Guest essay by Eric Worrall
US based SpinLaunch has performed their first 20% power launch, flinging a test payload “10s of thousands” of feet into the sky.
Alternative rocket builder SpinLaunch completes first test flight
PUBLISHED TUE, NOV 9 20211:19 PM ESTUPDATED TUE, NOV 9 20214:25 PM EST
Michael Sheetz@THESHEETZTWEETZSpinLaunch, which is building an alternative method of launching spacecraft to orbit, last month conducted its first test flight of a prototype in New Mexico.
The company is developing a launch system that uses kinetic energy as its primary method to get off the ground – with a vacuum-sealed centrifuge spinning the rocket at several times the speed of sound before releasing.
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“It’s a radically different way to accelerate projectiles and launch vehicles to hypersonic speeds using a ground-based system,” SpinLaunch CEO Jonathan Yaney told CNBC. “This is about building a company and a space launch system that is going to enter into the commercial markets with a very high cadence and launch at the lowest cost in the industry.”
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The SpinLaunch suborbital accelerator represents a one-third scale version, but – standing about 165 feet, “taller than the Statue of Liberty” – Yaney emphasized that it’s the size the company needs “to really prove the technology.”
The vacuum chamber holds a rotating arm, which Yaney said accelerates the projectile to high speed and then, “in less than a millisecond,” releases the vehicle for launch. The suborbital projectile is about 10 feet long, but “goes as fast as the orbital system needs, which is many thousands of miles an hour,” Yaney added.
“We can essentially validate our aerodynamic models for what our orbital launch vehicles are going to be like and it allows us to try out new technologies when it comes to release mechanisms,” Yaney said.
SpinLaunch’s first suborbital flight utilized about 20% of the accelerator’s full power capacity for the launch, and reached a test altitude “in the tens of thousands of feet,” according to Yaney.
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Read More: https://www.cnbc.com/2021/11/09/spinlaunch-completes-first-test-flight-of-alternative-rocket.html
A word of caution – SpinLaunch still have a long way to go, until they are ready to attempt their first true orbital launch.
So far that big carbon fibre arm has only been subject to 20% of its design tolerance. Pushing it to 100% or whatever the design velocity is will be a white knuckle ride. Any undetected mechanical flaw and the launcher could spectacularly disintegrate, with an energy release comparable to a rocket failure.
And like all ground based launchers, a course correction will be required once the payload is in space, otherwise the payload will come down on top of someone. Orbits mathematically tend to intersect the last point at which thrust was applied. So the launch vehicle will need a rocket or explosive charge which can survive the 10,000G initial launch to complete the orbital entry, to alter the trajectory once the payload is in space, to create a stable orbit which does not include re-entry into the atmosphere.
Before you dismiss this as impractical, consider that the extreme acceleration experienced by SpinLaunch payloads is comparable to the conditions experienced by an explosive smart projectile fired from a large artillery gun – so it is likely most of the technology required for the orbital insertion package has already been developed.
There will be plenty of uses for this launch system if they can get it working. Consumables like oxygen and prepared food can survive insane launch accelerations, so are obvious candidates for a high-G spin launch. Specially hardened satellites, even chunks of rock, to help transfer momentum to correct the orbit of large space stations, are all possible uses.
Even with a course correction component, SpinLaunch offers potentially enormous cost savings over a conventional launch. With conventional rocket launches, most of the mass of the launch vehicle is fuel. Think an enormous rocket with a tiny payload perched on top.
With SpinLaunch, only around half the mass of the launch payload will be fuel for the orbital insertion course correction, allowing far more useful payload to be lofted into space with each launch.
New and innovative technologies like SpinLaunch are a potential counter foreign space innovation efforts, like Russia’s nuclear powered launcher project, which if perfected could pose a significant challenge to US space dominance.
The following video provides more background on SpinLaunch.
Can we get Bezos and Musk be the first passengers?
May I suggest LGB be the first?
No offence Rio, but that would be a pay cut for me. But thanks anyway. Cheers.
Rio, we have the message now multiple times from you thanks, we don’t need it again and again.
And if I wasn’t retired that would be a massive pay cut for me as well.
Aw, don’t pick on him… that’s probably what he get paid to do, i.e. recruit other suckers :<)
Out of curiosity I clicked on Rio’s link but my computer won’t allow me to see what it is about, it says it is to a phishing site. Anyone else tried?
It seems the MODSquad deleted the Rio comment before I saw this.
But it does sound like whatever security program you’re running (OPPS! I’m old school. Should have said, “Apps you’re running”.)
work well.
Spin Launch just delivered Breakfast to the ISS, let’s see what we have this month…
Pancakes Again?
It’s always Pancakes!!!
LOL 🙂
It could make a pretty good Kinetic Energy Weapon though
Don’t forget the flatbread from time to time.
That pancake started out as William Shatner.
Crepes a mighty! Can’t we see a menu?
Spilled my coffee when I read that….very funny…
And scrambled eggs.
scrambled eggs, well they will be by the time they get them.
Musk would make his own, better version: his Boring company drills out a long tunnel that starts horizontal but eventually makes its way up a very high mountain, finishing up at 45°, say. The tunnel is fitted with a linear motor railway and a vacuum machine. The spaceship train is sped up with electricity like a maglev, to a few 1000km/h, and bursts through the top of the mountain where the air is thinner. It would need an awesome heat shield to survive the 1 second it would take for it to get to 100km.
I had exactly the same thought.
You’re both crazy then.
Have you ever read the Millennial Project by Marshall Savage?
He proposed something similar placed beneath/on Kilimanjaro due to it’s Equatorial location
Robert Heinlein: The Moon is a Harsh Mistress. Same principle
The Moon is a Harsh Mistress. Great book!
