
Arabsat-6A mission [video] - jacquesm
https://spacex.com/webcast
======
ninjamayo
I don't think that most people realise what an achievement this is. This is
major, three boosters landing simultaneously and one of them is landing on a
moving object in the middle of the ocean. And they will reuse the two side
boosters for the next FH launch.

~~~
GuB-42
I think most people realize it thanks to the very good communication by
SpaceX.

Personally, from a technology standpoint, I am not that impressed compared to
what we have done in the past when it comes to space exploration. Moon
landings, space shuttle, Mars rovers... The current state of rocketry all but
highlights how awesome it was before.

The awesome part about SpaceX is not that their rockets are the best humanity
can do. What's awesome is that it may very well make the first reusable
rockets that make economical sense. Unlike NASA in the past, they don't have
unlimited money, they are a private company, and even if they have help from
the US government, they have to work with a budget.

If anything the achievement is not the rocket itself but how it creates a
regain of interest in rocketry, both popular and economic. I mean, our
workhorse rocket (Soyuz) dates back from the 50s, and all of the awesome (and
too expensive) stuff like the Saturn V and shuttle are now lost.

~~~
stewfortier
> Personally, from a technology standpoint, I am not that impressed compared
> to what we have done in the past when it comes to space exploration.

This is possibly the most Hacker News comment I have ever seen.

~~~
vkou
It's been 62 years since the first spaceflight. There are currently six people
in space.

62 years after the first flight, world-wide air travel numbered a billion
passenger-miles _per day_.

So, pardon me, but the pessimism about space progress is fairly justified.

~~~
fulafel
Considering the havoc air travel is causing the environment, we should aim
away from mass space travel for the foreseeable future.

~~~
the_duke
Many people overestimate the environmental impact of air travel.

It's "only" about 2% of global energy consumption. Not nothing, but also not
that significant. There are much bigger energy wasters that can be targeted.

~~~
fulafel
It's the other way around unfortunately, people underestimate it: The effect
of air travel on global warming is much higher, due to emissions effects in
the upper atmosphere. Eg WP says 'Emissions weighting factor (EWFs) i.e., the
factor by which aviation CO2 emissions should be multiplied to get the
CO2-equivalent emissions for annual fleet average conditions is in the range
1.3–2.9'

And air travel is growing at a steep rate because air travel has gotten so
cheap and big populations in developing countries take up air travel.

------
errantspark
I can't think of anything that beats the dual hoverslam for cool factor. What
a breathtaking sight! Mad props to Elon and the team at SpaceX for getting the
hat trick.

~~~
imjasonmiller
The sonic booms were lovely as well! Gives you somewhat of a sense on how fast
they were coming down.

~~~
Klathmon
all 6 of them!

Each booster generates 3 distinct "booms". IIRC the causes of each are
slightly different, but it's nutty hearing it in person!

~~~
plttn
Yup!

One is from the engine bell, one from the widest part of the body by the
landing legs, and the third is the grid fins.

------
jedberg
I'm a grown man and I still cry every time a booster lands successfully and
every time a rocket clears the tower.

What a thing of beauty.

~~~
bahmboo
Grown men are supposed to cry

~~~
Agathos
Crying is nominal.

~~~
pedrocx486
Norminal.

(In case some don't get it, pay a visit to r/SpaceX on Reddit.)

------
dougmwne
Just watched the boosters come down on the Cape from near Cape Canaveral
National Seashore. Amazing to watch be able to see the separation, boostback
burn and landing burns with my own eyes. Beautiful and eerie sight.

~~~
jacquesm
Lucky you! Consider me slightly jealous, I have to do with the youtube feed,
but I have yet to miss a launch. This one kept me up way past my bedtime but
it was so worth it :)

------
rland
I have a question:

It seems to me like the rocket lifted off quite quickly, like the acceleration
at first (right at t=0) was very rapid compared to other launches I have seen,
especially launches with big rockets.

Is this because it's a satellite that can take higher G's? Is it because
they're launching a payload with low mass so it has low TWR? Do these engines
spool faster than the engines used in other rockets (like the ones used for
Apollo or the space shuttle)?

Or, am I just incorrect that this one is faster...

Jealous of everyone who could witness this up close, as usual.

