Amazing space 'facts' from official sources

[Thorsten]

Over the years, I've been reading quite a bit of Shuttle-related material. I've come across the following statement about the transition from RCS yaw jets to rudder in at least 2 hardcover books and 8 different web pages.

At Mach 3.5, the rudder become activated, and the aft RCS yaw jets are deactivated (approximately 45,000 feet).

That's right, the whole world seems to believe it all happens at 45,000 ft.

if you're not familiar with basic aerodynamics, it sounds innocent enough - but 45.000 ft is a bit higher than airliners reach - if you try to fly Mach 3.5 there, not only is drag and heat production enormous, but you'll also screw up your TAEM pattern.

I found it vexing that authors of spaceflight books as well as Shuttle fan pages didn't spot such a glaring typo (the number intended to be given here is probably 145.000 ft) - but they have the best of reference sources for the nonsense:

https://spaceflight.nasa.gov/shuttle/reference/shutref/events/entry/


Yep - NASA describes it that way. And they're not thinking of altering it (I wrote to the webmaster identified in the page index two years ago, my mail just got ignored).


Today I came across another one of the same type, having to do with the SRB sep sequence:


They can also ensure that the Pc - 50 message (chamber pressure greater than 50 psi) correctly appears on the major mode 102 (first stage) ascent trajectory CRT display before SRB separation

https://spaceflight.nasa.gov/shuttle/reference/shutref/events/1stage/

Well, if that were true we'd probably never leave the pad because the SRBs would be disconnected right after ignition. Well, okay, for this one has to know some engineering details to deduce that, but there's another way: I mean, it's not rocket science that a message PC < 50 doesn't mean chamber pressure greater than 50.

Okay - it'd be cheap to mock a few innocent typos - except that they don't get corrected even when someone notifies the page owner, and that they get copy-pasted by space afficinados all around the internet on the grounds that 'NASA wrote it, so it must be true' - that's kinda scary.

 

[Ravenous]

Sadly the various web sites don't seem to be a very high priority - they get written once and left for all time, I suppose. (I say this because some pages do look pretty dated at times.) Maybe they just don't have enough people looking after them...

 

[GLS]

A favourite of mine is:
the SSMEs must reach 90% of their rated thrust by T-3 seconds, or else the launch is aborted
...but then you look at a SSME thrust plot during ignition, and if that was true it would always abort. :lol: :facepalm:
The LCC has the RSLS checking the thrust at T-2 seconds, and that "matches" the SSME thrust buildup, so it is T-2s and not T-3s.

---------- Post added at 03:18 PM ---------- Previous post was at 03:15 PM ----------

Another one:
...loading the external tank with liquid hydrogen and liquid oxygen fuels...
:facepalm:

 

[Thorsten]

Maybe they just don't have enough people looking after them...

I fear it's the theme of our time - a disdain for knowledge in favour of story-telling. The website fulfills it's purpose in a way, which is tell people interested in spaceflight a story - NASA doesn't really care whether that story is scientifically accurate or not.

You only need to look as far as superluminal neutrinos or the BICEP2 gravity waves without background subtraction to get other prominent examples of the theme.

Knowledge generally is hard to acquire and takes effort to teach - story-telling is much easier and gets you all the funding...

I mean, seriously, if NASA's public relations department doesn't have the resources to have someone fix a typo on a website, then I don't know what they do...