Elon Musk Reddit AMA on BFR

[Craig_VG]

[mlindner]

Looks like the AMA is being a bit ruined by a user named __Rocket__. I've seen him a lot on /r/spacex and often makes bad leaps of logic in his posts and theorycrafts even far beyond what we do in this forum.

[Star One]

Looks like the AMA is being a bit ruined by a user named __Rocket__. I've seen him a lot on /r/spacex and often makes bad leaps of logic in his posts and theorycrafts even far beyond what we do in this forum.

That Space X Reddit in general has a bad rep from what I’ve read elsewhere on Reddit.

[livingjw]

This is an odd answer, three legs are more stable than four. I'll be back with links.

Edit: Can't find the link I was after (NASA study for lander legs, Mars Phoenix if I recall correctly) but basically three points define a plane so the lander won't rock. Where it is unlikely that four points on a rough surface form a plane, so it will wobble. Suspension can correct for this.

I would expect the legs to be self leveling.
John

[mlindner]

Looks like the AMA is being a bit ruined by a user named __Rocket__. I've seen him a lot on /r/spacex and often makes bad leaps of logic in his posts and theorycrafts even far beyond what we do in this forum.

That Space X Reddit in general has a bad rep from what I’ve read elsewhere on Reddit.

To be clear, he's not well liked there either. SpaceX subreddit is one of the few places on reddit with actual quality content. Quoting Chris.

Hold the r/space mods hostage until they move it to r/spacex

Or riot. 😉

[mlindner]

Looks like the AMA is being a bit ruined by a user named __Rocket__. I've seen him a lot on /r/spacex and often makes bad leaps of logic in his posts and theorycrafts even far beyond what we do in this forum.

__Rocket__ just posted questions that were in past days selected on SpaceX subreddit (when it wasn't sure which subreddit will host this QA session) - not sure if that was agreed ahead of time, or not, but in principle, I don't see a problem with reposting those questions in this QA.

Many people are saying that, but if you look, none of the questions he asked is actually from the SpaceX subreddit. At best some of the questions informed the question that he completely rewrote to his own question. So this is false. There was a prep thread, and several of the questions from it were asked by other people, but not him.

[yg1968]

Looks like the AMA is being a bit ruined by a user named __Rocket__. I've seen him a lot on /r/spacex and often makes bad leaps of logic in his posts and theorycrafts even far beyond what we do in this forum.

__Rocket__ just posted questions that were in past days selected on SpaceX subreddit (when it wasn't sure which subreddit will host this QA session)

He said that they were his own questions:

https://www.reddit.com/r/space/comments/76e79c/i_am_elon_musk_ask_me_anything_about_bfr/dodcpgk/?context=3

[mlindner]

AMA is over.

Thanks for tuning in to the AMA. Great questions nk!!

[Michael Baylor]

That was nearly three hours of Elon's time. Very generous of him considering how busy he is.

[Chris Bergin]

Looks like the AMA is being a bit ruined by a user named __Rocket__. I've seen him a lot on /r/spacex and often makes bad leaps of logic in his posts and theorycrafts even far beyond what we do in this forum.

That Space X Reddit in general has a bad rep from what I’ve read elsewhere on Reddit.

To be clear, he's not well liked there either. SpaceX subreddit is one of the few places on reddit with actual quality content. Quoting Chris.

Hold the r/space mods hostage until they move it to r/spacex

Or riot. 😉

I don't know about Reddit politics, per Star One's reference to what parts of Reddit think of other parts of Reddit, but the SpaceX Reddit is a *VASTLY* improved sub. It should have been on there.

[tvg98]

Looks like the AMA is being a bit ruined by a user named __Rocket__. I've seen him a lot on /r/spacex and often makes bad leaps of logic in his posts and theorycrafts even far beyond what we do in this forum.

That Space X Reddit in general has a bad rep from what I’ve read elsewhere on Reddit.

To be clear, he's not well liked there either. SpaceX subreddit is one of the few places on reddit with actual quality content. Quoting Chris.

Hold the r/space mods hostage until they move it to r/spacex

Or riot. 😉

I don't know about Reddit politics, per Star One's reference to what parts of Reddit think of other parts of Reddit, but the SpaceX Reddit is a *VASTLY* improved sub. It should have been on there.