~~~
JshWright
Falcon Heavy does indeed lift off the pad faster than many rockets (it's even
faster than the single-stick Falcon 9). This is because of its higher overall
TWR (since the two side boosters are functionally Falcon 9's without the mass
of a second stage and payload). Another rocket that really leaps off the pad
is Ariane 5 (once the SRBs light at T+8sec).

Generally speaking you want to accelerate as quickly as possible in the early
stages of the flight in order to reduce gravity losses (every second you spend
going "up", the more energy you have to spend fighting gravity). There are
other factors involved here though (if you get going too fast in the lower
atmosphere the losses due to drag start outweighing the savings, etc).

The spooling time of the engine doesn't really matter here, because the launch
clamps don't release the rocket until the engines are all up and running and
healthy, so when T-0 hits, the engines are already at full thrust.

~~~
saagarjha
> Generally speaking you want to accelerate as quickly as possible in the
> early stages of the flight in order to reduce gravity losses (every second
> you spend going "up", the more energy you have to spend fighting gravity).

This doesn't really make sense to me from a simple dynamics perspective. Why
does time matter, unless efficiency comes into play somewhere?

~~~
CydeWeys
A really stupid simple way to think of it is --

Imagine you're hovering a hundred feet off the ground. You still need to be
burning your engine at a full g, but you're not going anywhere. You're
spending LOTS of fuel for zero movement. Now imagine you can only burn at 1.01
g; you will VERY slowly start moving upwards, but you'll be spending a
colossal amount of fuel for the same result.

Now imagine instead you're burning at 3g; suddenly you're actually
accelerating quite quickly, and you're overall burning much less fuel to go
the same distance.

~~~
walrus01
a really good way to visualize this is to build some fat, awkward vessel in
Kerbal Space Program that has a thrust-weight ratio of only 1.2 or
thereabouts, and use mechjeb to watch the data during launch. It'll eventually
get to orbit (enough struts and boosters will do that, in KSP) but you'll see
how inefficient and slow it is, how much time it spends in the lower
atmosphere, compared to a properly optimized rocket.

------
Klathmon
And they just had confirmation of a good orbit on the payload, which means
every single part of this mission was a success.

Congratulations to the team at SpaceX!

------
andyzei
Did anyone else notice the object flying by @ 54:26? What was that? Looked
bigger than a piece of dust, was moving much faster than the upper stage and
payload. Is that normal? Did it pose any risk?

[https://youtu.be/TXMGu2d8c8g?t=3265](https://youtu.be/TXMGu2d8c8g?t=3265)

~~~
chiefofgxbxl
Interesting find! Earlier in the feed you can see a _solid piece of oxygen_
[0] bouncing off the engine. The particle you mentioned is going past the
spacecraft (forward), so I can't see it being solid oxygen. My guess is a
piece of dust that is being illuminated, and the camera is picking up the
reflection but is blurry, making the particle look bigger than it actually is.

[0] [https://youtu.be/TXMGu2d8c8g?t=2729](https://youtu.be/TXMGu2d8c8g?t=2729)

~~~
lutorm
It happens right as the spacecraft is recoiling from the separation impulse,
so I'd guess it's something coming off from the top of the stage and passing
by the camera.

------
jacquesm
Hah, they did it! 3 Landings (2 side boosters and the center core). What a
sight!

~~~
just_myles
The third one landed on a drone in the middle of the ocean. Call me crazy but
wouldn't that be a moving object?

Insane. All 3 rockets.

~~~
jacquesm
The drone ship does what it can to be as stationary as possible but the swell
will always move the platform to some extent so the ocean landings are a lot
more impressive than the land based ones.

~~~
ehsankia
I've always been curious as to why that drone is so damn tiny compared to the
rocket. Wouldn't make it slightly larger reduce your chances of missing the
platform, or are they just that confident about their accuracy?

~~~
ambicapter
The drone ship is almost the size of a football field.

~~~
ehsankia
Huh, you're right. It's really hard to get a sense of scale.

[https://www.teslarati.com/wp-
content/uploads/2018/02/OCISLY-...](https://www.teslarati.com/wp-
content/uploads/2018/02/OCISLY-and-Roomba-123117-johnabc123.jpeg)

------
spaceheretostay
FH is reliably going up and coming down, which is incredible: my attention is
barely here since they are building multiple Starship Hopper test articles in
the open fields of south Texas. [1, 2]

The increasingly most likely scenario with SpaceX and BO is that we'll have
self-sufficient Mars colonies and space colonies in the next few decades. The
funding is economics-based this time around rather than taxes and government
projects, making it less volatile and less likely to be cancelled. Pumped!

