
Space catapult startup SpinLaunch comes out of stealth - stingrae
https://techcrunch.com/2018/02/22/spinlaunch/
======
zurp
> Two sources say physicists who’ve looked into the company said a potential
> challenge could be air resistance on the cargo when the catapult fires.
> Earth’s atmosphere is so dense that it could be like the cargo was hitting a
> brick wall upon ejection.

Reminds me of the calculation that shows Santa Claus and his reindeer, if they
ever existed would have vaporized instantly at the beginning of first
Christmas delivery:

...353,000 tons traveling at 650 miles per second creates enormous air
resistance — this will heat the reindeer up in the same fashion as spacecraft
reentering Earth’s atmosphere. The lead pair of reindeer will absorb 14.3
QUINTILLION joules of energy. Per second. Each. In short, they will burst into
flame almost instantaneously, exposing the reindeer behind them, and create
deafening sonic booms in their wake. The entire reindeer team will be
vaporized within 4.26 thousandths of a second. Santa, meanwhile, will be
subjected to centrifugal forces 17,500 times greater than gravity. A 250-pound
Santa (which seems ludicrously slim) would be pinned to the back of his sleigh
by 4,315,015 pounds of force. In conclusion — If Santa ever DID deliver
presents on Christmas Eve, he’s dead now.

~~~
danbruc
Even ignoring air resistance, if your hypothetical spacecraft centrifuge had a
radius of one mile, then the spacecraft would still experience 114 g at 3000
miles per hour. If you more realistically spun up Apple's new headquarter with
a diameter of 461 meters [1] to one revolution per second, that makes 3240
miles per hour, the spacecraft and the outer wall of your centrifuge would
experience a centripetal acceleration of 928 g. Not going to happen. And 3000
miles per hour is also pretty slow, about half the speed in a geostationary
orbit, for a low earth orbit you need about 17,500 miles per hour [2] which is
almost 6 times faster and would increase the forces 36 times.

[1]
[https://en.wikipedia.org/wiki/Apple_Park](https://en.wikipedia.org/wiki/Apple_Park)

[2]
[https://en.wikipedia.org/wiki/Orbital_speed](https://en.wikipedia.org/wiki/Orbital_speed)

~~~
danielbarla
Those orbital numbers are sobering, but there may still be plenty of reason to
investigate a launch mechanism where the "fuel" comes from an external source.

I haven't run the numbers, but a quick look at typical delta-V budgets [1]
(which calculate atmospheric losses as 1.5 to 2 km/s of delta-v), if one could
accelerate something fast enough that it escapes most of Earth's atmosphere
(and only then burn for orbital velocity), you'd be saving ~17 to 20% on the
delta-v requirements. Due to the nature of the Tsiolkovsky equation, that
could be a very substantial saving.

That said, I'm also wondering why a centrifuge would be better than say, some
kind of low pressure tube / rail, but I'm sure these guys have done their
maths and believe in it.

[1] [https://en.wikipedia.org/wiki/Delta-
v_budget](https://en.wikipedia.org/wiki/Delta-v_budget)

~~~
nine_k
Scaled Composites tried to solve it by launching from a winged aircraft. (Too
bad they seem to have stopped.)

------
ChuckMcM
The fact that this seems demonstrably impossible on its face, and yet he is
raising money, always makes me curious.

During the 'Star Wars' period in the US when the military was going to buy up
thousands and thousands of launches to low earth orbit there were probably 1/2
dozen companies pursuing a single stage to orbit (SSTO) type solution. Gary
Hudson, the CEO of Rotary Rocket (one of the SSTO companies at the time), gave
a great example that showed that because the atmosphere was thick at ground
level and thin at altitude you wanted a velocity that proportional to
altitude. As he explained it, everything you do to a rocket to reinforce it
adds weight, and every pound you add is another 90lbs of fuel (or what ever
your mass fraction is). In that way your rocket could be as delicate as a
feather if you went very slowly down near the ground and hypersonic near the
edge of the atmosphere.

But systems that attempt to impart enough kinetic energy at altitude zero to
allow the rocket to coast to orbit require a rocket that is structurally
extremely rigid because it withstands both the force of acceleration and the
atmospheric drag at its worst. That is astonishingly hard to pull off.

I a serious challenge, first you have to actually start at higher than orbital
velocity because you're going to exchange a lot of energy with the air around
the air frame. Volcanoes are currently the champions at throwing things up
into the air, Mt St. Helens through ash over 100,000 feet up. But if you start
your orbit going straight up you won't be able to miss hitting the planet post
apogee. The more angled you make your initial shot, the more air you have to
go through before you are in space, the more energy you're going to dump in
the atmosphere, and the faster you'll have to start.

And all of that makes me really wonder about an engineering solution that fits
within all those constraints. What ever it is, it will be super amazing.

