Author Topic: Fairing reuse  (Read 477050 times)

Offline D_Dom

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Re: Fairing reuse
« Reply #620 on: 03/16/2017 03:15 PM »
Lifting the fairing does not seem to me nearly as challenging as catching one on the fly.
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Offline meekGee

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Re: Fairing reuse
« Reply #621 on: 03/16/2017 05:08 PM »
Lifting the fairing does not seem to me nearly as challenging as catching one on the fly.

True, but ironically, the same helicopter that can catch a fairing may not be able to take off with one...

Fuel weight is a big deal for helicopters in long range operations. 

Also, the weight you can carry while move forward is higher than what you can carry while hovering, so a helicopter may grab a fairing, and actually not be able to set it down, until later, when it burned off the rest of its fuel.

Ah, but at sea level you get more lift than at whatever altitude they'll be catching them at.  But then Florida air may be warmer.  Helicopters are a pain in the a**.
« Last Edit: 03/16/2017 05:09 PM by meekGee »
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Online envy887

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Re: Fairing reuse
« Reply #622 on: 03/16/2017 06:01 PM »
Why would they use precision GPS-guided chutes if they were going after them with a helo? The whole point of guidance is to drop them somewhere specific.

Offline Kaputnik

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Re: Fairing reuse
« Reply #623 on: 03/16/2017 06:29 PM »
If helicopters are out of the question, the only feasible alternative that I can think of is parachuting down onto a huge inflatable raft. But it really would need to be impressively large- precision airdrops are only 50m accurate and I'm sure that's with a relatively dense and sturdy crate as cargo, not a big floppy fairing half that catches the wind and probably needs a low impact speed.

You have to wonder how they would then retrieve the fairing from within the raft, which would need to be very soft to act as any kind of a cushion.

It will be fascinating to see how they are going to do this.
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Online Lar

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Re: Fairing reuse
« Reply #624 on: 03/16/2017 06:52 PM »
The fact that CCAFS is an air force base should fare well for helicopters catching fairings

Specifically, CCAFS and the 920th Rescue Wing (HC-130P, HH-60G) are both headquartered at nearby Patrick AFB.
Yeah, but it's not like SpaceX is going to use military assets to recover fairings.
Yeah, but that part of FL is pretty nice to live in, and ex Air Force helo drivers[1] that are hot shots might be fairly easy to find around there since they might want to retire there after 20 in the AF and out... So kind of using military SURPLUS assets, as it were. :)

1 - not that I know anyone like that.
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Offline Zed_Noir

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Re: Fairing reuse
« Reply #625 on: 03/17/2017 09:50 PM »
Lifting the fairing does not seem to me nearly as challenging as catching one on the fly.

True, but ironically, the same helicopter that can catch a fairing may not be able to take off with one...

Fuel weight is a big deal for helicopters in long range operations. 

Also, the weight you can carry while move forward is higher than what you can carry while hovering, so a helicopter may grab a fairing, and actually not be able to set it down, until later, when it burned off the rest of its fuel.

Ah, but at sea level you get more lift than at whatever altitude they'll be catching them at.  But then Florida air may be warmer.  Helicopters are a pain in the a**.

Just fitted an inflight refueling kit on the helicopter. So it isn't carrying a lot of fuel during the recovery, then top up after recovery.

Offline Robotbeat

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Re: Fairing reuse
« Reply #626 on: 03/18/2017 01:24 AM »
Oh great, inflight refueling...

This is looking more and more like a bad idea.
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Online dorkmo

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Re: Fairing reuse
« Reply #627 on: 03/18/2017 05:00 AM »
ignoring all the cons, would in-air recovery be the least stressful option on the fairing structure? or does it not even have that going for it?

Offline Kaputnik

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Re: Fairing reuse
« Reply #628 on: 03/18/2017 06:23 AM »
ignoring all the cons, would in-air recovery be the least stressful option on the fairing structure? or does it not even have that going for it?

It can be pretty gentle. The aircraft matches velocity with the target and then decelerates it gradually.
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Offline Hobbes-22

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Re: Fairing reuse
« Reply #629 on: 03/18/2017 09:56 AM »
ignoring all the cons, would in-air recovery be the least stressful option on the fairing structure? or does it not even have that going for it?

US armed forces and CIA use the Fulton surface-to-air recovery system to pick up people from the ground without landing. An agent behind enemy lines launches a balloon with a line attached to it. A C-130 flies over, snatches the line and then reels in the agent. By using a long line, the acceleration load on the agent was limited, "the person being picked up experienced less of a shock than during a parachute opening."

