
SpaceX lands rocket at sea second time after satellite launch - dnetesn
http://phys.org/news/2016-05-spacex-successfully-rockets-stage-space.html
======
kirrent
For those wondering, this isn't a simple repeat of CRS8 which landed on a
drone ship about a month ago. CRS8 was a mission to low earth orbit which left
the first stage with plenty of fuel to effect a landing. The landing was made
as slow as possible and limited only by how low a single engine could be
throttled. The re-entry burn which slows the rocket down before the landing
burn was also more agressive.

This mission was to launch JCSAT-14 to geosynchronous orbit which requires the
falcon 9 to move the already heavy satellite into a geosynchronous transfer
orbit. That meant the first stage had to do a lot more work and was left with
a lot less fuel as a result. Therefore, the re-entry burn was less aggressive,
the first stage came in with twice the speed, and SpaceX needed to do a far
harder landing with three engines lit in the quicker and riskier suicide burn.
Somehow, despite playing down expectations, they managed an even more precise
landing than last time.

~~~
downandout
From the video it looks like it lands on a ship in rough seas and they do
nothing to secure it. Won't it just fall over if the seas are rough enough,
and if so, why don't they have some sort of robotic system that locks it down
tight the moment it lands?

~~~
robin_reala
All of the centre of gravity is low down with the engines. The rest is
basically just a thin empty tube.

~~~
bkor
To add to above: In the previous barge landing they did weld the landing legs
to the barge using some kind of bracket. But they discovered that the centre
of gravity is low enough to not need any welding. During the previous attempt
the sea was heavier than this time.

Maybe they still weld it this time, but that is done by having someone go to
the barge and do it.

~~~
vermontdevil
Actually no they did not weld anything to the legs. Elon said that they
realize it wasn't needed. They did use octojack though to support the weight
off the legs.

~~~
tlrobinson
What's octojack? Can't seem to find any other references to that.

~~~
vermontdevil
Sorry meant Octoweb jacks

[https://imgur.com/5GTW1CO](https://imgur.com/5GTW1CO)

------
geerlingguy
What's notable about this attempt (as opposed to the last) is that the first
stage rocket was traveling twice as fast (4x the energy to overcome on
landing), and didn't have enough propellant to do a 'boostback' burn.

Instead, coming in very hot, the rocket had to use three engines (instead of
one) to slow for landing. The last time this was attempted, the first stage
put a nice hole in the deck of the drone ship.

Seeing the rocket dead-center on the barge was quite a sight!

~~~
prplhaz4
One of my favorite facts is that merely relighting the engine provides enough
thrust to lift the rocket (at its minimum throttle of 60%).

This means that it must slow to a standstill, cut the engines and hit the
platform at exactly the same time or it will either start going up again or be
dropped onto the platform from a less than ideal height.

~~~
542458
This maneuver (powered descent with high deceleration right before impact) is
called a "suicide burn"!

------
manaskarekar
Hosted webcast: [https://youtu.be/L0bMeDj76ig](https://youtu.be/L0bMeDj76ig)

Landing at 38:18mins
[https://youtu.be/L0bMeDj76ig#t=38m18s](https://youtu.be/L0bMeDj76ig#t=38m18s)

Great info on the thrusters on the first stage at 19:37.
[https://youtu.be/L0bMeDj76ig#t=19m37s](https://youtu.be/L0bMeDj76ig#t=19m37s)

Edit: Thank you and sorry about the time stamp link, I posted quickly from my
phone. Hopefully it works on shortlinks.

~~~
robbiemitchell
You link directly a specific place by adding this to the URL: #t=38m18s

~~~
chipaca
you can also make it a query parameter, which often works better. E.g.
[https://youtu.be/L0bMeDj76ig?t=38m18s](https://youtu.be/L0bMeDj76ig?t=38m18s)

------
js2
Webcast - [https://youtu.be/L0bMeDj76ig](https://youtu.be/L0bMeDj76ig)

First stage landing is just after 38 minutes -
[https://youtu.be/L0bMeDj76ig?t=38m](https://youtu.be/L0bMeDj76ig?t=38m)

------
EA
Doing it one time is a technological leap.