~~~
cwkoss
I wonder if you could sink a very buoyant rocket to the bottom of the ocean
with a weight, and then fire up the rocket engine as it breaks through the
surface of the ocean with a positive upward velocity.

Presumably drag in water is the biggest issue, which would be somewhat
mitigated by the aerodynamic shape of the rocket. I wonder what is the maximum
theoretical exit velocity from the ocean, using only buoyancy as propulsion.

~~~
cwkoss
Related interesting idea: creating a hydraulic catapult to launch the rocket.

[https://www.quora.com/Why-dont-we-launch-spaceships-from-
und...](https://www.quora.com/Why-dont-we-launch-spaceships-from-
underwater/answer/Bernard-Peek)

------
wrnu
This reminds me of the "Supergun" that Gerald Bull [2] was trying to build
with Saddam Hussein [1].

One of my professors, that worked with Bull at the University of Toronto, told
me all about his arms dealing/designing escapades. Bull was ultimately
assassinated outside his home in Brussels.

[1]
[https://en.wikipedia.org/wiki/Project_Babylon](https://en.wikipedia.org/wiki/Project_Babylon)
[2]
[https://en.wikipedia.org/wiki/Gerald_Bull](https://en.wikipedia.org/wiki/Gerald_Bull)

~~~
philsnow
I heard about Bull in the book Soonish [0], which has a whole chapter on cheap
access to space. Readers of this thread might be interested in it.

[0] [https://smbc-comics.com/soonish/](https://smbc-comics.com/soonish/)

------
ralphington
They mention in the article of being able to launch objects at 3,000 MPH.
That's a tad short of the typical 17,500 MPH used for low earth orbit, and
that's not counting the extra Delta-V required to resist atmospheric drag.

I'm very glad that this company exists, but this article doesn't help its case
very much other than "Hey look, they got a load of funding".

~~~
pesmhey
Just a wild guess here, maybe they’re using a variant of a ramjet, skipping
the inefficient speeds, and then propelling it to LEO speed once it’s
launched.

~~~
jcims
Ramjet would still require atmosphere. If you look at the Japanese SS-520 or
the RocketLab's Electron, you don't need a giant rocket to get a small payload
to orbit from a standing start. If you give your payload a Mach 5 kick you can
eliminate a lot of the propellant mass and get by with smaller rocket motors
optimized for high altitude operation.

Elon Musk wants to put 12,000 satellites into orbit. It would be very strange
to me if he doesn't have someone looking into the feasibility of a giant
subterranean launch tube to do something similar. Get the payload up to Mach
10 on terrestrial power and complete the orbit with a small single stage.

~~~
bboreham
> Elon Musk ... giant subterranean launch tube

Hyperloop?

~~~
manigandham
The Hyperloop is a rehashed vacuum-train idea originally from the 1800s
(reduce air and rolling resistance as the primary forces counteracting speed).
[1]

A launch tube would be very different, if for no other reason then the fact
that you need to actually jettison the payload at one end at high speed.

1\.
[https://en.wikipedia.org/wiki/Vactrain](https://en.wikipedia.org/wiki/Vactrain)

------
zaarn
I played enough KSP to know that this sort of thing is somewhere halfway up on
the list of "things that you might think go to space but don't".

Hitting the atmosphere after accelerating will probably cause most materials
outside of reentry heatshield to immediately melt, ignite and explode without
particular order of these events. After turning into a molten blob of lava or
a spent heatshield, it would still be nowhere close to orbital velocity and
would have to fire an engine that somehow survived A) the heat and B) the
intense G-forces involved.

I'll probably file this under "solar freaking roadways" and hope they don't
try to fire a human in this.

~~~
phire
Eh, I'm going to give them the benefit of the doubt, mostly because they
appear to be able to attract large amounts of VC funding.

When it comes to orbital mechanics, the idea works. You just need to make your
starting velocity high enough after it has decelerated though our atmosphere
slows down to orbital velocity. Then you just design your ascent capsule to
"deal" with the extreme declaration and heating, which isn't a huge problem:
Heat shields exist, and so do g-force hardened electronics. Nobody should be
under the impression that this will be used to launched anything other than
small specially designed g-force hardened satellites.

It's not like "solar freaking roadways" which has blearlying obvious economic
and efficiency flaws, the designs for catapult based launchers have been well
studied and there is nothing physically stopping them. It's more of a
engineering problem.

Honestly, I'm more concerned about the engineering practicalities of building
an extremely large centrifuge spinning at some absurdly high RPM (presumably
at the top of a mountain, so it bypasses some of our atmosphere)

~~~
zaarn
>Eh, I'm going to give them the benefit of the doubt, mostly because they
appear to be able to attract large amounts of VC funding.

