
Debugging a Live Saturn V - jlangenauer
http://www.zamiang.com/post/debugging-a-live-saturn-v
======
nn3
If you like these kinds of stories, Boris Chertok's memoirs have a lot more
from the Russian early launches during the space race. He was in charge of
electrical systems in many of the Russian rockets.

NASA history has an excellent four volume translation of his memoirs. In
volume 2 he describes the development and testing of the R7 (Soyuz) rocket:

[https://www.nasa.gov/connect/ebooks/rockets_people_vol2_deta...](https://www.nasa.gov/connect/ebooks/rockets_people_vol2_detail.html)

~~~
ufmace
That makes me remember some interesting things I read that explains how much
of the space race went:

In the immediate post-WWII era, the US had lots of experience with long-range
heavy bombers, and plenty of air bases close-ish to the USSR. So the US
focused on delivering nukes via aircraft and neglected rockets at first. The
Soviets weren't real into long-range heavy bombers, and didn't have many air
bases near the US anyways, so they went in on long-range rockets sooner and
harder. Their nuclear program was less developed too, so their bombs were
bigger and heavier. This means that their long-range bomb delivery rockets
were big and powerful enough to double as orbital rockets with minimal
changes. US bomb delivery rockets were significantly smaller, so we needed to
develop all-new rockets to start launching things into orbit.

The Soviets were also behind on electronics and automation. When they wanted
to do orbital surveillance and intelligence gathering, they put actual humans
in their satellites to do it. The Americans decided that it was better to use
electronics to do the same job. It was indeed better to use electronics for
the purpose of surveilence, but that also meant that the Soviets racked up a
lot of experience in running manned space stations that we didn't start to
touch until much later on.

Source: [https://selenianboondocks.com/2019/05/amistics-of-human-
spac...](https://selenianboondocks.com/2019/05/amistics-of-human-spaceflight-
or-how-autonomy-and-miniaturization-can-be-the-enemies-of-human-spaceflight-
part-1/)

------
imglorp
They were given permission to take that long list of risks because of the
urgency of the space program. I don't think anyone would dream of sending
people into a flammable, toxic atmosphere for electrical work these days. And
that's how we got to the moon.

~~~
pjc50
> And that's how we got to the moon.

With only three dead (due to the use of flammable atmosphere!) and the narrow
escape of another three. Better results than the average WW2 bombing mission,
I suppose.

~~~
rurounijones
Honestly I think you would find thousands of volunteers to do space
exploration with a much higher risk than we are willing to entertain today.

I sometimes wonder just how much we are handicapping ourselves as a
civilisation with the risk averseness we take to some tasks while being pretty
blase about others where the reward is nowhere near as high.

~~~
adamsea
I would argue the bigger handicap is the resource constraint for large
projects - from lack of funding as well as lack of resources since the major
sources Of taxable income (Amazon, Apple, etc) don’t pay tax.

~~~
pjc50
Resources are a choice. Nobody ever did a cost-benefit assessment for the
trillion dollars of Iraq war.

(Arguably the space programme worked as a proxy war with the Soviet Union;
America didn't want to let the Russians ""invade"" the moon first.)

~~~
adamsea
Apologies - not sure I understand. But I think I agree that societies choose
how to distribute their resources?

------
rwmj
Switching a relay in a flammable atmosphere is ... bold. Does anyone know what
voltages were used?

Edit: Seems like 28 volts DC unregulated supply
([https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/197400...](https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19740021163.pdf)),
which was regulated to 5V and 56V depending on where it was used
([https://en.wikipedia.org/wiki/Saturn_V_instrument_unit#Power](https://en.wikipedia.org/wiki/Saturn_V_instrument_unit#Power))

~~~
egdod
Was it a flammable atmosphere? Liquid oxygen would have been venting, but
there shouldn’t have been any significant fuel in the air.

~~~
lb1lf
-Given sufficient oxygen levels, anything is fuel - including engineers...

~~~
egdod
Well sure, but a tiny spark in a relay isn’t going to ignite the engineer.

~~~
Doxin
It might ignite the metal in the relay, before igniting the engineer.

------
jonplackett
This reminded me of a recent post about how we can’t do anything fast anymore.

[https://news.ycombinator.com/item?id=21848860](https://news.ycombinator.com/item?id=21848860)

This kind of daring/insanity that can only be justified as part of something
as important as the space race is possibly part of the reason.

------
venti
"We resealed the cabinet, signed off on all the paperwork and got the out of
there without any more sight seeing."

That's the NASA spirit!

------
gumby
Now I think of it, _of course_ they used switching relays in the 1960s.
But...I am astonished that they worked in such a high-vibration (and extreme
temperature) environment.

The entire enterprise remains incredible, and the more I learn about it the
more incredible it seems.

~~~
pjc50
I thought "NASA will have a spec for this", and sure enough a bit of Googling
finds this from 1973:
[https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/197300...](https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19730014020.pdf)
which references "Teledyne 422" relays. That is
[https://www.teledynerelays.com/Datasheets/420422.pdf](https://www.teledynerelays.com/Datasheets/420422.pdf)
, which claims 30g at 3000Hz. Apparently by using strong fields over short
distances.

(The first PDF is worth scrolling to the end for a full set of neat hand-drawn
mechanical and circuit diagrams. No CAD back then!)

~~~
kevin_thibedeau
Latching relays don't need to rely on field strength to hold contacts in
place. Then it's just a mechanical design problem.

~~~
gumby
In launch phase they presumably had plenty of power; I was thinking of
mechanical chatter (rising) in the contacts.

------
sizzzzlerz
OK, men, you're about to service a fully fueled Saturn V rocket that is
spewing all sorts of nasty gases and is an active spark away from blowing up
itself, and you, over a 5 mile radius.

Do you all have your plastic safety helmets?

------
prox
Amazing story, a once in a lifetime experience for sure!

~~~
eschneider
One in a lifetime, in a GOOD way.

------
ggerules
I love stories like these. Are there any more from engineers of the time?
Perhaps, are any more of his stories published anywhere?

~~~
Arainach
The best place to start is Apollo by Murray/Cox:
[https://www.goodreads.com/en/book/show/282086.Apollo](https://www.goodreads.com/en/book/show/282086.Apollo)
Rather than focusing on the astronauts, this is very much a story of the
engineering and management that made the project possible.

From someone who helped develop the lunar lander, there's Thomas J. Kelly's
"Moon Lander: How We Developed the Apollo Lunar Module":
[https://www.amazon.com/dp/1588342735/](https://www.amazon.com/dp/1588342735/)

Another good book (so I've heard - I own a copy but haven't made time to read
it yet) is Sunburst and Luminary by Don Eyles, who worked on the guidance
system at MIT:
[https://www.sunburstandluminary.com/SLhome.html](https://www.sunburstandluminary.com/SLhome.html)

For deep technical details (but light on first-person stories), there's How
Apollo Flew to the Moon:
[https://www.goodreads.com/book/show/2323178.How_Apollo_Flew_...](https://www.goodreads.com/book/show/2323178.How_Apollo_Flew_to_the_Moon)

Finally, not strictly related to the space race, but for some truly wonderful
first-hand tales from the development of rocket propellants, you can't beat
John D. Clark's Ignition!: [https://www.amazon.com/Ignition-Informal-
Propellants-Univers...](https://www.amazon.com/Ignition-Informal-Propellants-
University-Classics/dp/0813595835/)

------
lunkwill42
What a wonderful story - and a great way to honour and remember your
grandfather.

------
spicyramen
One of the best stories this year. Thanks for sharing

