JCRM

general recent conversations

Discussion on answer by jdunlop: What…

Imported from a comment discussion on worldbuilding.stackexcha...

JCRM

Feb 1, 2021 17:22

And American banks are immortal, soulless entities bent on taking the money of innocents and consuming everything in an unending, unslaking lust for wealth.

The Pod Bay

General discussion for space.stackexchange.com. Check our sche...

JCRM

Feb 1, 2021 12:28

Has it got FAA approval now/

JCRM

May 10, 2020 03:04

Here's a nice groundtrack for you @uhoh yellowdragonblogdotcom.files.wordpress.com/2019/01/…

JCRM

Mar 18, 2020 15:00

the second stage only has one engine (unless they've iterated)

JCRM

Mar 18, 2020 14:55

that's a shame. finding out what went wrong with the engine would have been helpful

JCRM

Dec 12, 2019 10:16

@OrganicMarble thanks

JCRM

Dec 9, 2019 14:46

Is there a handy-dandy set of equations I can plug numbers into to get a throat size for a given set of propellants, mix, flow rate and chamber pressure?

JCRM

Oct 9, 2019 21:53

I donated to the original fund-raiser to buy the source code for blender from NaN....

JCRM

Sep 20, 2019 14:28

multiple small engines not the thing?

JCRM

Sep 20, 2019 14:06

when they copy the N1 design, but improve it so it works @geoffc?

JCRM

Sep 20, 2019 14:06

they will have been going fairly close to it in any case.

JCRM

Sep 20, 2019 14:01

in reality you would need more than 11.2 km/s of delta-v to reach escape from the surface of the Earth, because of atmospheric losses, but escape velocity from the surface oft he Earth is 11.2 Km/s

JCRM

Sep 20, 2019 14:00

it' the speed you need to be going - it's irrelevenat of atmosphere.

JCRM

Sep 20, 2019 13:59

No, that's not what escape velocity means

JCRM

Sep 20, 2019 13:58

Escape veloicity id about 11.0 km/s at a low Earth orbit of 200 km put tli was at about 345km

JCRM

Sep 20, 2019 13:52

what is escape velocity at that altitude?

Discussion on question by Shana Jacks…

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JCRM

Sep 21, 2020 12:17

Either I'm completely missing what the question is, or there are an awful lot of words here that have nothing to do with the question.

Discussion on answer by Luc: Why use …

Imported from a comment discussion on security.stackexchange.c...

JCRM

Sep 21, 2020 11:54

What's your point @MechMK1? that it's harder, and therefore suddenly impossible? At exactly what point does it stop being hard, and start being impossible?

JCRM

Sep 21, 2020 11:54

quite often sombodies does, thanks for proving my point @MechMK1

JCRM

Sep 21, 2020 11:54

it would be entirely unexpected, yet it could be the first one @MechMK1

JCRM

Sep 21, 2020 11:54

@ConorMancone, no, you misunderstand probability.

JCRM

Sep 21, 2020 11:54

And yet they still might guess it on the first try @ConorMancone It seems you're making the mistake of thinking all combinations have to be tried before a password is brute forced, or that there is an "average" time taken. That's simply not true. I work on the basis that such a password "can't" be guessed, but if it were I'd be exceptionaly surprised, but I wouldn't claim it was impossible.

JCRM

Sep 21, 2020 11:54

I completely disagree @Luc. Yes, it drastically reduces the risk (which is why I use long and complex passwords to the point an attacker is more likely to hit a collision than my password) but that doesn't make my passowrd safe. Someone wins the lottery most weeks after all

JCRM

Sep 21, 2020 11:54

while a random string of 128 bits may vaporise the oceans @Luc, it might also be guessed first time. A strong password (and I use them myself, choosing more bits of entropy than the hash that stores it) only reduces the risk, not removes it.

Discussion on answer by Christopher J…

Imported from a comment discussion on space.stackexchange.com/...

JCRM

Aug 18, 2020 11:32

JBIS volume 73 No.4 (April 2020) has a paper "Conceptual Design of a Crewed Platform in the Venusian Atmosphere" -- Unfortunately I've not yet read it as I'm horribly behind.

