
Grasshopper 100m Lateral Divert Test - ash
http://www.spacex.com/news/2013/08/14/grasshopper-100m-lateral-divert-test
======
alex-g
September 21, 2012: Grasshopper hops 2m
([http://www.spacex.com/news/2013/02/08/grasshopper-takes-
its-...](http://www.spacex.com/news/2013/02/08/grasshopper-takes-its-first-
hop))

June 14, 2013: Grasshopper flies 325m straight up and down
([http://www.spacex.com/news/2013/06/14/grasshopper-
completes-...](http://www.spacex.com/news/2013/06/14/grasshopper-completes-
highest-leap-date)), which was hellishly impressive

Two months later, this test seems enormously more difficult than the flights
without the sideways maneuver. And it's not even a year since it left the
ground for the first time.

~~~
toomuchtodo
Move Fast. Be so good you don't break things.

EDIT: Downvotes? Hello SV echo chamber. SpaceX iterates almost as fast as any
tech startup in SV; and how many vehicle losses have they had?

~~~
GuiA
Well, they've had some failures:

[http://en.wikipedia.org/wiki/List_of_Falcon_1_launches#Launc...](http://en.wikipedia.org/wiki/List_of_Falcon_1_launches#Launch_history)

But yes, overall they're moving and iterating and learning super fast. To me,
it's one of the 21st century's most exciting companies so far.

~~~
nknighthb
As rocket failures go, SpaceX's have proven very boring. No booms, no light
shows, nothing likely to kill a hypothetical human crew. The first one was
actually kind of funny in the end. The satellite landed semi-intact in a
storage shed... a few feet from its own shipping container[1]. Too bad we
don't bother with parachutes on satellites, it probably would have been
reusable with little or no repair.

[1]
[http://www.usafa.edu/df/dfas/Papers/20062007/FalconSAT-2%20L...](http://www.usafa.edu/df/dfas/Papers/20062007/FalconSAT-2%20Launched%20\(and%20Recovered\)%20-%20France.pdf)

~~~
ash
Incredible!

> For years, cadets have trained falcons (the only performing mascot at NCAA
> division I football games). FalconSAT-2 showed its excellent homing skills
> in the launch failure by avoiding the sea and returning to its shipping
> container so it “could come home to roost.”

------
ash
It's interesting to compare this with DC-X "Swan Dive" test in 1995:

[http://www.youtube.com/watch?v=wv9n9Casp1o](http://www.youtube.com/watch?v=wv9n9Casp1o)

~~~
ChuckMcM
What makes the DC-X so freaking amazing to me is compare the sensors and
computers you had available in 1995 to ones you have available today.

It is a great illustration of the 'ecosystem effect' where adjacent technology
advances move the entire frontier of a technology forward.

~~~
jacquesm
That's a mighty impressive video, but 1995 was pretty good computing power
wise.

What blows me away is some of the stuff they did in the 60's, including the
moonshots.

~~~
dnautics
the DC-X was also designed to be bottom-heavy, which helps, a lot. Certainly,
once the falcon has deployed its payload, it's got a better balance situation
than before, but the geometry is very different from the DC-X.

~~~
jonmrodriguez
> bottom-heavy, which helps, a lot

I don't know enough about rocketry to know if you're correct. But if you are
just saying this and you're not sure, please look at the Pendulum Rocket
Fallacy:
[http://en.wikipedia.org/wiki/Pendulum_rocket_fallacy](http://en.wikipedia.org/wiki/Pendulum_rocket_fallacy)

~~~
dnautics
well, I learned something today. I just remember learning in high school that
the center of force is below the center of mass, so that vector determines the
direction of travel, and that always posed a challenge.

------
PhasmaFelis
OMG, is this actually supposed to be single-stage-to-orbit?

Ah, Wikipedia says it's two-stage-to-orbit. That's still impressive, but a
ship that can reach orbit in a single piece without having to jettison
anything is the Holy Grail of spaceflight.

And watching that blazing titan set down on the landing pad as gently as a
butterfly is awe-inspiring in any case.

~~~
nawitus
The problem with single-stage-to-orbit (SSTO) is mainly weight. I think using
composite tanks is enough to make a SSTO rocket. X-33 was supposed to use a
composite tank, but the fuel tank failed during testing in 1999. Recently,
NASA has succesfully tested a composite tank[1].

1\. [http://nasawatch.com/archives/2013/07/composite-
cryog.html](http://nasawatch.com/archives/2013/07/composite-cryog.html)

~~~
lobster_johnson
I was confused by this video [1], which looks like it shows _three_ stages.
All three stages are able to land on their own. Can you explain?

[1]
[http://www.youtube.com/watch?v=abLC1l3loFA](http://www.youtube.com/watch?v=abLC1l3loFA)

~~~
jlgreco
The Dragon capsule is more "payload" than "stage". The Falcon 9 will have two
stages (hopefully both eventually landing themselves). The Dragon (not always
used. Sometimes they may just stick a satellite or something on top) will also
be able to land itself.