Doing it twice in such a small window of time is a logistical/programmatic
leap.

~~~
xadhominemx
Were they different rockets? If so I don't see the logistical leap.

~~~
hoorayimhelping
Different use cases. This was a GTO launch which means the first stage had way
more energy and therefore way tighter margins than the last attempt. This
attempt used three engines to land and had a more difficult landing
trajectory.

------
mulmen
Looks like the landing was perfectly centered on the barge this time as well.
Does anyone know when they plan on reusing one of these recovered first
stages?

~~~
haser_au
They said at the beginning of the live stream that they plan to do a test fire
on the first recovered first stage "sometime soon".

~~~
agildehaus
The first recovered stage, F9-021, has already been static fired and will
likely end up as a monument outside of SpaceX HQ as they've filed an FAA
request to do so.

[https://oeaaa.faa.gov/oeaaa/external/searchAction.jsp?action...](https://oeaaa.faa.gov/oeaaa/external/searchAction.jsp?action=displayOECase&oeCaseID=277099798&row=292)

The second recovered rocket, F9-023, will be relaunched. It has already been
static fired with no announced problems. Elon said it'd be a few months before
a customer was announced, but the general feeling is that it will be an SES
satellite as SES has already publicly expressed interest.

~~~
kchoudhu
Do customers get a discount for launching on a used rocket?

~~~
lmm
The first one definitely will (unless negotiations break down and they decide
to launch without a customer, but that seems unlikely). Eventually when it
becomes routine maybe not.

~~~
Mchl
When it becomes routeine all clients get a discount as price per launch goes
down.

~~~
kchoudhu
Or not, because the next best alternative is much more expensive than SpaceX's
current pricing.

We're dealing with a corporation -- I'm not sure we can count of them to "pass
on the savings".

~~~
TeMPOraL
We're dealing with a group of people with strong ideas about space. They
probably won't pass on much of the savings, but for a different reason - they
need the budget for Mars project. That's the _whole purpose_ this company
exists in the first place.

~~~
stcredzero
If they're smart (and they are) they'll figure out ways to reduce the price of
launch in the right way to maximize an increase in their margins. They could
more than double the number of customers using secondary space in the "trunk"
and cube-sats. The secondary customers will pay far less than the primary
ones, but there will be many more of them.

If they're smart, they're figuring out ways they can own a big part of the
infrastructure for an emerging market.

------
ino
How are non-US space agencies and companies (like ESA, Russia, Japan, China,
etc) reacting to the SpaceX and Blue Origin achievements?

Are they also testing similar things but we aren't hearing? Or they aren't
threatened by the advances?

~~~
LocaX
I attended a conference from the head of the CNES (Centre National d'Etudes
Spatiales, ~ French NASA) in Paris a week ago and he talked about that.

Ariane 6 is going to be built with a cost effective approach and trying to
focus on market needs (3D printing of parts, reusability of the first stage,
etc.)

At first, concerning SpaceX, his group of experts told him that the design of
the rocket wasn't going to work and was going to explode at high altitude due
to fluctuation. They also told him that the first stage would just go through
the barge, sinking both the first stage and the barge. Now they are taking new
entrants way more seriously.

~~~
mikeash
I can't imagine how anyone with the slightest clue could conclude that the
first stage would sink the barge. The scales are just too different; the barge
outweighs the rocket by orders of magnitude.

I hope this is one of those "lost in translation" things, because otherwise I
fear for that group of supposed experts.

~~~
rdancer
> the barge outweighs the rocket by orders of magnitude

The energy amount the rocket impacts with is dominated by its speed, not its
mass. A small, fast-travelling projectile can make a hole in just about any
kind of armour. The terminal velocity is quite low, but that's in part because
of the way it is engineered — an ICBM would probably be able to put a hole
through a ship deck with ease.

There is a lot of reasoning by analogy vs. reasoning from first principles
going on, and the latter seems to be winning. But the main driver of the space
industry is governmental funding, not commercial. Much of those statements
were probably political; SpaceX have prevailed, and indeed found some
champions of their own (John McCain is rabidly behind them, and some of the
statements he comes up with are ludicrous in their own right, for example),
though not before enduring some setbacks.