Just because someone is giving them money doesn't mean they can do it.

>When it comes to orbital mechanics, the idea works.

Of course it does, similar systems have been suggested for lunar transfers to
earth (IIRC). Without atmosphere these systems are trivial to implement and
use. (Comparatively)

> Heat shields exist, and so do g-force hardened electronics.

Heatshields are rather large and expensive. There is also a difference between
heatshields for reentry and heatshields you'd need for leaving the atmosphere
efficiently.

At the moment, heatshields are basically ramming through the air and
compressing it in front of the aircraft, this is most efficient in reducing
velocity and can reduce the temperature at the shield somewhat.

When you fire something through the atmosphere with the goal to get it into a
suborbital trajectory you need a different solution; your aircraft becomes a
spike/spear, generating friction with air instead of compression. Friction is
harder to deal with if I recall correctly from various pages on the topic.

------
kuon
Realistically, what is the feasibility of a space catapult? I mean, the speed
at ground level to be able to reach orbit must be insanely high, no? This high
speed in a thick atmosphere would cause all kind of heating problem on the
catapult itself and the "rocket". I wonder what would be the actual numbers.

~~~
JoeAltmaier
Launch from near the equator, high in the mountains? Chimborazo, Ecuador? At
6000 feet, its half the air pressure of sea level, and 1/4 the atmosphere to
travel through. And accessible. A good start?

[https://www.google.com/maps/place/Chimborazo/@-1.4685873,-79...](https://www.google.com/maps/place/Chimborazo/@-1.4685873,-79.014542,11.22z/data=!4m5!3m4!1s0x91d372d7706a480b:0x69d5c66d2e629dff!8m2!3d-1.4693018!4d-78.8169396?hl=en)

~~~
jsmthrowaway
Going to space is not entirely about being high. It's about going sideways,
fast.

And if, at 6,000 feet, air pressure were half that of sea level, nobody would
live in Denver and most Tibetans would be dead. Half is more like 6,000
_meters_.

~~~
notahacker
Chimborazo is >6000m above sea level tbf and not 6000ft as the OP suggested.
It's actually the furthest point from the Earth's centre (the earth's shape
gives it a boost over mountains which are higher above sea level but further
from the equator)

For related reasons, its difficult-to-reach, low oxygen, snow-covered summit
is not ideally suited for building and maintaining a space launch site.

~~~
JoeAltmaier
"Not ideal" may overlap with 'tremendously cheap' if the SpinLaunch 10-100x
cost factor is true. So a few oxygen masks may be worth the trouble. And a
highway goes within a few miles of the peak right now.

~~~
notahacker
I've been on that highway. Trouble is you're still a few thousand metres of
relatively technical climbing or a helicopter ride away from the top. I mean,
people can work in some pretty inhospitable conditions if the cost advantages
are real, and the payloads you've got to get up there have to be relatively
comfortable with being moved to get fired into space anyway, but it's hard to
imagine anything on a Cape Carnaveral scale happening there even if Ecuador
decides the dollars from supporting space programmes are worth more than the
scenery and symbolism

~~~
wallace_f
I came across the idea of launches from Ecuador while reading about
spaeflight. IIRC, I assumed 3,000m launch (assumed a suitable site near Quito
exists), and calculated a disappointing, less-than 10% increase in payload,
assuming a BFR as the launch vehicle. However, for a kinetic energy launcher,
or small rocket like the new record-settinf Japanese SS-520, that improvement
would be a lot larger (and more importantly, the logistics a lot easier!).

The thing is, with rocket size increasing, payload increases cubically while
air resistance is squared. So for the really big rockets, altitude is not as
big of a factor as being near the equator.

If I am not wrong, propulsive landing on drone ships uses another roughly 10%
fuel (depends on launch trajectory, etc).

