
SpaceX test flight of Starship SN-5 [video] - lpellis
https://www.youtube.com/watch?v=NJR4gZBLMNw
======
martythemaniak
I really love the out-in-the-open development process. It doesn't cost SpaceX
anything, yet they attract lots of internet media where people set up streams,
discuss progress etc. The next year should be pretty exciting as they develop
things further. Starship has a number of big innovations, which are:

\- the raptor engine. This was developed behind closed doors and is sort of
finished. We won't see much of it, but it is the most advanced rocket engine
ever made and I'm not aware of any upcoming engine that can compete with it.

\- Stainless steel construction. What we're seeing with SN5 is the basic tank
structure of the second stage. The hopper that flew last year was a neat demo,
but SN5 was pressurized and the design is way closer to what the actual
starship will end up having. The first stage tanks will also be a stretched
version of these tanks, so that's why you see them focus on this so much right
now.

\- belly-flop landing. To land, starship will be coming downhorizontal until a
few hundred meters above ground when it'll make itself vertical to land. SN5
won't have the fins and cone to perform this, but SN6 will. It might be
possible to see this before the end of the year - SN6 (with 3 engines) goes up
20km, goes horizontal to burn off speed, then lands vertically.

\- belly-first re-entry. Instead of a heatshielf that withstands a high
temperature, Starship will burn off speed with its belly, but do it over a
longer time period of time so that while the total heat is the same, the max
temperature doesn't rise too much. The stainless steel can't take the
temperatures ablative heatshields on capsules can. Don't know if Starhip will
be able to perform this meaningfully without a booster.

\- in-orbit refueling. Starship is big and heavy and basically can't get
anywhere unless it's re-fueled in orbit. I don't think this has been done
before, definitely gonna need 2+ starhips and boosters to show this.

\- superheavy booster. This might be the simplest part of the whole system - a
first stage with 31 raptor engines.

Lots of stuff coming in the next few years.

~~~
dgritsko
> the most advanced rocket engine ever made

Would love to learn more about this, can you expand? What makes Raptor so
unique?

~~~
paulsutter
In addition to being full-flow, Raptor runs on methane (CH4, the simplest
hydrocarbon), which already exists many places in the solar system (including
Mars), and is easier to manufacture than kerosene or liquid hydrogen.

SpaceX developed an incredibly advanced simulator to make it happen:
[https://www.youtube.com/watch?v=vYA0f6R5KAI](https://www.youtube.com/watch?v=vYA0f6R5KAI)

~~~
apendleton
Slight clarification: while there have been traces of methane detected on
Mars, there's probably not enough to be able to easily use it as fuel. Methane
is still beneficial for refueling on Mars, though, because you can make it in
place out of water (which _is_ plentiful on Mars as water ice) and CO2 (also
plentiful, in the atmosphere) using the Sabatier process. So it remains the
case that methane as fuel lets you avoid needing to bring enough fuel for a
round trip.

~~~
SEJeff
Exactly. Elon has explicitly mentioned manufacturing metholox (the raptor
engine fuel) using a really beefy ISRU factory. It would be feasible, but is
still a lot of work required.

------
zizee
No one has seemed to have mentioned it yet, but the game changer of Starship
will be full reusability of both the first and second stage of the rocket.
Falcon 9's reusability of the first stage was a huge step towards making
access to space a lot cheaper. If SpaceX can realize full reusability with
Starship it will enable things like large scale moon bases, space hotels and
mars colonization. They still have a lot of challenges ahead of them, but
today's hop takes us that much closer to the future of space as presented in
films like 2001 A Space Odyssey.

The future is exciting!

~~~
llboston
Another significant thing is that Starship is designed to be mass manufactured
at a relatively low cost. SpaceX can crank out thousands of Starships, fly
them to Mars and build a million people colony. Starship is truly a game
changer!

~~~
themgt
Yep, and in addition to both of these, Starship is also designed:

* to be fueled / ignited such that it can be refueled in-situ on Mars & then launched back to Earth, without advanced rocket fuels or the TEA-TEB chemical igniter.

* to be able to refuel from another Starship in-orbit

The combination of all of this, if they pull it off, will be the ability to
send truly massive payloads to Mars, faster and cheaper than anyone could have
imagined just a few years ago.

