
New Shepard: Bezos claims success on second spaceship flight - lentil_soup
http://www.bbc.com/news/science-environment-34909713
======
vassvdm
Elon's reaction (quoted from Twitter):

"Congrats to Jeff Bezos and the BO team for achieving VTOL on their booster

It is, however, important to clear up the difference between "space" and
"orbit", as described well by [https://what-if.xkcd.com/58/](https://what-
if.xkcd.com/58/)

Getting to space needs ~Mach 3, but GTO orbit requires ~Mach 30. The energy
needed is the square, i.e. 9 units for space and 900 for orbit."

~~~
jacquesm
I don't see Blue Origin claiming 'orbit' anywhere so I fail to see why that
bit needed any clearing up. It is the L bit that SpaceX seems to have had some
problems with to date. Musk could simply congratulate Blue Origin and leave it
at that.

~~~
chriskanan
I'm guessing that Musk felt the need to do that because some of the early
reports about Blue Origin's success were using it as a platform to trash
SpaceX for failing to land on the barges. This Gizmodo article (before they
changed it due to all the comments complaining) was a good example:
[http://gizmodo.com/jeff-bezos-new-rocket-just-made-a-
control...](http://gizmodo.com/jeff-bezos-new-rocket-just-made-a-controlled-
vertical-l-1744370201)

It was significantly longer earlier today, but it contained a factually
inaccurate comparison.

Here are a couple more examples:

Wired: "Jeff Bezos just accomplished the near impossible: one-upping Elon
Musk"

Link: [http://www.wired.com/2015/11/jeff-bezos-brags-on-rocket-
land...](http://www.wired.com/2015/11/jeff-bezos-brags-on-rocket-landing-with-
mic-drop-first-tweet/)

Engadget: "Jeff Bezos beats Elon Musk's SpaceX in the reusable rocket race"

Link: [http://www.engadget.com/2015/11/24/blue-origin-reusable-
rock...](http://www.engadget.com/2015/11/24/blue-origin-reusable-rocket-
landing/)

~~~
jsprogrammer
That still has nothing to do with orbit, making Elon's tweet(s) a non-
sequitor.

Edit: I see the Musk posse has arrived at this comment.

~~~
dtparr
When stories with titles like "Your Move, SpaceX: Blue Origin Just Secretly
Landed a Reusable Rocket"[0], "Blue Origin Beats SpaceX In Landing Reusable
Rocket"[1], "Move over SpaceX! Jeff Bezos' Blue Origin successfully lands a
reusable rocket in Texas beating Elon Musk's firm to it"[2], are the main
articles about it for me on google news, I can understand how he might feel
the need to make the point to the general public that they've not achieved the
feat SpaceX is attempting.

[0] - [http://motherboard.vice.com/en_uk/read/your-move-spacex-
blue...](http://motherboard.vice.com/en_uk/read/your-move-spacex-blue-origin-
just-secretly-landed-a-reusable-rocket) [1] - [http://www.popsci.com/blue-
origin-beats-spacex-in-landing-re...](http://www.popsci.com/blue-origin-beats-
spacex-in-landing-reusable-rocket) [2] -
[http://www.dailymail.co.uk/sciencetech/article-3331885/Move-...](http://www.dailymail.co.uk/sciencetech/article-3331885/Move-
Space-X-Jeff-Bezos-Blue-Origin-successfully-lands-reusable-rocket-Texas-
beating-Elon-Musk-s-firm-it.html)

~~~
jsprogrammer
Through all the ads on those sites, I still saw nothing about orbit.

The reusable part of a Falcon (assuming it actually lands undamaged)[0]
doesn't go into orbit either.

Edit: Stay classy HN.

[0] "I don't expect the Falcon 9 to have a reusable upper stage"
[http://shitelonsays.com/transcript/elon-musk-at-mits-
aeroast...](http://shitelonsays.com/transcript/elon-musk-at-mits-aeroastro-
centennial-part-1-of-6-2014-10-24)

