

Rocket Will Be Recaptured in Midair with a Helicopter - DiabloD3
http://motherboard.vice.com/read/americas-newly-announced-rocket-will-be-recaptured-in-midair-with-a-helicopter

======
danpalmer
This is certainly an interesting approach, but more interesting to me is the
fact that ULA's new rocket (the first they are actually building) won't launch
until 2019. As SpaceX have been launching their own since 2010.

Also interesting is the reasoning behind capturing parts of the rocket (and it
is only parts) in midair. ULA say this is because the expensive bits are
small, and essentially imply that they can get most of the 'wins' with not
much effort when compared to SpaceX's "land it on a boat" approach. This may
well be true but it seems SpaceX's approach is thinking in wider terms of the
re-usability required for frequent space flight, rather than cheap space
flight.

I have a keen interest in space flight and SpaceX in particular, so take my
opinion with a pinch of salt, but this article reads to me like SpaceX are
well over a decade ahead of the ULA, much more forward thinking, and overall
the more exciting player in the commercial space-race.

~~~
ohitsdom
You probably already know this, but just want to point out that SpaceX's
approach goes way beyond "landing it on a boat". For today's launch (and
launches in the near future), they'll land it on their barge. But after the
landing system has been proven, they'll land it on the launchpad it took off
from. Work is already underway at Kennedy Space Center to make a launch site
capable to have a rocket landing.

Pretty cool animation here:
[https://www.youtube.com/watch?v=4Ca6x4QbpoM](https://www.youtube.com/watch?v=4Ca6x4QbpoM)

I do wonder how much this will save SpaceX in logistics cost once it's in
place. Seems a lot cheaper than coordinating a helicopter to catch a rocket
engine in mid air, land it on a barge, and ship it back to shore.

~~~
lloeki
Don't forget that SpaceX aims for that red rock out there. Reusability in this
case may go much farther than saving on convoluted blocks of metal but also
includes gathering data and experience for a surefire way to get there _and
back_.

------
madaxe_again
Hooray for 1950's technology!

This is how they used to recover corona/keyhole spysats.

They lost one in Mexico.

[http://news.discovery.com/space/history-of-space/the-
first-r...](http://news.discovery.com/space/history-of-space/the-first-
recovery-from-space-130812.htm)

Edit:

Uh, the Mexico thing may not be commonly known, it turns out. The chute failed
to deploy properly on a mission in '74, bounced off a C-130, and slammed into
a field in Mexico, but the payload canister was still intact. It's apparently
commonly written up as a UFO sighting called the "Coyame Incident".

------
ef4
I'm underwhelmed, and not surprised. Typically for the big, slow defense
industry players, they're planning a more complicated system that does less
and will not be ready until 2019.

Meanwhile, SpaceX will be attempting to land their _entire_ first stage again
_this afternoon_.

~~~
krschultz
I think it is more nuanced than simply ULA's system is _more complicated_. I
do however thing that the ULA system is a primarily-mechanical solution while
SpaceX is using a primarily-computer based solution.

Background - I have a BS in mechanical engineering, work professionally as a
software engineer now, and spent a few years in the defense industry working
on nuclear submarines.

Both approaches have key mechanical and computer/control challenges. However
ULA's primarily relies on increased mechanical complexity with relatively
simple computers. They are adding separation between the tanks and the engines
in the first stage. This is relatively proven tech - we separate stages all
the time - but it will complicate the piping and structural design of the
first stage considerably. There are also mechanical components related to the
hyper cone and the parachutes. The whole thing then follows a relatively
simple trajectory and then relies on the skill of human pilots to capture the
falling engines. We have done this, but again they're using mechanical systems
& proven techniques to recover the engines.

Meanwhile, the Falcon 9 doesn't use a whole lot of extra mechanical components
to be reusuable. Arguably the only extra bits are the legs and the grid fins.
The grid fins are very simple. The legs are a bit more complicated, but
probably less than what it takes to separate the entire engine assembly.
SpaceX puts all the complexity in the control _software_. The engines are re-
firing multiple times, and during the last few minutes of landing the computer
is doing some serious work to balance everything out. At the end of the day,
there is no human interaction on the landing.

You often see this trade off between mechanical complexity and software
complexity in systems that bridge the domains. I'd personally bet on the
company using the primarily software driven approach nearly every time.
Software is hard, but mechanical systems are even harder. The economics of
software are also way better. Manufacturing costs are pretty much linear to
number of rockets, there isn't that much scale in the current market to reduce
unit costs. Software costs are relatively fixed compared to number of
launches, plus lead times are dramatically different.