To me it does really show the benefit of taking a systematic approach, working
backwards from the goal "get to Mars and stay" in a resource-constrained
environment. They've very strategically targeted the technology/engineering
required to bring the costs down to something reasonable, while NASA's
approach for 50 years has basically been versions of "can you give us one
trillion dollars?" (or "we can put a couple humans on Mars for 3 days for $100
billion")

Today's Starship hop is getting very near the nail in the coffin for SLS. I
still have some concerns about their crazy re-entry flip, but the speed SpaceX
is moving is leaving everyone else in the dust.

~~~
wcoenen
> * (or "we can put a couple humans on Mars for 3 days for $100 billion")*

Is there actually a NASA proposal like that? As far as I know, orbital
dynamics don't allow for this. One has to wait for a Hohmann transfer orbit
window to return home.

~~~
garmaine
There are faster transfer opportunities, but not 3 days. But I think he way
saying 3 days of surface ops. Which is still an exaggeration. I think the NASA
reference mission is 30 days?

~~~
wcoenen
I had a peek at the Mars Design Reference Architecture 5.0 [1], and under
"trajectory options" they talk about two classes of missions.

"Opposition class missions" stay on the surface for 30 to 90 days.
"Conjunction class missions" stay for 500 days or more.

That confirms the 30 days that you mentioned as a reasonable minimum.

[1] [https://www.nasa.gov/pdf/373665main_NASA-
SP-2009-566.pdf](https://www.nasa.gov/pdf/373665main_NASA-SP-2009-566.pdf)

------
Diggsey
What you don't get a sense for in the video is the size of this thing... It's
absolutely bonkers.

9m (30 ft) in diameter 50m (160 ft) in height (or would be with the nose-cone)

That's the height of a 12-story building. And this is the _upper stage_ of the
full rocket.

~~~
mabbo
And it's being powered by _one_ raptor rocket. It's designed to have 6.

~~~
_kst_
And the first stage "Super Heavy" is designed to have 31.

Update: I think the hopper in the video is a prototype of the lower stage,
which is planned to have 31 engines. The upper stage is planned to have 6.

~~~
m4rtink
The small hopper in the video is an early general purpose prototype from heavy
duty steel, what flew today is a prototype of the second stage (Starship).

But assembly enclosure for the first stage (Super Heavy) is being built
already.

------
bfieidhbrjr
Does anyone else get super depressed by this?

I did some great work today. I coded something pretty cool and useful. I built
a little deck to explain it. My coworkers loved it. My job security went up. I
enjoyed it. The journey is the reward.

But these guys are making rockets in tents.

Should I be rethinking life? Because that's how it feels. I love it. I admire
them. But it feels unobtainable. I want to make that kind of a dent in the
universe. And yes I know it's thousands of people working there.

But still.

~~~
tjtrapp
We're hiring for Starship and Starlink software teams:
[https://grnh.se/080f65d02us](https://grnh.se/080f65d02us)

It sounds like you're passionate about your work and that's an important
quality. As gorgoiler points out, "Making a difference in the world is what
counts."

If you'd like to help, consider applying! :)

~~~
pinewurst
The application forms are pretty ridiculous with theIr insistence on
school/graduation dates (some reqs) and SAT/ACT scores (all).

As a very experienced engineer, I can’t accept being judged on (historical)
trivia.

~~~
rbanffy
Same here. Understand they need to somehow weed through their applications.
Experienced engineers are costly to assess and having a cheap test to remove
the obvious negatives helps them at the cost of a few false ones. :-(

I'm also not a US citizen, so that's another cheap test I can't pass.

~~~
skissane
> I'm also not a US citizen, so that's another cheap test I can't pass.

Unlike other "cheap tests", that one is imposed by US government regulations,
not SpaceX's own decisions.

I imagine SpaceX would be quite happy if ITAR was loosened, but I doubt that
will happen.