As fossil fuels are non-renewable, and Hydrogen expensive, I am very sure (and
even hope to be correct) that in the future we will see launches from high-
altitude equatorial regions, using booster-capture technologies and perhaps
even terestial-power-assisted launches. Those things may reduce the fuel-cost
of escape velocity by 30+%, and when we're sending enough stuff into orbit
that this is too advantageous to ignore, we will do it.

But for now, the best way to go is to get really good at building bigger
rockets.

------
Pica_soO
Could you lift the whole catapult setup to a higher altitude with a greatly
reduced atmosphere before firing?

Or create a tunnel ahead of the projectile? You could use a laser to
facilitate a artificial lightning strike- and fire the projectile up the
thunder-tunnel of the lightning.

------
KaiserPro
I assume they are using a cyclotron accelerator.

Basically its a large disk with a spiral track on the inside. The disk is then
oscillated in along its flat plane, like this:
[https://www.youtube.com/watch?v=OPLzsRojo_A](https://www.youtube.com/watch?v=OPLzsRojo_A)

There was a video of a marble cyclotron, that basically had a spiral like the
above, but instead of tilting, the whole disk moved along the z axis (as we
look at it, x up, y left and right) it was about 1 meter wide, and was
oscillating at about 2hz, that was capable of ejecting marble sized objects at
about 500 mph or something similar.

So I can see the method, but I doubt how payloads will survive that level of
G.

 _edit_ This idea:
[https://www.youtube.com/watch?v=UnZWu1FXxd4](https://www.youtube.com/watch?v=UnZWu1FXxd4)

------
blackrock
Since we're talking about space, I am wondering when some nation can build a
rotating space station.

Null-gravity is nice to play in, and some null-g research is necessary. But to
work, and operate normally, null-g sucks. Especially if you need to handle
fluids.

And if you need to do an emergency surgery in space, then dealing with
floating blood is disgusting and biologically hazardous. As well as dealing
with used surgical tools that can float around.

I would rather live in a centrifuge space station, and go to the null-g zone
to conduct my work research.

It's interesting how in all scifi movies, all the spacecraft have an
artificial gravity.

It's too bad China's proposed space station, will not break new ground, and
have a rotating space station. They would need to spend much more money on
designing and building it, than what they are willing to spend.

~~~
skookumchuck
You don't actually need a wheel. Just a counterweight and a cable.

It's unlikely a full g is necessary, anyway. A half would do well.

~~~
lorenzhs
You might be able to get by with even less if your goal is to provide a
consistent up/down and not have to velcro everything down. I don't have any
sourcing for it and obviously it's from a Sci-Fi book, even if it's one that
is rather well-researched, but in the Expanse series they use accelerations of
around 0.3g a lot (both for stations and ship drives). Would be nice to know
if they pulled that number from thin air or what the thought process behind it
is.

------
newnewpdro
Isn't this obviously impossible?

What sort of launch vehicle or payload is going to tolerate the Gs of being
spun at such a high rate. How on earth does this even raise a dollar of
funding?

It has crossed my mind in the past why we don't use something like a linear
electric motor to help get rockets going off the pad, even just a hundred
yards or so of acceleration assist might save a good chunk of fuel. But the
rockets aren't exactly designed to have acceleration applied anywhere other
than at the engine, so maybe you end up having to add the weight you'd save in
fuel back in structure for the ancillary acceleration source.

~~~
throwaway99OO
At its face it does sound pretty crazy but I found some analogs of previous
and ongoing projects that provide some reason to suspend disbelief.

Here's what I can find on high G launch vehicle's and payloads:

Breakthrough Starshot: Backed by physicist and VC Yuri Milner and lead by
former director of NASA Ames, Peter Worden. 10,000 G's. Project Ongoing. [1]

Hiller Hornet: US Army helicopter, powered by jet turbines located at the tips
of the helicopter blades. The turbines operated under 14,000 Gs. Project
Completed [2]

HARP Project: Joint US Army & Canadian effort. Successfully launched
electronics (radios, control systems, etc) and solid fueled rockets. 10,000+
Shock G's. Project Completed. [3]

A variety of documents come up while researching g-hardening electronics. The
US Army Research Lab a a few papers. Linked one of them. 30,000 + Shock G's.
Various Projects Completed and Ongoing[4]

The Hiller Hornet is likely the most applicable given it is a propulsion
system operating at over 10,000 G's. I wonder how they designed the Hornet's
turbine given Finite Element Analysis wasn't really a thing in 1950.

[1]
[https://en.wikipedia.org/wiki/Breakthrough_Starshot](https://en.wikipedia.org/wiki/Breakthrough_Starshot)
[2]
[http://www.aviastar.org/helicopters_eng/hiller_hoe-1.php](http://www.aviastar.org/helicopters_eng/hiller_hoe-1.php)
[3]
[http://www.astronautix.com/a/abriefhistoheharpproject.html](http://www.astronautix.com/a/abriefhistoheharpproject.html)
[4] [http://www.arl.army.mil/arlreports/2006/ARL-
TR-3705.pdf](http://www.arl.army.mil/arlreports/2006/ARL-TR-3705.pdf)

------
soared
> SEC documents show that Yaney raised $1 million in equity in 2014, the year
> SpinLaunch was founded, $2.9 million in equity in 2015, $2.2 million in debt
> in mid-2017 and another $2 million in debt in late 2017. Now Yaney confirms
> SpinLaunch has raised a total of $10 million to date, and that he’s
> personally an investor... “The current status of our Series A raise is that
> we are still taking meetings with potential investors and have not yet
> received an executed offer.”

Do I not understand how series of funding works?

------
WilliamSt
Which startups are trying to build a launch loop or space towers? I'd love to
keep track of those startups.