[1] Tethered first test:
[https://twitter.com/elonmusk/status/1114390314565787648?s=19](https://twitter.com/elonmusk/status/1114390314565787648?s=19)

[2]
[https://forum.nasaspaceflight.com/index.php?topic=47730.msg1...](https://forum.nasaspaceflight.com/index.php?topic=47730.msg1934099)

~~~
losteric
> we'll have self-sufficient Mars colonies and space colonies in the next few
> decades. The funding is economics-based this time around rather than taxes
> and government projects, making it less volatile and less likely to be
> cancelled

Lunar and asteroid support colonies, sure, but what is the sustainable profit
model for Martian colonies?

~~~
philipkglass
I seem to recall that Robert Zubrin's book "The Case for Mars" suggested
selling Martian deuterium to Earth. That idea is tied with "mine the Moon for
helium 3" as the least plausible business idea that otherwise-smart people can
suggest with a straight face.

EDIT: he also shared this idea in articles.

[https://space.nss.org/the-promise-of-mars-by-robert-
zubrin/](https://space.nss.org/the-promise-of-mars-by-robert-zubrin/)

 _Deuterium, the heavy isotope of hydrogen currently valued at $10,000 per
kilogram, is five times more common on Mars than it is on Earth. Deuterium has
its applications today, but it is also the basic fuel for fusion reactors, and
in the future when such systems come into play as a major foundation of
Earth’s energy economy, the market for deuterium will expand greatly._

 _Martian colonists will be able to use rocket hoppers using locally produced
propellants to lift such resources from the Martian surface to Mars’ moon
Phobos, where an electromagnetic catapult can be enplaced capable of firing
the cargo off to Earth for export. ..._

~~~
mikeash
Is it really cheaper to get deuterium from Mars than it is to refine it from
water on Earth?

~~~
philipkglass
No.

------
taylorlapeyre
At about 45:45 of the stream, there's a quick video of what looks like camera
footage of purple gas or liquid swirling around — really unworldly! Does
anyone know what that video is of?

[https://youtu.be/TXMGu2d8c8g?t=2745](https://youtu.be/TXMGu2d8c8g?t=2745)

~~~
taylorlapeyre
More information from my friend at SpaceX:

> This camera is on the second stage inside of the liquid oxygen tank. It’s on
> the top of the inside of the tank looking straight down, and what’s in the
> middle there between all lines pointing outward is the outlet of the tank
> that feeds the engine. I have no idea why the liquid oxygen looks kind of
> purple but this is a super cool shot because you can see the outlet, which
> has a device on it to make sure we don’t suck any gas through, and on the
> left side you can see one of the black tanks we fill with gas to keep the
> tanks pressurized to feed the engines!

~~~
phkahler
They used to show tank footage more. IIRC they don't any more for secrecy
reasons (government request?). Managing fuel in the tank is probably non-
trivial.

------
blhack
How incredible is it that FH is launching, and that they landed all three
boosters, AND that it isn't even a news story anymore. Amazing.

~~~
jacquesm
It's funny, if it went wrong more often it would be news but they make it look
so easy.

~~~
ridgeguy
They really do make it look easy, don't they?

These days, it seems like the hardest part of a SpaceX launch is maintaining
the drone recovery ship video link.

Even though it looks easy, it's never gonna get old. Not for me, anyway. So
great!

~~~
himlion
I really hope this will get old eventually, that means we have truly entered a
new era for space launches and hopefully space exploration.

------
mikejb
For those not lucky enough to explore this in person, Destin Sandlin from
Smarter Every Day made a video [1] (from the test launch last year) that gives
you a somewhat acoustical representation and a lot of good explanations.

I haven't seen a Falcon Heavy launch, but I've been lucky enough to see a
'normal' Falcon9 launch. There's 2 things that I know I didn't expect: The
sound is just beyond anything. And I think the video above brings that across
at least to some extend. The other part that surprised me when seeing a launch
with my own eyes: The exhaust is _bright_. It gets lost quite a bit through
cameras, so I was surprised how bright those flames are - even 30-45 seconds
in, when the rocket is dozens of miles away.

[1] [https://youtu.be/ImoQqNyRL8Y](https://youtu.be/ImoQqNyRL8Y)

~~~
JshWright
I recently took my daughter to a Falcon 9 launch (the launch that included the
moon lander that failed yesterday, actually). It was a night launch, and the
exhaust was almost painfully bright.