Sort of like how the Saturn V is considered a 3-stage rocket, even though
during the later Apollo missions it had on top a service module, a command
module, and a (two stage!) lunar module.

~~~
lobster_johnson
So what modules does the video show?

Also, if the mission is something like transport astronauts to the ISS, why
eject any stages at all? Why not just make the rocket capable of flying to the
ISS, let the whole thing dock to the ISS, exchange astronauts, then detach and
land back on Earth?

(Of course, if there are tons of missions happening around the same time, all
requiring a first stage rocket, and each mission has a period that doesn't
require any rocket, then I see the point of letting the rocket go back and be
used for other things.)

~~~
jlgreco
The video shows the lower stage and upper stage of a Falcon 9 taking off, then
landing. These two stages are shown launching a Dragon spacecraft. The Dragon
spacecraft is shown docking with the ISS. The pressurized half of the Dragon
spacecraft is then shown landing (the unpressurized trunk section, with the
solar panels attached, burns up in the atmosphere (though this is not shown in
the video)).

Staging is done because not doing it ("SSTO" or "single stage to orbit") is
_extremely_ hard. In fact, it has never been done before from earth. When that
second stage burns, it is only accelerating the mass of itself and the Dragon
spacecraft on top. Having it accelerate the mass of the lower stage as well
would be massively inefficient, requiring _much_ more fuel to be used. So much
more fuel that there most likely would no be any mass left over for the Dragon
spacecraft. Without staging we wouldn't be able to put things in orbit at all
(today and in the past anyway), let alone reuse rockets.

~~~
lobster_johnson
Thanks. I assumed the section with the solar panels somehow retracted the
panels before re-entering the atmosphere, but they skip that part, and I now
see that the part re-entering is actually a bit smaller.

~~~
jlgreco
Yup, that part burns up.

It's not a complete waste though. I believe at the ISS they usually pack those
sorts of parts (parts that burn up that is. Other examples being the Russian
"Progress" spacecraft or the ESA's ATV) full of garbage before sending them
off. Intact reentry volume/mass is valuable (currently only the Soyuz and the
Dragon can do that) so they just let all of their trash burn up. Here's a neat
picture of the first ATV, carrying a bunch of ISS trash, burning up:
[http://en.wikipedia.org/wiki/File:Jules_Verne_Automated_Tran...](http://en.wikipedia.org/wiki/File:Jules_Verne_Automated_Transfer_Vehicle_re-
enters_Earth%27s_atmosphere.jpg)

------
bionerd
This is incredible. Yes, it would be insanely cool to live in 2500s with all
that privately affordable faster-than-light travel and everything but still...
it's very exciting to see the progress being made by private/commercial space
programs. I wish them all luck. It must be an amazing feeling to be a part of
all this.

This is actually the only thing that's giving me hope that man could really
step a foot on Mars or mine valuable resources on asteroids in a (hopefully)
not _too_ distant future.

~~~
dclowd9901
Maybe life extension will progress as well? :P

------
wil421
Glad to see that Space is going to be a commercial business instead of private
governments doing everything. This gives me hope that Space will be a place
that consumers can enjoy.

That said I think that Elon Musk is doing a lot to make things like Space and
Electric cars more accessible to the average person. Even though the costs of
Tesla cars are high now for the average Joe to afford, they will hopefully be
down in the near future. I hope that the same will happen with Space-X.

~~~
nawitus
>Electric cars more accessible to the average person.

That's starting to be a pretty moot point given the Nissan Leaf.

~~~
toomuchtodo
Edit: Disagree.

The Nissan Leaf is an atrocious electric vehicle, with the same baggage the GM
EV1 had. 80 mile range. Barely. If you don't use the heat or AC.

[http://www.digitaltrends.com/cars/how-does-gms-fabled-
ev1-st...](http://www.digitaltrends.com/cars/how-does-gms-fabled-ev1-stack-up-
against-the-current-crop-of-electrics/)

Nissan has to continue to slash the price to move them, while people will pay
top dollar for Tesla vehicles (and, I argue, will continue to do so, not only
for the high end but also the lower priced models when they're
announced/produced).

Disclaimer: I'm super long TSLA

~~~
ricardobeat
The Leaf is a superb vehicle in every aspect, except for range and price.
Given a little time the tech will come close to Tesla's.

They could license Tesla's battery technology, but I doubt Musk would help set
up competition to the future Model E.

~~~
nawitus
>The Leaf is a superb vehicle in every aspect, except for range and price.

It's the most affordable electric car out there.

>Given a little time the tech will come close to Tesla's.

What tech?

>They could license Tesla's battery technology

Why would they? My understanding is that there's nothing special about Tesla's
battery technology. Leaf just has less batteries (in kg) in them, so the range
is lower.

