/29/business/elon-musk-
spacex...](https://edition.cnn.com/2019/09/29/business/elon-musk-spacex-mars-
starship-cost/index.html)

------
abledon
I would love to know what the "Day-in-the-life" of a welder working on those
ships would be. Did they train specifically for aerospace welding? How did
they land that specific gig. Must be so inspiring to wake up and work on that.

~~~
discordianfish
I'd love to know the hiring process. There must be many people applying for
these positions and I doubt that whiteboard welding is a thing. Or is it? :)

~~~
RandomTisk
AFAIK it's uncommon skill, you need the steady hands of a surgeon to have a
chance. Definitely not work I could do, I know that.

~~~
52-6F-62
My dad did this kind of work in the oil industry for 30+ years as a pipe
fitter. His specialty was stainless and they had to be x-ray perfect welds. He
recently retired but was always very proud of his work. It took me a long time
to understand why.

I wish he could have gotten into the space industry vs oil refineries. The
latter is much harder on a person.

~~~
abledon
Was he prudent in maintaining good work habits? I hear the industry can be
quite hard on people if they are not careful in how they work[1]

[1] [https://www.thefabricator.com/article/safety/the-
invisible-r...](https://www.thefabricator.com/article/safety/the-invisible-
risks-of-welding)

~~~
52-6F-62
Ahaha absolutely. He's as square and as prudent as it gets. I mean to an
extreme. My siblings have always laughed at him for it [outside of the
workplace and in everyday matters where he carries those habits on].

It's hard on people regardless. And the oil industry is not known for being
prudent in looking after their workers' health.

They got real pissed when he filed a workers compensation claim for a hearing
aid before he retired. Thankfully he had support from his union.

And the number of stories he's told me where he was nearly killed...

I've no sympathy for the industry.

~~~
goldenkey
I've no sympathy for the industry.

 _puts sunglasses on_

Yeaaaahh!!!!!!

------
JulianMorrison
1950s Science Fiction illustrators are feeling so vindicated right now.

~~~
wanderfowl
That was my very first thought, seeing that image: Ray Bradbury would be
absolutely beaming to see it.

------
schizoidboy
The SpaceX/Musk presentation video:
[https://www.youtube.com/watch?v=sOpMrVnjYeY](https://www.youtube.com/watch?v=sOpMrVnjYeY)

------
mpweiher
For me the biggest "wow" (and there were a lot of those) was the capacity
comparison:

Currently the entire world has a launch capacity of 200-300 tons into LEO per
year.

With just ten starship/booster combos, that will change to a max capacity of
over a _million_ tons into LEO per year.

A factor of over a thousand. The entire current capacity (including the
Falcons) at less than 0.1% of the new capacity, a mere footnote. Not even a
footnote, really. And apparently they're cheap(er) to build as well. Complete
game changer. And game over for everybody else in the launch business.

 _Wow_

------
agumonkey
I'm surprised to hear Musk tone. He's not that friendly usually. Maybe it's
because Tesla is a different business and its struggle got to him. Maybe it's
because his inner child dreamt of this ship for decades..

~~~
ChrisClark
I think it's been a good week for him. The Starship of course, but on the
Tesla front they are coming up on the end of a quarter with record deliveries,
shipping Smart Summon which might let them finally add the FSD revenue to the
Tesla reports, etc.

~~~
agumonkey
In his starship talk he recalled how spacex was one failure away from
bankruptcy. Crazy to imagine if spacex folded before even vertical landers..

------
RivieraKid
I've had to dismiss 3 popups after opening the article on mobile. This is
ridiculous.

~~~
jniedrauer
If you have ublock origin, it redirects you to a "please disable adblocking"
page. Blocking scripts prevents the redirect.

~~~
megaremote
Why is spacex trying to show you ads?

~~~
oska
The submission is of a space.com article.

------
martythemaniak
That was a very dense an informative presentation last night, but I think the
main take away is that rapid reusability is a game changer. In fact, game-
changer is probably an understatement, basically every intuition and rule-of-
thumb we have about space launches and travel will have to be rethought. And
this will be true even of SpaceX falls well short of meeting their stated
targets (2020 orbit, 150t capability, multiple refights per day, etc.

Musk stated (I think he just did some mental napkin math at one point) that if
they meet their goals, the world's launch capacity will be expanded by two
orders of magnitude. How often does any new development in any field bring
about two orders of extra capacity? How does this incredible capacity change
how you use this thing?