~~~
fbender
You perfectly expressed what I feel (and tried to say in my comment below).

To emphasize on "always bet on software": As seen on the landing video of the
(marginally failed) attempt today/yesterday, they are having issues with the
dampening of their control software during precision landing. While the field
of control software is hugely complex, once the parameters are known, it is
trivial to set these values and (later) tweak them. You cannot do that with a
(largely) mechanical system. Furthermore, it's easier to run simulations with
different sets of control parameters than redo all the FEM-et-al. stuff needed
for a modified mechanical design. If ULA wanted to take a slighly different
approach than what they proposed here (e.g. when the first tests don't work as
expected), they'd basically need to redesign the whole propulsion "stage".
SpaceX can alter just their software.

[As always, it's not black-or-white. ULA may also fix (most of) their issues
with software updates. SpaceX may need to add more fins or legs, re-distribute
weight, or require more fuel for the landing. That does not invalidate the
point above, though.]

~~~
fbender
Correction: It seems that the tilt maneuver at the end is intentional[1] to
not hit the barge full force if something goes wrong. Instead, the control
system did not account for (all of the) lag in the propulsion system (time
between command and applying force).

[1] based on multiple comments, e.g.
[https://news.ycombinator.com/item?id=9386127](https://news.ycombinator.com/item?id=9386127),
and a (presumably deleted) tweet by @elonmusk

------
chiph
Why use a helicopter, when a system like the Fulton surface-to-air-recovery
system already exists? Inflate a balloon from the top of the parachute, use a
C-130 to grab the line.

Batman even used it in _The Dark Knight_ :)

[http://en.wikipedia.org/wiki/Fulton_surface-to-
air_recovery_...](http://en.wikipedia.org/wiki/Fulton_surface-to-
air_recovery_system)

~~~
JshWright
The idea is to keep it out of that nasty salt water (cold salt water + hot
rocket engines is a bad combination...).

That's why they're going for a Corona style recovery.

~~~
chiph
Corona used a C-130 system as well.

[http://en.wikipedia.org/wiki/Mid-
air_retrieval#/media/File:C...](http://en.wikipedia.org/wiki/Mid-
air_retrieval#/media/File:Corona_recovery_sequence.PNG)

Thinking about it, it might be a weight constraint to cause them to use a
helicopter. The sudden capture of an object weighing a few thousand pounds by
a plane flying 350 mph could be too dangerous.

~~~
JshWright
The major difference between Corona and Fulton is that Fulton is not mid-air
(and therefore involves the thing being retrieved getting a saltwater bath).

------
fbender
Interesting concept, but – as others said – it seems rather hacky. Sure, from
one engineering perspective it's straightforward to only collect the engines.
Others say that re-assembly and especially the proposed collection process
adds its own complexity.

I think that the collection process is more involved (concerning number of
"moving parts", i.e. requiring a number of independent systems to work in
perfect synchronicity) than what SpaceX does. The F9R does have a more complex
navigation and guidance system due to the landing option. But apart from the
fins and legs[1] (which are of minor complexity), there's no additional
subsystem required for the landing capability. Everything's already there and
used in other parts of the launch – including major parts of the _landing_
navigation and guidance system. And SpaceX could launch another F9R with the
same 1st stage on the same day – ULA would need days, at least.

So I think ULAs approach is over-engineered and does little to improve on the
idea of launcher reusabilty.

[1] Actually, the legs may be used before launch in the future, so one less
surplus subsystem ;)

~~~
astrodust
I'd hope that SpaceX spends more than a day examining the engines for
fractures and potential problems before launching the thing again.

~~~
TeMPOraL
In the beginning, sure, but it is reasonable to expect they'll iron out the
kinks and the engines will eventually have < 1 day maintenance delay.

------
ansible
It is an interesting approach by the ULA, but I have concerns.

