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3d Model here: https://www.cgtrader.com/3d-mo....dels/aircraft/helico

A giant helicopter, with a rotor diameter bigger than the length of a football field. It would be capable not only of transporting a Saturn five S-1C first stage to the launch site - but of actually catching it in midair as it fell on a parachute - ready to be reused.

This is one of the biggest mind boggoling space concepts that was never built - developing a reusable rocket technology - but in the 60s.

Today on our new space channel, we will be covering one of my favorite, yet unkown, insane plans, an aircraft built to play catch with a moon rocket - the Hillers Air Tug.

It was monstrous huge, with a rotor diameter over 400 feet, or 120 meters for our European friends.

These rotors would have jet engines on the tips, that would allow the rotors to make one rotation per second - which is very fast for something so dam wide - but i'll get to the physics problem in just a second.

Its vast engine would be situatied vertically in its rotor stem, and it would have two curving sides to help stablise the rocket in flight.

This size would have a huge eight of 450,000 pounds (200,000 kilograms) and with his huge rotors, be able to carry 550,000 pounds (250,000 kilograms) - a total, for those playing along at home, with a gross weight of 1 million pounds - impressive ideed.


According to Hiller, it was technically not a helicopter but rather a Rotary Wing System for Booster Recovery - but if it looks like a helicopter and goes woom woom woom like a helicopter - then it is, with the added nick name the Air Tug.


The helicopter design of course, made it also avaliable for other operations

well outside simple booster recovery, such as operating as a sky crane, or a aerial transport for cargo both in the military and civil markets.

Perhaps this helicopter would have gotten revenge for the hillers contract loss to the Hughes OH-6A Cay-use helicopter to the army, a light scout helicoper used throughout the vietnam war.

So... how exactly did this helicopter, or flying tug boat, - catch - a rocket in midflight... well hold on, because this ride is about to get real bumpy - yee ha!

When the rocket was fired, the helicopter would take to the skies from a nearby airbase. It would fly to the zone that the booster, the S-1C, would land, and lotier in the area for up to six hours with its large fuel tanks - hovering at around 15,000 to 20,000 feet (4,500–6,000 meters).

When the booster seperated and began its decent,

it would deploy a sort of double tandum parachut, the upper section would have a hook.

The air tug would approach the decending rocket, and meet it at around 10,000 feet (3,000 meters). At this point the rocket would be descending along a glide path with more forawrd than doward velocity, making it perfect for a intercept by the helicopter.

The Air Tug would fly the same glide path, matching the speed and trejectory, it would dploy a grabbling hook, and with help from a viewing plafrom on the side, it would snag the upper parachut, or pickup chute.

Then the helicopter would slowly slow its decent, taking on more and more of the boosters weight, and centering the rocket directly underneath it, assuming the same center of gravity. once it was sufficently slow enough and the heclipter was carrying the full load, the boosters parachouts would deflate and the fuslage suspended 700 feet below the helicopter.


If the first pass was unsuccessful, sufficient time would remain for two more attempts before the booster was too near the ocean's surface for another try.

But its not over there - the helicopter would then reel in the booster using its powerful winch - which again, was onboard somewhere, and rotate the booster horizontal under the helicopters u shaped fuslage - fitting snuggly and more aerodynamically sound. The air tug would then return to base for the booster to be prepped for another launch, or other operations.

Expensive as such a helicopter would have been at the time to develop, the huge aircraft would have paid for itself with the first several recoveries.

So simple in theory, but there was one major flaw with the concept.