Flying in Space

As an engineer I grew up assisted by one of the most amazing piece of hardware ever build, the Hewlett Packard HP 41C; I received it as a XMas present from my father in 1982 and I still have it; it works fine and I sometimes look at it with a sort of nostalgia.
I learned programming and I learned a beautiful reverse way to calculate, the RPN. And even now, after almost 30 years, I always keep the compiled microkernel in all my devices, MacBook, iPhone, iPad, iPod.
But one thing surpassed the joy of my first programs (mostly around math, science and grammar): NASA did choose the HP-41C as an emergency computer on the Space Shuttle in case the main controller failed during reentry; the small calculator, build on a 4 layer assembled chip, had a trajectory software capable to bring back the astronauts manually, although this has never happened.
The space agency developed a special ROM and a keyboard layer for it (as seen in the picture with astronaut Sally Ride) in order to avoid the data being lost in case of a MEMORY LOST, which is the situation when the 41C do erase everything.
The calculator was simply fantastic, reliable, light, easy to program and with enough memory; HP formed with it a plethora of scientists and engineers, one of them is myself. Actually I am deeply thankful and respectful; not only to them, but to my father as well; he bought that XMas two HP 41, one 41CV for my brother and one 41C with less memory for me. The price adjusted by the inflation is about 2000 Euros each.