From [1]:

 _Vulcan, slated for its maiden launch in 2019, will be powered by either a
pair of exotic Blue Origin BE-4 liquefied natural gas main engines for 1.1
million pounds of thrust or two conventional Aerojet Rocketdyne AR-1 kerosene
powerplants for a million pounds of thrust._

I'm also concerned about using fewer larger engines. While this can be more
reliable (less moving parts means less chance of failure), it also means there
is no engine-out capability to continue the mission. This also means a lower
production volume, which means higher cost per engine, all other things being
equal (which they aren't).

The word 'exotic' also gives me pause.

At any rate, it should be interesting. I hope they post testing videos!

[1] [http://spaceflightnow.com/2015/04/13/ula-unveils-its-
future-...](http://spaceflightnow.com/2015/04/13/ula-unveils-its-future-with-
the-vulcan-rocket-family/)

~~~
JshWright
What do you mean by fewer? Vulcan is replacing the Atlas and Delta platforms.
Both use a single engine per core (the Atlas uses the Russian RD-180, while
Delta uses Aerojet's RS-68).

This will actually double the number of engines they're using.

~~~
ansible
_What do you mean by fewer?_

1 or 2 vs. 9 for a Falcon9 core.

~~~
JshWright
Falcon 9 is a SpaceX rocket, not a ULA rocket.

There are advantages and disadvantages to both approaches. ULA has a long
track record of going to space very reliably on single engine platforms.

~~~
ansible
_Falcon 9 is a SpaceX rocket, not a ULA rocket._

Yes, I'm aware of that.

 _There are advantages and disadvantages to both approaches. ULA has a long
track record of going to space very reliably on single engine platforms._

That's true. Both the Atlas and Delta programs have been pretty reliable.

------
curtis
Here are a couple of relevant articles that people may find interesting:

An overview of a 2008 ULA proposal for mid-air recovery of first stage rocket
engines: [http://selenianboondocks.com/2008/09/partial-rocket-reuse-
us...](http://selenianboondocks.com/2008/09/partial-rocket-reuse-using-mid-
air-recovery-a-review/)

An article about Hiller's 1965 proposal for using a giant helicopter to
recover an entire Saturn V first stage:
[http://www.thespacereview.com/article/1045/1](http://www.thespacereview.com/article/1045/1)

------
_Adam
This is unimpressive at best, and impractical at worst.

Rather than ULA expending the intellectual effort to build the control and
guidance systems needed to land the entire rocket as SpaceX does, they took
the lazy route and added a few steps to their existing process.

The fact that they're willing to suggest that something like this is
innovative is just further proof that the entire ULA is staunchly resistant to
change. I'm not entirely sure this system will even have a chance to be used.

------
damon_c
Doesn't this mean there will need to be a dynamically detachable connector
between every fuel/gas line and every electrical wire that runs between the
tank and the engine?

