Posted on 05/10/2022 6:51:02 PM PDT by LibWhacker
It’s called SpinLaunch, and it’s a novel approach to launching small payloads into orbit. The idea of a kinetic launch system translates to spinning a payload in a centrifuge to over 1,000 miles an hour and then releasing it for its journey to the stars. The concept requires no onboard fuel, so there’s no danger of explosions, and since it’s completely electrical, it offers a sustainable solution that doesn’t pollute the environment. “The SpinLaunch Orbital Launch System is a fundamentally new way to reach space,” states the company website. “The velocity boost provided by the accelerator’s electric drive results in a 4x reduction in the fuel required to reach orbit, a 10x reduction in cost, and the ability to launch multiple times per day.”
The test was the eighth major test of the centrifuge, which is officially called the “suborbital mass accelerator,” and the ten-foot-long projectile which this time had an “optical payload” (camera) on board to capture the launch from the projectile’s point of view.
The video shows the projectile spinning violently as it erupts from the mass accelerator to a maximum test altitude of 25,000 feet (7,620 meters). Consequently, the video image induces a bit of queasiness on the part of the audience, but it turns out that’s by design.
Angled fins on the projectile induce the rapid rate of spin in order to stabilize the projectile during launch, in order to prevent it from tumbling during its 82-second ascent. The result is “like a bullet firing out of a gun,” says David Wrenn, vice president of technology at SpinLaunch.
SpinLaunch Larger Version to Launch Payloads to Orbit What’s even more interesting is that the SpinLaunch suborbital mass accelerator is a one-third scaled-down model for testing, and so far has only fired projectiles at a fraction of the speed it is capable of achieving. The company plans on building a larger version of the accelerator, which is capable of launching a payload in excess of 440 pounds (200 kg) and at speeds of over 5,000 miles an hour, plenty of speed to reach low earth orbit.
And while the test was deemed a huge success, the real important milestone was for the camera itself to survive the intense G forces that build up in bringing the mass accelerator up to its 1,000-mile speed. To do so means that SpinLaunch will continue to be able to document launches onboard the payloads, as they become larger and heavier, and do it without destroying the cameras themselves.
The survivability of the cameras, which will soon become more advanced and heavier, also indicates that delicate scientific instruments meant for low earth orbit will also be able to withstand the stress of launch without breaking.
The SpinLaunch Payload Projectile SpinLaunch Back in April, NASA and SpinLaunch signed an agreement for NASA to fly a payload with the company’s mass accelerator to test its launch characteristics, with the goal being to assess the system for potential future commercial launch opportunities.
SpinLaunch plans to continue pushing the envelope for a centrifuge launch system, adopting a stepped approach of larger payloads and higher speeds, with two launches per month. And the cameras will be on board to document every second.
First customer launches are planned for 2025.
Velocity goes downhill from that point.
Through a couple of these posts, what Fester is missing and Alex isn’t mentioning specifically - G-forces aren’t just from going forward(up): while spinning in the centrifuge, the centripetal acceleration is going to be extremely high, as in order to spin, you are ALWAYS accelerating towards the center of the circle, that’s how you’re changing direction. The faster you rotate, the higher the Gs. So, assuming the final velocity (initial/launch velocity, I mean final from the centrifuge) has to stay the same, you change your acceleration by either the square of the angular velocity (how fast you spin), or linearly with the radius of the circle. (I think the equation is a=w²*r, been a while.) So in order to reduce your G forces, you need to lower the acceleration, which means lowering the angular velocity, which can only be done by increasing your radius. I don’t remember the equation for this, but off the top of my head I think it’s something around cutting Gs in half requires four time the radius of the centrifuge. So it’s gonna get big fast, or you just have to stick with lots of Gs on your package.
Check Wikipedia for rocket details.
Yeah: A net that would instantly vaporize as if struck by a meteor as soon as it "caught" the projectile.
Regards,
Quite correct, Svartalfiar!
Ultimately, this leads to a linear accelerator - for example, an electric rail gun. But I didn't want to "muddy the waters" by going down that road. Eventually, you end up realizing that a rocket sled would be more feasible. From there, it's only a step until you're back to a conventional, vertically launched rocket. Boring!
The article speaks of a centrifuge, so I stuck to that benighted premise!
Unless you're talking about a centrifuge the size of a Ferris Wheel (terribly impractical!), the g-forces will crush any projectile made of conventional materials.
Centrifuges of a "sensible" size could be used to lob, at best, tungsten projectiles slathered in ablative materials and containing - at most - a few kg of water into low-earth orbit. And even then, I'm thinking that some rocket-assist would be indispensable.
Regards,
I found the company’s website lacking in detail. That’s why I looked for additional info.
Don’t know if it’s been discussed but I wonder how the imbalance of the wheel is compensated at release? Too much wear and tear.
We are talking at cross-purposes, I fear.
To reiterate: When you start talking about making the centrifuge bigger and bigger (in order to attain high speeds without high g-forces - a reasonable notion!), you soon smoothly transition to linear accelerators (electric rail guns), then rocket sleds, then conventional vertically launched rockets. That's simply how the conversation always evolves!
Regards,
P.S.:
"High-speed centrifuges are specialized centrifuges that reach maximum speeds between 18,000 and 25,000 rpm (they can generate around 60,000 g). They are cooled and normally have a vacuum system to prevent the rotor from heating up due to friction with the air." - website of Kalstein centrifuge manuf.
I would hate to have to design the safety protocols for a Ferris Wheel-sized centrifuge required to withstand even only 60 g! And that in a vacuum! And to then have to slide open a panel to release the projectile while at the same time dealing with all the problems of pressure-equalization!
I think that I watched Wiley E. Coyote using a system like this once. I believe that ACME holds the patent on the technology.
There’s a lot they haven’t mentioned.. The inside is a vacuum, so when the projectile is ‘fired’, first thing in does is hit a solid wall of air...
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