The repairs to the cracks in the first Orion capsule have withstood static stress tests.


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I’m so glad: The repairs to the cracks in the first Orion capsule have withstood static stress tests.

In addition to the various loads it sustained, the Orion crew module also was pressurized to simulate the effect of the vacuum in space. This simulation allowed engineers to confirm it would hold its pressurization in a vacuum and verify repairs made to superficial cracks in the vehicle’s rear bulkhead caused by previous pressure testing in November.

The November test revealed insufficient margin in an area of the bulkhead that was unable to withstand the stress of pressurization. Armed with data from that test, engineers were able to reinforce the design to ensure structural integrity and validate the fix during this week’s test. [emphasis mine]

I love how this NASA press release describes the cracking of the capsule bulkhead during the November testing, indicated in bold. “Insufficient margin”, eh?

Normally I am very forgiving when things fail during engineering tests, but for the bulkhead of this capsule to crack during these tests was actually pretty shameful, considering the decades of engineering work previously done in the building of space capsules and submarines. Things can certainly go wrong when you build something new, but I don’t see anything particularly revolutionary about Orion’s design. Lots of things might fail, but making sure the bulkhead could withstand the normal and well known stresses of spaceflight should not have been one of those things. The bulkhead failure suggests to me some sloppy engineering work took place in Orion’s initial design.

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3 comments

  • joe

    What is going to be the purpose of this capsule, how much more of a payload is it going to handle, mission to the moon or some other rocky orb? As I remember, the Apollo missions were 3 man crew and did not have too much of a payload out side of the crew and some rocks, those capsules did their mission well, I realize that when talking about space, that lightness is a priority except over safety of the crew.

  • Pzatchok

    All those waffle looking panels are made of 2 inch thick rolled and then CNC milled aluminum. Carved out to that waffle pattern to make them lighter.

    They ran into a problem when they tried to make the inside corners of the waffle pattern to tight of a radius.
    they ran into this same problem with passenger jet air craft back in the early 60’s. They made the windows look almost fully rectangular and that concentrated all the stresses into the sharp corners. The sheet metal skins started to stress fracture and rip at and in some cases the windows started to fall out of the planes.
    After that they made the windows almost oval in shape removing sharp corners and directing stress around the windows.

    During the first stress tests it was all those corners that took all the stress and many started to crack and after they all needed to be repaired and buttressed.

    A problem that was noticed and fixed 50 years ago. But somehow with a billion dollars to spend they forgot this commonly known problem.

  • Pzatchok

    http://en.wikipedia.org/wiki/De_Havilland_Comet

    Three planes lost before they decided to test and inspect the craft and found it was a multitude of factors with one of them being the window shape.

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