~~~
Ftuuky
Are you referring to the space tower hypothesized by Thoth Technologies?

[http://thothx.com](http://thothx.com)
[https://en.wikipedia.org/wiki/ThothX_Tower](https://en.wikipedia.org/wiki/ThothX_Tower)

------
mywacaday
The child/mythbuster in me wonders what would have if you spun a large disc at
this speed and tried to skim it across an ocean

~~~
alex_duf
probably a lot of smoke and noise, I'd watch it though

------
tony_rusi
Dana Andrews used this Spinlaunch idea in his University of Washington
Undergraduate Astronautics Capstone Engineering Class to launch Lunar Mining
Ores from the moon cheaply. Maybe they intend to use it on the Lunar Poles?

------
skookumchuck
What has happened with all the studies about launching to orbit after being
dropped from a jet at high altitude?

------
Ftuuky
Would it help to catapult the cargo at high altitude where the air is
rarefied? That way you have to deal with less atmosphere and the initial
energy required for the catapult is smaller. Idk where, maybe the Andes?

------
jlebrech
you could have a covered (hyperloop) train go round and round in the antarctic
(against the earth's spin) until in reached escape velocity and segment of the
loop would detach and point the train up the space.

A second idea would be to create a bridge from the closest points of africa
and south america, use it as a standard bridge between launches, the launches
would only have to do 2g to get to escape velocity.

------
SteveGerencser
I think that this is cool, but I recall reading papers for rail launched
vehicles, mostly from the moon, back in the early 80s.

~~~
alex_duf
from the Moon I can see how it makes sense. From Earth I still have trouble to
believe it would work.

That being said I had trouble believing you could land two rocket boosters
simultaneously so at worst I'm not surprised, at best it works

------
anotheryou
It's a flywheel, some really good clutch mechanism and a straight track for
linear acceleration, right?

