sgt_flyer Posted March 7, 2016 Share Posted March 7, 2016 (edited) 16 minutes ago, fredinno said: RUAG is not making fairings for F9. i know - i just used Ruag costs as a comparison, and to answer to cfds. Fairings manufacture is not something that can be made through mass production... (SpaceX use carbon fiber/aluminum composite, with honeycomb structure) , so i doubt even SpaceX can lower a lot costs through that - i still proposed a much lower price figure for spaceX than what Ariane is spending for it's own fairings (because even if it cannot be turned into mass production, SpaceX would still try to find ways to limit production costs, and don't have european administration overheads - still, even for airplanes they don't massproduce carbon composites...). Edited March 7, 2016 by sgt_flyer Link to comment Share on other sites More sharing options...
fredinno Posted March 7, 2016 Share Posted March 7, 2016 13 minutes ago, sgt_flyer said: i know - i just used Ruag costs as a comparison. Fairings manufacture is not something that can be made through mass production... (SpaceX use carbon fiber/aluminum composite, with honeycomb structure) , so i doubt even SpaceX can lower a lot costs through that - i still proposed a much lower price figure for spaceX than what Ariane is spending for it's own fairings (because even if it cannot be turned into mass production, SpaceX would still try to find ways to limit production costs, and don't have european administration overheads - still, even for airplanes they don't massproduce carbon composites...). You can mass-produce fairings- divide it into 4 segments, then you make 4 per rocket. Link to comment Share on other sites More sharing options...
magnemoe Posted March 7, 2016 Share Posted March 7, 2016 3 hours ago, fredinno said: http://www.nasaspaceflight.com/2016/03/spacex-falcon9-ses-9-launch/ I meant that the fairings should have a similar impact per kg as recovering the 1st stage- there is no need for fuel, but need to add shielding, RCS, parafoil, etc, increases it- not to mention the fairing is taken off almost 1 minute after 1st stage separation. There is no reason why it's impossible, but I would rather see a larger diameter F9 to support 2nd stage reuse, and a 3rd stage for high-energy orbits than this right now. You need parachute obviously, don't see why you need RCS, assuming its aerodynamic stable, neither much shielding except a few places but you might want to redesign them to be more heat resistant. Think they have recovered some fairings after splashdown and they looked nice except damage then hitting water. Link to comment Share on other sites More sharing options...
sgt_flyer Posted March 7, 2016 Share Posted March 7, 2016 18 minutes ago, magnemoe said: You need parachute obviously, don't see why you need RCS, assuming its aerodynamic stable, neither much shielding except a few places but you might want to redesign them to be more heat resistant. Think they have recovered some fairings after splashdown and they looked nice except damage then hitting water. For the rcs, it seems it would be just to put the fairing in the correct attitude for reentry (at least, according to the diagram) with a mass of less than 1 ton and only the need to change the attitude though, they won't need lots of dV for the manoeuver (guess a small cold gas based rcs would be enough) Link to comment Share on other sites More sharing options...
magnemoe Posted March 7, 2016 Share Posted March 7, 2016 10 minutes ago, sgt_flyer said: For the rcs, it seems it would be just to put the fairing in the correct attitude for reentry (at least, according to the diagram) with a mass of less than 1 ton and only the need to change the attitude though, they won't need lots of dV for the manoeuver (guess a small cold gas based rcs would be enough) They might need an system to orient it correctly at least both to deal with heat but also to get an more predictable trajectory, don't think they will do much more. Link to comment Share on other sites More sharing options...
sgt_flyer Posted March 7, 2016 Share Posted March 7, 2016 1 hour ago, magnemoe said: They might need an system to orient it correctly at least both to deal with heat but also to get an more predictable trajectory, don't think they will do much more. yup. if low isp cold gas thrusters are enough to change the first stage's attitude, guess small ones would be enough for that still, as for what the 'puffs' coming from the fairings are (the leading theory on the reddit is still RCS) another possibility could be the venting of the gases from the pneumatic release system of the fairings. we can see the pneumatic system on the image there (with pressure vessels on one side) http://www.spacetest.org/1/post/2013/04/spacex-payload-fairing-test-at-plum-brook-after.html with the 'pushers' and pressure bottles only on one half (the other is passive). on the video, the two distinguishables 'puffs' coming from the fairings both came from the same half (barely discernable at 5:20, clearly visible at 5:27) venting those pressurised gases before reentry could prevent overpressure buildup because of reentry heat (having a small amount of unpredictable debris could add some minimal risks if a boat was near the trajectory, as a debris would not have the same drag as the fairing) still, that's just a possibility they could have also added the prototype attitude control rcs system to only one half to monitor how the fairing behaves during reentry, without adding too much unnecessary dry weight Link to comment Share on other sites More sharing options...
sevenperforce Posted March 7, 2016 Share Posted March 7, 2016 For the upcoming ISS resupply mission at the end of this month, does anyone know whether they'll attempt landing at the pad or on a boat again? The ISS is not a high-velocity target so I'd imagine they'd have plenty of propellant for the boostback burn...unless, of course, it's a particularly heavy resupply and they need extra fuel to lift it. Link to comment Share on other sites More sharing options...