Musk better name a StarShip after Heinlein!! Seems like most of his books that I read featured a rich engineering entrepreneur pushing the envelope. Still remember the nuclear space ship that used zinc as fuel.
The flaw in your reasoning here is the Boring is actually a real company and not a massive publicity stunt.
Boring is what? A decade plus old? Where is the amazing super tunnels it was apparently going to build to replace freeways?
Drilling through rock isn’t THAT hard.
Also… not sure your maths is correct. 1km per second is, if my fingers and toes are correct, 3600kmh. 100km per second is 360,000kmh. I tried to convert this into mach using a little ap from the NASA website but that topped out at 7867 metres per second and Mach 25.78
Don’t they have a tunnel running in Las Vegas in circle so you can go nowhere, just like their plans?
At those speeds, you can’t hear yourself scream.
Craig posted:
There are MANY, MANY more fatal flaws in PCman999’s reasoning (actually, proposed launch concept) than just the proposal to use the Boring company.
Craig,
No, the Boring Company, like all of Elon’s projects has a very practical use…on Mars. Everything he is doing is to either get to Mars (SpaceX), or live on Mars (solar panels, electric cars, tunnel boring machines, orbital communications network). He’s just perfecting the technology here on Earth and, if possible, making a little money from it.
Just meant to give a ballpark figure on replacing the first stage. If you pay me I will give you the full engineering design and environmental assessment. But with your nitpicky attitude towards a quick comment on a informal website, don’t expect a discount on my fee just because you post here.
Being serious for a moment, the goal is to somehow replace the big expense of rockets first stage that barely operates for 2 minutes and brings the rocket up to only about 5-7000 km/h (typical Falcon 9 Heavy range, which is a very fast starting rocket). Of course the goal includes the vehicle not melting when trying to do those speeds at sea level. So a vacuum and high altitudes are involved.
I would think that since the projectile must be traveling at greater then escape velocity when it leaves the vacuum into the atmosphere that almost instantaneous resistance would destroy almost anything. Kind of like hitting water really fast for us. Or am I missing something? Also, if I could get something like this working, I would send cubed containers holding H2O that can interlock. With this you could build a radiation resistant habitat that contains possible fuel and oxygen source if needed.
I stand corrected. I was simplifying the math by using 3600mph and the 60mile Karman Line, but skipped over the minutes in going from hours to seconds.
So, 1 mi/s and boosters mostly separate at under 50 miles so 50 seconds but hopefully only really half that, that the rocket would thermal protection for. I’m thinking the air is very thin at 100,000 ft, ~20 miles ~30 km, so might get by with 20 seconds of hell. Shame that the tallest mountains are less than 6miles/10km high.
I think Jules Verne proposed that approach in From the Earth to the Moon. 🙂
PaulH,
Nope. Verne proposed a massive cannon (ref: https://en.wikipedia.org/wiki/From_the_Earth_to_the_Moon )
Yes, you’re correct! I should re-read that story; timeless stuff. 🙂
PCman999,
Uhhhh . . . 2000 km/h is about 0.56 km/sec, so it would take 180 seconds (3 minutes!), not 1 second, to travel 100 km, even assuming no slowing from atmospheric drag.
You have a “slight” math problem in your post . . . but it may be “close enough for government work” as the saying goes.
But orbital velocity is on the order of 28,000 km/hr. Given the rapid deceleration due to atmospheric drag at low altitudes, it would have to be going a lot faster than even that in order to reach orbit. And imagine the magnitude of the sonic boom it would generate!
The concept, as shown in the video linked in the above article, is that the SpinLaunch vehicle will have an onboard propulsion system, presumably to provide the delta-V impulse to raise orbital perigee above Earth’s “sensible” atmosphere (i.e., >160 km). It is this additional impulse that gets the orbital velocity to around 28,000 km/hr after the projectile has reached a apogee outside of Earth’s atmosphere.
Thus, no sonic boom at the orbital velocity.
Left unsaid is the manner in which a bipropellant or solid propellant propulsion system could be designed to (a) withstand 10,000 g transverse loading at time of launch, and (b) have enough impulse-density (impulse per unit volume) to fit with the size of the SpinLaunch vehicle that has been cartooned in the video.
Personally, I am very confident, engineering-wise, that the two shall never meet.
(Note to self: Next time put the heat shield on the top instead of the bottom.)
I can see it has potential. Let private industry pursue it without taxpayer dollars.
There was an SF story (Analog, I think) that had a curved launch tube in the Himalayas. This used a linear accelerator, and the ‘g’ force was apparently suitable to launch humans. This was only a background to the real story out in space. But basically, anything you can think of, some SF write thought of it first!
Good luck to those astronauts..
I thought we were getting replacements … but NOOOO…Pancakes again
More bloody damn pancakes
Wouldn’t a been bloody if’n that little mouse hadn’t a sneaked in :<)
Flat rat?
This seems like a sensible concept. You would probably want to locate it further south to take advantage of the Earth’s rotation, like NASA do.
I’d hate to hear the sonic boom as it hits the air!
Space craft would need some kind of heat shield.
Building a space craft that can withstand 10K G’s is not going to be cheap, and all that strength will add a lot to weight as well.
I don’t believe this concept will fly.
I vaguely remember, there went smith wrong with the Columbia shuttle at reentry in the atmosphere…
The first cosmic Velocity at the dense atmosphere…
No material can withstand it.
But yes, if you install the launcher on the Moon, it will be a great option!
For nothing but PANCAKES
OK I’ll stop the pancake jokes…they seem to be falling flat anyway
Wouldn’t have happened if you had used enough spin.
More dough.
Seadragon concept use the lift from water to accelerate the rocket. Also a wild idea never to be realized?
The problem with Seadragon is that cryogenic fuels turn it into an Ice Queen.
OK, I thought this was a joke when I first saw it, but this is just plain cool. A better way to get liquids into space, like water and oxygen…etc.