So even with a fixed-wing aircraft, this recovery method can be made survivable for humans and other fragile loads.

Offline Zed_Noir

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Re: Fairing reuse
« Reply #630 on: 03/18/2017 02:00 PM »
Oh great, inflight refueling...

This is looking more and more like a bad idea.

Most of the combat SAR helos of the USAF are already equipped with the inflight refueling kit. They need it for extended operational radius and/or time on station. 

Offline JamesH65

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Re: Fairing reuse
« Reply #631 on: 03/18/2017 02:50 PM »
Oh great, inflight refueling...

This is looking more and more like a bad idea.

Most of the combat SAR helos of the USAF are already equipped with the inflight refueling kit. They need it for extended operational radius and/or time on station.

They have unlimited cash, and own the refueling tankers...and they ain't cheap.

Offline meekGee

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Re: Fairing reuse
« Reply #632 on: 03/18/2017 03:50 PM »
Oh great, inflight refueling...

This is looking more and more like a bad idea.

Most of the combat SAR helos of the USAF are already equipped with the inflight refueling kit. They need it for extended operational radius and/or time on station.

They have unlimited cash, and own the refueling tankers...and they ain't cheap.
Heli-on-barge is an option to consider, since it eliminates half the range, and maybe the whole "fly out before launch" thing.

If the fairing ends up close enough to the barge, the helicopter might take off only after launch.

(On RTLS launches, there isn't even a conflict)
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Offline chalz

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Re: Fairing reuse
« Reply #633 on: 03/18/2017 10:31 PM »
Not to state the obvious too much but since fairings come in halves all these special operations have to be done twice and simultaneously. This makes catching it look daunting. Two barges, two landing pads, two refuelling ops, two specialist pilots. How close could the Heli's get to each other? And what happens if you only catch one, how useful would it be without its partner?

Offline meekGee

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Re: Fairing reuse
« Reply #634 on: 03/19/2017 12:53 AM »
Not to state the obvious too much but since fairings come in halves all these special operations have to be done twice and simultaneously. This makes catching it look daunting. Two barges, two landing pads, two refuelling ops, two specialist pilots. How close could the Heli's get to each other? And what happens if you only catch one, how useful would it be without its partner?
Yup, from day one, the helicopter side seems very very difficult.

Unless they are unmanned, it pushes every edge of the envelope, and as you point out, including safety.

But clearly SpaceX has some plan in mind.  Hope we find out soon.
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Offline Zed_Noir

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Re: Fairing reuse
« Reply #635 on: 03/19/2017 01:48 PM »
After some thinking. Maybe SX will just added a parachute with radar transponder and some floatation devices to the PLF. Then fished the 2 PLF halves out of the water with a crane. Might need a couple of spotter aircraft to tracked the PLF descends and maintained visual contact until recovery assets are on the scene.

Offline guckyfan

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Re: Fairing reuse
« Reply #636 on: 03/19/2017 07:01 PM »
After some thinking. Maybe SX will just added a parachute with radar transponder and some floatation devices to the PLF. Then fished the 2 PLF halves out of the water with a crane. Might need a couple of spotter aircraft to tracked the PLF descends and maintained visual contact until recovery assets are on the scene.

Sounds reasonable but Gwynne Shotwell said in her LC-39A interview that they don't want the fairing to get wet. Which surprised me somewhat.

Offline Bargemanos

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Re: Fairing reuse
« Reply #637 on: 03/19/2017 09:08 PM »
After some thinking. Maybe SX will just added a parachute with radar transponder and some floatation devices to the PLF. Then fished the 2 PLF halves out of the water with a crane. Might need a couple of spotter aircraft to tracked the PLF descends and maintained visual contact until recovery assets are on the scene.
Sounds reasonable but Gwynne Shotwell said in her LC-39A interview that they don't want the fairing to get wet. Which surprised me somewhat.
Encapsulate just before splash down? Somewhat like the mars rovers.

Or is it possible to use the gliding shape of the half fairing to slow down speed enough to splash down real gently. Maby with the use of droge chutes for stability and if needed main chutes to slow down even further
« Last Edit: 03/19/2017 09:09 PM by Bargemanos »

Offline matthewkantar

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Re: Fairing reuse
« Reply #638 on: 03/19/2017 09:36 PM »
SpaceX has stated the fairing are not going in the water.

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Offline Space Ghost 1962

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Re: Fairing reuse
« Reply #639 on: 03/19/2017 09:42 PM »
They aren't intended for immersion. You'll have to get them w/o reaching the water.

Which means either airborne recovery e.g. snag them with a drone, not unlike with Smart recovery, or you fly them back to land, and somehow recover them.

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