I honestly can't see why ITAR applies to citizens of friendly countries such
as Canada or the UK. The point of ITAR is to stop unfriendly countries like
China, Russia, Iran or North Korea getting access to technologies with
sensitive military applications. The US trusts its closest allies in so many
other ways (e.g. UKUSA "Five Eyes" intelligence sharing agreement, the 1958
Mutual Defence Agreement under which the UK and US share nuclear weapon design
information), why not in this?

~~~
rbanffy
A country is friendly until it isn't. I understand it's not a requirement
imposed by SpaceX, but it also prevents them from getting a lot of
applications they wouldn't be able to turn into hires.

~~~
skissane
> A country is friendly until it isn’t

If the US can trust the UK with information on nuclear weapon designs and
delivery systems, surely it can handle a few UK citizens working for SpaceX?

In the unlikely event that the UK and US had some falling out, the US
government could always order SpaceX to lay off UK citizen employees.

~~~
garmaine
> If the US can trust the UK with information on nuclear weapon designs and
> delivery systems.

Bad example. The soviets got the bomb because of British spies in the
Manhattan project. After that, there was _very little_ collaboration to this
day.

~~~
skissane
What about the 1958 Mutual Defence Agreement? That led to sharing of nuclear
weapons design information, over a decade after the Manhattan project.

[https://en.m.wikipedia.org/wiki/1958_US–UK_Mutual_Defence_Ag...](https://en.m.wikipedia.org/wiki/1958_US–UK_Mutual_Defence_Agreement)

~~~
garmaine
Read the details; it wasn’t free exchange of information. It was basically a
way for the US to allow sales of some nuclear plants and material, and sharing
of design work only when it overlapped significantly with what the UK already
did.

~~~
skissane
Which details? Wikipedia says:

> The Americans disclosed the details of nine of their nuclear weapon designs:
> the Mark 7, Mark 15/39, Mark 19, Mark 25, Mark 27, Mark 28, Mark 31, Mark 33
> and Mark 34. In return, the British provided the details of seven of theirs,
> including Green Grass; Pennant, the boosted device which had been detonated
> in the Grapple Z test on 22 August; Flagpole, the two-stage device scheduled
> for 2 September; Burgee, scheduled for 23 September; and the three-stage
> Halliard 3. The Americans were impressed with the British designs,
> particularly with Halliard 1, the heavier version of Halliard 3. Cook
> therefore changed the Grapple Z programme to fire Halliard 1 instead of
> Halliard 3.[85] Macmillan noted in his diary, with satisfaction that:

>> in some respects we are as far, and even further, advanced in the art than
our American friends. They thought interchange of information would be all
give. They are keen that we should complete our series, especially the last
megaton, the character of which is novel and of deep interest to them.

> An early benefit of the agreement was to allow the UK to "Anglicise" the W28
> nuclear warhead as the Red Snow warhead for the Blue Steel missile.[87] The
> British designers were impressed by the W28, which was not only lighter than
> the British Green Grass warhead used in Yellow Sun, but remarkably more
> economical in its use of expensive fissile material.

Wikipedia doesn’t appear to support your version of events. (Of course,
Wikipedia is sometimes wrong; but if you think it is wrong, which of the above
claims it makes is wrong specifically?)

------
aphextron
Official video: [https://youtu.be/s1HA9LlFNM0](https://youtu.be/s1HA9LlFNM0)

~~~
Taniwha
So what's burning above the motor, I thought these were closed cycle engines?

Were they incredibly lucky

~~~
Tuna-Fish
There's a lot of speculation on that, it's probably either wiring/tubing
insulation or paint that got ignited, or a small leak. It seems to put itself
out at 0:51.

------
Jaruzel
As a child I read all the Tintin books. My favourite ones were Destination
Moon, and Explorers on the Moon. The rocket used in those stories is iconic.
For me, Starship taps directly into those memories. I know it's infeasible,
but if they ever painted the production Starships white and red, it would make
me SO happy.

I'm too old now (approaching a de-orbit burn for 50) to be able to go to
space, but I'm still loving the thought that my future grand-kids should be
able to.

~~~
buzzwordninja
One thing I remember from those books is how they lay on their stomach during
acceleration, whereas I believe all real life astronauts have been sitting, or
on their backs:

[http://www.projectrho.com/public_html/rocket/images/deckplan...](http://www.projectrho.com/public_html/rocket/images/deckplans/Tintin5.jpg)

Which is also interesting given the recent (well... not even so recent now)
discovery of the benefits of placing COVID patients in a prone position to
ease breathing.

------
BbzzbB
What a week for SpaceX! Two days ago they landed Bob and Doug, and now they
succeeded to hop a water tower (as a side project nonetheless, AFAIK only a
small part of SpaceX is on this team)! Can't wait to see future iterations and
improvements of this beast, especially to see more Raptors strapped on!