You could potentially launch modular space station components this way – build a space habitat bit by bit.
If the launch costs are cheap enough, launching water ice into orbit would set the stage for more space development.
Put an orbital transfer vehicle in orbit to collect the blocks of ice for later processing.
It all depends on the launch costs. It’s always depended on the launch costs. We need to get them down.
Cubes containing ice with solar panels to provide energy to convert ice to thrust as needed. Blocks lock together and create structures that provide rad protection and fuel source.
How much energy is used per launch? What is the source of the energy?
Solar power? Or lithium batteries? Ha ha.
Less than a rocket. That is the point, with a rocket the bulk of the fuel is used getting the bulk of the fuel off the ground.
As mentioned below it could be solar power, especially attractive for launching things off the Moon or Mars rather than making fuel there and using up that precious water.
I’m surprised that Musk is not more into this. With all the panic about CH4 (and LOX shortages) these days he’s bound to get more and more flack from the eco-brigade in the future. Many of them are potential Tesla customers so he doesn’t want to annoy them too much.
Musk? I’m not.
Musk isn’t THAT creative. He knows what he wants and then gets established engineering and science together.
Tesla? Is a car. We have had cars before. We have had electric motors before.
Space X? Is a rocket. We have had rockets before.
He didn’t invent any of these things. At best he combined some existing tech and has motivational vision strong enough to predict markets.
Also, he is not a Lizard Person. That counts for a lot in Big Tech these days.
Musk is one of those guys I love and hate. He’s PT Barnum and Leonardo rolled into one. He has a great imagination but spouts off a little too much about his accomplishments before they actually happen. Where’s my class 8 truck?
Sure, just a simple scale-up of his HyperLoop system, right?
Speaking of which, whatever happened . . .
Hamsters, running very fast.
At least 1.6 MJ (mega-joules) per kg of mass to sling something vertically upward to 160 km altitude.
See my extended post below.
A new career for DJs spinning satellites instead of records?
Reminiscent of Jules Verne where ‘From Earth to the Moon’ used a large long barreled cannon..
It makes a lot of sense to do the acceleration at ground level rather than carrying a lot of reaction mass to altitude first.
Well good luck to them
I think I’d probably use a long linear accelerator to throw a sabot encapsulated missile…
It does but you are at full velocity in the densest part out the atmosphere. Lots of heat to get rid of.
Put it atop Mauna Kea
Using a airplane to lift the space craft up to 20 to 30 thousand feet makes a lot more sense. It also doesn’t require all kinds of exotic materials to build.
And it doesn’t buy you much in energy savings, given that you need to have a circular orbit altitude of more than 200 miles (>1 million feet) to have any multi-year orbital life.
For reference, the ISS orbits at an average of about 250 miles altitude, yet still requires periodic orbital velocity boosting to make up for atmospheric drag losses at that altitude.
It completely eliminates the need for a first stage.
The first stage adds quite of bit of tangential velocity as it is also vertically lofting its “payload” which are the upper stages and payload.
This is clearly seen in the rapidly increasing “downrange” parameter during first-stage burns.
Airplanes add a lot of tangential velocity as well.
Again, required tangential velocity for a 160 km altitude circular orbit is about 7,800 m/s.
The SR-71 aircraft, one of the fastest ever built, flies at about 2,500 mph (about Mach 3.8) at 85,000 feet (where the air is very thin relative to sea-level).
2500 mph is 1120 m/s, or about 14% of the required orbital velocity.
In comparison, most large commercial jet airplanes, such as the L-1011 used to carry the Orbital Sciences Corporation/Northrup Grumman Pegasus launch vehicle during horizontal flight, fly subsonic at a maximum speed of about 600 mph. This speed is only about 3% of the above-stated orbital velocity,
I will go so far as to agree that “it’s a start”.
You are counting the total tangential velocity added by all stages, and comparing it to the tangential velocity added by an airplane.
You need to limit this comparison to just the tangential velocity added by the first stage.
I have been unable to locate any reference that states the horizontal (i.e., tangential-to-Earth horizon) velocity of any first stage rocket booster at the time of its separation from the upper stages.
However, there is this from Wikipedia (https://en.wikipedia.org/wiki/Saturn_V ) about the S-IC, the first stage of the Saturn V rocket stack:
“During launch, the S-IC fired its engines for 168 seconds (ignition occurred about 8.9 seconds before liftoff) and at engine cutoff, the vehicle was at an altitude of about 42 miles (67 km), was downrange about 58 miles (93 km), and was moving about 7,500 feet per second (2,300 m/s).”
The Saturn V SA 503 Flight Manual (available at https://history.nasa.gov/afj//ap08fj/pdf/sa503-flightmanual.pdf ) shows the Saturn V launch stack begins its pitch-over maneuver about 9.6 seconds after liftoff, so it starts developing horizontal velocity very quickly in the boost phase. That would leave (168 – 8.9 – 9.6) = 150 seconds for first stage horizontal velocity buildup based on the horizontal vector component of thrust during this time.
And most significantly, that same flight manual shows the Saturn V stack has a flight pitch angle of about 25 degrees off-vertical at 1 minute after liftoff, a flight pitch angle of about 60 degrees off-vertical at 2 minutes after liftoff, and a flight pitch angle of about 67 degrees off-vertical at S-IC engine cutoff.
The manual gives a S-IC cutoff inertial velocity of about 9,000 ft/sec, quite a bit higher than that given above in the Wikipedia excerpt (7,500 ft/sec). Even if we go with the lower figure of 7,500 ft/sec inertial, that value at a (90-67) = 23 degree vector angle above horizontal yields a purely horizontal (i.e., tangential to Earth) component velocity of 6,900 ft/sec, or 2,100 m/s.