~~~
ansible
_The energy amount the rocket impacts with is dominated by its speed, not its
mass. A small, fast-travelling projectile can make a hole in just about any
kind of armour. The terminal velocity is quite low, but that 's in part
because of the way it is engineered — an ICBM would probably be able to put a
hole through a ship deck with ease._

While what you've said is true, in practice it isn't a problem.

If the F9 first stage is out of control and going too fast, it will almost
certainly miss the barge to begin with. The barge is small, the ocean is big,
and the F9 has to maneuver very precisely to reach it.

If it does reach the barge, it will likely be moving relatively slow, and thus
is less likely to sink the barge, even it things go crazy at the last moment.

~~~
MertsA
That brings up an interesting question, can't the range safety officer just
scuttle the first stage after separation? I can't imagine that they don't have
that capability after separation.

~~~
ansible
After a certain point in the stage 1 ascent, they disable the FTS (flight
termination system). I suppose they could turn it back on for landing.

------
iamcreasy
A white ball of fire. And then there it is...resting! Beautiful!

~~~
russdill
Love how the autobalance on the cameras cut almost everything to black so you
could not see the rocket at first, until it emerged from the darkness.

~~~
glaberficken
Moon landing deniers will have a field day with that camera's footage.

~~~
adventured
Much like with the moon landings, then SpaceX will do it another dozen times,
and the deniers will pretend there was only one landing so as to fit the
narrative better.

------
zupreme
I remain confused about why SpaceX is getting so much fanfare and praise. What
have they accomplished that NASA didn't already accomplish during the Apollo
missions?

I know SpaceX is doing it all more cost effectively, because we have better
technology, but have they actually accomplished anything tangible that NASA
didn't a generation ago?

~~~
simonh
The Apollo missions were one-offs. They left nothing behind that future
missions could utilize. Everything was disposed of after use, even Spacelab
which had a very short life and completed a specific programme of missions and
then burned up.

The shuttle was the first attempt at re-usability but was far too expensive to
be viable. Only the space station is genuinely long term re-useable
infrastructure. It's something you can actually use as a platform for further
missions beyond it's initial purpose but it also has been excessively
expensive. We can't go on like this. Nobody is talking about a replacement
space station, the appetite just isn't there. Unless somebody does something,
the space station might be the last long term repeatedly occupied human
habitat in space.

SpaceX is doing something about that. If they really can reduce launch costs
by a factor of 100:1, it will change the fundamental economics of everything
we do in space. Suddenly going to the moon stops being a pointless gesture and
becomes an economically viable long term proposition. Human habitats in space
of the scale of the ISS or bigger become affordable. They're even talking
about colonizing Mars and plan to do what's effectively a tech demo of that in
2018.

For the first time the rocket man dreams of the 1970s look like they could
actually happen. For a lot of people, that's pretty exciting.

P.S. Downvotes for this question? Really? I'm as much a fan of SpaceX as
anyone but it's a fair question, SpaceX haven't even launched one of their
recovered rockets yet.

~~~
unethical_ban
The only two questions I see in your post are in the P.S. What am I missing?

~~~
simonh
I was referring to the question I was answering, which was getting greyed out.
My bad, it was ambiguous and I should have tried to that clearer.