~~~
Robotbeat
The water tower was last year. This is a prototype using the same production
technique as for the production versions.

EDIT: More grain silo than water tower. ;)

~~~
byw
Is it just me or does the workmanship look like a step up?

~~~
djaychela
They've been interating on the construction process with each one built. I've
been welding (DIY) for 30 years, and the first ones looked pretty bad to me -
lots of distortion, and I actually thought the first one was just a mock-up.
But the process is clearly improving with each build. I still think the nose
cone looks like it will improve in the future, as it doesn't look as precise
as the main body is now looking, but I'm sure they're working on it.

This, overall, is an amazing achievement. I watch every F9 landing that I can,
and it never ceases to amaze me. The FH two-booster landing looked like
straight out of a SciFi movie. But this... this is next level again. The 20km
flight will be truly incredible.

~~~
fiftyfifty
It's also worth pointing out that the new prototypes, like SN5 that flew
today, are made with significantly thinner steel over what "Star Hopper" was
made with last year. They have spent a lot of effort perfecting their
manufacturing technique so they can make these things as light as possible and
still achieve the safety margins that they need to support manned flight.
That's why they need the 22 ton weight on the top for this flight, because
they can't throttle a single Raptor engine low enough to hover these new
designs.

------
sfjailbird
Thank God for that guy in the corner helping me to know how to feel.

Seriously though, this has been an incredibly annoying trend for a few years,
everything has to be tagged with some pre-packaged emotional reaction. Such a
dumbing down of public discourse.

Someone linked the official video and it's amazing:
[https://youtu.be/s1HA9LlFNM0](https://youtu.be/s1HA9LlFNM0)

~~~
martindbp
See also "Youtube face".

~~~
smusamashah
There is also a "Dreamworks Face"

~~~
db48x
Doesn't Japanese television have a lot of reaction shots too?

------
ChuckMcM
Always impressive to me. And I know that people will say "Yeah, basically the
only thing 'new' here is the engine" but there are also a bunch of other
things that struck me;

It did the hop 'off balance' (the final version expects to have 3 raptor
engines working together) so the engine out scenario for landing still seems
pretty safe.

There is something like four more advanced vehicles in the warehouse section
at various stages of completion. So scaling up making them seems to be working
out.

It looks "small" in the images but when you see people working on it you can
tell its grain silo big. That is a heck of a thing to fly overhead.

Rockets taking off and landing vertical has amazed me ever since I saw the
DC-X do it once.

~~~
rbanffy
The DC-X still manages to look modern next to it. Had it succeeded, it'd have
done something not even SpaceX is doing, which is a fully reusable single-
stage-to-orbit craft.

I don't think we have the advanced materials for that.

~~~
ecpottinger
I think the Delta-X could have done the job, what went wrong was letting NASA
taking control of it. Remember these are also the people who went with
segmented solid fuel boosters, these were the people who thought the
VentureStar with three new techs that all had to work at the same time but
rejected the designs that did not need as much new tech, these are the people
who let the SLS design go forward.

The Delta-X was an interesting design until NASA was involved.

~~~
mschuster91
The Wikipedia article on DC-X is interesting.

> In a post-accident report, NASA's Brand Commission blamed the accident on a
> burnt-out field crew who had been operating under on-again/off-again funding
> and constant threats of outright cancellation.

That is the reason why SpaceX is so much more efficient and revolutionary,
compared to what Boeing/ULA on US side and EADS/Ariane on EU are doing - they
are cutting politics out of the equation and with it, a whole boatload of
issues.

~~~
cryptonector
Contractors like Boeing for SLS generally have sweetheart cost+ deals. They
have zero incentives to cut costs -- nay, they have an incentive to increase
costs because their profits are the "plus".