~~~
ChrisClark
You are focusing on the word 'orbit' and not the overall meaning. The forest
for the trees. You are being downvoted for arguing about something completely
pointless.

~~~
jsprogrammer
If my comments are pointless arguing, so are Elon's.

Worse, Elon's are just factually incorrect (e.g. "The energy needed is the
square, i.e. 9 units for space and 900 for orbit.") [and, yet, it remains,
uncontested, at the top of this thread].

>It is, however, important to clear up the difference between "space" and
"orbit", as described well by [https://what-if.xkcd.com/58/](https://what-
if.xkcd.com/58/)

is a non-sequitor because no one seems to have confused space and orbit.
Additionally, the comparable part of SpaceX's machines (the first stage of the
Falcon 9) doesn't go into orbit (it is supposed to land not far from the
launch site and _does not_ loop around the Earth to do it).

What is the import of "orbit"? Elon is the one that brought the word into the
conversation, not me.

>You are focusing on the word 'orbit' and not the overall meaning.

Then, please, what is the overall meaning of those tweets?

~~~
dtparr
Regarding the factually incorrect bit, could you elaborate? I was under the
impression that the energy required was proportional to the square of the
velocity, so a 10x increase in velocity (from ~Mach 3 to ~Mach 30) would
result in a 100x increase in energy required, which seems to be what he's
saying.

Is my understanding inaccurate?

~~~
jsprogrammer
Well, if you take the sentence:

>The energy needed is the square, i.e. 9 units for space and 900 for orbit.

at face value. It is either claiming that 9^2 = 900 or, it either mistated the
units for space or mistated the units for orbit. This is incorrect.

If you take into account the context of the prior sentence:

>Getting to space needs ~Mach 3, but GTO orbit requires ~Mach 30.

you can probably work out 3^2 = 9 and 30^2 = 900. However, as InclinedPlane
said, that's only in an idealized number, in reality, you must expend even
more energy than that to achieve Mach 30 from the surface of the Earth.

We can check back to the prior contexts:

>Congrats to Jeff Bezos and the BO team for achieving VTOL on their booster

>It is, however, important to clear up the difference between "space" and
"orbit", as described well by [https://what-if.xkcd.com/58/](https://what-
if.xkcd.com/58/)

To be short: you'd need to find where Jeff Bezos or the BO team claimed
anything about "orbit".

Since others have already given up on this conversation, I probably will too.

~~~
mikeash
You simply misunderstand the "square" statement. It is factually correct.

You seem to understand it later, where you say that 3^2 = 9 and 30^2 = 900, so
what's the deal?

~~~
jsprogrammer
>so what's the deal?

I assume you stopped reading mid-sentence.

Getting to orbit from the surface of the earth requires more energy
expenditure than "the square" of getting to space.

------
ColinWright
The same thing is being mentioned in several places elsewhere, but to put some
numbers on it:

Orbital velocity is in the vicinity of 7500 to 8000 m/s. At that speed your KE
is 1/2.m.v^2 which is about 32e6 Joules/kg.

Orbits are, conveniently, at about 320 km, so your PE is m.g.h, or about about
3.2e6 Joules/kg.

In other words, the energy to get to orbit is ten times the energy to get to
the altitude of orbit, and this exercise only got to 1/3 of that. So the
energy involved was about 1/30 of that required to put something in orbit.

It's still a fantastic achievement, and an important - nay, critical - step on
the way to properly reusable rockets, but it does lend some perspective to it.

~~~
waterlesscloud
That's neat.

But what I see on video is Bezos landing a rocket and Musk blowing up a
rocket.

I understand the technical differences, but in terms of media, this is a pure
win.

~~~
rakoo
What I see is Musk supplying the ISS, and Bezos doing a PR stunt.

Let's try comparing those on more than just media, shall we ?

~~~
fixermark
Perhaps, perhaps not.

Financially speaking, between the two goals, there's enough money concentrated
in private individuals' hands that you might be able to find six people
willing to shell out for space tourism.

Government funding supplies the ISS. A laudable goals, but there's a grim
realpolitik view that suggests it's not as guaranteed sustainable of a market
as space tourism.

On the other hand, SpaceX's goals also allow for deployment of orbital
payloads... Now _that 's_ lucrative.

------
danielvf
I noticed a major difference in the landing sequences of the New Shepard and
Falcon 9 first stage.

The Falcon 9 first stage, if I recall correctly, is incapable of either
hovering or slowly decending. The engine has simply too much power. A Falcon 9
first stage, stopped mid air has two choices, keep the motor on and go up, or
turn the motor off and fall - and I don't think the motor has too many extra
restarts available.