~~~
ericd
There's a lot more to the Tesla battery management than a bunch of laptop
batteries wired together. Cooling, wear leveling, charge management, LiOn
combustion containment.

------
johlindenbaum
Few questions. Is Grasshopper intended to be a vehicle that ships a payload
into a low earth orbit and return itself back to the launch pad?

With that, a question of descent, once it's reached orbit and released its
payload, would it re-enter with a short burn towards its earthly destination,
decelerate with, say, parachutes, and then do its final descent onto the pad
with the rocket? I can't see it doing its entire descent with a rocket, that
would use so much fuel, and require so much extra weight.

~~~
jlgreco
Grasshopper is a test vechicle, they plan on doing this with the F9R. My
understanding is that the F9R will burn once to de-orbit (well, the first
stage will be suborbital to begin with), aerobrake without a parachute for a
short period, and then burn again for the final landing. I may be wrong about
the aerobraking step, but they aren't planning on using a parachute
regardless.

IIRC they are expecting a 10% drop in total cargo to LEO when the F9 is used
in the reusable configuration. It takes _far_ less fuel to get down than it
does to get up since they only have to decelerate the lower stage (not the
upper, or the cargo) and since the lower stage will be mostly empty at that
point ( _much_ lighter). Furthermore the initial decent burn will be at a much
lower outside atmospheric pressure (near vacuum?) resulting in a higher
efficiency.

~~~
puetzk
Also, the rocket will be falling at its terminal velocity, having lost the
rest of its speed to air drag. Even without parachutes (and they don't intend
to carry any), that's only ~120 m/s - the upper stage and payload are gone,
the 1st stage has big tanks but only a little fuel left, so its density is
low. The final burn for propulsive landing only has to cancel that last little
bit.

~~~
jlgreco
Yup, air resistance works with you on the way down, not against you, and it is
courteous enough to start small and work itself up when you are on the way
down.

~~~
troels
Doesn't it result in a lit of heat from the friction? Or is that only a
problem at much higher speeds?

~~~
jlgreco
There will be heat; even the suborbital Mercury-Redstone missions needed heat
shields.

I don't know how SpaceX is planning on handling that. Maybe the trajectory
they put themselves on is going to be slow enough to survive reentry using
just the main engine nozzles as make-shift heat shields?

~~~
antubbs
Can't speak to the plan for the second stage (which will do a once-around and
de-orbit if I understand correctly), but the first stage will not be following
a ballistic trajectory and re-entry like a normal suborbital launch. Its goal
is to return to the pad a few minutes after launch.

~~~
jlgreco
I suspect they will still do a single burn somewhere around apogee of the
first stage; if I understand correctly they are well into their gravity turn
by the time it separates so they'll have some horizontal velocity they will
need to get rid of.

Maybe they are going to push the gravity turn later into the flight so that
the first stage doesn't participate in that as much?

------
moocowduckquack
I can't help but think of Tintin - Destination Moon, when I see that.

~~~
SuperChihuahua
And I can't help to think of that old computer game Lunar Lander where you
were supposed to land a small craft in a rocky terrain:
[http://www.thepcmanwebsite.com/media/lunar_lander/](http://www.thepcmanwebsite.com/media/lunar_lander/)

~~~
lmm
It's probably been mentioned enough already, but if you enjoy playing with
rockets Kerbal Space Program is excellent.

------
chm
Excellent work. Really fine engineering we've witnessed there.

------
ARothfusz
Holy crap. Suddenly I feel like it's the 21st Century.

------
stcredzero
Two Stage to Orbit, with vertical rocket-thrust tail-landing for both stages,
eschewing carbon fiber for aerospace aluminum and using friction stir welding,
rejecting exotic engine designs for proven ones, and financing from dot-com
tycoons:

I'm not affiliated, and the end is kinda corny, especially if you are a
typical skeptic/rationalist Silicon Valley type. It's not exactly how it
happened with SpaceX, but there are quite a few parallels:

[http://www.amazon.com/The-Rocket-Company-Library-
Flight/dp/1...](http://www.amazon.com/The-Rocket-Company-Library-
Flight/dp/1563476967/)

EDIT: In case you are not sure, it's a fiction book. It's interesting because
it presages some things SpaceX did later.

~~~
tantalor
In case anybody else was as confused as I was, this is a story about a
fictional rocket company.

