Though the principle of "performance loss for reusability" still applies.
Any idea when this will be flying? Only on Heavy or on F9 also?
Quote from: Lar on 02/24/2017 08:02 pmI like the idea that they built a cheap but heavy fairing .... What makes you think it's cheap? Elon said it was "millions of dollars", which is quite a lot for a structure this size.
I like the idea that they built a cheap but heavy fairing ....
Quote from: envy887 on 02/26/2017 01:16 amAny idea when this will be flying? Only on Heavy or on F9 also?there isn't going to be a different fairing for the heavy
Quote from: meberbs on 02/23/2017 06:43 pmQuote from: meekGee on 02/23/2017 06:28 pmQuote from: Jim on 02/23/2017 06:18 pmQuote from: meekGee on 02/23/2017 06:14 pmIn that case, the loading seems to me very similar to what a fairing normally experiences, or even more benign.It is nowhere near the same. On most other vehicles, the fairing never sees any loads from the payload. They could not be used in the sameJust a matter of distributing the loads. SpaceX clearly designed for this, but it shouldn't double the mass of the fairing. Worst case they'd have added a ribbed structure from the support point to the payload ring, which would not weight multiple tons. (And I don't think they needed to do that either).What makes the SpaceX fairing twice as heavy as other fairings has to be a fairing-wide issue, and the only thing that fits the bill is either incompetence (they don't know how to build a lightweight fairing) or some unique aerodynamic requirements - and the second option is staring us right in the face, since we know they're trying recovery.Or a structural requirement. The pictures clearly show the fairing with enclosed payload being lifted by the middle of the fairing. From other's comments here, such an operation never happens with fairings for other rockets. SpaceX probably does this for some reason based on their processing flow (maybe not having to have special equipment to deal with the torque on the payload adapter before the adapter gets attached to the rocket.)Aerodynamic concerns for recovery don't make sense, because information relating to fairing recovery has indicated that the current fairings were not designed for recovery. The current fairings were designed long before they would have been ready to seriously consider fairing recovery.Also, you are really, really oversimplifying structural analysis in some of your posts.Of course I am... I also don't have the details of their structure necessary to even start a more complex analysis.... But neither do the other posters...All I'm saying is that the extra weight of the fairing (twice what a normal fairing would weigh) seems excessive for the support outlined, since IMO at the worse case it would have been a small penalty, or more likely, none at all.OTOH, those fairings are doing something else very differently from regular fairings.... trying to perform controlled re-entry... so that should be the likely suspect.As for when did SpaceX start thinking about fairing recovery - I don't know, and neither do you. It's clearly not the final design, but whether they were built more robustly to enable even initial experimentation - we simply can't tell. But probably earlier than a year ago...
Quote from: meekGee on 02/23/2017 06:28 pmQuote from: Jim on 02/23/2017 06:18 pmQuote from: meekGee on 02/23/2017 06:14 pmIn that case, the loading seems to me very similar to what a fairing normally experiences, or even more benign.It is nowhere near the same. On most other vehicles, the fairing never sees any loads from the payload. They could not be used in the sameJust a matter of distributing the loads. SpaceX clearly designed for this, but it shouldn't double the mass of the fairing. Worst case they'd have added a ribbed structure from the support point to the payload ring, which would not weight multiple tons. (And I don't think they needed to do that either).What makes the SpaceX fairing twice as heavy as other fairings has to be a fairing-wide issue, and the only thing that fits the bill is either incompetence (they don't know how to build a lightweight fairing) or some unique aerodynamic requirements - and the second option is staring us right in the face, since we know they're trying recovery.Or a structural requirement. The pictures clearly show the fairing with enclosed payload being lifted by the middle of the fairing. From other's comments here, such an operation never happens with fairings for other rockets. SpaceX probably does this for some reason based on their processing flow (maybe not having to have special equipment to deal with the torque on the payload adapter before the adapter gets attached to the rocket.)Aerodynamic concerns for recovery don't make sense, because information relating to fairing recovery has indicated that the current fairings were not designed for recovery. The current fairings were designed long before they would have been ready to seriously consider fairing recovery.Also, you are really, really oversimplifying structural analysis in some of your posts.
Quote from: Jim on 02/23/2017 06:18 pmQuote from: meekGee on 02/23/2017 06:14 pmIn that case, the loading seems to me very similar to what a fairing normally experiences, or even more benign.It is nowhere near the same. On most other vehicles, the fairing never sees any loads from the payload. They could not be used in the sameJust a matter of distributing the loads. SpaceX clearly designed for this, but it shouldn't double the mass of the fairing. Worst case they'd have added a ribbed structure from the support point to the payload ring, which would not weight multiple tons. (And I don't think they needed to do that either).What makes the SpaceX fairing twice as heavy as other fairings has to be a fairing-wide issue, and the only thing that fits the bill is either incompetence (they don't know how to build a lightweight fairing) or some unique aerodynamic requirements - and the second option is staring us right in the face, since we know they're trying recovery.
Quote from: meekGee on 02/23/2017 06:14 pmIn that case, the loading seems to me very similar to what a fairing normally experiences, or even more benign.It is nowhere near the same. On most other vehicles, the fairing never sees any loads from the payload. They could not be used in the same
In that case, the loading seems to me very similar to what a fairing normally experiences, or even more benign.