Discussion on question by Erkin Alp G…

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JCRM

Jul 29, 2020 14:26

If you put your object in orbit around the sun at 50 K au, it'll be equidistant past four decimal places...

Discussion on question by Niobium_Sag…

Imported from a comment discussion on worldbuilding.stackexcha...

JCRM

Jul 27, 2020 12:28

except in the "Operation Doomsday" storyline where the bad guys switched the lawgivers to destruct in (and with) the hands of the Judges @Ewan

Discussion on answer by JCRM: ICBM an…

Imported from a comment discussion on space.meta.stackexchange...

JCRM

May 25, 2020 12:13

Indeed, @uhoh, complacency isn't the solution.

JCRM

May 25, 2020 12:13

and there's only one user that aggressively complains about it @uhoh youtu.be/pKRj7QCIXnY?t=30

JCRM

May 25, 2020 12:13

No, the main meta @uhoh -- you seem to believe the feature doesn't work as designed, so take it there and see if you can't get it fixed.

JCRM

May 25, 2020 12:13

Then take it to Meta, and qualify it "forlow usage sites" @uhoh

JCRM

May 25, 2020 12:13

Quick closing is as designed @uhoh, to prevent people from posting answers to questions. You could take a suggestion to the main Meta, that closes are not allowed for the first 24 hours, to give people a chance to answer a question.

Discussion on answer by Starfish Prim…

Imported from a comment discussion on space.stackexchange.com/...

JCRM

Jan 25, 2020 17:56

Still not addressing the point

JCRM

Jan 25, 2020 17:56

Yep, not addressing the point.

JCRM

Jan 25, 2020 17:56

still not addressing the point

JCRM

Jan 25, 2020 17:56

Your answer is factually incorrect, as the RB2000 is not available. But yes, I downvoted you because anyone who resorts to namecalling to defend their answer clearly knows they are on shaky ground

JCRM

Jan 25, 2020 17:56

Still not addressing the points, are you.

JCRM

Jan 25, 2020 17:56

comments are places to discuss how answers can be improved. You categorically state that it will not work, but seemed reluctant to say why. of the reasons you've given lubricant is the most likely to cause issues, but without knowing what lubricant is in use it would be difficult to say whether that is a real issue. I am particularly intrigued in why you think a thruster needs to be redesigned (it would benefit from it, undoubtedly, but would work well enough)

JCRM

Jan 25, 2020 17:56

If it's obvious you should be able to say why it isn't able to work. As you appear unable to say why it isn't able to work then it appears it isn't obvious

JCRM

Jan 25, 2020 17:56

you seem to think a vacuum is somehow magic, and a device that operates in atmosphere will necessarily not operate in vacuum. So yes, someone has big problems.

JCRM

Jan 25, 2020 17:56

I see you still can't say it why wont work. Namecalling may make you feel better, but isn't really encouraged here.

JCRM

Jan 25, 2020 17:56

No, it's not clear. equipment built for use in a temperate atmosphere may or may not work in a vacuum

JCRM

Jan 25, 2020 17:56

such as? pressure fed peroxide thrusters have been used in a vacuum (I'm not saying it would work, just that the reasons for it not doing so are not obvious)

JCRM

Jan 25, 2020 17:56

why wouldn't it work in a vacuum?

Discussion on question by Wyglaf: Cou…

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JCRM

Jan 8, 2020 14:13

@slebetman just about all trajectories work on the basis of using the least amount of energy to meet their mission requirements

JCRM

Jan 8, 2020 14:13

There are, however, questions that do not show any research effort @DiegoSánchez - space is not about going high, it's about going fast and "stopping" isn't going fast.

Discussion on question by uhoh: What …

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JCRM

Sep 30, 2019 14:43

The key is to ask good questions. If it's not a good question I'll downvote it. If 5 minutes research means you've answered the question it's not a good question - it's a conversation starter, When you ask good questions I upvote them.

JCRM

Sep 30, 2019 14:43

If you're going to ask a question you intend to answer, answer it.

JCRM

Sep 30, 2019 14:43

That question showed more research than this one, and I'm happy with my downvote on the question there, and the upvotes on the answers.

JCRM

Sep 30, 2019 14:43

lack of research @uhoh. Gyro failure, plan to jury rig star-tracking, return to service hoped for January