So, you can see that just the first stage of the Saturn V rocket stack added 2,100/7,800 = 27% of the tangential velocity needed for a 160 km altitude circular orbit.
As per my previous post, this 27% can be compared to the 14% available at SR-71 max speed or the 3% available at an L-1011 top speed.
{N.B., In all these discussions I have taken the worst case of having to achieve orbits in a N-S direction. For the easier case of pure E-W (equatorial) orbit, in the direction of rotation of the Earth, the necessary orbital speed (to be more precise, the necessary delta-V increment would be reduced by the E-W speed of Earth’s surface as it varies by latitude. . . any rocket stack already has this E-W tangential velocity at the latitude of the launch site.}
I hope someone is doing a high definition video of this. I hope they’re standing a long way away.
JF
Good grief, we really have all lost our minds
(Well not completely, doncha love the slo-mo Space Odyssey images of The Projectile bursting through the virginal white ‘screen’. any more transparent and they’d be invisible)
No matter – can we please get over the Space Exploration bit – what goes up, comes down.
So they’re lauching ‘science’ experiments?
Why. There’s no way anyone can verify the results and if you do ask, you’ll be dumped upon with squigga gigga trigga bytes of impenetrable data and told to ‘get on with it’
Meanwhile they themselves will use the data and The Authority of The Sputnik to rain down fear and loathing so as to obtain power, control and money.
So they launch Smart Technology, for phones or TVs or computers.
Sorry. Not buying tyhat either-. There is no ‘smart’ anything, only (by implication) Dumb Users.
Thanks for nothing
Or Sputniks to relay ‘media’
Don’t we have enough hysterical brain dead mendacious paranoid panic-stricken fear-inducing junk already?
Enough of that:
I see at 3:59 they tell of 2,200 Celsius, a ‘heatsink nose-cone’ and a’surface energy flux’ of 3kW per square centimetre
Errm, 3kW/sq cm is 30 Megawatts per square metre. That is the the energy flux on the surface of old El Sol and its temperature is just a tad warmer than 2200°C
What are they making this thing out of AND, where is the ‘heatsink’ sinking the heat to?
OK
They’ve built a huge rotating machine and The Prime Requirement for any and all rotating machines is that they are and remain ‘in balance’.
What they have here is a machine that, while the Sputnik is still in there: In balance
But at the instant of release (yeah right, back to slo mo virgins) – this machine deliberately puts itself out of balance and as they say, to the tune of over 11 Tonnes.
Isaac Newton will be either spinning in his grave or laughing fit to die – Action and Reaction. Anyone?
Thus when they release that 11 tonne Sputnik in one direction, very effectively a mirror image Sputnik, just as heavy and moving at the same speed. hits that machine from the opposite direction.
I don’t see in the video any accommodation for that. Guns carriages were fitted with wheels, they recoil and in a conventional rocket it is the propellant itself that absorbs the recoil
Always goof (edit= innit great how D is next to F?) for a laugh are videos of windmills losing a blade out there, just one blade falls off (is released) and within seconds the whole machine is a tangled mess on the floor – and the wing-tip on those are only moving at 200mph, not Mach 11
which school did these clowns attend – did they ever even go to school?
(We do recognise something either Bojo or JoBo Brandon would be ‘all over’ as devices to save the world. Thus how we recognise sugar & alcohol poisoning and dementia. One leads to the other)
missed the 2nd edit:
So it worked at 20%
Remember the recoil, the out-of-balance bit?
That goes as the square of the speed of the projectile.
The shock hitting that machine when its going at full tilt will be easily 20 (twenty) times greater.
I repeat ‘which school’
Gerald Bull, the engineer between Saddam Hussein’s Iraqi supergun, successfully fired artillery shells above the atmosphere, so it is unequivocally possible to build projectiles which can survive such extreme atmospheric heating.
The question then becomes, is it possible to launch anything more delicate than solid lumps of iron.
Additionally, the speeded needed to get something “above the atmosphere” is well short of the speed needed to put something into orbit.
“In Project HARP, a 1960s joint United States and Canada defence project, a U.S. Navy 410 mm (16 in) 100 caliber gun was used to fire a 180 kg (400 lb) projectile at 3,600 m/s (12,960 km/h; 8,050 mph), reaching an apogee of 180 km (110 mi), hence performing a suborbital spaceflight.”
—source: https://en.wikipedia.org/wiki/Space_gun
I believe nothing yet has surpassed this accomplishment.
Also, for confirmation of your post, there is this from the same Wikipedia webpage:
“The most prominent recent attempt to make a space gun was artillery engineer Gerald Bull’s Project Babylon [1988-1990…GD], which was also known as the ‘Iraqi supergun’ by the media. During Project Babylon, Bull used his experience from Project HARP to build a massive cannon for Saddam Hussein, leader of Ba’athist Iraq. Bull was assassinated before the project was completed.”
His dream was always to create a cannon that could shoot things into orbit. He only went to work for Saddam because Saddam was the only one who would fund his research. He didn’t care that Saddam wanted to build a cannon that could threaten Israel, so long as he could develop and prove his tech.
He should have cared. It probably cost him his life.
Bull’s design involved a smoothbore cannon with the barrel evacuated and sabot skins that peeled off the projectile as they heated red hot. Canadian military test acknowledged projectiles reaching 40 km. altitude after which it appears the test program wound down probably die to the introduction of the Bomarc missile program.
It is sometimes claimed that he was assassinated by the Mossad because the technology put all the Israeli population within range of Hezbollah artillery. Militarily…has long since been superseded by cruise missiles and drones.
Uhhhh . . . the Bomarc missile program was in service from 1959 through 1972. It ended some 16 years before Bull started his Project Babylon misadventure with Saddam Hussein.