Isn't that introducing quite a few potential points of failure? Or was this
all thoroughly solved in the 60s and is boring and not an issue?

~~~
ansible
_Doesn 't this mean there will need to be a dynamically detachable connector
between every fuel/gas line and every electrical wire that runs between the
tank and the engine?

Isn't that introducing quite a few potential points of failure? Or was this
all thoroughly solved in the 60s and is boring and not an issue?_

This happens at lift-off for all rockets. The rockets are fueled at the pad,
and the connections stay attached until the last moment.

This kind of thing was also done with the Space Shuttle.

------
nkoren
There's a lot to like about this rocket:

1.) It's good to see ULA stepping up to the plate and actually innovating.
SpaceX will need some competition by then, to keep the industry healthy.

2.) The name, "Vulcan", is pretty badass. Certainly far better than the other,
embarrassingly jingoistic candidates they were considering.

3.) The inclusion of innovative NewSpace companies like Blue Origin and Xcor
is pretty exciting, even if ULA hasn't actually committed to using their
technologies yet.

That said, there are ways in which the Vulcan seems like it was designed by a
committee, and doesn't quite seem fully-baked. In particular: the "dial-a-
rocket" approach of strapping on solid boosters is at fundamental odds with
the economics of reusability.

In an expendable rocket, solid boosters are used because you need a lot more
thrust early in the ascent (to overcome gravity losses), and solid rockets are
a relatively cheap way to achieve that. (Solids generate a lot of thrust
during a short period of time, but their efficiency over long-duration burns
is relatively poor, which is why they're generally not used all the way to
orbit). You could accomplish the same thing by using more liquid fuel and more
engines in the primary booster stage -- but turbopump-driven liquid engines
are a good deal more expensive than solid boosters, so it doesn't make sense
to do this if you're going to dump them in the ocean after a minute or two.

On the other hand, if you're recovering the engines, then using more of them
is _absolutely_ the right thing to do. In that case, the tradeoff isn't
between the cost of liquid engines vs. solid boosters; it's the difference
between the cost of _refurbishing_ liquid engines (and some extra fuel) vs.
solid boosters. In this case, the latter is likely to be more expensive by an
order of magnitude. So if your hardware is reusable, then it's better to have
one or at most two vehicle configurations, and simply accept that most of the
time your vehicle will be oversized for its payload. You also get some
additional benefits from doing this, such as greater mass-produceability and
engine-out capabilities, etc.

I suspect that the problem is that aerospace engineers are used to doing high-
level trade studies using a crude $$$/kg costing for the cost of a rocket --
at least, this is how I've frequently seen them do it. If this is how you
think, then you want your vehicle to be no larger than the payload requires --
and that's what the dial-a-rocket approach allows you to do. But it's kind of
like assuming that a truck costs $$$/kg, and therefore if you need to carry a
load across town, you should build a truck which is as large as you need and
no larger. This makes sense if you take it as a given that you will always be
building your trucks by hand, and that they will be thrown away after every
journey. But if both of those assumptions are false, then so too is the "build
the truck to fit the payload" design philosophy.

It doesn't look like ULA has figured this out yet -- but they've definitely
realised that there's a fire under their tail, so hopefully they will do so
eventually!

~~~
ansible
Yeah, I don't get the sense that they're trying hard enough to optimize the
operational cost that well.

The SpaceX approach sacrifices performance, in the sense that you need to
leave some (heavy) fuel in the tank for recovery. That is delta-V that you
could use to loft a heavier payload.

I'm impressed by the SpaceX approach in general. They're using and re-using
the most proven technologies in an innovative way. I think powered landings
are the way to go.

------
MPSimmons
I haven't heard the phrase "human related" in relation to this. Anyone know if
ULA will seek human spaceflight rating for this rocket?

~~~
rkangel
It would be somewhat surprising if they didn't.

I imagine that they won't want to talk about humans until they can reliably
get them off the pad without blowing up.

------
okasaki
Rocket engine, not rocket.

~~~
astrodust
If the only thing missing is a fuel tank, that's like saying it's not a pen
until you have an ink cartridge loaded.

~~~
whoisthemachine
I think the distinction is important, especially for a headline. They _aren
't_ capturing the full rocket, just the rocket engine. That's a much lighter
load to capture, and likely much more feasible than catching a full rocket.

------
TeMPOraL
I understand there is some engineering rationale provided, but it seems to me
just like showing off, a spaceflight version of "longest e-penis" competition.
"You can land your rocket at a ship? Well, then we'll catch ours mid-air!".

~~~
ezegolub
Seems kinda hacky, instead of investing the time & money needed for full
reusability, they'll do a fraction of the work and hope for a successful
helicopter recovery, which seems kinda hard. I know they tried a capture like
that with some probe and it failed. I can't figure out it that's brilliant or
stupid.

~~~
JshWright
Catching things falling from space is actually something that was done pretty
regularly in the past. Before we had digital imaging sensors spy satellites
had to rely on film. Orbiting imaging platforms would 'drop' film canisters,
which would be caught by waiting aircraft, and flown back to a processing
center to be developed.

[https://en.wikipedia.org/wiki/Corona_%28satellite%29](https://en.wikipedia.org/wiki/Corona_%28satellite%29)

~~~
ezegolub
Nice catch!

------
proteusguy
"Vulcan will be partially reusable (eventually)" Haha what a joke. The whole
point of reusability is to be able to land the rocket, refuel it, and send it
back up the next or even same day!

"ULA says it's going to try to capture only the most valuable parts of a
rocket"

So... how about when we fly NY -> LA in our 777 we only bother to land the
passengers in the remaining "valuable" parts of the airplane? See the point
ULA? We're trying to make spaceflight just like commercial airline traffic.
That's the ONLY way to make it commercially viable. Your cost-plus methods of
building expensive as possible single use bottle rockets are over man!!