------
taylorlapeyre
There it is! [https://imgur.com/a/gPBmGzj](https://imgur.com/a/gPBmGzj)

------
mikepurvis
Looks like no word yet on fairing recovery— according to the reddit thread,
there were ships assigned to that duty, but it wasn't mentioned in the webcast
and there's no updates I can see on it.

~~~
teabee89
Elon just said, they recovered the fairings from the water undamaged and they
are intending to reuse them for Starlink later this year. Source:
[https://twitter.com/elonmusk/status/1116514068393680896](https://twitter.com/elonmusk/status/1116514068393680896)
and
[https://twitter.com/elonmusk/status/1116514534557016064](https://twitter.com/elonmusk/status/1116514534557016064)

~~~
DennisP
Jeez I had no idea the fairings had their own thrusters, steerable parachutes,
and avionics.

------
ninjamayo
Truly amazing stuff! SpaceX deserves all the credit. Three boosters landing is
an amazing feat.

------
ebg13
At 45:09 (T+ 00:25:12) for less than a second the video flips
to...something...weird. Anyone know what that is?

[https://youtu.be/TXMGu2d8c8g?t=2707](https://youtu.be/TXMGu2d8c8g?t=2707)

Screenshot: [https://imgur.com/GcDytsl](https://imgur.com/GcDytsl)

~~~
ajuca
LOX tank cam - similar to this:
[https://www.youtube.com/watch?v=PPnCKK1isMI](https://www.youtube.com/watch?v=PPnCKK1isMI)

------
natch
Going for 4 for 4! Let’s not forget the successful payload orbit insertion.
:-) We’ll see in ~15 minutes. Edit: Congrats SpaceX!

~~~
jacquesm
Nailed that too. What a day!

------
ricardobeat
I always wonder why they don't deploy a [flying] drone next to the drone ship,
to film and broadcast the landing from a safe distance. Probably just not
worth the effort.

~~~
brandonjm
Good question, and you are probably correct, not worth the effort. There was
one launch where they broadcast the drone ship landing from a nearby support
ship (or helicopter, I don't remember exactly) which was cool to see but I
haven't seem them do it since.

------
bane
Jawdropping.

At this point, how far ahead is SpaceX from any other launch effort? 5 years?
10?

~~~
nickik
The only competition is BlueOrigin really. They are optimistically only 3-4
year behind. Then they should have a rocket comparable to Falcon Heavy.

The Russians are not really playing other then cheap mass production of old
tech.

The European spent 4 years arguing and then came up with a something to
compete with at the point when they started arguing. Now it will take another
4 years and then they are still far behind what SpaceX had 10 years ago. And
that is totally without re-usability, in that they are another 5-10 years
behind.

China is doing lots of things, but not as advanced or impressive and while
they grind ahead consistently they are not close to SpaceX right now. At least
they progress forward.

ULA is like Europe, targeting what SpaceX had 7 years ago and they will get
there in 2-3 years. And then it will be far less impressive still in terms of
re-usability.

India is just deploying cheap old tech.

That's basically it. SpaceX owns 50% of the US government launches, 50% of
global commercial launches (large once at least). All the survives are 100%
government depended, the commercial launch market is basically not close to
profitable for anybody but SpaceX.

In terms of engine technology, its the same SpaceX and BlueOrigin are about to
surpass the old glory of the US and the Russians and are moving into a new
area.

~~~
djsumdog
You forgot about RocketLabs in Auckland. (I know they're no where near to
SpaceX/BlueOrigin, but I know people who work there, so it kinda has a special
place in my heart).

~~~
nickik
I love RocketLabs. But lets be real, that's a tiny launcher. It really not in
the same market as SpaceX, BO, ESA, ULA and so on.

There are quite a few tiny launchers coming and RocketLabs is ahead of
everybody. They did a great job, major probs.