------
grondilu
This success was unexpected. That means that they can recover a stage from a
higher speed than previously thought. Does that mean that the recovery of the
second stage from LEO may actually be feasible?

~~~
mikeash
Second stage recovery is a whole different beast. Recovering the first stage
on a flight like this is a delicate dance because margins are so small, so
everything has to go _exactly_ right. The previous attempt (SES-9) didn't
quite go exactly right, and made a big boom, perhaps because the engine burns
were slightly mistimed.

Recovering the _second_ stage is difficult because it's coming in from a much
higher speed. The first stage came in doing about 2km/s. The second stage
would come in doing 8km/s or more. That means 16x more kinetic energy to deal
with and 64x more heating. You need a proper heat shield, not just clever
engine burns. There's much less extra margin to play with as well. The second
stage does most of the work but is much lighter, and one pound on the second
stage is worth ten pounds on the first stage.

SpaceX definitely believes second stage recovery to be feasible at some point,
but not on the current Falcon 9.

~~~
ctthill
KE = 0.5mv^2, so the second stage would only have 16x the kinetic energy if
the two stages had the same mass.

The dry mass of the first stage is approximately 25,600kg. At 2km/s, its
kinetic energy is 51.2 terajoules. The dry mass of the second stage is
approximately 3,900kg. At 8km/s, its kinetic energy is 125 terajoules.

So the KE of the second stage is actually about ~2.4x that of the first stage.

Here is were I found the masses of the stages:
[http://spaceflight101.com/spacerockets/falcon-9-v1-1-f9r/](http://spaceflight101.com/spacerockets/falcon-9-v1-1-f9r/)

~~~
mikeash
I meant relative to the mass of the stage, since that's what's relevant to the
challenge.

------
tdrd
Here's the landing from the webcast video on youtube
[https://youtu.be/L0bMeDj76ig?t=2300](https://youtu.be/L0bMeDj76ig?t=2300)

------
Gravityloss
It could be argued that flying to orbit with a first stage that's being reused
will be as historical when SpaceX will do it.

The Space Shuttle did reuse SRB casings and the orbiter, it was a bit
different but a great achievement too.

However this time there is more potential for cost savings. It can still
happen that they can't be realized because of some details or even
fundamentals we don't understand from the outside.

------
samstave
Can someone please explain to me how the falcon orients itself during this
total process??

Does it use fins, or simply engines and whatever those little jets are that,
say, the space shuttle had around its nose...

How does the falcon manage to physically orient its body?

Also, is that process completely autonomous? Is there a remote flight engineer
steering this to the barge - or is it completely self-guided

~~~
cloudwalking
In space it uses nitrogen thrusters to orient. Once in the atmosphere it uses
grid fins to orient. The entire liftoff and return is piloted by Falcon's
flight computers -- no humans involved.

~~~
samstave
Thank you - how does the barge communicate with the falcon? And what types of
comminucations are they having. I assume the barge is stating its GPS
location, but does it also communicate things like sea conditions - and its
elevation (what is it called to describe the condition of the sea), as well as
wind, north-south orientation, etc...

I am impressed - but I want to know how this works.

~~~
cletusw
Rumor is
([https://www.reddit.com/r/spacex/comments/3b0stk/falcon_9_wha...](https://www.reddit.com/r/spacex/comments/3b0stk/falcon_9_what_technology_is_used_to_have_it_land/))
that the barge does not communicate any information to the booster. Instead,
it uses GPS and some ingenious motors to maintain position and orientation,
and the Falcon booster uses a radar altimeter to judge accurate vertical
distance.

~~~
samstave
Thats just fucking awesome if true. Its like "how can we maximize the use of
some 'cheaper' technology and a shit-ton of math to accomplish this in the
technologically simplest way?"

Wow.

------
Kinnard
I wonder if there's coordinate potential with seasteading? Astronauts are
gonna want all sorts of goods and services upon landing I imagine. Having
someone stationed nearby will mean swifter pickup of equipment and astronauts.
And if there's someone stationed nearby they'll want goods and services as
well.

~~~
mattbeckman
I don't think astronauts would land on the droneship, as that's just for the
first stage. When the Crew Dragon lands, it would be coming in from orbit, so
I imagine they would just target the landing platform at the Cape as part of
their de-orbiting plan.

