Quote from: Johnnyhinbos on 05/07/2018 03:41 pmI’m pretty sure those are rivets connecting the carbon fiber leg “fairing” to a stiffener made out of another material. This would run from hinge point down to contact point.I'd agree that they're fasteners, but what you're calling a stiffener I'd guess is more like a metal doubler that, along with the fasteners, acts to clamp the two composite pieces (outer and inner faces) of the leg together. Carbon fiber is already so stiff that the leg cross-section should be more than strong enough without stiffeners, and the relative narrowness of that strip, just wide enough to carry the bearing stress of the fastener heads, makes me think it's for that purpose.Probably SpaceX came up with a more efficient manufacturing process for the legs, one that requires some assembly but makes the composite parts easier to fabricate.QuoteTheoretically, all composites could be adhesively bonded. However, many manufacturers avoid adhesive bonds where joints undergo large amounts of stress; thus, fasteners are still specified for many joints. Also, some structures and components are so large that they preclude the use of the special lay-up tooling and curing equipment needed for most adhesive applications, making fasteners cost-effective for such cases.http://www.machinedesign.com/basics-design/joining-composites
I’m pretty sure those are rivets connecting the carbon fiber leg “fairing” to a stiffener made out of another material. This would run from hinge point down to contact point.
Theoretically, all composites could be adhesively bonded. However, many manufacturers avoid adhesive bonds where joints undergo large amounts of stress; thus, fasteners are still specified for many joints. Also, some structures and components are so large that they preclude the use of the special lay-up tooling and curing equipment needed for most adhesive applications, making fasteners cost-effective for such cases.
Are there any examples of companies in the aerospace world that don’t (generally) maintain a high level of prudence and caution?
Quote from: Lar on 05/08/2018 05:43 pmQuote from: Rabidpanda on 05/07/2018 10:01 pmAre there any examples of companies in the aerospace world that don’t (generally) maintain a high level of prudence and caution? NASA lost not just one, but two, shuttles because of a lack of " high level of prudence and caution" IMHO.That is out of line, especially for a moderator.
Quote from: Rabidpanda on 05/07/2018 10:01 pmAre there any examples of companies in the aerospace world that don’t (generally) maintain a high level of prudence and caution? NASA lost not just one, but two, shuttles because of a lack of " high level of prudence and caution" IMHO.
The question was asked, (tangentially) if there were organizations that did not always operate in a certain way. An answer was given,
Quote from: Lar on 05/08/2018 06:29 pmThe question was asked, (tangentially) if there were organizations that did not always operate in a certain way. An answer was given,That was 15 and 30 years ago. We are talking now.Are you being held to asinine things you did 15 and 30 years ago?
In that case, I submit that planning to launch a crewed circumlunar mission on the second flight of a new launch vehicle is a good example.
That’s something NASA is happy about: the Block 5 is the rocket that SpaceX will use to launch NASA astronauts to the International Space Station, as part of the Commercial Crew Program. So this version has been built to meet all of the space agency’s rigorous safety standards. NASA is requiring that SpaceX fly the Block 5 at least seven times successfully, without any major changes, in order to certify it for human flight. It’s a stringent requirement, especially for a rocket that’s flown numerous times before. In comparison, NASA’s future Space Launch System will only do one test flight before it’s certified to fly humans. And the Space Shuttle’s very first flight had humans on board. “SpaceX is going through a level of rigor and improvement that far exceeds everything that’s been done in human spaceflight,” says Autry.
So I would like to ask what type of mission would be good for the first attempt to fly the Block 5 for a third time? Would an LEO lower stress mission be best? Is there something upcoming that might provide advantages as a third mission? What about the Max-Q abort test? Should this test be done with a block 5 to be as close to real world crewed flights as possible?
Quote from: robert_d on 05/09/2018 07:23 pmSo I would like to ask what type of mission would be good for the first attempt to fly the Block 5 for a third time? Would an LEO lower stress mission be best? Is there something upcoming that might provide advantages as a third mission? What about the Max-Q abort test? Should this test be done with a block 5 to be as close to real world crewed flights as possible?I don't think it will matter. That's the key to the whole reuse bit. It doesn't matter what type of mission they fly, they'll still reuse the booster. The abort test can use a solid booster and it would still give the exact same test conditions. The in-flight abort test is only about the capsule's abort performance in the worst-case flight conditions, nothing at all to do with the booster.
From the press kit:Mission Timeline (all times approximate)COUNTDOWNHour/Min/Sec Events- 00:38:00 SpaceX Launch Director verifies go for propellant load- 00:35:00 RP-1 (rocket grade kerosene) loading underway- 00:35:00 1st stage LOX (liquid oxygen) loading underway- 00:16:00 2nd stage LOX loading underwayCompared to Block 4:COUNTDOWNHour/Min/Sec Events- 01:13:00 SpaceX Launch Director verifies go for propellant load- 01:10:00 RP-1 (rocket grade kerosene) loading underway- 00:35:00 LOX (liquid oxygen) loading underwayFalcon 9 will be loaded up with RP-1 and LOX a lot faster than usual. Are they trying to keep the propellants as cold as possible before launch?
Worth noting it is the same loading they were doing pre-Amos 6. This time with redesigned COPV's it will not be so risky.