Agreed. The mods over there do a good job and I'm also not sure why Elon didn't do the AMA there. 

[Ronsmytheiii]

Really wish Elon would do another interview with NSF (NSF interviewed him back in the Falcon 1 days in 2006, has to mean something!)

https://www.nasaspaceflight.com/2006/07/elon-muskspacex-interview-part-1/

Edit: With NSF excellent community and moderators, preselecting forum questions for Elon to answer would be much more efficient and effective than any AMA.....

[Michael Baylor]

Really disappointed that we didn't learn if they plan to use 39A for BFR. 

That was my question, of course it ended up way down at the bottom under the stack of __Rockot__'s questions.

Unbelievable that they allowed unlimited questions per person.

[Geron]

Thank you Elon for doing the AMA.

My favorite Q and A with Elon was when Helodriver got him nailed down at the SpaceX Dragon 2 revealing. The question quality was superb, the answers flowed freely. It was amazing. 3 Cheers for Helodriver!!

[Geron]

Really wish Elon would do another interview with NSF (NSF interviewed him back in the Falcon 1 days in 2006, has to mean something!)

https://www.nasaspaceflight.com/2006/07/elon-muskspacex-interview-part-1/

Edit: With NSF excellent community and moderators, preselecting forum questions for Elon to answer would be much more efficient and effective than any AMA.....

I think this is why Elon did it in Space and not SpaceX. Last time the mods removed any questions not asked by mods/voted up. I can understand from a mod perspective its nice if only moderators ask questions, but it kind of goes against the spirit of an AMA if no one actually there can participate in the AMA, if its all just arranged ahead of time.

[Mongo62]

Looks like the AMA is being a bit ruined by a user named __Rocket__. I've seen him a lot on /r/spacex and often makes bad leaps of logic in his posts and theorycrafts even far beyond what we do in this forum.

That Space X Reddit in general has a bad rep from what I’ve read elsewhere on Reddit.

To be clear, he's not well liked there either. SpaceX subreddit is one of the few places on reddit with actual quality content. Quoting Chris.

Hold the r/space mods hostage until they move it to r/spacex

Or riot. 😉

I don't know about Reddit politics, per Star One's reference to what parts of Reddit think of other parts of Reddit, but the SpaceX Reddit is a *VASTLY* improved sub. It should have been on there.

Agreed. The r/spacex subreddit is surprisingly high quality -- not up to NSF levels, of course, but still good -- but the r/space subreddit is considerably lower in quality. I seem to recall that an earlier AMA by another high-level SpaceX employee ended up being held on r/AMA, and it was basically ruined by the low-quality questions asked. The r/spacex people were furious, given that they had thought the AMA would be held on their subreddit, and had assembled a list of questions that had been high quality, but were left unasked by the r/AMA people. This time was not as bad, but the r/spacex questions would have been better (including many great questions by helodriver).

[tvg98]

Really disappointed that we didn't learn if they plan to use 39A for BFR. 

That was my question, of course it ended up way down at the bottom under the stack of __Rockot__'s questions.

Unbelievable that they allowed unlimited questions per person.

I limited myself to about three questions cause I felt anything beyond that would be equivalent to spamming. Oh well. At least a few good questions got answered 

[RedLineTrain]

I don't think the Reddit format is conducive to getting a lot of high quality questions asked in a reasonable amount of time.

[Lars-J]

I don't think the Reddit format is conducive to getting a lot of high quality questions asked in a reasonable amount of time.

Perhaps, but we still learned a lot. An imperfect format, but beggars can’t be choosers, as the saying goes.

[Aussie_Space_Nut]

This is an odd answer, three legs are more stable than four. I'll be back with links.

Edit: Can't find the link I was after (NASA study for lander legs, Mars Phoenix if I recall correctly) but basically three points define a plane so the lander won't rock. Where it is unlikely that four points on a rough surface form a plane, so it will wobble. Suspension can correct for this.

It is simply geometry.

If you draw 3 points evenly spaced around a circle and then connect each point with a line it creates a triangle.

If you draw 4 points evenly spaced around a circle and then connect each point with a line it creates a square.

Now measure the distance from any side to the centre.

You will now see why 4 legs are preferred. The 3 legged version side distance to centre is much smaller than the 4 legged version.

In other words, the 3 legged version may not 'rock' but it will tip over way easier than the 4 legged version.