That being said, would you want to be in the nearby path of the rockets if
they were going to be ditched?

------
leecarraher
Am i missing something, is the need to land vertically a requirement of a
fragile fuselage? Seems wasteful to carry extra anything (in this case rocket
propellant) to space, just to avoid having to re-right the rocket when you get
it back on earth for a subsequent launch. Is extra fuel payload < landing gear
or parachutes?

~~~
usrusr
Lack of wings. (That's obviously for the landing gear part of the question)

But fragile fuselage is certainly spot on. Parachute-landings still have quite
some impact velocity. Strengthening an object the size of a Falcon 9 first
stage to survive that impact would require a much stronger and thus
prohibitively heavy structure, even if the parachute itself was free. The nice
thing about powered upright landing is that all the forces involved are pretty
much the same as during launch so that there is little (if any) additional
strengthening required.

Note also how the ULA plans for the use of parachutes to recover first stage
engine blocks require the parachute to be caught in-flight by a helicopter to
avoid any uncontrolled ground contact.

~~~
gozur88
Even if you were sure the engines would survive impact, you wouldn't want your
expensive, complex rocket engine to take a dunk in salt water.

------
brianwawok
Here is the video

[http://www.space.com/32811-spacex-rocket-landing-
jcsat-14-la...](http://www.space.com/32811-spacex-rocket-landing-
jcsat-14-launch.html)

Hopefully we won't have the typical hacker news discussion about why the
employees chant USA.

~~~
shiven
Yoo.Ess.Ae! Yoo.Ess.Ae! Yoo.Ess.Aeh!

There. See. No harm, no foul.

Anyways, as a non-American living in the US since 2001, I fail to see an issue
with chanting USA, one way or another.

It is an American company, with majority US employees, running this project
(mainly) for an American entity (NASA), on US sovereign territory (or ocean?),
using a significant chunk of US resources. So, it is their company and their
country. I say, let them do what they want with it. And if chanting USA is
what they wish to do, I have no problem with that.

~~~
fit2rule
I think its offensive to have nationalistic robot-like-chanting being defended
as an okay thing. Its the sort of thing you expect people to do at rallies or
cult gatherings, and from an outsider perspective it always tarnishes what is
otherwise a very rational event, because its an implied irrational, collective
mindset. As a non-American, I wish it'd stop - its a major turnoff for these
events, and I switch away when it starts up.

I know, I know - Americans have a right to be proud, and they do. But
expressing it with a cult-like mechanism that is, essentially "our group is
great, nobody else can/has done this" is just .. revolting.

I say this, knowing full well I'm going to get down voted for it, but I really
do wish you Americans would think about it from the other side of your dark
mirror. Can't we come up with a chant that includes _all_ of humanity? After
all, America wouldn't be the nation it is today without all other nations on
Earth, including the ones that America has invaded, and destroyed completely,
wantonly, for decades.

EDIT: Feel how this post detracts from the main article, and is a distraction
from the feel-goodness of SpaceX's accomplishments? For us non-Americans,
thats how the USA-cult chant feels - a total distraction. I wish I could down
vote the chanting when I see it on TV, too.

~~~
david-given
You're getting downvoted into oblivion, but yeah, that's basically how I feel.
Cultural differences, I'm sure, because I'm not USian; but every time I see it
on the youtube videos it makes me deeply uncomfortable.

~~~
Kratisto
I'm an American, and I'm just wondering why it makes you uncomfortable? Does
chanting at sporting events make you uncomfortable as well?

edit: Reply button showed up finally

~~~
fit2rule
Its a collective/cult response, is why it makes me uncomfortable. "Everyone
else is doing it, so should I", and while its occurring, no other rational
thought is occurring. It is a known thought-stopping technique in cults.

I also despise it when it happens at sports events. Its just demeaning to
whoever doesn't fall in line and start the goose-step.

~~~
Kratisto
First "and while its occurring, no other rational thought is occurring". I'm
not really sure how to respond to that. Of course no rational thought is
taking place. It's a celebration. They aren't trying to have a rational
discussion.

