The space shuttle never lived up to it's impossibly high expectations. The idea sounded good - a mostly reusable spacecraft that can be processed and readied for another launch in about 3 weeks - but the idea was never practical. As indicated above it was extremely complex and what is also obvious to anyone with any experience with aeronautics, it's exceptionally heavy and inefficient.bradshsi:
The sad part was that we scrapped our Saturn1B and Saturn V booster capability as well as the Apollo Command and Service Modules to fund the shuttle program. In the mid 70's they represented a simple, practical, reliable, relatively inexpensive and extremely capable booster system with much more payload capacity than a shuttle.
The F1 boosters on the Saturn first stage were very rugged and it is estimated they could have been flown on at least 5 flights. So a more evolutionary approach of developing a recoverable first stage based on the Saturn V first stage and possibly a reusable command module would have made much more sense to cut launch costs.
The shuttle was a large leap backwards in capability, but sounded good in the press - at least until Challenger. For example the ISS could have been put in orbit much faster and in much bigger chunks if the design had been limited to Saturn booster capabilities rather than those of the Shuttle and the far fewer launches required would have resulted in less money and much quicker construction.
The irony here is that the "new" launch vehicle being developed to replace the shuttle follows the Saturn/Apollo concept with a conventional booster rocket and a command service module that looks like it could have sat atop a Saturn rocket. And NASA finally seems to have accepted that it makes more sense to send up the crew and large payloads separately than it does to send up an over weight and overally complex vehicle to try to carry both.
So I guess I do not see NASA using an Air 2 as automatically being a glowing endorsement and you are far better off assessing the Air 2 in terms of how it full fills your particular needs.
To be honest I use one on my doubles when configured for a FFM and gas switching block as it provides a limited capability for air sharing (I am almost always solo in that configuration or diving with competent and self reliant divers who are fully redundantly equipped already) and it provides an alternate second stage in the very unlikely event that my primary second stage fails. So it does everything I need it to do and does it with one less hose and very good streamlining. If it works for me, I am not concerned how anyone else feels about it.
An Air 2 also makes a great deal of sense for a recreational diver as it is ammenable to the reality that an OOA buddy will most often mug you for your primary without asking. The easy to find, self flushing, always ready to use qualities of the Air 2 are very beneficial in that situation. And mechanically speaking it is a very good balanced inflator and the reg side of it is a very simple and reliable downstream design.
