[OT] Space shuttle explosions and computers (was Re: Who invented the internet?)

From: Jerome Fine <jhfine_at_idirect.com>
Date: Wed Feb 17 23:22:00 1999

>Eric Smith wrote:

> Allison wrote:
> > FYI the speed attained at
> > that point is some 3600mph far from orbital velocity.
>
> I'm not sure how to parse that. Are you saying that it was traveling at
> 3600 MPH, which is far from orbital velocity (i.e., a missing comma), or
> that it was travelling at 3600 MPH less than orbital velocity?
>
> (In any case, the use of the word velocity is incorrect. Velocity is
> a vector, as I had drilled into me in Physics class.)

Jerome Fine replies:

If Allison was able to see the screen while she was sending that
reply, then the "missing" comma is not the only thing that Eric
Smith seems to be missing. I can still remember that day in
a far more vivid manner than I care to recall how I felt and
how sad the whole of the US was in regard to the fatalities.
A neighbour who lost a part of her life in that tragedy is
more than sufficient justification to drop a comma, let alone
be reason enough to use velocity as opposed to speed.

So Eric Smith is technically correct. But, in my humble
opinion, it is he, not Allison who is missing something!!

> The NASA reference I posted earlier claims:
> At this point in its trajectory, while traveling at a Mach number
> of 1.92 at an altitude of 46,000 feet, the Challenger was totally
> enveloped in the explosive burn.
>
> The best information I have suggests that the Space Shuttle does not
> use the Honeywell DDP-516 in any capacity, and that engine control is performed
> by the some of the IOP processors that are part of the IBM AP-101S
> computers. The entire AP-101S, including both the GPC and IOP, occupies
> about 0.025 cubic meters, masses about 30 Kg, and consumes about 550 W.
> A DDP-516 occupies about 2.5 cubic meters, masses about 250 Kg, and consumes
> over 1000 W.
>
> The AP-101S replaced an earlier AP-101B computer that was twice the size.
> Anybody know where I can find one for my collection? :-)

I suggest that you wait for an appropriate time and do not link the AP-101S
to the Shuttle program for a while. Please give Allison some time to heal those
scars which will never disappear.

Allison, please accept this apology from the rest of the group, as well as from
Eric Smith (I would hope) for any insensitive treatment of you remarks.

Sincerely yours,

Jerome Fine
Received on Wed Feb 17 1999 - 23:22:00 GMT

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