Second "Its just demeaning to whoever doesn't fall in line and start the
goose-step". I have never seen anyone that is somewhere people are chanting it
and be ridiculed for not joining along. It is completely up to anyone whether
they want to participate.

I think space exploration/achievement is a very big point of pride for
Americans. Ever since the moon landing, everyone has fell in love with the
space program. Chanting USA! doesn't mean give up all rational thought and
blindly follow the countries leaders. It means a bunch of Americans just did
something amazing. I'm glad to be a part of this country that is doing great
things. It also doesn't mean go USA fuck Europe. Sure there is a little bit of
a competitive undertone, but so what. If SpaceX says look what we did, I dare
you guys to do better well then good. Competition is the reason why space
programs are where they are. Sorry you don't like how one country likes to
celebrate. Luckily everyone is free to do whatever they want.

------
ck2
The long-term plan is to put humans on these right?

How many years out is that?

~~~
lfuller
One. They're planning on testing manned missions with their Dragon 2 and
Falcon Heavy in mid-2017.

~~~
ck2
Wow are they really ready for human life onboard in a year?

Unmanned failure doesn't bring much press.

Kill a few people and it will set back the whole program years.

~~~
mikeyouse
Since they don't have to deal with the insulation issues like the shuttle did,
the most dangerous phase of flight for a crew is during launch. Last Spring,
SpaceX demo'ed their launch abort system which in theory should be able to
protect the astronauts against any launch problems;

[https://www.youtube.com/watch?v=1_FXVjf46T8](https://www.youtube.com/watch?v=1_FXVjf46T8)

------
Ferver777
Simply incredible. Elon Musk is the New Thomas Edison

~~~
bryanlarsen
Musk would probably be offended by that comment -- Nikola Tesla and Thomas
Edison were bitter rivals and enemies.

~~~
mathgenius
I get the impression that Edison was more of a showman than a business man.
Musk is at a whole other level.

~~~
j1vms
Tesla is _really_ great, but there exists a "take" on Edison that makes him
also not so bad.

Here, listen to Linus talk about him a bit:

[https://youtu.be/o8NPllzkFhE?t=17m24s](https://youtu.be/o8NPllzkFhE?t=17m24s)

Linus: "I'm more of an Edison..." (TED2016, Feb. 2016)

------
hcrisp
"One if by land, two if by sea..."

------
hoorayimhelping
> _P.S. Downvotes for this question? Really?_

There are always people on HN who love being contrarian and trying to diminish
amazing things. It's like they hate seeing people excited for something and
want to point out that this isn't that big of a deal.

We're literally watching things happen for the first time ever, and this
person's response is "what's so great about this?" while implying that people
who are excited about this are fanboys. I can understand the downvotes
honestly.

~~~
mattmanser
This is a new thing, 2-3 years ago downvotes were still rare, these days
people treat it like reddit where it means disagree rather than inappropriate.
The culture's changed.

~~~
eric_h
The karma threshold for downvotes likely means that there are far more people
with the ability than there were 3 years ago. Honestly, I only collected
enough karma recently to down vote (and it's a privilege I use quite
sparingly).

------
neals
I always try to watch the webcasts and I can't help but cringe so hard when
they start chanting 'USA USA USA', every single time.

What is up with that?

~~~
simonh
As a Brit we don't have anything as catchy. UKGBNI, or even just UK doesn't
have the same ring to it. 'Enganld' wouldn't work because we're too diverse.
It would be a bit like the SpaceX folks cheering 'California' in that I'm sure
a lot of them are from elsewhere.

I've come across it in a few other contexts and I take it like a football
chant.

~~~
Udik
"God save the Queen"?

That would be great fun.

------
smegel
This is one of those turning points in human history.

~~~
fixermark
Not quite "The polio vaccine," but certainly higher up than "laser-based
Christmas decorations." ;)

------
jklinger410
I find the level of criticism for SpaceX on this site to be incredible.

I understand this is a place for intelligent discussion, but sometimes I feel
like I can't find a single thread on this site without someone in the comments
presuming they are smarter than someone else.