KerbonautInTraining Posted March 7, 2016 Share Posted March 7, 2016 11 minutes ago, sevenperforce said: For the upcoming ISS resupply mission at the end of this month, does anyone know whether they'll attempt landing at the pad or on a boat again? The ISS is not a high-velocity target Yeah, 17 200 mph is nothing. They should be able to boost back to the pad IIRC. Link to comment Share on other sites More sharing options...
sgt_flyer Posted March 7, 2016 Share Posted March 7, 2016 (edited) i don't know if they changed something, but the spacexstats (not affiliated with SpaceX) is stating a barge landing attempt. https://spacexstats.com/missions/spacex-crs-8 Elon Musk tweet is unhelpful to know if they attempt RTLS or barge landing notable payload include the Bigelow Expandable activity module in the trunk Edited March 7, 2016 by sgt_flyer Link to comment Share on other sites More sharing options...
sevenperforce Posted March 7, 2016 Share Posted March 7, 2016 If it's carrying both a Dragon 1 full of supplies plus the Bigelow Expandable module, it may need extra umph to get the second stage up to speed, burning too much fuel for a boostback and necessitating a droneship landing. If it sticks the landing, when do we think that rocket might fly again? Link to comment Share on other sites More sharing options...
fredinno Posted March 7, 2016 Share Posted March 7, 2016 5 hours ago, sevenperforce said: For the upcoming ISS resupply mission at the end of this month, does anyone know whether they'll attempt landing at the pad or on a boat again? The ISS is not a high-velocity target so I'd imagine they'd have plenty of propellant for the boostback burn...unless, of course, it's a particularly heavy resupply and they need extra fuel to lift it. 4 hours ago, sgt_flyer said: i don't know if they changed something, but the spacexstats (not affiliated with SpaceX) is stating a barge landing attempt. https://spacexstats.com/missions/spacex-crs-8 Elon Musk tweet is unhelpful to know if they attempt RTLS or barge landing notable payload include the Bigelow Expandable activity module in the trunk WUT? Even at worst-case scenario, (full payload both pressurized and unpressurized, full propellant load) Dragon is still 11.5 T, more than ENOUGH for the Falcon 9 for a land landing. Unless they want to practice barge landings. Link to comment Share on other sites More sharing options...
DerekL1963 Posted March 7, 2016 Share Posted March 7, 2016 28 minutes ago, fredinno said: Unless they want to practice barge landings. Barge landing are going to be important for recovering the core of F9H. Link to comment Share on other sites More sharing options...
sevenperforce Posted March 7, 2016 Share Posted March 7, 2016 8 minutes ago, DerekL1963 said: Barge landing are going to be important for recovering the core of F9H. The JASON mission was actually a successful landing, but they lost the rocket in an "unrelated" mount accident a few seconds later. Link to comment Share on other sites More sharing options...
SgtSomeone Posted March 7, 2016 Share Posted March 7, 2016 (edited) 6 hours ago, sgt_flyer said: Elon Musk tweet is unhelpful to know if they attempt RTLS or barge landing Several news sites have a copy of the live stream video. It shows the barge getting brighter as the rocket gets closer, and then displays 'no signal', which generally does not indicate anything good edit: I see now that you were talking about the next launch (Musk's tweet was for the last one). Feel free to disregard this post. Also: if anyone knows if/where SpaceX released the actual landing video, let me know! Edited March 7, 2016 by SgtSomeone Link to comment Share on other sites More sharing options...
sevenperforce Posted March 7, 2016 Share Posted March 7, 2016 1 minute ago, SgtSomeone said: Several news sites have a copy of the live stream video. It shows the barge getting brighter as the rocket gets closer, and then displays 'no signal', which generally does not indicate anything good "No signal" is not in and of itself problematic; the landing is a highly...energetic...affair, and has a tendency to mess with communications. But Musk has already announced it was an overly-hard landing. We don't know whether it missed or crash-landed or broke apart or what, though, since SpaceX hasn't yet released the full video from the barge. More interested in whether the ISS resupply mission at the end of the month will be a barge landing or a return-to-launch-site landing. Link to comment Share on other sites More sharing options...