First consider prices. A launch would cost fuel + support operations +
amortized cost of rocket. The last two will tend towards zero as they can be
increasingly automated and will be a small fixed cost. IIRC, fuel costs
roughly $60-100 per kilo to LEO, a 100kg person with 100kg of supplies and
life-support equipment can reasonably expect to get to LEO for $20000 in fuel
costs. Ok, so you need to "rent" the rocket (you want to stay there at least a
few days), pay operations, SpaceX margin, R&D etc. Even then, imagine weekend
LEO launches for $50,000 in the late 2020s. That's astounding. Given
millenials' propensity for "experiences", they're going to have hoards of
people buying this.

But what about risk? They've been trying to launch Crew Dragon for many years
and still haven't. Well, with expandable rockets, you have to establish a
safety record, it takes multiple flights, it's extremely expensive, you need a
new rocket for each one. With fully reusable rockets, you can literally
establish a safety record for an _individual rocket_ within a matter of weeks,
not years. Even launching once every three days (ie, far from their daily
targets), it would take only a year to do more launches than Falcon or Arienne
5 have made in decades. Also, people are far more willing to take risks than
organizations like NASA. Consider a thought experiment: SpaceX does 100
launches of Starship and establishes a safety record of 99% (1 blew up). They
then start selling tickets, will people still buy, fully signing away any
liability? Yes, you'll still have hoards of people lining up for a chance.

Finally, this is going to change science as well. Today, sending a 1 ton rover
to the surface of Mars is a Really Big Deal. Hence, probes are made very
carefully, very expensively and very very slowly. Not just design and build
(it takes a decade), but operations as well (Curiosity traveled only 20km in
the last 8 years). Everything is essentially super-low bandwidth. But once you
know you can get a cheap ride to Mars (of anywhere else) any time, you don't
have to go to such extremes. You can easily send more rovers, more radio
relays, they can travel further, experiment more, take more risks and if you
lose one, it's just not a big deal anymore!

~~~
hwillis
SpaceX is completely changing the opportunities of getting to space. The
reduction in price has been nuts.

According to NASA the space shuttle was ~$450 million per launch, or $16,364
per kg to LEO. The Delta 4 Heavy is $12,156 per kg. For some launches it's
even higher- the Air Force paid $15,109 per kg for four launches.

The Falcon 9 is $62 million, or $2,719 per kg to LEO. The Falcon Heavy is
$2,351 per kg when expendable or $1,411 when reused.

The BFR is supposed to have 2.5x the payload for 8% of the cost: $46 per
kilogram. Even fully expendable it's $2,233 per kg. That's INSANE. It's space
elevator money:

> For a space elevator, the cost varies according to the design. Bradley C.
> Edwards received funding from NIAC from 2001 to 2003 to write a paper,
> describing a space elevator design. In it he stated that: "The first space
> elevator would reduce lift costs immediately to $100 per pound"
> ($220/kg).[1]

If the BFR actually becomes reality it turns a journey to orbit into an
airplane ride. A $10,000 airplane ride that will shake your fillings loose,
but make no mistake: that completely changes everything about space. It makes
putting satellites in orbit around Jupiter as hard as visiting the north pole.
Fucking TV hosts will be able to go for a quick jaunt around the moon.

If the BFR happens, we'll have a mars base just because it would be so cheap
it's a no-brainer. Building a new ISS would be about as hard as building a new
Sealab.

[1]:
[https://en.wikipedia.org/wiki/Space_elevator_economics](https://en.wikipedia.org/wiki/Space_elevator_economics)

~~~
DennisP
It's the dawn of the true space age.

And though Musk isn't a fan, this could even make solar power satellites
economical. The monolithic designs from the 1970s would be absurdly expensive,
but modern designs like SPS-Alpha get economies of scale by using lots of
small identical parts that self-assemble in orbit. According to the book _The
Case for Space Solar Power_ , a 2GW satellite would deliver electricity at 15
cents/kWh at pre-SpaceX launch costs. I plugged BFR's $50/kg into its cost
breakdown and got 4 cents/kWh, which is pretty good for zero-carbon baseload.
Ground solar is cheaper by itself, but probably not after including storage.

The basic idea is geosynchronous orbit, microwave power transmission with a
phased array device that requires a reference signal from the target location,
and a wire mesh collector several miles wide. Over 24 hours, a solar panel in
geosynch collects 5.4 times as much light as one on Earth. At the time the
book was written, the power transmission had been tested over a couple dozen
miles, and was 40% efficient.

Longer-term, if we collect fuel from the moon to go from LEO to GEO, we could
make it even cheaper.

~~~
newguynewguy
Aren't there some pretty serious health and ecological problems with such
large-scale microwave transmission?

