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I think there is a huge difference between NASA trying to find a viable rocket design for manned flight and building an aircraft carrier - they already have des

I think there is a huge difference between NASA trying to find a viable rocket design for manned flight and building an aircraft carrier - they already have designs for catapult and arresting systems that are much more reliable and cheaper than the new ones they decided to try out on the new class of carrier ( and using the same metaphor with NASA, they chose a company that had never designed a rocket engine to design rockets for manned space travel to put on top of a Saturn V stage 1), and if they continue to stick with the new unproven designs, they won't be able to deliver for many, many more years, if ever. If they had stuck with the proven design with just improvements, they might have been able to deliver the ship three years ago on time. The new electric only system means they committed to not routing steam from the nuclear power plant to the catapults so that would be a major retrofit for that one completed new style carrier. The new electric systems when they do fail, they disable the entire catapult launch capability of the aircraft carrier, the contractor made a really poor design decision here that they apparently cannot fix. The steam catapults can be taken offline individually and worked on, leaving the others in service.

myrandomcomment 9y ago
They did not just say, hey this steam thing sucks, let's do something different. While a mature technology it has its issues. The routing of the steam pipes and battle damage issues, the fact that it cannot be tuned exactly based on weight load, etc. They had a reason beyond steam sucks. It will get worked out.
killjoywashere 9y ago
The big issue is that the EMALS system is easier on the airframes. In a conventional steam catapult, the steam head hits the piston face at max pressure and expands as it accelerates the aircraft, but max acceleration occurs at the beginning. This means there's much more load on the aluminium components of the airframes. As aluminium has no elastic limit, all deformation is bad. The Navy goes through a lot of airframes compared to the air force. The EMALS system is intended to spread the load out continuously during take-off so the max load is much lower, thereby dramatically increasing the lifespan of the airframes.
- zaroth 9y ago
  Intended, yes, except it actually fails to do this currently and potentially indefinitely.
  - myrandomcomment 9y ago
    There was a more balanced story awhile back that talked about this in detail and it said they believe they can make software tweaks and a few other changes to resolve that. However they where not 100% and where doing testing.

myrandomcomment 9y ago

They did not just say, hey this steam thing sucks, let's do something different. While a mature technology it has its issues. The routing of the steam pipes and battle damage issues, the fact that it cannot be tuned exactly based on weight load, etc. They had a reason beyond steam sucks. It will get worked out.

killjoywashere 9y ago

The big issue is that the EMALS system is easier on the airframes. In a conventional steam catapult, the steam head hits the piston face at max pressure and expands as it accelerates the aircraft, but max acceleration occurs at the beginning. This means there's much more load on the aluminium components of the airframes. As aluminium has no elastic limit, all deformation is bad. The Navy goes through a lot of airframes compared to the air force. The EMALS system is intended to spread the load out continuously during take-off so the max load is much lower, thereby dramatically increasing the lifespan of the airframes.

zaroth 9y ago
Intended, yes, except it actually fails to do this currently and potentially indefinitely.
- myrandomcomment 9y ago
  There was a more balanced story awhile back that talked about this in detail and it said they believe they can make software tweaks and a few other changes to resolve that. However they where not 100% and where doing testing.