Mitchz95 Posted March 7, 2016 Share Posted March 7, 2016 CRS-8 is tentatively scheduled for March 30, according to Wikipedia. Doesn't say where they're planning to land. Link to comment Share on other sites More sharing options...
Motokid600 Posted March 7, 2016 Share Posted March 7, 2016 2 hours ago, sevenperforce said: "No signal" is not in and of itself problematic; the landing is a highly...energetic...affair, and has a tendency to mess with communications. But Musk has already announced it was an overly-hard landing. We don't know whether it missed or crash-landed or broke apart or what, though, since SpaceX hasn't yet released the full video from the barge. More interested in whether the ISS resupply mission at the end of the month will be a barge landing or a return-to-launch-site landing. Not to mention that time around the Falcon was coming down on three engines instead of one. That's gotta be hell for cameras and communications. Link to comment Share on other sites More sharing options...
StrandedonEarth Posted March 8, 2016 Share Posted March 8, 2016 Why was it coming down on 3 engines? First I've heard of that for a landing burn (not the entry burn). Link to comment Share on other sites More sharing options...
Motokid600 Posted March 8, 2016 Share Posted March 8, 2016 (edited) 22 hours ago, sgt_flyer said: something interesting from this video was posted on the SpaceX reddit - at around 5:27 on this video, there is what looks like a puff of RCS coming out of one of the fairing's halves. https://www.reddit.com/r/spacex/comments/4990yt/rcs_exhaust_from_ses9_fairings_at_520_and_527/ one of the theories given on the reddit post, was that spaceX is experimenting on fairing recovery. one reply point out to two things to give weight to this theory : this diagram, which would point out to an helicopter mid-air recovery of the fairings : http://imgur.com/Otj4QCN,QMXhN9I and this old tweet from Elon Musk : Very interesting, but... I saw no puffs what so ever coming from the fairings. Only the first stage. Edit: No I'm sorry never mind I saw it! Very subtle... could just be the separation motors venting excess gas. Edited March 8, 2016 by Motokid600 Link to comment Share on other sites More sharing options...
fredinno Posted March 8, 2016 Share Posted March 8, 2016 12 minutes ago, StrandedonEarth said: Why was it coming down on 3 engines? First I've heard of that for a landing burn (not the entry burn). Higher speed when coming down due to lack of entry burn. Link to comment Share on other sites More sharing options...
sevenperforce Posted March 8, 2016 Share Posted March 8, 2016 How do we know it was still on three engines? I thought it was standard to do the re-entry burn on three engines and the landing burn on one engine. Link to comment Share on other sites More sharing options...
Motokid600 Posted March 8, 2016 Share Posted March 8, 2016 (edited) 8 minutes ago, sevenperforce said: How do we know it was still on three engines? I thought it was standard to do the re-entry burn on three engines and the landing burn on one engine. There was no reentry burn. That's why. They needed three engines because they were hauling that much more ass. Really puts it into perspective. I read that from another user a few days back so I'm trying to find a source now. Aaaand I cant find it. I heard it from a guy on the internet isn't that enough?! Lol... Nevermind. Here A source. http://www.spacelaunchreport.com/ Right on the front page. "The first stage only performed a three-engine reentry burn and a never-before-attempted three-engine final landing burn" Edited March 8, 2016 by Motokid600 Link to comment Share on other sites More sharing options...
Mad Rocket Scientist Posted March 8, 2016 Share Posted March 8, 2016 So, there's no way that the 2nd stage performed a 3rd burn, as the GTO injection was MRS* to get that supersynchronus orbit for a more efficient and faster SES-9 GEO injection. *Not just my username, but a acronym: Minimal Residual Shutdown, as apposed to command shutdown, which gets less DV, but is more precise. Link to comment Share on other sites More sharing options...
sgt_flyer Posted March 8, 2016 Share Posted March 8, 2016 (edited) looks like Falcon Heavy delays are beginning to impact spaceX customers... http://spacenews.com/inmarsat-worried-about-spacex-falcon-heavy-delays-books-reservation-for-ils-proton-launch/ Edited March 8, 2016 by sgt_flyer Link to comment Share on other sites More sharing options...
sevenperforce Posted March 8, 2016 Share Posted March 8, 2016 15 hours ago, Motokid600 said: They needed three engines because they were hauling that much more ass. Really puts it into perspective. I read that from another user a few days back so I'm trying to find a source now. Aaaand I cant find it. I heard it from a guy on the internet isn't that enough?! Lol... Nevermind. Here A source. http://www.spacelaunchreport.com/ Right on the front page. "The first stage only performed a three-engine reentry burn and a never-before-attempted three-engine final landing burn" What are the differences between using a short three-engine suicide burn and a longer one-engine suicide burn? It's the same total dV, right? Link to comment Share on other sites More sharing options...
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