Quote from: robert_d on 03/23/2016 09:05 pmHas anyone considered going the other way with the Faring? By that I mean make it super cheap like the wrapping on a candy bar? I know there are aerodynamic loads and all that but just wondering if a dry nitrogen pressurized gas bag made out of some tough material could be used. After all NASA is investigating inflatables for potential reentry use, so maybe not so crazy? Just wondering.It's not just aero loads. The fairing shroud also provides an acoustic, thermal, chemical, & EMI environment that keeps the payload safe while waiting for launch as well as during ascent to orbit. No cheap bag of gas is going to work for all those requirements.
Has anyone considered going the other way with the Faring? By that I mean make it super cheap like the wrapping on a candy bar? I know there are aerodynamic loads and all that but just wondering if a dry nitrogen pressurized gas bag made out of some tough material could be used. After all NASA is investigating inflatables for potential reentry use, so maybe not so crazy? Just wondering.
Fairing halves will stay separate once separated. As Stan-1967 said, rejoining would be of overwhelming complexity.
Quote from: robert_d on 03/23/2016 09:05 pmHas anyone considered going the other way with the Faring? By that I mean make it super cheap like the wrapping on a candy bar? I know there are aerodynamic loads and all that but just wondering if a dry nitrogen pressurized gas bag made out of some tough material could be used. After all NASA is investigating inflatables for potential reentry use, so maybe not so crazy? Just wondering.there is a thread on this and reasons that it is not feasible.
I think you could potentially be trading one complex problem for a slightly less complex problem.in a hypothetical world where joining the halves makes rentry significantly more survivable, i think youd want to consider it.edit: and to satisfy the calls for realism. the new thrusters could enable a rejoining operation. plus they make a lot of docking hardware/software for dragon already.
the fairings can actually be made even lighter because they don't leave the vehicle.
Quote from: sevenperforce on 03/24/2016 02:35 pm the fairings can actually be made even lighter because they don't leave the vehicle. Can't say that. Keeping them open and the landing loads would likely make them heavier than stand alone.
They aren't support structures.Easier (from a weight basis) than making them reusable independently.
Quote from: sevenperforce on 03/24/2016 03:26 pmThey aren't support structures.Easier (from a weight basis) than making them reusable independently.Again, you have no data to support your claim. All that might be needed to support independent reusability (as in standalone) is an attitude control system and parachute. Supporting the fairing on the stage partially open for entry and landing will require major reinforcement of the fairing.
Parachutes are heavy. The reinforcement would primarily be needed for the landing legs, but they already need to be really strong.
You know, if it would be possible to hinge the damn thing, why not simply hinge it along one long edge? Then it could open along that edge and tumble away still connected.
Quote from: sevenperforce on 03/24/2016 04:11 pmParachutes are heavy. The reinforcement would primarily be needed for the landing legs, but they already need to be really strong. More (and heavy) reinforcements are needed for the fairing to handle to the additional loads that I list.
Quote from: sevenperforce on 03/25/2016 03:19 pmYou know, if it would be possible to hinge the damn thing, why not simply hinge it along one long edge? Then it could open along that edge and tumble away still connected.Aerodynamics, while minimal at the altitudes that fairings are generally dropped from, would likely either bounce the fairing pairs back into the rocket, or simply tear them apart at the hinge.
Quote from: sevenperforce on 03/25/2016 03:19 pmYou know, if it would be possible to hinge the damn thing, why not simply hinge it along one long edge? Then it could open along that edge and tumble away still connected.If you push a long edge hinged fairing over the other long edge, you get an inward movement of the hinge.You can add a reaction beam to keep the hinge clear from the payload, but this would increase the mass of the fairing.