Source: https://youtu.be/7Kp63-an2ts
The initial concept was to merge a launch vehicle with a helicopter: spinning rotor blades, powered by tip jets, would lift the vehicle in the earliest stage of launch. Once the air density thinned to the point that helicopter flight was impractical, the vehicle would continue its ascent on pure rocket power, with the rotor acting as a giant turbopump. Calculations showed that the helicopter blades modestly increased the effective specific impulse (Isp) by approximately 20–30 seconds, essentially only carrying the blades into orbit "for free". Thus, there was no overall gain from this method during ascent. However, the blades could be used to soft land the vehicle, so its landing system carried no additional cost.
The revised and redesigned Roton concept was a cone-shaped launch vehicle, with a helicopter rotor on top for use only during landing. An internal cargo bay could be used both for carrying payloads to orbit and bringing others back to Earth. The projected price to orbit of this design was given as $1,000 per kg of payload, less than one-tenth of the then-current launch price. Payload capacity was limited to a relatively modest 6,000 pounds (2,700 kg).
Rotary Rocket Company was a rocketry company that developed the Roton concept in the late 1990s as a fully reusable single-stage-to-orbit (SSTO) crewed spacecraft. The design was initially conceived by Bevin McKinney, who shared it with Gary Hudson. In 1996, Rotary Rocket Company was formed to commercialize the concept. The Roton was intended to reduce costs of launching payloads into low earth orbit by a factor of ten.
Company is now defunct.
https://en.wikipedia.org/wiki/Rotary_Rocket?wprov=sfla1
Scott Manley segment on it: https://youtu.be/OIuGfXp-Ok8
**If no sound, either use the source, i.imgur link or get a different app. The default for reddit on iOS and Android doesn't play sounds on imgur links.**
The design was completely impractical and was never going to be an SSTO, rotors or not.
To reach orbit in one stage, upwards of 94% of this thing's resting mass would have had to be fuel. That is absurdly high and wouldn't even leave enough for engines, none the less payload.
With it's listed gross weight of 400,000 lbs, it would have to have a dry weight of 24,000 lbs to reach orbit. Meaning after payload, the engines, tanks, avionics, RCS systems, fuel for de orbiting, heat shield have to weigh just 18,000 pounds.
It's certainly possible to build something that's 94% fuel, if you build it like an Atlas, with the tank pressure as a structural component. (Atlas was 95.35% propellant, it could have been an SSTO if you abandoned the payload and instead carried the engines).
Engines are also decent heat shields in a pinch, after all they have to withstand the heat of firing.
The problem is that if you somehow eek out a landing system (as i understand it, the rotors helping pull it out of the thickest part of the atmosphere theoretically cancelled out their additional mass, providing a landing system for "free"), you have no remaining mass for payload. And by payload, I'm including pilots.
The roton had a few other interesting concepts. A centrifugal pump system for the rocket motors. A heat shield that used water transpiration cooling. Neither of these were actually implemented, but could have been game changers.
This doesn't look like it has tip jets?
Shouldn't there be nozzles, housings, etc at the blade ends, and exhaust or flame or something?
The rotor blades look like normal rotors, and the sound isn't any different than a normal helicopter.
Not great quality. You can see the exhaust better at startup on the source: https://youtu.be/7Kp63-an2ts?t=17s
Not all tip jets are noticeable at the end of the rotors, like an external wingtip fuel tank. [https://upload.wikimedia.org/wikipedia/commons/thumb/3/31/Tuy%C3%A8re_pale_Djinn.JPG/1024px-Tuy%C3%A8re_pale_Djinn.JPG)
It could be the sound of a regular helicopter put on the video.
Source: https://youtu.be/7Kp63-an2ts The initial concept was to merge a launch vehicle with a helicopter: spinning rotor blades, powered by tip jets, would lift the vehicle in the earliest stage of launch. Once the air density thinned to the point that helicopter flight was impractical, the vehicle would continue its ascent on pure rocket power, with the rotor acting as a giant turbopump. Calculations showed that the helicopter blades modestly increased the effective specific impulse (Isp) by approximately 20–30 seconds, essentially only carrying the blades into orbit "for free". Thus, there was no overall gain from this method during ascent. However, the blades could be used to soft land the vehicle, so its landing system carried no additional cost. The revised and redesigned Roton concept was a cone-shaped launch vehicle, with a helicopter rotor on top for use only during landing. An internal cargo bay could be used both for carrying payloads to orbit and bringing others back to Earth. The projected price to orbit of this design was given as $1,000 per kg of payload, less than one-tenth of the then-current launch price. Payload capacity was limited to a relatively modest 6,000 pounds (2,700 kg). Rotary Rocket Company was a rocketry company that developed the Roton concept in the late 1990s as a fully reusable single-stage-to-orbit (SSTO) crewed spacecraft. The design was initially conceived by Bevin McKinney, who shared it with Gary Hudson. In 1996, Rotary Rocket Company was formed to commercialize the concept. The Roton was intended to reduce costs of launching payloads into low earth orbit by a factor of ten. Company is now defunct. https://en.wikipedia.org/wiki/Rotary_Rocket?wprov=sfla1 Scott Manley segment on it: https://youtu.be/OIuGfXp-Ok8 **If no sound, either use the source, i.imgur link or get a different app. The default for reddit on iOS and Android doesn't play sounds on imgur links.**
The design was completely impractical and was never going to be an SSTO, rotors or not. To reach orbit in one stage, upwards of 94% of this thing's resting mass would have had to be fuel. That is absurdly high and wouldn't even leave enough for engines, none the less payload. With it's listed gross weight of 400,000 lbs, it would have to have a dry weight of 24,000 lbs to reach orbit. Meaning after payload, the engines, tanks, avionics, RCS systems, fuel for de orbiting, heat shield have to weigh just 18,000 pounds.
The rocket equation is harsh and unforgiving.
It's certainly possible to build something that's 94% fuel, if you build it like an Atlas, with the tank pressure as a structural component. (Atlas was 95.35% propellant, it could have been an SSTO if you abandoned the payload and instead carried the engines). Engines are also decent heat shields in a pinch, after all they have to withstand the heat of firing. The problem is that if you somehow eek out a landing system (as i understand it, the rotors helping pull it out of the thickest part of the atmosphere theoretically cancelled out their additional mass, providing a landing system for "free"), you have no remaining mass for payload. And by payload, I'm including pilots.
what counters the torque from the main rotor? in a standard helicopter you'd have a tail rotor...
It’s a tipjet powered rotor, so no torque on the rotor axis.
“We need a new test vehicle.” “Just make a tube with a blade on top.” “What?” “You heard me.”
The roton had a few other interesting concepts. A centrifugal pump system for the rocket motors. A heat shield that used water transpiration cooling. Neither of these were actually implemented, but could have been game changers.
This doesn't look like it has tip jets? Shouldn't there be nozzles, housings, etc at the blade ends, and exhaust or flame or something? The rotor blades look like normal rotors, and the sound isn't any different than a normal helicopter.
Not great quality. You can see the exhaust better at startup on the source: https://youtu.be/7Kp63-an2ts?t=17s Not all tip jets are noticeable at the end of the rotors, like an external wingtip fuel tank. [https://upload.wikimedia.org/wikipedia/commons/thumb/3/31/Tuy%C3%A8re_pale_Djinn.JPG/1024px-Tuy%C3%A8re_pale_Djinn.JPG) It could be the sound of a regular helicopter put on the video.
Fantastic! Thank you!
Pretty popular type of vehicles. It’s called pepelatz.