Because of this inability to hover the Falcon 9 first stage, SpaceX is
attempting to have the rocket's vertical velocity reach zero at the exact
moment the rocket reaches the pad. This is why when you watch the grasshopper
or other SpaceX landing videos, you always wonder for a split second if the
rocket has just smashed into the ground. In order for this to work, all nine
axis (three each of position, rotation, and velocity) must be brought to zero
at exactly the same fixed time. This is insane level control theory here.

Now this type of landing is theoretically possible - and I think it has been
tested on the grasshopper at lower speeds, but it scares the willies out of
me. There's almost no room for error nor for the chaos of the universe.

New Shepard on the other hand, comes to a hover about 100? feet above the pad,
moves horizontally to be above the pad, stops, then lowers itself down. This
is tremendously simpler since the rocket only really cares about one or two
set of axis at a time, it does not have to be nearly as precise, and you have
time to fix anything that's not lined up.

I'm still curious to see if SpaceX can pull off their landing style, or will
instead change so that their first stages will be able to hover.

~~~
sandworm101
Hovering is also an insane balancing act for a rocket. At speed a rocket can
use aerodynamic forces to keep everything lined up. In a hover everything
literally turns on the engine gimbals. So there is something to be said for
coming to an abrupt halt and landing immediately, before things start getting
tipsy.

~~~
danielvf
The hardware and engineering to make a hovering a rocket is amazing. But the
control theory behind the hover is just not that tricky - It's very similar to
hovering a quad copter.

If you had a JavaScript rocket simulator, with clean position, rotation, and
velocity data, you could probably code a hover in five or six lines. Now it's
not quite that easy in practice, but the theory is still simple.

The Apollo lunar modules were capable of hovering, using only a portion of a
0.001Ghz 16 bit computer.

~~~
Retric
Hovering in 1.622 m/s² gravity in a vacuum is significantly simpler than
hovering in 9.807 m/s² gravity plus wind.

That said, it's clearly possible.

------
sandworm101
So this was just a vertical hop?

It would seem that SpaceX remains in a totally different league. By only going
vertical, this is a very limited "spacecraft", more akin to the Virgin
spaceplane than SpaceX's launch vehicles. For proper access to space, rather
than tourist hops, everyone wants to see a reusable launch vehicle --> a craft
to actually boost something towards orbit rather than an altitude record. That
means returning to some sort of landing after huge downrange progress. So
while this is an impressive achievement for space tourism (roller-coasters for
billionaires) I still see SpaceX's efforts as the more revolutionary.

~~~
cmsmith
Highest altitude followed by a powered landing by SpaceX: 1,000 m

Highest altitude followed by a powered landing by Blue Origin: 100,500 m

Moreover, SpaceX has gotten close to a powered landing from space a half dozen
times, but has mostly failed in the last 100m. You could argue that Blue
Origin just did the hard part that SpaceX hasn't been able to do. Obviously
the difficulty doesn't really scale linearly like that, but I wouldn't be so
quick to dismiss this accomplishment.

~~~
sandworm101
What Kerbal does teach users is that altitude is irrelevant for space travel.
Speed is what matters. The "hard part" is pushing something to a useful
velocity before attempting a landing. Returning a booster from to near-zero
velocity from a near-orbital velocity is far more of an accomplishment than
returning from altitude.

~~~
cmsmith
As far as I know, the Falcon 9 first stage has never gotten close to orbital
velocity. 2km/s is better than 0 km/s, but is a long way from 7 km/s.

------
Already__Taken
This is super cool, in case any of their engineers read this thread
congratulations.

To jump in with the inevitable SpaceX comparison. Worth noting is you see the
Blue Origin booster: fall, slow, hover, correct any drift, descend then land.
The SpaceX booster cannot hover, it has more thrust than it weighs.

~~~
alienasa
Further point of clarification, the SpaceX booster has more thrust than it
weighs because it is capable of delivering payloads to orbit, which the Blue
Origin booster cannot do.

~~~
ggreer
All rockets have more thrust than their weight, otherwise they would not get
off the ground.

Hover ability comes from having a rocket engine that can throttle down enough
to match the weight of the almost-empty rocket. Blue Origin's BE-3 can
throttle down to 20% of its design thrust, possibly lower.[1] SpaceX's Merlin
1D can throttle down to 70%.[2] Apparently, even with only one of the nine
engines firing, it's enough to lift the almost-empty Falcon 9 first stage.

