I think Titan-Centaur did for its shroud.
Can you say if SuperZip is still in use on Atlas-V Centaur now?
Quote from: strangequark on 11/20/2012 08:00 pmCan you say if SuperZip is still in use on Atlas-V Centaur now?Atlas doesn't use it now or in the past.
Any word as to the likelihood that this was the cause of the GLORY failure too? IIRC, in both cases the PLF didn't separate.
Are you implying that any problem can be solved by using enough explosives
Quote from: kevin-rf on 11/23/2012 02:51 pmAre you implying that any problem can be solved by using enough explosives When the problem is how to separate Part A from Part B, absolutely!
It boils down to whether or not you are content to have both parts reduced to confetti or whether you want one or both parts relatively intact.
Pegaus only uses frangibles for the base ring, not the sep plane between the fairing halves, which eliminates charge holder slumping as a failure mode. If NASA thinks it affects Pegasus, then Atlas V may have some explaining to do too.
1. The only joint on Pegasus is oriented perpendicularly to the axis where charge holder slumping is a concern. If NASA is really thinks it affects Pegasus, it means they think the material's property issue can be a primary cause of failure, rather than just a contributor.
3. Had the Centaur on Atlas used SuperZip, the vendor might be different, but it's still an aluminum extrusion of the same/similar alloy. Some confidence testing, or at least a comprehensive requirements review, would be in order.
What I think Gerst is referencing in the article is that we've also determined, recently, that for some rails the property in question varies pretty dramatically along the length of the extrusion. It's something that you don't necessarily pick up on unless you measure every inch or half inch. Luckily, it is something that can be measured, even for an installed vehicle.
1) Frangible Joint Subsystem failure caused fairing not to separate. It could not be determined if the frangible joint base ring fractured completely as designed. An incomplete fracture could have resulted in the fairing not separating. The MIB looked at the materials used and their characteristics and made the following recommendations: 1. Verify that the Taurus launch vehicle frangible joint (fairing rail, base ring, and Stage 2/ Stage 3) extrusions have a traceable pedigree on future NASA missions. If pedigree cannot be verified, remove and replace the assigned hardware with frangible joints that have a complete pedigree. 2. Establish a single heat treat lot requirement for aluminum used to manufacture extrusion and perform sub-scale tests on the lot. 3. Institute permanent marking (which cannot be removed during processing) along the length of the extrusion at intervals to ensure traceability.4. Implement a common procurement and assembly process for frangible joints used on Taurus similar to Orbital’s other programs.