Good point about the imbalance at time-of-projectile-release, but I guess you missed to “subtlety” that they will simultaneously be releasing an identical mass on the other side of the platter that then just harmlessly (yeah, right) smashes downward into Earth.
You can see just a tiny portion of the exit cute for this counterbalance on the shadowed side of the SpinLaunch test build in the photo at the top of the above article.
Or at least I think so. 🙂
Make that “chute” instead of “cute”. Darn auto-spell feature.
I’ve always liked a ‘cute chute’.
Was going to say I’ve always had a soft spot for a cute chute, but that would be counter-productive.
Was going to be cynical about this, but the point of putting payload into orbit seems pretty valid.
You would need a second vehicle to collect the payload and deliver it to where it needs to go (insert Pancakes Again! joke) but within those parameters it seems a valid idea.
Can’t see it being a useful satellite launcher. There is the final positioning problem and the fact that all components will need to withstand massive G loads.
Probably. It is the weekend and I am not going to try too hard to do maths 🙂
Out-of-balance after payload release is easy to handle by releasing a ballast to opposing direction. The next problem is, how to recover the kinetic energy of the ballast.
To stay in balance, the counterweight is going to have to directly opposite the launch vehicle. So if the launch vehicle is going up, then the counterweight will have to be heading down. So unless the spinner is built on the edge of a cliff, the point of impact for the counterweight is going to be at the foot of the spinner. I don’t see how you are going to be able to use one of these spinners more than once.
Should be called Trebuchet.
Won’t work to put something into space. Drag, anyone? But might become a weapon outperforming hypersonic gliders.
Gerald Bull, the engineer between Saddam Hussein’s Iraqi supergun, successfully fired artillery shells above the atmosphere, so it is unequivocally possible to build projectiles which can reach space after being accelerated up to full speed on the ground. Whether they can repeat this feat using a big spin launcher is an open question.
There’s a big difference between launching a lump of iron and launching a satellite.
Another issue is that cannons have long barrels, this spreads out the total acceleration over a long distance, possibly several hundred feet.
This dramatically reduces the worst case G forces that the projectile experiences.
Smart weapons fired from artillery experience similar G-forces, they have onboard electronics which survive the launch.
It is not true that they experience similar G forces. Smart weapons are only fired a few dozen miles and they are fired out of a barrel that stretches out, and therefore lessens the accelerations involved.
A few hundred, vs 10000G’s.
My cousin and I discussed a similar technology over a decade ago, one using a circular rail-gun to launch the projectile. He thought he had come up with a great new way to get into space but, when I did some back-of-the-envelope calculations, I demonstrated that it wasn’t very feasible. Here’s what I wrote back then:
Using a maximum of 100 g’s as a starting point and using the same equations as in my last email, I can tell you that the diameter of the circle needed for reaching orbital velocity would be about 123.5 km and the circumference would be about 387.9 km. To shrink the diameter to 12.3 km and the circumference to 38.8 km would require the capacity to withstand 1,000 g’s. This is probably well beyond the ability of any spacecraft to withstand, let alone the human occupants.
The other issues you mention can probably be overcome. The change in velocity once the projectile leaves the gun can be surmounted by increasing the final (muzzle) velocity slightly. An additional 500 m/s would be probably be sufficient to account for both wind resistance and the Earth’s gravity. Travelling at 28,000 kph, the time to 250 kms altitude is in the order of about 35 seconds and, during this time, the effects of both these phenomena would be constantly decreasing. Increasing the speed to 30,000 kph would offset these effects and would require only a slightly larger circle.
The issue of the impact of the projectile on the atmosphere as it leaves the gun and the shockwave generated by it is more problematic. It could probably be mitigated somewhat by pumping a stream of air at high velocity along the same axis as the projectile from ports around the “muzzle” of the gun. This air would be travelling at a speed much closer to that of the projectile than stationary air and might reduce the shockwave to a manageable level.
The change in the vector of the G force is the real doozy of a problem though. To maintain whatever G force you set as your maximum requires that you maintain a circle of the same size as the first one. However, only a quarter of the circle is required to translate motion from the horizontal to the vertical (1/4 x 360° = 90°) but this still means an additional 97 kms of track (at 100 g’s), much of which would be vertical. By the time the projectile left the “muzzle” of the gun, it would be high enough up (60 kms) that wind resistance would be of little consequence and the effect of Earth’s gravity much reduced. The real difficulty lies in building a structure over 60 kms tall.
If they can get an idea like this to work (and that’s a very big if), it could only ever be used for cargo delivery – a cargo module attached to a solid rocket booster – because, anything delicate would not withstand the G forces involved.
Absolutely, cargo only – but Gerald Bull, the engineer between Saddam Hussein’s Iraqi supergun, successfully fired artillery shells above the atmosphere, so projectiles can survive the journey up through the atmosphere into near Earth space.
Three points
1) Bull was launching a solid mass of iron. He also used a barrel which allowed the projectile to be accelerated over time, drastically reducing the worst case G load.
2) A spinner is going to see greater G loads and they will have to be endured over a longer period of time.
3) Getting something above the atmosphere is easy, however that is still far short of orbital velocity.
“could spectacularly disintegrate, with an energy release comparable to a rocket failure.”
Not so. Rocket propulsion is spectacularly inefficient.
You might be able to mitigate the shock wave by placing the exit port in the bottom of a large depression. The sides of the depression shaped in such a way that the shock wave would be deflected upwards.
Scott Manley has a very good YouTube video on how this is working.
The delivery system still has a second stage so the initial launch doesn’t require for the vehicle to reach orbital velocity.
The acceleration forces on the payload are huge but within tolerances for the type of payloads the launch system is being designed for. Some payloads are less sensitive to g forces than others.
According to the article, G forces are around 10000G, that’s several orders of magnitude more than the G forces seen during a launch. Most launches with humans aboard don’t go above 4 or 5 G’s. Non-human launches can go above that, but rarely do by much.
