This is very similar to proposals made in the 1960’s by Hiller Aircraft to recover Saturn V first stage boosters using a massive helicopter with blades longer than a football field. There is a model of the recovery scenario in the Hiller Aviation Museum in San Carlos, CA.
As the article states: Those were the days. People knew how to dream big.
As discussed at the linked article, the helicopter idea is problematic. What’s the empty weight of a Falcon 9 V1.1 first stage plus what’s the expected residual propellant load? How many helicopters are available that can handle that kind of load? (Not many). Will the rotor downwash affect the stage’s stability?
Some commentors mentioned using a line topped with a parachute that the helicopter can snag. You can’t do that if the rocket is hovering because the chute would collapse, so that would only work if you were able to snag the stage while it’s still descending. A balloon at the end of the cable would work but that adds extra complication.
If landing on a barge would require low sea states, then perhaps something along the lines of the approach used on the X-13 Vertijet would work. It’d have to be gyrostabilized to account for sea induced movement.
I think a net covering an obsolete aircraft carrier would make reasonable target. Catching it in a net seems to solve a lot of recovery problems if it can hover reasonably close to the net before shutdown. Now what would the net be made of?
Isn’t the dry weight of the fist stage of the F9 v 1.1 something like 30,000 pounds?
So, any helicopter used would need a bit more lift capacity than that to handle any snatch on the line after hookup, but still, 30,000 lbs? That’s 10k more than the skycrane can lift. One of the thread posters says that the Russian MI-26 is the only chopper with the ability, and fast and maneuverable it isn’t. I also would not like to be apart when the attempt is made; it sounds risky as hell.
I also wonder if there are any upper end plausible attach points on the first stage? I don’t think so; it’s not designed for that kind of loading. And netting it? Yipes… and for a hookup, how exactly do you make the hookup fast? Also, hovering over a propulsive rocket imparts downdraft issues on both rocket and helicopter.
IMHO, this concept is impracticable, and the development costs and risks exceed any potential gain.
If SpaceX really wants to recover one of these early F9 1.1 first stage (without landing legs), wouldn’;t it be far easier to build a large floating bowl out of plastic sheeting and a ring of inflated tubing, fill it with firefighting foam (to avoid the seawater issues) hover next to it, and topple in? The foam should cushion the impact sufficiently (some of that stuff, like the kind used for foaming runways, can be pretty dense).
My guess; it’s not with the cost to develop a system to recover the early test stages.
Also, Blue Origin is trying to patent the idea of barge landings (that have been around for years)? Is it too late for me to patent the idea of landing on an island? Or landing on land? Or landing an aircraft at an airport?
Zero G got a business-method patent for their idea of using an airplane to fly people during the day and cargo at night. It appears you can patent anything.
The CH-53E has a sling load capacity of 32,000 pounds. From what I’ve read, the Marines are retiring them so it’s possible some might be available. They’re pretty worn out, though, and trying to hover over a burning rocket stage sounds pretty damned sporty to me.
There have been a lot of these studies over the years. They always seem to evolve toward flyback/rocketback to launch site, as the studies progress and the problems of recovery at sea become more and more apparent.
I think the major problem they have had with water landings is the lightweight construction methods they use. The stage simply cannot withstand impact. Also it is false that a rocket cannot restart after being immersed into salt water. Try reading about Truax’s Sea Bee.
I think their Grasshopper VTVL recovery method makes much more sense for Falcon 9.
This is very similar to proposals made in the 1960’s by Hiller Aircraft to recover Saturn V first stage boosters using a massive helicopter with blades longer than a football field. There is a model of the recovery scenario in the Hiller Aviation Museum in San Carlos, CA.
http://www.thespacereview.com/article/1045/1
As the article states: Those were the days. People knew how to dream big.
As discussed at the linked article, the helicopter idea is problematic. What’s the empty weight of a Falcon 9 V1.1 first stage plus what’s the expected residual propellant load? How many helicopters are available that can handle that kind of load? (Not many). Will the rotor downwash affect the stage’s stability?
Some commentors mentioned using a line topped with a parachute that the helicopter can snag. You can’t do that if the rocket is hovering because the chute would collapse, so that would only work if you were able to snag the stage while it’s still descending. A balloon at the end of the cable would work but that adds extra complication.
If landing on a barge would require low sea states, then perhaps something along the lines of the approach used on the X-13 Vertijet would work. It’d have to be gyrostabilized to account for sea induced movement.
I think a net covering an obsolete aircraft carrier would make reasonable target. Catching it in a net seems to solve a lot of recovery problems if it can hover reasonably close to the net before shutdown. Now what would the net be made of?
Isn’t the dry weight of the fist stage of the F9 v 1.1 something like 30,000 pounds?
So, any helicopter used would need a bit more lift capacity than that to handle any snatch on the line after hookup, but still, 30,000 lbs? That’s 10k more than the skycrane can lift. One of the thread posters says that the Russian MI-26 is the only chopper with the ability, and fast and maneuverable it isn’t. I also would not like to be apart when the attempt is made; it sounds risky as hell.
I also wonder if there are any upper end plausible attach points on the first stage? I don’t think so; it’s not designed for that kind of loading. And netting it? Yipes… and for a hookup, how exactly do you make the hookup fast? Also, hovering over a propulsive rocket imparts downdraft issues on both rocket and helicopter.
IMHO, this concept is impracticable, and the development costs and risks exceed any potential gain.
If SpaceX really wants to recover one of these early F9 1.1 first stage (without landing legs), wouldn’;t it be far easier to build a large floating bowl out of plastic sheeting and a ring of inflated tubing, fill it with firefighting foam (to avoid the seawater issues) hover next to it, and topple in? The foam should cushion the impact sufficiently (some of that stuff, like the kind used for foaming runways, can be pretty dense).
My guess; it’s not with the cost to develop a system to recover the early test stages.
Also, Blue Origin is trying to patent the idea of barge landings (that have been around for years)? Is it too late for me to patent the idea of landing on an island? Or landing on land? Or landing an aircraft at an airport?
Blue Origin is patenting more than that.
http://www.citizensinspace.org/2013/04/blue-origin-and-the-patent-race
Zero G got a business-method patent for their idea of using an airplane to fly people during the day and cargo at night. It appears you can patent anything.
The CH-53E has a sling load capacity of 32,000 pounds. From what I’ve read, the Marines are retiring them so it’s possible some might be available. They’re pretty worn out, though, and trying to hover over a burning rocket stage sounds pretty damned sporty to me.
There have been a lot of these studies over the years. They always seem to evolve toward flyback/rocketback to launch site, as the studies progress and the problems of recovery at sea become more and more apparent.
I think the major problem they have had with water landings is the lightweight construction methods they use. The stage simply cannot withstand impact. Also it is false that a rocket cannot restart after being immersed into salt water. Try reading about Truax’s Sea Bee.
I think their Grasshopper VTVL recovery method makes much more sense for Falcon 9.