Thread

1. ggm · 1790747290 · focus · HN ↗

   A couple of questions/observations:

   1) when people say "destroyed the jigs, tools and spares in 2007" What do they actually mean? Burying things isn't destroying. Putting them in a furnace is destroying. Is it possible that both parts, and tools actually are recoverable e.g. from the seabed? The dimensional stability might be off, but to help reconstruct tools, it's not nothing. Likewise digging up something buried in its packing crate is not rocket science.

   2) "that would be ludicrously expensive" doesn't mean much any more. It's not unlike "we can't make a saturn 1 any more because the tools were destroyed and it would be ludicrously expensive to make an F1 engine" -well yes, but thats not impossible, it's just unlikely and expensive. So maybe this is unlikely, expensive but ... has a unicorn sugar daddy?

   3) there are craft in all sorts of places. Not just on sticks outside NASA property. I am not a historian or a federal government employee, but I wouldn't think it impossible for people to ask other agencies to let you inside the shell and remove the bits you want, or even ask for it back. The one on a stick in Balboa Park San Diego might have associated boxes of bits-and-bobs..

   4) its a titanium alloy. It's temperature and corrosion resistant, noting some things (like chlorine according to the web) are bad for it. It's not made of pure chinesium or balsa wood. Interior surfaces would be in pretty good shape.

   1. Beretta_Vexee · 1790761238 · focus · HN ↗

      So titanium alloys are not completely resistant to all forms of corrosion. They are particularly prone to galvanic corrosion, which means that specific tools must be used, all forms of ferritic contamination must be avoided, special tools must be used, and they must be stored separately, etc.

      This is very labour-intensive, which is why it is generally carried out in dedicated workshops, with specialised equipment, and so on, by staff who have been specifically trained and do nothing else.

      If you add jigs, production-specific tools, and so on, all of that has been lost and needs to be recreated: staff need to be trained, QA defined and workshops need to be reorganised. This can take decades to return to the expected standard. You can throw as much money at this sort of problem as you like without actually being able to speed things up.

      Finding the drawings and dimensions is the easy part of reverse engineering a mechanical device. The real challenges lie in identifying the manufacturing processes and quality control procedures, and achieving the expected performance with an acceptable scrap rate.

      If I place a monocrystalline turbine blade on your desk, you’d be able to draw up the plans for it. But that would tell you absolutely nothing about the processes required to produce a monocrystalline ingot of a nickel superalloy.

      Source: former mechanical engineer in the nuclear industry, managing obsolescence was one of my day-to-day tasks.

      1. Tangurena2 · 1790790410 · focus · HN ↗

         > They are particularly prone to galvanic corrosion, which means that specific tools must be used, all forms of ferritic contamination must be avoided, special tools must be used, and they must be stored separately, etc.

         The C4 Corvette had a titanium component back in the early 1980s (I worked for GM back then). The piece was flat and mechanics tended to use it to hold tools. Leaving the tool on that piece when closing the hood resulted in a dented (fiberglass) hood. Most tools (at least back then) have a cadmium coating (to keep them shiny). Cadmium causes corrosion to titanium. There were lots of service bulletins about this.

         1. gurumeditations · 1790792045 · focus · HN ↗

            Do you mean the magnesium pizza box?

Unofficial Hacker News client; not affiliated with Y Combinator.