It’s time to lean how UAPs do it. (UFOs for those of you not following this interesting issue)
Somebody was talking about hypersonic missiles the other day saying the missiles go so fast through the atmosphere that they create an ionizing field around themselves and this interferes with picking them up on radar.
Then one participant compared the ionized air around a hypersonic missile to the apparent ionized field around some UFO’s and wondered if this was the reason they did not get picked up on radar sometimes.
It’s my understanding that some U.S. air assets can generate their own tailored ionized field around their aircraft to ward off radar detection.
Oh boy, whenever I see some contraption that functions within a hidden chamber, I cant help but think of a magician pulling a rabbit out of a hat. It’s not magic, folks, it’s merely a fun illusion. Next thing you know, they’ll be handing out balloon animals.
Until I can see it working within the secret magic mystery vacuum chamber, in my view it will remain little more than a fun illusion.
Oooh neat..
A simple CCTV camera in the vacuum chamber would be all you need.
This is cool. In the video, the narrator mentioned the need to instantly re-balance the rotor when the projectile is released. I wonder how they do that.
The G-force would be kind of hard on the equipment and deadly to humans. This does look like an interesting way to launch artillery shells—those are built for high-G. Interesting, but kludgy. Why not a long, linear accelerator? (see The Moon is a Harsh Mistress”.) Yes we have an atmosphere, but its impact can be overcome, too, to simply get the booster segment up, beyond most of the atmosphere.
Wasn’t there a sci-fi story that suggested using liquids to cushion the high g forces?
A lot of them. Heinlein seems to have also invented the water bed for Valentine Michael Smith.
Interesting idea for suitable and less sensitive payloads.
The idea of this launcher is “Newton’s Cannon”, a drawing of a cannon shooting projectiles into earth orbit, which was published pothumously in a collection of Isaac Newton’s works.
Here is a interactive,on-line version of Newton’s cannon. Just get the projectile moving fast enough (“escape velocity”) and the cannon will automatically launch the projectile into orbit!
https://physics.weber.edu/schroeder/software/NewtonsCannon.html
[Hint: try 7200 m/s :-]
Does this machine get a satellite higher in the atmosphere than simply carrying it up with an aircraft and launching from say 30,000+ feet? That would seem to be the natural competition for the machine.
That is IT!
A flying version of this “machine.”
https://www.aerotime.aero/27041-Why-do-companies-use-airliners-to-launch-space-rockets
Maybe an alternative to a Lunar Mass Driver.
I watched the video, and even at the modest speed the projectile was going, the skin heated up significantly. At full speed, friction from the air may destroy the module. I would put this on top of a mountain in the Andes to reduce the initial drag. At 18,000 feet the density of air is about half that at sea level, and cuts your problem in half as well.
Just think of how hot spacecraft coming back down from orbit get. They are going slower than the projectile when it leaves the spinner, and the air density is thousands of times higher.
Didn’t Wile E. Coyote use this to try to catch the Roadrunner?
Great toy for geo-engineering. Deliver large volume of sulfur compounds to stratosphere at low cost and cool the earth.
Don’t give them any ideas.
I strongly suspect that every penny that is saved on launch vehicles will be spent building a space craft that can stand the 10,000 G’s experienced during launch.
Another problem with these kinds of launch systems is that greatest velocity is seen at the same place where the atmosphere is the densest. Talk about your sonic booms.
Hmmm, just like the centrifugal pumpkin chuckers.
Current records for the centrifugal category:
“3245.58 ft”
That’s a pretty good toss!
It’s a danged amazing toss!
Bad to the Bone used a rusty old truck to power their centrifugal machine. The truck would rock and shake as the operator gunned the fuel pedal till the machine was in maximum spin.
Trying to exceed his own record the centrifugal arms broke. His attempts to rebuild the centrifuge kept failing as tried longer arms.
I haven’t seen him back.
The Smokin Lamas used human powered bicycles to achieve their throws with a centrifuge.
Many of the more powerful pumpkin chuckers suffered frequent disintegration of the pumpkin at launch. Counts as a failed throw attempt. Any weakness and the projectile breaks apart.
Finding volunteers to ride the rockets may be a problem…
And are we to assume spacecraft launched this way will be ball or football shaped?
I hate to throw a wet rag on this concept, but it really is totally impractical for getting payloads into near-Earth orbits.
Let’s say we want to get a spacecraft into a circular orbit, just outside most of Earth’s sensible atmosphere so that it might have a mission life of, say, one or two weeks before it decays to atmospheric reentry . . . we’re talking something around 160 km (100 statute miles) altitude.
For reference, the ISS has to have periodic orbital velocity boosting to maintain its nominal altitude against continuous atmospheric drag, even though it flies at about 400 km (250 statute miles) average altitude.
One can use one of several on-line calculators (e.g., https://keisan.casio.com/exec/system/1224665242 ) to find that a 160 km altitude circular orbit altitude requires an orbital velocity of 7,810 m/s.
So, for a 160 km circular orbit, the kinetic energy per kilogram of vehicle will be 0.5*m*v^2 = 0.5*1*(7,810)^2 = 30.5 MJ, where MJ is mega-joules.
Now let’s compare that necessary kinetic energy with the necessary potential energy that is associated with just vertically raising a kilogram of mass to the altitude of 160 km above Earth’s surface. This is the only energy that the SpinLaunch system can provide with a vertical launch.
The potential energy required to raise mass vertically in a gravitational field is ~m*g*(delta-h), neglecting the slight decrease in gravity over the relatively small delta-h vertical distance. On a per kilogram basis, the associated potential energy would be ~1*9.8*160,000 = 1.57 MJ.
