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Comment by weinzierl | Hacker News Reader

"There was no payload; this was a test flight with the goal of gathering data not just on the rocket, but all the various systems involved."

I'm out of aerospace for about 15 years and only worked there as a junior engineer, so take this with a grain of salt:

There is always a payload. You could not just launch a rocket with an empty payload fairing. The payload dummies used are not only trimmed for appropriate mass and COG but also for the proper frequency response.

I know this, because as a young engineer I did the FE-models of the MaqSat (H2 and B2 IIRC) dummies for the Ariane 5 and spent days trimming their frequency responses.

http://astronautix.com/m/maqsat.html

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I think you're taking it too literally. It's meant to convey the meaning of "Delivering a payload wasn't the goal, testing the rocket and all associated systems was the goal".

It seems to be the standard for internet discussions: if there's the slightest caveat to something that someone wrote, even if the meaning should be obvious to a reader from the context, someone else will take the time to point out that caveat.

(As someone who doesn't require absolute precision in all things) I find myself often wondering why. To feel smart? Argumentitiveness? A deep psychological need for precision?

I hate when people are like that, but I wasn't. I just added a little tidbit of information that most people wouldn't assume to be true. Some may find it interesting, others won't.

Thank you, that was insightful and a genuinely a good comment.

Fair enough - no offense intended. Have a nice day :)

There wasn't even a payload, since the definition of that word requires it to be valuable in some way. We can just call it a load, I guess.

Well, it is certainly valuable and payed for. I know because part of that money used to pay my bread;-)

Even if the money doesn't come from an external customer it's payed for. In addition to that, the fact that for the Ariane it is ultimately all tax money anyways makes the way it flows even less important.

It carried a load of hopes and dreams of future mars explorers. :)

Freeload?

Dead weight.

A very sophistically designed and expensive deadweight.

It wasn't a criticism. I just thought it is an interesting detail few people would be aware of

That load doesn't pay though, it's a dummy load. You are talking about mass, the article, if we allow a little more leeway to the term "payload" than the strictest monetary sense, was talking about purpose and the purpose was certainly not to get ballast to Hawaii.

That aside, I presume those frequency responses are not on the electromagnetic spectrum but about mechanical resonance? Was that a process to make the dummy better resemble whatever real payload it was supposed to represent or was that something that simply needs to be done for any load, dummy or not? An interesting little glimpse into what actual rocket science is like for us clueless software-heads.

Yes, mechanical vibrations was what I was talking about, but of course there are also requirements regarding the electromagnetic environment.

Every payload has to be matched to the spectrum of the carrier. For the MAQSATs is was just easier than usual, because of their simplicity. The Ariane 5 Users's manual is actually public[1] and you can look up the actual requirements in Chapter 3, if you are curious.

[1] https://www.arianespace.com/wp-content/uploads/2015/09/Arian...

Thanks for pointing this out. From the phrasing in the article, I assumed it flew indeed empty, just as an aircraft can and frequently does in fact fly without payload (and by that I mean without pax and cargo, whether or not someone paid for it or not).

Starship might not have a real payload at all because in theory it’s only payload is people inside it so it might just have a bunch of mass dummies distributed where they expect weight to be when they build the interior in the future

Thanks for your input. This is why I come here, to learn more about various industries.

Really, I do appreciate people like you who do not abstain from explain things.

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