SpaceX isn't interested in a sweetheart subsidy deal. They are _competing_.
That's why their contracts with NASA are fixed price: it gives SpaceX every
incentive to keep costs down so as to maximize profit.

Surprise! SpaceX is doing better than the competition that gets sweetheart
deals. It should really not be a surprise to anyone though, but it probably is
to some.

------
modeless
Direct link to the launch time:
[https://youtu.be/NJR4gZBLMNw?t=2183](https://youtu.be/NJR4gZBLMNw?t=2183)

------
valine
That was a sight to behold, history in the making for sure.

This was the first flight of a vehicle which may someday take humans to mars.

------
mitchellgoffpc
Man, I saw that thing moving sideways right after liftoff and I thought it was
a gonner! Huge congrats to SpaceX for landing with an offset engine like that
on their first try!!!

~~~
Cogito
In addition to the other replies, it is also standard for rockets to 'clear
the pad' as soon as possible, to avoid damaging the ground support equipment
as much as possible.

The amount of kick to the side is almost certainly due to the offset engine,
but they would definitely design the flight path (with that in mind) to clear
the pad as fast as reasonable as well.

~~~
m4rtink
Yep, pretty much every rocket is much much cheaper than the often one-off
launch infrastructure.

From what i remeber some Soviet rockets had after a string of pad destroing
failures any abort commands disablee for the first 30 seconds of flight -
regardless of what happens, it must not hit the pad, or Barmin (the chief
designer of most Soviet launch complexes) will be angry and you don't want
that.

------
daveslash
This might be petty and off topic, but do others find this sort of streaming-
commentary off-putting? I don't so much mind the informational commentary, but
the emotional outbursts of yelling, hooting, and hollering is just... not for
me and really makes me want to mute the video. Like I said, maybe off topic,
but I see this becoming more and more common and wanted to know what people
here think?

------
doomlaser
This is the first time I've seen video of a starship test that didn't end in
catastrophic explosion, so this is great news!

I'm still worried about the overall design, specifically when it comes to
landing. The current procedure is for it to fall into the atmosphere flat on
its side, then continue to fall for a long time, and then only when it's near
the ground it must reorient 90 degrees to upright and then do a final suicide
burn to land. It seems like it has too many chances to fail with no recovery,
but I'm no rocket scientist.

~~~
avernon
One thing to think about is that the heating/energy is exponential. So doing
the belly flop lowers the heating and the energy the rocket is carrying quite
a bit.

Planes make 90 degree turns all the time! And in actuality this rocket could
be less complex than a modern airliner as far as number of parts and
processes.

They have taken huge leaps in engine technology with Raptor that allow for a
lot of simplification across the rest of the rocket and which could make it
airliner level safe someday.

~~~
rbanffy
It'll still be fun to hear the pilot announcing to the passengers that "We are
now preparing for the suicide burn. Please make sure your seatbelts are
fastened and your trays are securely stowed away. We wish you an enjoyable
landing. Thank you for flying SpaceX".

------
mchusma
Congratulations to SpaceX! Helping make the pandemic more bearable one hop at
a time.

------
api
So much less sooty with methane instead of kerosene!

~~~
modeless
It's not just the fuel but the way it's burned. The older Merlin engines don't
burn all the fuel, by design. The new Raptors do, and it's actually quite an
achievement. More information than you ever wanted to know about it is here:
[https://everydayastronaut.com/raptor-
engine/](https://everydayastronaut.com/raptor-engine/)

------
zionic
[https://www.youtube.com/watch?v=s1HA9LlFNM0](https://www.youtube.com/watch?v=s1HA9LlFNM0)

Is a much better video :)

------
snoshy
Pretty wild. Seems like it took out a chunk of the pad on the way up as well.
Those Raptors are no joke.

------
Ajedi32
Official video from SpaceX:
[https://youtu.be/s1HA9LlFNM0](https://youtu.be/s1HA9LlFNM0)

~~~
zionic
This should be the link, it's way better!