1\. [https://en.wikipedia.org/wiki/BE-3](https://en.wikipedia.org/wiki/BE-3)

2\.
[https://en.wikipedia.org/wiki/Merlin_(rocket_engine_family)#...](https://en.wikipedia.org/wiki/Merlin_\(rocket_engine_family\)#Merlin_1D)

------
Symmetry
I'm sure SpaceX will land their Falcon 9 sooner or later but I think this goes
to show that being able to hover makes things a lot easier. Real rockets can't
be set to any throttle like in Kerbal Space Program, most can't throttle at
all. The Merlin's ability to throttle down to 70% is impressive, and the
BE-3's ability to throttle down to 25% is _very_ impressive.

~~~
sandworm101
"Throttle" is a term for rocket engines, not rockets. Being able to throttle a
single engine to 25% doesn't matter so much if you can instead shut down 3 of
4 engines and throttle the remaining.

For a single-engine booster, 25% is still way too much thrust if you are
shooting for orbit. A modern booster is 90+% fuel. So the empty or near empty
returning booster will need an engine running at around 10% of launch thrust
at the moment of landing. That's pretty much what SpaceX is doing by shutting
down 8 of 9 engines and throttling the last to 80ish%.

~~~
vectorjohn
It's not pretty much what SpaceX is doing. Even down to 1 of 9 engines and
throttled as far as they can (they can go to about 70%), it has too much
thrust to hover. So the amount a single engine can throttle is indeed
important.

SpaceX plans to solve it by extremely accurate timing so they don't need to
hover.

------
adwn
Direct link to video:
[https://www.youtube.com/watch?v=9pillaOxGCo](https://www.youtube.com/watch?v=9pillaOxGCo)

The landing footage begins at 1:40.

~~~
epalmer
The video speaks volumes about this accomplishment. The landing is
spectacular.

~~~
ChristianGeek
The landing IS spectacular. The girl at the end trying desperately (and
unsuccessfully) to get her champagne bottle to pop is irony at its finest.

~~~
ChristianGeek
Her gender is irrelevant to the irony.

~~~
thescriptkiddie
In the English language we generally do not use genderless pronouns to refer
to humans.

------
andys627
Video I think is from yesterday...
[https://www.youtube.com/watch?v=9pillaOxGCo](https://www.youtube.com/watch?v=9pillaOxGCo)

------
gchokov
Amazon Prime next-day deliveries to the International Space Station just got
one step closer...

~~~
asavadatti
That would be amazing given that a (orbital) day on the ISS is about 90
minutes.

------
butwhy
I find it quite amusing that Bezos does this and what's everyone's first
reaction? Let's find out what Elon has to say!

~~~
sharkweek
Two billionaires trying to revolutionize space flight - it's pretty damn
fascinating

------
leroy_masochist
Just watched the video....I think it's pretty lame that Jeff Bezos has no idea
how to spray champagne out of a bottle.

~~~
legohead
spraying champagne out of bottle is lame, anyway.

someone did that at my wedding, it got on my hair and my suit. it was on me
all day. it's sticky.

~~~
leroy_masochist
It's certainly lame if someone does it to you at your own wedding without you
asking for it! I'd be pissed too.

------
ctdonath
Looks like they'll be taking passengers soon. Expected ticket price? Waiting
list time?

~~~
tertius
By the looks of the capsule hitting the ground I'm not emptying my checking
account just yet.

~~~
dtparr
What about it hitting the ground bothered you? It apparently touched down at
4.4 mph which is a little slower than if you stepped off an 8in. platform.
Basically find a standard staircase and slip off the bottom step and that's a
touch less jolt.

~~~
Scramblejams
The rocket touched down at 4.4 mph. The capsule looked like it came down much
harder than that.

~~~
saganus
Maybe they didn't really need the capsule to touch down at a lower speed since
it can withstand this, so they save a bit on cost with smaller parachutes?

Not really sure if this item alone would make any difference, but if they do
plan on putting humans instead, I too would hope it doesn't land as hard as
the capsule seemed to.

------
throwaway000002
I'm far from being an expert on such matters, but why doesn't SpaceX attempt
to lasso the upper part of the rocket on landing? How about a super big soft
pillow? At the very least spread out some huge arms to aid stability?

~~~
Bjartr
They're trying to build a system that will work for a mars landing where there
will be zero infrastructure on the ground.

