Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

OpenRocket

openrocket.info

Post reply on HN
Print view View original

91–100 of 128 posts

Re: OpenRocket

#91

Post by jaredhansen »

sibovg wrote: post #80
_moof wrote: post #63

Software developers: I am begging you to put representative screenshots on the home page. This has become a real widespread problem. I know you want to tell us all about the amazing (sincerely!) stuff under the hood, but to users, the interface is the product.

Thanks for the suggestion, I've added it to our home page.

This is one of my favorite things about HN.

I'm into rockets, and clicked the link earlier today. I shared the suggestor's view, but didn't bother to post. I came back now, saw the comment thread had updated significantly, noticed that OP had addressed the suggestion, clicked again -- and noticed, hey wow, there are cool screenshots now, these are a lot more interesting, this is better than I thought!

Re: OpenRocket

#92

Post by peterus »

Our university rocket team uses openrocket extensively for doing fast design iterations early in the design phase. We have also used Rasaero II which is meant to be more rigorous above transonic speeds. We have an Ansys CFD too but that requires significantly more time to set up. We still use openrocket on launch days to do pre launch sims, but we override some of the parameters based on the more rigorous simulations.

Re: OpenRocket

#93

Post by akie »

chasd00 wrote: post #38
aliljet wrote: post #4

I wonder how crazy the scale here can get. How far can I go? The bps.space guy is heading into space. Can the community hit the moon? Literally.

Amateurs have reached the karman line, orbit is still pretty much out of reach. The people who get close to the karman line use two stage passive stabilized airframes and solid fuel motors. The airframes are basically works of art and it takes a lot of luck because of passive stabilization and Mach 3+ speeds. Many pictures of these rockets have their paint and leading fin edges burned off when they're recovered. Prop…

> 293k feet

89 kilometers

Re: OpenRocket

#94

Post by lovlar »

p-o wrote: post #36
lovlar wrote: post #22

Earlier quoted context omitted.

Space Concordia, a Canadian university space-oriented student group, which is sort of amateur-level given that it’s driven by students and donations, attempted to reach space not that long ago with a liquid fueled single staged rocket. Here is a video of the launch https://www.youtube.com/live/610YciEs8qg?t=4594&is=aAWo8Y7vi...

Thank you so much for sharing this video, it's just amazing to see a bunch of young amateurs getting so excited about things that would have been virtually inaccessible 20 years ago.

It’s beautiful to see. They have put in such extreme amounts of hard work to get that thing into the air. Designing a robust affordable liquid propelled rocket from scratch is hard. There are so many design decisions, complex simulations, manufacturing difficulties, and tests for every little part of that 11+ m rocket. Accounting for extreme forces, heat variations, vibrations, wind, atmosphere, liquid sloshing, rotation, etc during ascent and descent. It’s not only mechanical/aviation engineering but also software, electrical, sourcing donations, documenting everything in forms of design and risk assessment reports etc etc.

You also have to try to account for every little possible failure mode before launching which is why rockets seldom succeed on the first attempt.

And then dealing with authorities to create new launch sites and permits which probably hasn’t been done in decades in Canada.

Re: OpenRocket

#95

Post by alexpopow »

What about misuse for weapon development? Does the project not massively cut R&D costs (hence lowering the entry hurdle) for potentially malicious actors on the planet?

Re: OpenRocket

#96

Post by tjomk »

alexpopow wrote: post #95

What about misuse for weapon development? Does the project not massively cut R&D costs (hence lowering the entry hurdle) for potentially malicious actors on the planet?

Anything can be misused by the bad actor. Knives, guns. With AI things are getting easier to develop bio-chemical weapons. There was recently a video of a YouTuber creating a portable rocket launcher in <100 USD.

Re: OpenRocket

#97

Post by SiempreViernes »

alexpopow wrote: post #95

What about misuse for weapon development? Does the project not massively cut R&D costs (hence lowering the entry hurdle) for potentially malicious actors on the planet?

No, actually building the things are most of the work and this program isn't intended for weapons development so you will just save a few tests at most, so it helps marginally.

Re: OpenRocket

#98

Post by vrganj »

alexpopow wrote: post #95

What about misuse for weapon development? Does the project not massively cut R&D costs (hence lowering the entry hurdle) for potentially malicious actors on the planet?

Sure, but it's not like the actors currently able to pass the entry hurdle are not malicious.

Maybe we (or somebody in, say Ukraine or Rojava) will need this to defend themselves from the actors having access to missiles right now.

Re: OpenRocket

#99

Post by lm28469 »

stackedinserter wrote: post #77
lm28469 wrote: post #61

Earlier quoted context omitted.

I highly recommend you to open a few foreign newspapers and lurk in foreign forums, groups, &c. you're either misinformed or blind > don't even have boots on ground Anyone with half a brain cell knows this would be the biggest strategic, tactical and political blunder of the century > What do they hold, exactly? What they hold exactly is: - middle eastern countries who've been greasing Washington's palms for influenc…

No, _I_ highly recommend you to open a few foreign newspapers and lurk in foreign (to whom?) forums, groups, &c. you're either misinformed or blind, based on these bullet points. Stop reading r/iran or CNN or whatever bs you pump into your brain. This war sucks but it's very far from "Iran is holding".

They're getting absolutely wrecked, but it doesn't mean it's good for the US. This is basically warfare 101, you can have a undisputed tactical victory and a complete strategic failure at the exact same time, in that case the tactical victory is bombing a country which is like 20 years behind in technology and spend 10% as much as the US on defense (wow good job!), the strategical blunder is that it did not achieve anything good for the short nor long term for anyone involved, if anything it helped Russia and China which kept being mentioned as the US arch enemies

Iranians don't like their current government much but they don't particularly like getting fucked up by Israel and the US either, especially when you kill 170 kids on day 1 and then lie about it on live tv. How did it go in Syria, Libya, Afghanistan, Iraq? Yeah, not so good. It's always about "preventing wars" and "bringing freedom", but it ends up being "bringing wars" and "consolidating authoritarian regimes"

Re: OpenRocket

#100

Post by hermitcrab »

plugger wrote: post #78
hermitcrab wrote: post #32

We used OpenRocket for designing our rocket for UK youth rocketry competition UKROC[1]. It is great for getting a 'spherical cow in a vaccuum' idea of likely altitude with different motors, centre of pressure, center of mass etc. But it obviously doesn't take account of detailed aerodynamics etc and we found the maximum altitude estimates were about 15% too high. But it was still very useful. [1] UKROC is an amazing…

> we found the maximum altitude estimates were about 15% too high. this often happens when the wrong rocket finish is selected. Everyone chooses a polished finish when in actuality they've just sprayed the thing with paint. Skin drag is real.

Possibly. I don't remember the details. Also, it isn't a full aerodynamic simulation. Plus the hobby motors are not manufactured to NASA standards. So you can't expect it to be too accurate.
Post reply on HN