Aside: does Amazon not categorize its books by "fiction" or "nonfiction"?

~~~
stcredzero
Sorry, I thought "the end is kinda corny" would be enough indicator that this
is fiction. It does predate SpaceX getting on the public radar, though.

------
joss82
Hello, fellow HNers.

So you love rockets and have plenty of time on your hands?

Here is Kerbal Space Program, enjoy!

[http://kerbalspaceprogram.com/demo.php](http://kerbalspaceprogram.com/demo.php)

------
cwkoss
Now I want to see what Kerbal Space Program ships the SpaceX guys are making
when they are goofing off.

~~~
alexhawdon
Probably none.

KSP was mentioned to Elon in some post-talk Q&A session - he hadn't heard of
it and seemed unimpressed.

~~~
ash
SpaceX software engineers on Reddit AMA:

> > First question: do any of you guys play Kerbal Space Program?

> Are you kidding? That’s how we design our rockets!

[http://www.reddit.com/r/IAmA/comments/1853ap/we_are_spacex_s...](http://www.reddit.com/r/IAmA/comments/1853ap/we_are_spacex_software_engineers_we_launch/c8bp6sx)

------
kilroy123
Launching a ten story tube into the air, and safely landing it on the ground
really is impressive.

------
kfury
Does SpaceX document all their tests publicly? Or are we just seeing the
successful ones? (If they've all been successful ones, will we see
unsuccessful ones if they come in the future?)

~~~
lutorm
Well, it's kind of hard to keep the tests secret:
[http://youtu.be/i9n6rYoSGNQ](http://youtu.be/i9n6rYoSGNQ)

~~~
kfury
Ahh, yes. A little digging shows that these tests are done at their McGregor,
TX test site, and McGregor is well within hearing and visual range of the
tests.

[https://www.google.com/maps/preview#!q=spacex&data=!1m4!1m3!...](https://www.google.com/maps/preview#!q=spacex&data=!1m4!1m3!1d4031!2d-97.459888!3d31.400645!2m1!1e3!4m10!1m9!4m8!1m3!1d4556!2d-97.4079412!3d31.4347774!3m2!1i1293!2i909!4f35&fid=7)

------
Gravityloss
I wonder how useful the Lunar Lander Challenge was in being a trailblazer.
Here's one of Masten Space's 2009 flights. Rock solid transfer from one pad to
another, with a 90 second hover. They had hired a guy from Draper Labs to do
the control code and won, snatching the big price from Armadillo. Impressive
control.
[http://www.youtube.com/watch?v=oaXW5TaFwAE](http://www.youtube.com/watch?v=oaXW5TaFwAE)

------
ondross
This is also using a fairly new engine, the Merlin 1-D
[http://en.wikipedia.org/wiki/Merlin_1D#Merlin_1D](http://en.wikipedia.org/wiki/Merlin_1D#Merlin_1D).
It is designed for mass production, using nearly 50% fewer components than the
1-C, and it seems to be flying great! Can't wait for the next launch!

------
marshc1
Anyone else seeing the youtube loaded bar as gray? Is this a custom overlay?

see: [http://imgur.com/wKOB6jh](http://imgur.com/wKOB6jh)

~~~
xnxn
It's an option in the embedded player API.

[https://developers.google.com/youtube/player_parameters#colo...](https://developers.google.com/youtube/player_parameters#color)

------
agumonkey
Each videos is more awesome than the previous one, but one thing remains
constant, the incredibly short time between low altitude and stable landing.

------
amorphid
Useless speculation: Hyperloop is a red herring meant to distract us from the
rocket that will get you from LAX (not Sylmar) to SFO in 15 minutes!

------
ballard
Elon gets that humans need to go to the stars to ensure our survival. That's
the big idea. The neat part is writing history along the way.

------
vecinu
I don't mean to stir controversy but I am curious how many countries are
thinking 'I want one of these for my military'.

Hear me out, wouldn't this technology allow for more advanced ballistic flight
across Earth and perhaps even become more efficient than anti-ballistic
missiles, evading any 'danger'?.

~~~
ljd
I don't know anything about military strategy or missile technology but I'm
having a hard time seeing how a missile making a turn that slow would really
be effective at evading any kind of supersonic defensive weapon.

Also, missiles have to explode to be useful; a safe relaunch would be a bit
worthless.

Just to add a pedantic remark, if the missile is guiding itself then it's not
a ballistic missile anymore.

~~~
nobodysfool
Yes, it's a guided missile not ballistic so those anti-ballistic things would
be useless anyway. The best defense against guided missiles would be to
disrupt the guidance system. However, there is technology being developed with
the accuracy to allow a missile to use inertial navigation systems in the
absence of gps.

~~~
greedo
It's already been developed in the 1980s with the Pershing 2 systems. They
used inertial navigation, then terminal homing via a radar transmitter.

------
abalone
Pretty cool how the lens flare forms an "X" around the exhaust.

------
adamwong246
Beautiful!

------
iotakodali
this should make space travel more affordable

------
vpayette
Wow, amazing

