The SR-71 Blackbird Astro-Nav System worked by tracking the stars

Post by failuser » Mon, Sep 25, 2023, 11:29 PM UTC

jacurtis wrote: post #32

> the flight plan was recorded on a punched tape that told the aircraft where to go, when to turn, and when to turn the sensors on and off. This is equally fascinating to me. Before each flight, someone had to generate a flight plan and punch it onto a physical tape, then load it into the plan. T No mid-flight "re-calculating route" if stuff goes wrong. One of the most interesting and under-appreciated aspects of ear…

Post by arbitrage » Mon, Sep 25, 2023, 11:34 PM UTC

elzbardico wrote: post #61

jacurtis wrote: post #32

> the flight plan was recorded on a punched tape that told the aircraft where to go, when to turn, and when to turn the sensors on and off. This is equally fascinating to me. Before each flight, someone had to generate a flight plan and punch it onto a physical tape, then load it into the plan. T No mid-flight "re-calculating route" if stuff goes wrong. One of the most interesting and under-appreciated aspects of ear…

America was not critical defeating Germany. The soviets did this one.

Post by dheera » Mon, Sep 25, 2023, 11:35 PM UTC

_moof wrote: post #35

fidotron wrote: post #6

Earlier quoted context omitted.

The F22 had an unintentional problem of being unable to cross the international date line, which was discovered when attempting to fly from Hawaii to Japan. Given that it may very well be better to assume that anything untested doesn't work at all and to live within those restrictions.

The International Date Line and the 180-degree line of longitude have bitten a _lot_ of folks who don't think to test at the boundaries.

Post by singleshot_ » Mon, Sep 25, 2023, 11:37 PM UTC

dboreham wrote: post #21

cmiller1 wrote: post #9

Earlier quoted context omitted.

I got to see an SR-71 on display in New York several years ago. What really struck me was how BIG it was, seeing pictures of it doesn't really give you sense of scale, it was a massive plane.

Even more impressive seeing it sweat fuel onto the apron in the afternoon sun for a few hours then engine ignition with Chevy V8 start cart, takeoff followed by low level transonic flyby. Fairford IAT 1989.

Post by supportengineer » Mon, Sep 25, 2023, 11:38 PM UTC

tgsovlerkhgsel wrote: post #45

How complicated/expensive would it be to build an open source star tracker nowadays? How accurate of a fix could you get just by pointing a phone at a sky? Or a DSLR on a commercial gimbal?