------
brett40324
Is there a calculation to determine a max spin speed of an object? Can an
object spin infinitely faster and faster if it had unlimited energy and force
spinning it? Is there a name for where centrifugal force is so high that an
object rips itself apart? Picturing hand tossing pizza dough as a simple
example, but what about massive structures?

~~~
andbberger
> Can an object spin infinitely faster and faster if it had unlimited energy
> and force spinning it?

Nope. Eventually the centrifugal force exceeds inter-molecular forces.

Not quite what you were asking, but related
[https://www.wikiwand.com/en/Roche_limit](https://www.wikiwand.com/en/Roche_limit)

------
nathannecro
The idea of launching objects into space using a catapult interests me if only
because my physics profs in high school and university all have at one point
or another shot down the idea of space catapults. Since I don't remember
exactly what their beef with space catapults was about, I figured I'd have a
go and see if I could get an estimation of feasibility myself.

I am also not an aeronautical engineer (or even close to being one), but I do
have some free time and I have a notepad.

According to Wiki[1], ∆V to LEO is ~8km/s plus 1.5km/s to account for drag (so
a total of 9.5km/s total). The article claims that the craft exits the launch
device at ~1.3km/s which leaves 8.2km/s to be accounted for. For the purposes
of our math, let us assume that the craft has an alternate way to get up to
speed. We'll note that SpinLaunch is not throwing their spacecraft into space
at all; in fact, they're barely getting their spacecraft off the ground
(relative to LEO).

Even with the significantly reduced launch speed, getting the craft spun up to
speed is no small task. The equation for relating linear speed to angular
speed is:

    
    
       [Linear Speed] = [Rotational Speed]*[Radius]
    

Since we have a linear speed in mind, we can make assumptions for rotational
speed or for the radius of the launching arm and solve for the other. I think
revolutions per second is easier to imagine, so we'll just Fermi this out.

If your maximum angular speed is one revolution per second (~6.3rad/s), then
your launching arm will need to be ~213m long. To put that in perspective, the
centrifuge would need to be about four football fields in diameter. Not only
that, but it would be hurling a spacecraft around the circumference once every
second! Because the relationship is linear, if you want to halve the angular
speed, then you'd have to double the radius. Just building a structure that
can not only support the weight of a spacecraft at the tip, have a diameter of
450m, and complete full revolution every second seems like a challenge
already.

Additionally, unlike a regular centrifuge, this launch structure would likely
not be parallel to the ground either; you want to launch your craft into space
after all. Which means that you'll have to deal with unequal forces and
accelerations as you spin.

To really put things into perspective, the largest centrifuge in the world is
the TsF-18 in Russia and it has a radius of 18m and can only manage 0.65
rotations per second at maximum speed[2].

But hey, I'm no mechanical engineer either, so maybe that's no big deal. Maybe
introducing a vacuum in the launch structure makes such a huge difference that
getting up to speed is easy enough.

How does one exactly create such a big vacuum chamber though? Even if the
height of the chamber is only 5m tall, the total volume is ~710,000m3. The
largest vacuum chamber is the Space Power Center and it has a maximum volume
of 22,653 m3[3].

You'll need to build something that outspins the largest centrifuge in the
world (by more than an order of magnitude) and outsucks the largest vacuum in
the world (by more than an order of magnitude). If somehow SpinLaunch can
build the most spinniest and suckiest structure ever built, you're still only
13% of the way into space.

Really puts into perspective how outrageous SpinLaunch's claims are.

1: [https://en.wikipedia.org/wiki/Delta-
v_budget](https://en.wikipedia.org/wiki/Delta-v_budget)

2:
[http://www.rusadventures.com/tour35.shtml](http://www.rusadventures.com/tour35.shtml)

3:
[https://www1.grc.nasa.gov/facilities/spf/](https://www1.grc.nasa.gov/facilities/spf/)

~~~
throwaway99OO
I have a bit of background on rotor systems. That TsF-18 is puny compared to
other rotational systems. See below.

Largest Centrifuge: Regarding the largest centrifuge in the world, perhaps the
TsF-18 in Russia has a large diameter but the JET Tokamak [1] flywheel spun a
775 TON rotor at a speed nearly 6 times what is cited for the TsF-18. The
Tokamak's centrifuge's provided over 3.8 gigajoules of energy. To provide a
more intuitive sense of that energy, 3GJ is equivalent to a 100kg mass
traveling at 7.7km/s [2].

Fast Flywheels: OakRidge National Laboratory [3] achieved over a 1.4 km/s tip
speed and that was back in 1985.

Large Vacuum Chambers: The Large Hadron Collider[4] is a vacuum system over 5
miles in diameter although toroidal in nature.

1: [https://www.euro-fusion.org/fusion/jet-tech/jets-
flywheels/](https://www.euro-fusion.org/fusion/jet-tech/jets-flywheels/) 2:
[https://www.calculatorsoup.com/calculators/physics/kinetic.p...](https://www.calculatorsoup.com/calculators/physics/kinetic.php)
3: [http://www.guinnessworldrecords.com/world-records/fastest-
ro...](http://www.guinnessworldrecords.com/world-records/fastest-rotating-
flywheel/) 4:
[https://en.wikipedia.org/wiki/Large_Hadron_Collider](https://en.wikipedia.org/wiki/Large_Hadron_Collider)

~~~
nathannecro
First off: thanks for the reply. Secondly, how could I forget about the
LHC...doh!

So it does seem like it is possible to get a spacecraft spinning up to speed.
It'll just require a lot of effort and even more capital.

------
aventrix
The physics of this makes no sense...

------
robkop
I wonder how they plan to reduce the costs of fairings when spaceX fairings
cost most than their entire launch cost.

------
Pica_soO
So the projectiles are spun, to generate a sort of carvatation effect in
atmosphere? Rather brilliant.

------
p0wn
I'm picturing a daredevil getting shot out of a cannon. Where is super dave
when you need him? Could be the spokesperson.