------
fnord77
Is there an official spacex feed?

~~~
Robotbeat
No, but there were no fewer than 3 hosted live-streams (one which had 3
different HD live cameras you could switch to) with countdowns and technical
commentary. All by non-traditional media. Remarkable what is possible
nowadays.

Here they are:

[https://www.youtube.com/watch?v=VwC6LG_z8zE](https://www.youtube.com/watch?v=VwC6LG_z8zE)

[https://www.youtube.com/watch?v=NJR4gZBLMNw](https://www.youtube.com/watch?v=NJR4gZBLMNw)

And the last one is constantly streaming 3 live feeds of the SpaceX Boca Chica
facilities 24/7:

[https://www.youtube.com/watch?v=5QbM7Vsz3kg](https://www.youtube.com/watch?v=5QbM7Vsz3kg)

EDIT: And by remarkable, I don't just mean technical capability but the really
impressive non-traditional media community that has grown up around New Space
the last 5-10 years. Here's amazing, close-up 4K video of the hop by yet
another non-traditional space media person:

[https://www.youtube.com/watch?v=HXzPu6MM99Q](https://www.youtube.com/watch?v=HXzPu6MM99Q)

------
ackbar03
What was the context behind this launch? Did they just luanch a grain silk
just for kicks or something? That can't possibly be the new design for a
rocket

~~~
rwcarlsen
This is a prototype for the upper (second) stage of spacex's next-gen rocket
[1] they are developing that uses their new full-flow staged combustion raptor
engine [2]. This is the ship they plan to use for upcoming mars, moon, etc.
missions that will basically replace all other spacex rockets as soon as they
can figure out how to get it operating. This prototype is missing the
nosecone, control surfaces, and other details, but has the most important
parts - engines (one instead of 6 like it will eventually have) and
fuel+oxidizer tanks.

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

[2]
[https://en.wikipedia.org/wiki/Staged_combustion_cycle#Full-f...](https://en.wikipedia.org/wiki/Staged_combustion_cycle#Full-
flow_staged_combustion_cycle)

~~~
app4soft
This is a prototype _of the bottom part_ for the upper (second) stage of
_SpaceX_ 's next-gen rocket — _Starship_.

~~~
m4rtink
While it does not look that way without the pointy nose cone, this is the
prototype of the second stage.

The first stage will be a bit longer than this & its build enclosure is
already being uilt.

~~~
garmaine
That’s what he said.

------
ninjamayo
This was incredible. I've been waiting to see this launch for months,
especially after a few failures with previous versions. But it's all worth it.
This is it! Next step will be even bigger and better. More hops, reigniting
the engine and then 20km.

------
mosselman
I was just looking at the stream and what struck me is that people were
donating to the channel... Why would you ever do this? $20, etc even.

------
Element_
Anyone here work on the flight control software? What's it written in? ada?

Curious how complex it is since it has to handle multiple engine failure
scenarios etc...

~~~
mulcahey
I'd check out the sofware AMA they did a few months ago on /r/spacex

[https://www.reddit.com/r/spacex/comments/gxb7j1/we_are_the_s...](https://www.reddit.com/r/spacex/comments/gxb7j1/we_are_the_spacex_software_team_ask_us_anything/)

------
fermienrico
Can someone please explain the significance of this milestone for a space-
ignorant person like myself?