But it like comparing electric scooter company compared to Tesla.

------
any626
Screenshot: [https://imgur.com/a/qocmdE1](https://imgur.com/a/qocmdE1)

------
monkin
Congrats to everyone at SpaceX for this epic achievement!

------
jaytaylor
What are all the debris in the image [0] while the payload is coasting @ 192km
above the earth?

[0] [https://youtu.be/TXMGu2d8c8g?t=2740](https://youtu.be/TXMGu2d8c8g?t=2740)

~~~
KindOne
[https://youtu.be/TXMGu2d8c8g?t=2864](https://youtu.be/TXMGu2d8c8g?t=2864)

Solid oxygen.

~~~
monk_e_boy
Fluffy frozen oxygen, low mass. Bleeds from tank, all normal apparently

------
Udik
I can picture the engineers of all the other commercial space companies in the
world watching this and laughing, cheering and crying at the same time :)

------
nickik
This will be the closed to full reusability we ever came. The only thing that
is not reused is the second stage. The boosters, core and the fairing are all
removed, getting you up to 80% of the capital cost can be recovered.

------
slics
Amazing and beautiful engineering. Imagine the satisfaction and the feeling
you get knowing that you are part of a team that made all of that soar through
the sky and back home safely. /applause

------
shafyy
FUCK YEAH.

------
joebubna
Great job SpaceX!!!

So proud of them for pushing human space exploration forward.

------
makosdv
Luckily, I heard about it on the radio on the way home from work and got home
a couple minutes before the launch, so I could watch it from my front yard.

------
hsnewman
Thank you Elon for advancing mankind in such a spectacular way! You are a good
person.

------
OrgNet
Oops... forgot to walk outside to take a look.

------
dantheman
Amazing! Such an inspiration!

3 for 3, Good job SpaceX!

------
NeoBasilisk
This still looks like sci-fi to me.

------
jeffnappi
That was fun to watch ＼(＾O＾)／

------
perilunar
3 for 3! Beautiful!

------
qwertox
Historic

------
hsnewman
My congratulations to Elon!

------
aphextron
How on earth could they have not solved the drone ship landing video feed
issue yet? Is it really that hard to keep a video camera working near a
landing rocket? Even if the feed cuts out, can they not just record it locally
and rebroadcast? It makes absolutely no sense.

~~~
walrus01
It makes absolute sense considering the live video feed is probably coming via
a motorized 3-axis tracking Ku-band maritime VSAT system. If you look at
aerial photos of the drone ships you can see the radome.

I suppose if they wanted to keep a feed up it would be possible to connect the
cameras/network equipment on the ship to something with an ordinary 10Gbps
1310nm LX fiber SFP+ in it, attach 1 km of submarine rated fiber optic cable
to a series of floats, and run a fiber optic cable to a small nearby ship with
the satellite uplink mounted on it.

~~~
drcross
Great idea. Fouling the rotating props as they maintain GPS dead reckoning may
be a risk they don't want to take.

~~~
walrus01
Yeah, it'd have to be some kind of weird setup with the fiber coming off an
extension arm sticking out from the side of the barge, and then at an angle
into the water. Dynamic positioning vessels generally don't take kindly to
having rope shaped things hanging around in the water near their thrusters.

If you have a ship nearby with the VSAT uplink, another way to do it would be
a really low cost IP data point to point link in the 900 MHz band, even if the
fresnel zone is deep into the water, it'll be good enough for 15-20 Mbps of
traffic. Way more than the bitrate of the video coming off that camera.

Something like two Cambium PMP450i radios, two dual polarity 3 ft long yagi
antennas, set up as a layer 2 ethernet bridge. The spread of that type of
link's RPE in the 900 band means that as long as the VSAT uplink ship had
_some_ ability to stationkeep relative to the barge, you wouldn't even need
motorized tracking antennas on both barge + uplink ship.

~~~
dzhiurgis
Or just use something like Iridium...

Or keep it as it is. Adds to the drama.

~~~
walrus01
Iridium in its current form is 2400-3000 bps... The next generation network is
not really commercially available yet. Can't squeeze much h265 video through
that.

~~~
dzhiurgis
That's Iridium Go - pocket sized device. Certus devices (new constellation)
does 360kbps, probably more if you signup for something.