~~~
throwaway000002
Wow, that is crazy ambitious. Why aim for the problems of today when you can
solve the problems of tomorrow.

SpaceX, by now, should have enough people with strong applied math backgrounds
to tell them, given a formal specification of the control systems on the
rocket, whether what they're even trying to do is possible (within probability
bounds).

I'd be interested in seeing their calculations. I just hope they're not
throwing more computation at a problem that's totally dependent on how fine
they can a) sense their position and momentum, and b) do something to adjust
it.

~~~
lmm
They are very happy with the calculations - they've given presentations to
this effect already, and they've successfully landed the "grasshopper" test
vehicle. The issues with their previous attempts have all been mechanical
problems (running out of hydraulic fluid the first time, stuck valve the
second time, a structural failure earlier in flight the third time).

~~~
JoeAltmaier
From that description, it sounds like there's barely enough rocket there to
succeed. A sample size of 4, no statistics yet possible about whether its
getting better or not? Anyway, its amazing how many stuck valves have derailed
grand plans. The rover rocket static test had that problem (nuclear engine for
Mars mission back in the 60s(?)) and killed that program.

------
scentoni
The Delta Clipper was historic. This has been a followon.
[https://en.wikipedia.org/wiki/McDonnell_Douglas_DC-X](https://en.wikipedia.org/wiki/McDonnell_Douglas_DC-X)

~~~
InclinedPlane
Still historic. But incrementally so. The DC-X flew to 3km, the New Shepard
launched its capsule to 100km.

------
yavramen
Is this is the first attempt by Blue Origin? The first one turned to be
successful?

~~~
Tarrosion
Second attempt, I believe. Last time they recovered the crew capsule as
planned but lost the rocket.

~~~
yavramen
Thank you. It's interesting to look into this statistics with all the players
out there (SpaceX; Blue Origin; Virgin)

------
borplk
Elon Musk and Jeff Bezos competing with each other? That's great!

------
Swannie
I used to be enough to get lots of big boats:

Larry Ellison; Oracle:
[http://www.superyachtfan.com/larry_ellison.html](http://www.superyachtfan.com/larry_ellison.html)
(including his Americas Cup yachts)

James (Jim) Clark; Silicon Graphics, Netscape:
[http://www.superyachtfan.com/sailing_yacht_athena.html](http://www.superyachtfan.com/sailing_yacht_athena.html)

Paul Allen; Microsoft:
[http://www.superyachtfan.com/paul_allen.html](http://www.superyachtfan.com/paul_allen.html)
(3 very large vessels)

And more recently:

Larry Page; Google:
[http://www.superyachttimes.com/yachts/details/333](http://www.superyachttimes.com/yachts/details/333)

Now you need a rocket! OK, Paul Allen did go there first, as far as I can
tell.

------
oska
/r/spacex discussion:

[https://www.reddit.com/r/spacex/comments/3u2gwm/apparently_b...](https://www.reddit.com/r/spacex/comments/3u2gwm/apparently_blue_origin_flew_a_rocket_up_to_100_km/)

------
JoeAltmaier
Is this what happens when an Engineering company decides to go to space? The
video ([https://www.blueorigin.com/news/blog/historic-rocket-
landing...](https://www.blueorigin.com/news/blog/historic-rocket-
landing#youtube9pillaOxGCo)) of the booster coming down like a freight train,
igniting, arresting velocity and correcting for yaw, then landing on a dime
was absolutely uncanny. This thing reeks of technical competence and flawless
execution.

~~~
Symmetry
The New Shepard is just getting up to space rather than all the way to orbit.
If you'll recall SpaceS's Grasshopper was just as uncanny in it's landings.
Now, the New Shepard has a harder job since it's going to space so it's much
more impressive than Grasshopper that they succeeded. But by the same token a
Falcon 9 first stage has much thinner mass fractions to work with and has to
deal with horizontal velocity so landing one of those is much more impressive
still.

~~~
HCIdivision17
This illustrates the almost unfathomable scope involved here. Each
accomplishment is at least an order of magnitude or more harder than the last,
and each one is truly impressive on their own. Yet each shadows the last!

Pretty cool times for space; I'm stoked for what comes next!

------
saneshark
Does anyone know why it is 5x the effect of gravity for reentry? I would think
it would just fall back into the Earth's gravitational pull after its
thrusters are turned off. Or is it because it has an arcing path, and
thrusters are deliberately not turned off during reentry so that the rocket
spends less time burning up in the atmosphere? Anyone know? It's not clear to
me why it would be 5x the effect of gravity on reentry.