I thought SpaceX does these types of landings all the time. :)

~~~
nieksand
SpaceX as a company is trying to solve the "transportation problem" of
becoming a spacefaring civilization. Specifically, how do you reduce the cost
of access by multiple orders of magnitude?

There are three big targets they need to hit:

1\. Make Low Earth Orbit (LEO) cheap with a combination of launch cadence and
reusability.

2\. Reset the rocket equation in LEO by doing in-orbit fuel transfer.

3\. Reset the rocket equation at Mars by generating fuel from the environment.

* The reasoning...

(1) A high launch cadence means you can switch from artisanal to mass
production. You drastically reduce fixed costs of ground equipment and
personnel. Experience translates to increased knowledge, reliability, and
safety. You are less prone to schedule slip costs because there are more
trains leaving the station.

(1) Reuse lets you get more life out of expensive components. It also helps
you hit a higher launch cadence with less manufacturing capacity, further
reducing costs.

(2) In orbit propellant transfer lets you start with a full tank again in LEO.
It might take four tanker launches to refill one tank, but ultimately you can
increase payload to non-LEO destinations by an order of magnitude. Being less
mass constrained also makes things simpler and cheaper for payload
development.

(3) Propellant production, aka in-situ resource utilization, lets you fully
refuel at Mars or the moon. This lets you send non-trivial payloads in the
return direction.

* The progress so far...

SpaceX has regular reuse of the 1st stage of their Falcon 9 and Falcon Heavy
rockets. They have begun catching the fairings (nosecone) in giant nets
mounted on ships and reusing those too. The 2nd stage is not reused. Doing so
is difficult because it's much further downrange and has much larger velocity.

SpaceX has used their progress on reusability to drive down costs and capture
a large part of the commercial launch market.

SpaceX is launching Starlink satellites to provide a global, low-latency,
high-bandwidth internet access. Existing satellite internet is based on
geosynchronous orbit satellites which have high-latency and low-bandwidth.
SpaceX hoists 60 Starlink satellites per Falcon 9 launch. There are a couple
hundred satellites in orbit already with several thousand planned. Their low
orbit means they have a lifetime of just a few years and require regular
replacement. If Starlink is a commercial success, then SpaceX will have found
the "demand" needed to drive a high launch cadence.

* Why the SN-5 hop matters...

SN-5 is a prototype second stage for the "Starship" rocket. This rocket has
both a massive payload capacity and _full_ reuse. In conjunction with Starlink
this would solve (1). This prototype is demonstrating progress on the
manufacturing process and viability of the design. There is still tons of work
to be done.

SpaceX is already planning to do in-orbit propellant transfer using Starship,
which then solves (2).

SpaceX has not begun on (3). However, the Mars 2020 rover mission actually has
an experiment on board which does propellant production at demonstration-
scale. The chemical reactions (sabatier process) are pretty straight forward,
but providing sufficient energy and gathering the resources is a massive
engineering challenge.

Ultimately, SpaceX has a coherent, achievable vision for reducing space
transport costs by multiple orders of magnitudes and has made demonstratable
progress towards that vision.

~~~
ianhorn
> 2\. Reset the rocket equation in LEO by doing in-orbit fuel transfer.

What do you mean by this? If you want to propel a mass M to delta-v V, you
need a certain amount of initial mass. Dividing it into stages is already
taken into account. If you split the lower stages into multiple trips, you
might change the mass per trip, but you don't change any of the total early-
stage mass required, right? Doesn't the rocket equation still apply in exactly
the usual way?

~~~
jecel
The total fuel required is the same in both cases, but to do it in a single
trip the upper stage would have to be nearly twice as large and the lower
stage exactly twice as large. This is already far larger than anything that
has been done before, so making it twice the size would be a significant
problem.

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smusamashah
Why is it shaped like this? Why the fire seems to be not exactly in center and
how it managed to keep balance with that?

~~~
db48x
It's a prototype of the lower half of a larger rocket, and it's not intended
to fly very high or fast, so it doesn't need a nice nose-cone. The single
rocket engine is mounted in the center, and it gimbals to the side to make the
rocket move sideways. The on-board computer is balancing the whole rocket on
that flame the whole time, adjusting it continuously to keep everything in
balance and the rocket moving towards the landing zone; imagine balancing a
pencil on your fingertip. The real rocket will have a lot more than just one
engine, but for this test they only needed the one.

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sidcool
The rate of innovation at SpaceX is mind blowing. There is little doubt they
will achieve their Mars dream.

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throwaway0a5e
If I were the CEO of Molson Coors I'd tweet Elon about buying advertising
space right about now.

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dgritsko
Did they already do it?

~~~
lpellis
Just did a minute ago, it worked! 6:57 in the the timestamp on the top right,
I dont think I can link to a time in a live youtube video

~~~
ajaimk
Yes you can. FYI ->
[https://youtu.be/NJR4gZBLMNw?t=2190](https://youtu.be/NJR4gZBLMNw?t=2190)

~~~
lpellis
That 'copy video at current time' option wasnt available until the livestream
ended though. I should have tried manually adding it.

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Jemm
"Norminal!"

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jvanderbot
I cannot get over how it looks like an ork built this.

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brianolson
skip to 36:20 for the action

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monadic2
It’s times like these I turn to “Whitey On The Moon” by Gil Scott-Heron.