These simple calculations show that SpinLaunch system provides energy that is only 1.57/(1.57+30.5) = 4.9% of that needed for putting a payload/vehicle into a 160 km circular orbit around Earth. The conclusion, of course, is that any projectile launched using the SpinLaunch system has to provide at least 95% of the energy it would need if just launched from Earth’s surface using standard rocket technology.
And that 5% energy savings from a SpinLaunch comes at a heavy price (pardon the pun) . . . all of the vehicle structure, avionics, propulsion system and payload must be designed to withstand the 10,000 g launch forces cited in the above article. To put that in perspective, almost every rocket launch system for putting payloads into space limits peak sustained acceleration forces to less than 30 g’s.
Yes, in the above I have neglected the energy losses associated with hypersonic vehicle flight (aerodynamic drag) through the lower portion of Earth’s atmosphere, and I have not cared to discuss the enormous problems of aerothermal heating associated with such flight, both of which are maximized in the SpinLaunch concept.
So, bottom line, SpinLaunch might eventually find limited use for suborbital, near-vertical launches to 150-200 km altitude, but forget about it being enabling for orbital missions.
The next SpinLaunch prototype won’t be vertical, the plan is for SpinLaunch to contribute to horizontal velocity. So if everything works out it will be capable of supplying a much large portion of the energy required to achieve a stable orbit.
Gerald Bull, arguably the greatest artillery genius of the 20th century, thought it could be done..
Yeah, I saw that in watching the video that was linked in your article (thank you for including that, BTW). Problem with going on a projectile path that is not vertical is that you extend the time-of-hypersonic flight in the atmosphere due to the resulting “slant range”, increasing the issue of managing aerodynamic heating and aerodynamic stability.
Next, there is the issue of orbital mechanics that says an object in an orbit, having no additional velocity increments, will return to same given orbital point within one orbital period (in the case of SpinLaunch, the projectile won’t have enough energy to even hit Earth on the “opposite” side in its parabolic ballistic arc, much less go completely around Earth to impact generally westward along the latitude of the SpinLaunch launch site.
Next, as I mentioned above, the orbital velocity needed for just a 160 km altitude circular orbit is 7,810 m/s. Assuming absolutely no aerodynamic drag and negligible energy to raise the projectile against gravity, that speed would be equivalent to Mach 22.8 at the launch . . . and NOBODY knows how to make a vehicle withstand heat loads or be dynamically stable in atmospheric flight at that speed.
Finally, the projectile, fired at ANY angle, will still need to provide its own velocity increment (via on-board propulsion system) to circularize the orbit (or at least to reduce its ellipticity so that perigee would be moved above Earth’s “sensible” atmosphere (e.g., > 200 km altitude).
Whether or not Gerald Bull knew the intricacies of orbital mechanics, I will not speculate.
That brings up the questions why and what, Eric.
Specifically, what could survive those G forces and still function after reaching orbit?
The answer is not much as we know right now. Unless they plan to launch solid projectiles like bombs. The Webb telescope certainly wouldn’t survive the trip.
A slightly different answer arises, if they only seek a way to launch supplies into orbit for pickup by the space station or similar.
No, there is a much more serious issue to the “pickup” of cargo from a SpinLaunch projectile for supplying the ISS (or similar).
An orbital rendezvous (to enable a gentle transfer of cargo) necessarily requires the matching of orbits . . . to be totally correct, the matching of orbital ephemeris, for the SpinLaunch vehicle carrying the cargo and the vehicle that is to pickup the cargo. This will require: (a) a tremendous amount of propellant mass to decelerate a cargo vehicle that is orbiting connected to/alongside the ISS, and (b) a tremendous amount of propellant mass to then boost the cargo vehicle (with cargo) back into the ISS orbit and to perform rendezvous with ISS.
And this is assuming the SpinLaunch projectile first gets itself into a stable LEO orbit.
If one consider the projectile just being on a (non-orbital) ballistic arc, then the “orbit” matching and cargo transfer will have to been performed near apogee outside of Earth’s atmosphere and within 5 minutes or less to enable the cargo transfer ship enough time to add the boosting delta-V needed to prevent atmospheric reentry.
We’ll have to have a lot of water ice in space if we are going to do large-scale space development.
The current plan is to get it from the Moon.
If this, or another launch system proves cheap enough to operate, then we could get the water ice from the Earth.
Tom,
There are also plans to manufacture water in space by recovering residual propellants from LOX/LH2 upper stages that are placed into LEO or Moon orbit, and in turn running the boiloff oxygen and hydrogen through fuel cells to generate both electricity and pure water.
This approach would be more efficient and much more simple than having to travel to/descend into the Moon’s gravity well, only subsequently to have to launch out of that well (with TBD water/ice mass) to supply any manned space station, whether orbiting the Moon or Earth.
It was estimated that the Space Shuttle’s External Tank would still have 15 to 20 tons of propellants left in it after reaching orbit.
This was for a study done about taking the ET all the way into orbit along with the Space Shuttle.
Just so.
The problem is the minimal altitude that the Shuttle ET would be placed into. Under a normal STS launch, the ET reached perigee (the release point for the Orbiter) at about 113 km altitude, and did not have enough kinetic energy to complete even one orbit of Earth.
Even if addition propulsive impulse was added to circularize the ET orbit at this altitude, it would likely have reentered the atmosphere is a mere matter of days due to atmospheric drag.
To have placed the ET in a circular orbit equivalent to that of ISS would not have been possible unless an STS launch did NOT include boosting the Orbiter.
Then too, the ET was not designed to minimize boil-off of LH2 (such as the design of a LH2 storage dewar), so most of that residual propellant would have been vented off by time of rendezvous with ISS.
It will be a hell of a lot cheaper to use a rail gun on the moon to get such stuff into Earth orbit.
It is impossible to be on a Moon-Earth trajectory and also “enter” Earth orbit without delta-V being used to change orbital parameters.