~~~
DennisP
Not really. Even at the intended target, it's diffuse enough not to raise body
temperature much. Birds could fly through without harm. Under the antenna,
there'd be very little microwaves leaking through. Aim anywhere without a
homing signal and you lose the coherent beam, making it much more diffuse.

~~~
Rediscover
iirc, Novar Conrols/Novar Electronics out of Barberton Ohio (at the time) was
testing the phased arrays using bees and their hives and what ever else got in
the area. Oh, yeah, and apparently some of the engineers and the boss.

(I used to work in a lab there next to some of the equipment and one day I
asked my good friend about it - he had been there for decades.)

------
mlindner
Some quotes from Elon Musk in the presentation:

"If the schedule is long it's wrong, if it's tight its right."

"The best part is no part."

"The best process is no process."

This really is different compared to how the space industry has done things in
the past.

~~~
woodandsteel
In an interview Musk said there is this strange rule that no matter what you
make the schedule, it takes twice as long, so what makes the most sense is to
just set it unreasonably short, and then it will take longer, but be as fast
as possible.

------
chriselles
I’d be interested to learn if advances in digital computing/controlling
potentially solve most of the problems that were seemingly unsolvable in the
Soviet era N1 rocket failures.

I’m assuming the inability to control and harmonise 30 rocket engines on the
N1 first stage for pitch/yaw contributed significantly to the N1 failures and
cancellation.

Will digital computing/control advances control for that and the 42 rocket
engines on the SpaceX starships 1st stage?

Or are there other major engineering problems(such as aeronautical/mechanical)
to solve as well?

~~~
socialdemocrat
Falcon Heavy managed 27 rocket engines just fine, so the N1 problems has been
solved. In fact I don’t think multiple rocket engines ever was a problem with
the N1. Its problems were quite different.

SpaceX is able to shut down failing engines quickly, as has been demonstrated
so multiple engines don’t present added risk.

Vibrations from multiple engines is something they are able to model much
easier with computer simulations today.

------
Symmetry
I'm slightly reminded of Sea Dragon[1]. That is, using fairly standard steal
construction has the possibility to decrease costs even if it increases the
net weight of the vehicle simply because it's so much easier to work with and
cheaper than minimum weight high tech alloys. Also, because both are quite big
though Elon's ship isn't as huge as Sea Dragon was proposed as being.

[1][https://en.wikipedia.org/wiki/Sea_Dragon_(rocket)](https://en.wikipedia.org/wiki/Sea_Dragon_\(rocket\))

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computerex
I just want to point out that SpaceX has not yet successfully put a human in
LEO. The moon seems well beyond their technical capabilites at the moment and
Mars seems like a fools dream at this point in time.

~~~
wongarsu
Getting anything, including humans, to LEO is the hard part though. Once they
have brought crew to the ISS and have demonstrated a spaceship flying to the
moon, landing and returning to earth they will have solved most of the
challenges of bringing humans to the moon. And they make good progress on both
fronts.

~~~
computerex
I disagree. Going to LEO vs going to the moon vs going to Mars each pose a
unique set of challenges. Manned flights to the moon for instance is many
times harder to achieve than putting someone in LEO. U.S, China and Russia
have all achieved manned flights to LEO for decades whereas only the U.S was
successfully able to put someone on the moon.

~~~
wongarsu
>only the U.S was successfully able to put someone on the moon

But is that because it's hard to put people on the moon or because only one
country tried? (Sure, the USSR tried too, but they stopped trying before
succeeding to put a large enough rocket into LEO).

There is a very unique challenge in landing on the moon, and most moon
landings still fail. But that can be perfected with unmanned landings, and
Space X has the unique advantage of having plenty of experience with powered
landings, and not requiring a separate lander.

~~~
simonh
As you say yourself, the USSR did try and failed. The N1 failed in all four
launch attempts, including destroying the launch complex. They even orbited
two prototypes of their lander design. I think that counts as trying.

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woodandsteel
It is going to be interesting to see what happens to SLS once SS/SH starts
flying. I am guessing there is going to be big public campaign for NASA to
cancel SLS and go with the SpaceX craft.

~~~
Ajedi32
Yeah, I've been wondering about this too. In my opinion, it's been apparent
for some time now that newer commercial launch providers are going to render
SLS obsolete too early in its lifecycle for it to be worth the ongoing costs
of continuing to develop it.

You might even argue that it's already obsolete, as despite it still
potentially being the most capable rocket for some subset of missions, the
per-launch costs are so high it might arguably be better to re-architect those
missions to use multiple launches of a cheaper vehicle rather than launch on
SLS. (You can launch _10_ reusable Falcon Heavys for the cost of a _single_
SLS launch.)

