One way to catch both halves with one rig is to have one net deployed and lowerable with winches while the other net is furled and stretched between two of the masts. Line would go from each end of the furled net to the opposite mast on each side, through a pulley and to another winch. This would be similar to how a rubber-banded spinnaker is released on sail boat.The first fairing hits and is lowered to the deck in maybe fifteen seconds. The second net is deployed by running the winches, in a minute or so, and the second half is caught. This would explain the height of the masts on Mr Steven. Matthew
How's this arrangement to capture 2 fairing halves: two nets, one attached on the left side, with cables to pull it open to the right side. The other net attached on the right, with cables that pull it open to the left. Start with both nets folded, first pull the cables to stretch out the left net, capture one fairing half, then pull the cables back to fold the left net with the fairing half inside, and stow it to the left of the deck. Next open the right net, capture the other fairing half, then fold it back to stow the fairing.
Quote from: Jcc on 12/20/2017 11:06 pmHow's this arrangement to capture 2 fairing halves: two nets, one attached on the left side, with cables to pull it open to the right side. The other net attached on the right, with cables that pull it open to the left. Start with both nets folded, first pull the cables to stretch out the left net, capture one fairing half, then pull the cables back to fold the left net with the fairing half inside, and stow it to the left of the deck. Next open the right net, capture the other fairing half, then fold it back to stow the fairing.We may not be seeing everything yet by I like this idea better. I am thinking that lack of attach points may actually argue against a complicated net and winch system. It may possibly indicate 2 inflatable structures, port and starboard that would catch the fairings coming in from behind at say a 15 degree angle. They would slide to the center with a center cushion to prevent contact.
I wonder if GO Mr. Steven can fit back through the Panama Canal with this superstructure on it?
you think the fairing support arms are only 3M beyond the hull? I think someone would need to measure it but I'm dubious, more like almost the hull width again on each side. but I could be wrong. That still easily fits through the canal but I see it as quite ungainly.
I’m not convinced that the arms aren’t mounted on rotating bases that would allow the arms to ‘fold’ in and lie within the draft of the vessel. It’s unclear whether they would be hydraulically driven or just manual with locking pins. The latter is certainly simpler.
There might be a very obvious answer to this question but since it's not obvious to me I'll ask it. Why can't the two halves be caught in the same net despite contact. Would the damage be that great that would render the effort worthless? I don't know enough about the material and speed of landing to be able to discern the impact. Also seems to me that the first try is more about catching than using the fairings that were caught.
I'd not be surprised if jcc was close https://forum.nasaspaceflight.com/index.php?topic=37727.msg1761981#msg1761981. Two large floating air cushions, port and starboard, one per half. One issue I see with nets is t some kind of shock absorbing mechanism the fairing half will decelerate pretty quickly.
Quote from: Stefan.Christoff.19 on 12/20/2017 03:48 pmThere might be a very obvious answer to this question but since it's not obvious to me I'll ask it. Why can't the two halves be caught in the same net despite contact. Would the damage be that great that would render the effort worthless? I don't know enough about the material and speed of landing to be able to discern the impact. Also seems to me that the first try is more about catching than using the fairings that were caught.I am not sure about this at all, but my speculation is that Mr. Steven will be catching exactly one half of the fairing this attempt. Any of the "multiple catch" scenarios (except maybe the double decker net) or offloading between catches treat these fairings much more robustly than I think they are built. The cost estimates are currently somewhere between "pallet of cash" and the $6m neighborhood of comparable fairings. To me, this means that these are complicated, expensive, and therefore fragile, delicate, high grade aerospace carbon composite structures that cannot be "slid" off nets, or moved by hand, or hastily moved by crane. I think any contact between the halves would be an instant deal-breaker as well. This is why I suspect that they will catch only one half this attempt.Supposing that they do in fact catch only one half this time, will it be able to be re-used? What I mean, is are the fairing halves built to be paired with a specific second half, or are they interchangeable, even in theory? If they catch one half, or course it is good practice for future efforts and proof of concept, but without the second "matching" (I in no way claim to know that they need to be matched, but it seems possible to me at first thought) fairing half, is it potentially useless for reuse?