~~~
VLM
Someone else can provide the math, but if due to the tanks being mostly empty
you can burn anything from practically 0 to 5 G thrust, intuitively you burn
the least total fuel by flooring it to 5G at the last minute.

Consider the alternative of burning less than 1G of acceleration, you'll fail
to slow down although you'll descent acceleration will be somewhat lower. At
exactly 1 G it'll keep falling at a constant speed till it runs out of fuel,
then impact.

Or if you're asking why performance is so much more spritely at the end of
mission, unlike boats or cars the fuel in the tanks is like 95% of the mass of
the rocket, so something that barely waddles off the launch pad with full
tanks weighs practically nothing at landing when the tanks are nearly empty.

------
pilatesfordogs
Investing in space is great for humanity in general but what's gonna stop this
industry from going the way of the airlines?

Is this gonna turn into a price war ?

~~~
JshWright
New Shepard does not compete with Falcon 9 (or any 'real' launcher). It made a
vertical hop to 100km, with a very light payload. It didn't come anywhere
close to orbit (which is what Falcon 9 does).

Obligatory: [https://what-if.xkcd.com/58/](https://what-if.xkcd.com/58/)

------
Twirrim
Between SpaceX, Blue Origin and co it is great to finally see such competition
and progress in the space sector.

As the great philosopher Mike Tyson once said: _I 'm a dreamer. I have to
dream and reach for the stars, and if I miss a star then I grab a handful of
clouds._

------
Shivetya
The video was really exciting to watch. It does appear they come back much
more rapidly than Space X but this might be due to video editing. I also did
not notice visible attitude thrusters, was it all done via that main motor
gimbal?

~~~
hydrogen18
They talked about brakes, I'm assuming its a combination of some gimballing
and some brake modulation. Brakes can't be terribly effective at low speeds
however.

------
treblig
Space noob here: why is it that just after liftoff, the rocket swings out to
the right, and corrects. Is this intentional?

[https://youtu.be/9pillaOxGCo?t=55](https://youtu.be/9pillaOxGCo?t=55)

~~~
rrrrrraul
shooting from the hip... a) gust of wind; b) planned engine gimbal

------
adam12
Elon's Grasshopper from 2 years ago:

[https://www.youtube.com/watch?v=9ZDkItO-0a4](https://www.youtube.com/watch?v=9ZDkItO-0a4)

The New Shepard went much higher though (100.5km vs 744m).

------
dfar1
That landing was pretty amazing! I was expecting parachutes.

~~~
softbuilder
It came in so fast though! With the fuel it still has on board it's one
malfunction away from a cruise missile.

------
ogezi
The spacecraft did not exit the atmosphere, but this is certainly a
prepossessing feat. Congratulations to Bezos and Blue Origin.

------
gchokov
Check the latest Elon Musk's tweets about that.

~~~
mozumder
I think the big advancement here is the "reusable space rocket landing" part,
not the "getting to space" part.

~~~
unavoidable
Yes, but if your rocket is smaller and nimbler because you only designed it to
go to an altitude of 100km, isn't it easier to land?

~~~
mabbo
Probably. SpaceX clearly have a huge lead, but in either case we have
_competition_. We've got a good old fashion biggest dick contest for rockets
and space. Look what that did in the 1960s!

~~~
TeMPOraL
Maybe we'll get the BFR sooner!

------
Rathan
Great Job! Amazing rocket that 'LANDS'.

------
butwhy
So.. they beat spacex?

~~~
wolf550e
As Elon Musk wrote [1]:

    
    
      It is, however, important to clear up the difference between "space" and "orbit", as described well by https://what-if.xkcd.com/58/
    
      Getting to space needs ~Mach 3, but GTO orbit requires ~Mach 30. The energy needed is the square, i.e. 9 units for space and 900 for orbit.
    

1 -
[https://twitter.com/elonmusk/status/669129655597731841](https://twitter.com/elonmusk/status/669129655597731841)

~~~
andygates
Of course, going slower means less acceleration, which means less high-G
discomfort for paying passengers. A vertical hop makes perfect sense for
meerkat-mission tourism.