First post to NSF so forgive the likely uninformed intrusion on a long-running discussion, but what if the reasoning for the heavier fairing design was as follows: by integrating structural support for the payload during launch and MaxQ into the fairing rather than the payload adapter it allows them to jettison the weight of said support when fairing separation occurs meaning less weight is riding on stage 2 afterwards. If all the support is in the payload adapter, then you haul that and it's extra weight all the way out to your destination. Does the SpaceX fairing design allow a lighter payload adapter that is consequently lighter. I've not seen anything in the discussions I've visited thus far indicating one way or the other. Anyone with some insight that can chime in on the hypothesis I put forward?Sent from my iPhone using Tapatalk
...Does the SpaceX fairing design allow a lighter payload adapter that is consequently lighter. I've not seen anything in the discussions I've visited thus far indicating one way or the other. Anyone with some insight that can chime in on the hypothesis I put forward?Sent from my iPhone using Tapatalk
Quote from: cppetrie on 02/26/2017 02:03 am...Does the SpaceX fairing design allow a lighter payload adapter that is consequently lighter. I've not seen anything in the discussions I've visited thus far indicating one way or the other. Anyone with some insight that can chime in on the hypothesis I put forward?Sent from my iPhone using TapatalkThe Payload Adapter Fitting (PAF) comes in two standard versions: the light PAF payloads weighing up to 3,453 kg (7,612 lb), and the heavy PAF up to 10,886 kg (24,000 lb).
Quote from: cppetrie on 02/26/2017 02:03 amFirst post to NSF so forgive the likely uninformed intrusion on a long-running discussion, but what if the reasoning for the heavier fairing design was as follows: by integrating structural support for the payload during launch and MaxQ into the fairing rather than the payload adapter it allows them to jettison the weight of said support when fairing separation occurs meaning less weight is riding on stage 2 afterwards. If all the support is in the payload adapter, then you haul that and it's extra weight all the way out to your destination. Does the SpaceX fairing design allow a lighter payload adapter that is consequently lighter. I've not seen anything in the discussions I've visited thus far indicating one way or the other. Anyone with some insight that can chime in on the hypothesis I put forward?Sent from my iPhone using TapatalkWelcome to the forum.The fairing only supports the payload, via the PAF, during ground handling: rotation from vertical to horizontal, any horizontal handling and horizontal integration onto the rocket. Payload mass throughout launch and MaxQ is supported by the upper stage, via the PAF.
Quote from: meekGee on 02/23/2017 02:28 pmQuote from: woods170 on 02/23/2017 01:06 pm[...]And this news article shows a rare image of an encapsulated payload going horizontal: https://www.noozhawk.com/noozhawk/print/falcon_9_rocket_moving_toward_nasa_launch_at_vandenberg_afbYou will notice that the payload and fairing are not held via the PAF (Payload Attachment Fitting), but via the fairing halves. Consequently, the load of the payload goes thru the fairing, not the PAF. This requires a strong fairing. Much stronger than those from RUAG et al.The fairing doesn't carry the payload since it doesn't touch it. At worst, during horizontal integration, the fairing half carries its own weight.There was never a good explanation of why they are heavy, except perhaps the desire for them to survive reentry.This photo posted above by @woods170 is pretty definitive. The fairing is carrying the weight of the payload.
Quote from: woods170 on 02/23/2017 01:06 pm[...]And this news article shows a rare image of an encapsulated payload going horizontal: https://www.noozhawk.com/noozhawk/print/falcon_9_rocket_moving_toward_nasa_launch_at_vandenberg_afbYou will notice that the payload and fairing are not held via the PAF (Payload Attachment Fitting), but via the fairing halves. Consequently, the load of the payload goes thru the fairing, not the PAF. This requires a strong fairing. Much stronger than those from RUAG et al.The fairing doesn't carry the payload since it doesn't touch it. At worst, during horizontal integration, the fairing half carries its own weight.There was never a good explanation of why they are heavy, except perhaps the desire for them to survive reentry.
[...]And this news article shows a rare image of an encapsulated payload going horizontal: https://www.noozhawk.com/noozhawk/print/falcon_9_rocket_moving_toward_nasa_launch_at_vandenberg_afbYou will notice that the payload and fairing are not held via the PAF (Payload Attachment Fitting), but via the fairing halves. Consequently, the load of the payload goes thru the fairing, not the PAF. This requires a strong fairing. Much stronger than those from RUAG et al.
Are the payloads designed to be positioned with a specific CG inside the fairing? The picture shows it perfectly balanced, but the lift points don't look repositionable, so it's not clear how they deal with different payload sizes and masses. Maybe they add ballast to 'even out the scales'?
Quote from: RoboGoofers on 03/15/2017 03:50 pmAre the payloads designed to be positioned with a specific CG inside the fairing? The picture shows it perfectly balanced, but the lift points don't look repositionable, so it's not clear how they deal with different payload sizes and masses. Maybe they add ballast to 'even out the scales'?There are two cranes in use. One is attached to the aft of the fairing.
The fact that CCAFS is an air force base should fare well for helicopters catching fairings
Quote from: IanThePineapple on 03/15/2017 09:12 pmThe fact that CCAFS is an air force base should fare well for helicopters catching fairingsSpecifically, CCAFS and the 920th Rescue Wing (HC-130P, HH-60G) are both headquartered at nearby Patrick AFB.
Honestly I would be very surprised if SpaceX wants to recover the fairings, for the sole purpose of saving money, by catching them on the fly with (military) helicopters. In my opinion they will come out with something much less expensive, even if it will take some time to develop the technology to do so
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