Quote from: RoboGoofers on 03/21/2017 06:57 pmThe catch idea seems a bit crazy to me because if you could catch a fairing, why not a second stage?If you have to ask, you need to do more researchThe fairings don't re-enter from orbital speed, come in not too far from the launch site, have low ballistic coefficients and terminal velocity, have much lower mass, and detract from payload at well below the 1:1 ratio of the second stage.
The catch idea seems a bit crazy to me because if you could catch a fairing, why not a second stage?
Quote from: Comga on 03/21/2017 07:09 pmQuote from: RoboGoofers on 03/21/2017 06:57 pmThe catch idea seems a bit crazy to me because if you could catch a fairing, why not a second stage?If you have to ask, you need to do more researchThe fairings don't re-enter from orbital speed, come in not too far from the launch site, have low ballistic coefficients and terminal velocity, have much lower mass, and detract from payload at well below the 1:1 ratio of the second stage.yeah just hand-waving away all of that. After all, catching something as large as a fairing hasn't been done before, either. Then again ULA plans to air-catch their Vulcan engines.
Do you think ULA was serious when they said they will catch the engines? Was it not only because at the time, SpaceX announced something crazy about landing a stage, and they felt compelled to say something as crazy? Sorry I do not follow the ULA forum so maybe I do not have new info on the subject.
Quote from: RoboGoofers on 03/21/2017 07:53 pmQuote from: Comga on 03/21/2017 07:09 pmQuote from: RoboGoofers on 03/21/2017 06:57 pmThe catch idea seems a bit crazy to me because if you could catch a fairing, why not a second stage?If you have to ask, you need to do more researchThe fairings don't re-enter from orbital speed, come in not too far from the launch site, have low ballistic coefficients and terminal velocity, have much lower mass, and detract from payload at well below the 1:1 ratio of the second stage.yeah just hand-waving away all of that. After all, catching something as large as a fairing hasn't been done before, either. Then again ULA plans to air-catch their Vulcan engines. It is not clear who you are accusing of "hand waving".Vulcan engine recovery will also be from speeds well below orbital, plan on using a massive heat shield, and are again part of the first stage, not the second. (Fairings come off around staging, so their trajectories and mass impacts are very much like first stage elements.) And it's still a decade out on ULA's plan.
darkenfast, yes I was also surprised by that declaration. What I mean is: composites should have a pretty good resistance to saltwater, the fairing is not made out of mild steel; we are also talking about few hours max, not years floating in the sea. If recoveries become the norm they can always invest in better paint, sealing etc.
Quote from: manoweb on 03/22/2017 04:58 amdarkenfast, yes I was also surprised by that declaration. What I mean is: composites should have a pretty good resistance to saltwater, the fairing is not made out of mild steel; we are also talking about few hours max, not years floating in the sea. If recoveries become the norm they can always invest in better paint, sealing etc.Maybe the problem is bouncing around unpredictably on the waves?
Quote from: Zed_Noir on 03/18/2017 02:00 pmQuote from: Robotbeat on 03/18/2017 01:24 amOh 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.
Quote from: Robotbeat on 03/18/2017 01:24 amOh 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.
Oh great, inflight refueling...This is looking more and more like a bad idea.
Quote from: Lars-J on 03/20/2017 10:00 pmHow in the world is precision touchdown on ship/barge/raft unworkable?Airborne Systems Dragonfly precision drop system, good for 10,000 lbs, only specs a 250m accuracy.http://airborne-sys.com/wp-content/uploads/2016/08/ASG-DragonFly-20170206-English.pdf
How in the world is precision touchdown on ship/barge/raft unworkable?
You can get GPS-guided parafoil payload systems that, with tweaking, can reliably hit the barge deck of an ASDS (50m x 90m). So maybe put a huge net on 4 poles (one on each corner of an ASDS) 15m high.
Is that because 250m is the best theoretically achievable with current technology, or because there has been minimal incentive so far to improve the system to better than 250m accuracy?
Quote from: Robotbeat on 03/23/2017 10:29 pmYou can get GPS-guided parafoil payload systems that, with tweaking, can reliably hit the barge deck of an ASDS (50m x 90m). So maybe put a huge net on 4 poles (one on each corner of an ASDS) 15m high.That leads to the, unanswerable by us, question of how many fairings would they have to recover to pay for at least two, but more likely four, additional ASDS?