NASA/Congress has been stubbornly continuing to develop SLS despite that, but
how much longer will they be able to hold out? Surely they won't be able to
justify continued spending on SLS once there's another operational rocket
that's both more capable in every respect, _and_ a couple orders of magnitude
cheaper to operate?

So at what point will they finally give up? Are they going to wait until after
Starship hops? Until after it reaches orbit? Until after it achieves in-orbit
refueling? Until after it lands on the Moon? Until after it lands on the moon,
with crew? When?

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sbr464
Is there a better site with fewer ads?

~~~
ninjamayo
Teslarati might be slightly better.

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ryanmarsh
How do they plan to get 100 tons of cargo from atop the starship down to the
surface of Mars? Do you use a crane? I mean, cranes are heavy, right?

~~~
anonytrary
I think you're getting downvoted because of your flippant tone, but I am also
curious how the cargo would get on/off the ship.

~~~
SECProto
Pop open a hatch, crank out your jib crane [1], use a long steel cable to
lower loads down. Pay attention to weight distribution inside starship to
ensure it doesn't tip over.

[1] like this old-fashioned warehouse
[https://en.wikipedia.org/wiki/File:Pl_gdansk_zuraw_dlugiepob...](https://en.wikipedia.org/wiki/File:Pl_gdansk_zuraw_dlugiepobrzeze2006.jpg)
or the more modern style [https://www.acklandsgrainger.com/en/category/Jib-
Cranes/Cran...](https://www.acklandsgrainger.com/en/category/Jib-
Cranes/Cranes-and-Festoon-Equipment/c/10826)

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Tepix
If you've followed the progress of Starship closely over the last months (and
its progress has been stunning), you didn't hear much new stuff at the
presentation. We heard there will be Starship Mk 1 through 4 before we see
manned flights. I wonder what their test payloads are going to be when they go
for orbit.

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RegW
> This is the rocket that will launch ... a handful of artists on a trip
> around the moon in the 2020s.

... and so programmed to crash just like Golgafrinchan Ark Fleet Ship B?

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kfrzcode
Truly this is faith in humanity boosting stuff. Great news

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qaq
And US mil. will get a super cheap way to deploy kinetic bombardment system
with cost per rod on par with cruise missile.

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dopylitty
‘Tis a fine water tower or grain silo, but sure it is no starship, Boerish.

------
known
Does it have Internet connectivity?

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a_imho
One of the worst GDPR blocks I've encountered in the wild.

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35787
Eventually the shell will be a single large roll of steel that is unrolled,
bent into a tube with a seam going hotdog that is welded. It will be very
strong, lighter than the current patchwork, and extremely beautiful. More
similar to the renderings. Can’t wait.

~~~
hwillis
Definitely not hotdog (assuming that's from stem to stern). Musk wasn't
totally clear when describing it, but he said mk3 would be in three months.
The circumference of starship is 28.26 meters. For a single weld the entire
length of the ship, the roll itself would need to be that wide.

The largest rolling mills in the world are ~4 meters wide[1]. They require
backup rollers[2], ie rollers that push down the rollers that push down the
rollers that push down the metal. Bending deflection increases with width^2. A
28 meter wide rolling mill does not exist AFAIK and cannot be built in three
months.

[1]: [https://www.aleris.com/company/rolled-
products/](https://www.aleris.com/company/rolled-products/)

[2]: [http://www.yourarticlelibrary.com/metallurgy/types-of-
rollin...](http://www.yourarticlelibrary.com/metallurgy/types-of-rolling-
mills-metallurgy/95337)

~~~
35787
Wow what an incredibly substantive comment. I remember pretty clearly he said
that there would be a single seam weld. Maybe I’m remembering wrong. Or maybe
they’ll seam weld multiple rolls into a really wide roll and the only weld
required to turn the final roll into the shell is that final hotdog weld.

~~~
paragraft
I think the idea's to go like a Pringles can, with a spiraling single seam.

~~~
hwillis
_maybe_ , but that's also pretty unlikely. For reference here's where musk
talks about it:
[https://youtu.be/sOpMrVnjYeY?t=3156](https://youtu.be/sOpMrVnjYeY?t=3156)

No real indication he means a spiral.

There are a _lot_ of problems with a spiral. Thin sheets of steel, even hot
rolled, are very affected by the rolling process. There's also the weld line
going up in a spiral. That will cause uneven heat diffusion and expansion,
which is a recipe for disaster given that the skin will be cold enough to
liquify helium on one side and boiling hot on the other. Then red hot during
reentry. Straight lines don't have the same problems.

