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"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 aerospa
by weinzierl 3y ago
"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 http://astronautix.com/m/maqsat.html
- capableweb 3y agoI 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".
- donkeyd 3y agoThere 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.
- Zondartul 3y agoFreeload?
- weinzierl 3y agoWell, 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.
- justinclift 3y agoIt carried a load of hopes and dreams of future mars explorers. :)
- mft_ 3y agoIt 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?
- weinzierl 3y agoI 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.
- weinzierl 3y agoIt wasn't a criticism. I just thought it is an interesting detail few people would be aware of
- usrusr 3y agoThat 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.
- weinzierl 3y agoYes, 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/Ariane5_users_manual_Issue5_July2011.pdf https://www.arianespace.com/wp-content/uploads/2015/09/Arian...
- FabHK 3y agoThanks 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).
- spookie 3y agoThanks 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.
- Shawnj2 3y agoStarship 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