~~~
typon
What is it about software development that brings out these kinds of people?

~~~
ekun
Ive noticed it in any technical field. People love to hear themselves talk and
miss out on a lot by not listening to others.

------
thrownear
Ok. Can we have less of Tesla/SpaceX posts. There is already one discussion
about this in the front page...

~~~
castis
Be the change you wish to see in the world.

------
SagelyGuru
Good work! I still think that they should have some grippers on the barge, or
a net, ready to spring and grasp the rocket on landing, instead of carrying
flimsy legs all the way to space and back.

~~~
ohitsdom
The current legs aren't flimsy, and they seem way less complicated than a
gripper system would have to be. How would a gripper system handle off-
centered landings? It would have to catch the falling rocket very quickly
because there's not much fuel left in the tank to hover. Your proposed system
would add a lot of complexity, all for the small decrease in launch mass.

~~~
taneq
I'm still surprised there's no active system on the barge to secure the
rocket. Even now they seem to be able to stick the landing with some
reliability, it's always nice to have belt and suspenders.

I'm thinking a system with a pillar at each corner of the barge, pairs of
cables between opposite pillars, and puller cables to open out the main cables
into an iris-type aperture which can be rapidly closed on the rocket after it
lands to keep it upright. Do that at 2-3 heights above the barge and it'll
cradle the rocket even in heavy seas.

~~~
JshWright
The center of mass of the rocket is _very_ low. According to Elon, the CRS-8
core was very stable (it needed even less stabilization than they thought it
did).

They may add some means to secure it if it needs to travel through rough seas
on the way home, but if the conditions are calm enough to land, they're calm
enough for the stage to be stable. Watch the CRS-8 landing and look at how
much the barge is rolling while the stage is parked on it...

~~~
omni
The response crew comes and secures the legs on the barge immediately after
landing. They bolt them down somehow, I think.

~~~
taneq
There's a response crew? Like, people? Are they on a boat nearby? I may have
misinterpreted "drone ship". :/

~~~
JshWright
Yes, the Go Quest is nearby with a support crew to deal with the stage after
it lands.

------
gist
The big difference between landing at sea and on land seems to be the PR
value. Otherwise a target is a target, taking any differences in weather into
consideration. In fact it seems that landing at sea is actually less pressure
since you don't have the same safety concerns and crash pictures (which are
bad for publicity) the rocket simply disappears.

~~~
aerovistae
Completely incorrect.

The question to ask is, _why_ are they bothering to land at sea?

And, if you had done any cursory research instead of just announcing that
SpaceX is making a PR grab because it sounded good to you, you would have read
in the abundantly available explanations that this launch was to geostationary
transfer orbit, rather than low earth orbit. GEO is a lot, lot higher than
LEO, which means the rocket has to be going a LOT faster to get there. This
uses up a lot of fuel, leaving them very little to slow down from an even
higher speed than the normal mission. Decelerating from a much higher speed
takes MORE fuel than decelerating from a low speed, and they have less fuel
available because so much got used up in getting to that speed.

So it's not plausible to get all the way back to the launch site. Instead they
position a droneship way downrange so the rocket doesn't have to go as far
back to land. But it's still going EXTREMELY fast, and managing to slow down
all the way and land is an incredible accomplishment.

~~~
gist
> So it's not plausible to get all the way back to the launch site.

I never said return to the launch site. I said return to land.

> if you had done any cursory research instead of just announcing that

Unnecessary to speak that way in order to make your point unless you are
trying to specifically make someone feel bad for voicing their thoughts.

~~~
aerovistae
I'm not trying to make you feel bad, I'm trying to point out that you
deliberately chose pejorative phrasing without having done any research. I'm
trying to point out that it's not constructive to talk about someone else's
work like that without at least learning what they're even doing or why
they're doing it.