That “stuff” the lunar railgun launches to Earth better be contained within a vehicle having a very accurate navigation system and a significant propulsion system for mid-course corrections and for breaking into Earth orbit.
The lower the angle, the more time is spent in the atmosphere and the more energy lost to drag.
There’s a huge difference between a cannon and this device.
I’d like to see that. Imagine flinging John Kerry into space!
Probably improve his facial structure.
10,000G
———-
Color me skeptical. The loads to reach orbit are similar to a space elevator.
The problem is similar to anchoring in deep water with a rode that is heavier than water. Eventually the weight exceeds the yield strengrh as depth increases.
That can be fixed with a broader base. Its load / square meter which matters, not total load per projectile.
The problem is the arm and the radius of the spin. I show in another post that a radius of 100 feet is approaching the limits for carbon fiber even before you attach a payload.
Before dismissing this concept, just take a look at the basics. Launch speed about 5000 mph…velocities of this magnitude in the lower atmosphere appear to be well studied, and tried. I was immediately concerned about the heat up upon exiting the device…but that appears to be well handled by materials and geometry. The 10k G is scary, but as noted, there are a lot of materials and operational mechanisms that can withstand this kind of force.
Their forte would seem to be rapid launch of relatively light payloads. Perhaps this is how Musk can get enough fuel up to his Mars bound spaceship….
If launch cycle time is short, then imagine launching 1000 identical payloads in a relatively short period of time.
It will be very interesting to see how this pans out….great to see folks actually trying these ostensibly unusual methods of orbital insertion…
I will look forward to seeing a cost analysis of orbital insertion vs full fuel on board systems.
I quite agree…I can’t do the maths to know if orbital speeds are obtainable so I leave that to the experts. However, great to see others prepared to risk their and their shareholders’ money to try out these new concepts. They might just get a win. Who ever thought rockets could land on an ocean barge and be reused up to 10 times… However, not sure I want to invest just yet! I’ll leave that to the brave and daring.
This device makes much more sense as a bunker buster. Armed with a tungsten penetrator and fired into a mountain from a few feet above the ground it would pulverize any nuclear weapons or labs within the mountain. Equally effective against nuclear silos.
Yes, but not exactly portable or mobile though…
And the time required to put this facility in place in a hostile territory would be . . .?
These devices could be placed into orbit as Reagans star wars solution to counter hypersonic missiles. Also Iran and N Korean weapons research killer. 15000 mph penetrator launched at point blank range.
Do they bail out with the money at 30% or 40%?
Winan steam gun used during the American civil war.
The arm is a problem
A carbon fiber rod more than 100 feet long will fail under its own weight at 10 kG.
A foot of carbon fiber 1 inch in section weighs 1 pound and has a yield strength of 500 kpsi.
A rotating carbon fiber rod at 10 kG has an average load on 5 kG and will weigh on average 5000 lbs per foot.
A rod 100 feet long has a force of 500 kpsi at the inner attachment. Maybe this can be solved by tapering. Increasing the fiber section towards the center of spin.
Probably not impossible. Make more sense in space launching two objects in opposite directions.
On earth filling with hydrogen might reduce cost as compared to pulling a vaccum in such a large structure.
So, maybe my physics is rusty, but why 10,000 Gs? If I add centripetal acceleration at 2G/second, then during the entire “spin up” phase, I’m only experiencing 2G of acceleration – even through my accumulated velocity is insanely high.
Then, when I’m released, I go from 2G to 0G – no more acceleration. I experience a -2G acceleration.
Am I thinking of this wrong? Or are they talking about 10,000 Stapps (jerk force – rate of change of acceleration)?
You thinking is wrong. There is centrifugal (mistakenly called “centripetal”) acceleration from forcing an object to remain on a curved path (e.g., remain attached to a spin arm as it rotates) and there is, separately, the tangential acceleration of the projectile as the rate of spin is increased, starting from zero.
(I will not go into the details of why there really is no such thing as centripetal acceleration, but instead there is such a thing as centripetal force that is needed to counteract centrifugal acceleration. Detailed explanation available on the Web.)
There IS a variable rate of spinning up that could add 2 g per second (the centrifugal acceleration scales a (RPM^2)*r, where r is the radial distance from the center of rotation), but in the case of SpinLaunch I believe they are talking about 2 g (not 2 g/second) in the tangential direction.
In any event, the final g’s reached in either direction will depend on the g/second rate TIMES THE NUMBER OF SECONDS IT IS APPLIED. Alternatively, one could simply state an object on the end of the spin arm experiences a constant tangential acceleration of 2 g (not 2g/sec), which is what you seem to be asking about, but this would say nothing about the centrifugal acceleration that is developed because the time of action is left undefined.
Also, please note that at any given RPM, the tangential rate of acceleration could be dropped to zero (this is, keeping the RPM at a constant value) but the centrifugal acceleration at that constant RPM would still exist.
The tangential acceleration will be near zero at the time of projectile release from the spinning arm (design maximum RPM is obtained) but just prior to release the projectile will be experiencing 10,000 g of centrifugal acceleration.
Latest News: SpinLaunch researchers invent efficient way to turn astronauts into peanut butter. Film at 11.
I’m dating myself so bad….does anyone watch the nightly News any more? Do they still say that or is it now “video at 11”?
Jokes aside, good luck to them at SpinLaunch.
Wheeeee! But I’m going to be really dizzy by the time I get into orbit.
Does not say how fast. Escape velocity is ~37,000 ft/sec (>30x SOS). It says 20% power, not sure if that implies 20% speed (is power/speed ration linear or x^2?)
I would say military use lobbing projectiles hundreds of miles may be more practical. But will it be “net zero”? That seems to be the military’s big concern these days.
If nothing else it will work great to hit enemy satellites.