
Elon Musk, ask me anything about BFR - weeber
https://www.reddit.com/r/space/comments/76e79c/i_am_elon_musk_ask_me_anything_about_bfr/
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jv22222
Very cool that in the same IAmA Musk answers deeply complex questions as chief
rocket engineer and, then, answering a side question offers up a potential low
level architecture for how to make an internet feed work from earth to mars.

It would be interesting to know what the max capacity is for the human brain
to store these kind of multi disciplinary low level details.

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loeg
The internet response is very vague and not particularly insightful to anyone
who has worked on any internet protocol. It's not evidence he's an
interdisciplinary mastermind. (It's not evidence he _isn 't_, either.)

> Elon: But, yes, it would make sense to strip the headers out and do a UDP-
> style feed with extreme compression and a CRC check to confirm the packet is
> good, then do a batch resend of the CRC-failed packets. Something like that.
> Earth to Mars is over 22 light-minutes at max distance.

~~~
justicezyx
There is a thing called delay tolerant networking, which is specialized in
building interplanetary communication. Vint Cerf is one of the people who
initiated that research. Though it fades away quickly now no one cares much
about this DTN thing.

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greglindahl
Infinipath and at least the first generation of Intel Omni-Path does delay-
tolerant networking inside the datacenter. It's not rocket science.

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justicezyx
I am not sure these are the same thing I am talking about. These are for data
centers?

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greglindahl
I was giving additional examples of the same concept (tolerating long delays)
in a different domain (inside a datacenter). You are correct that I was not
referring to Vint Cerf's work.

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Animats
From Twitter: (2017) "elonmusk: Falcon Heavy maiden launch this November".

Is that still on? Or are they announcing the next model before shipping the
current model?

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jessriedel
/r/spaceX lists it as "December", and they cite some SpaceX report (more
recent than Musk's July tweet) saying that Falcon Heavy is targeted for "no
earlier than the end of 2017".

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Animats
It was originally scheduled for late 2013. Sigh.

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nickik
While that it is true it hides what is going on. Falcon Heavy was delayed
because they managed to massively improve F9 and many of the Falcon Heavy
contracts are actually now flown on the F9. The last couple flights that did
not land were all FH contracts.

So the Falcon Heavy we are gone get now is way, way more powerful and all 3
boosters will land and be reusable. The side boosters are actually reused F9
boosters.

So its really not the same as 2013.

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politician
Is it possible to generate propellant for the Mars transit from Lunar ISRU?
Are the right source materials available there?

~~~
simonh
I’m afraid not. The SpaceX ISRU plan is to extract water from ice and
electrolytically split it into hydrogen and oxygen. The hydrogen is combined
with CO2 from the Martian atmosphere to produce Methane fuel, while the oxygen
is chilled for use in the rockets as well.

On the moon you have water (ice), but no carbon dioxide. You can split the
water into hydrogen and oxygen to use as fuel, but the BFR requires methane
fuel.

Why use methane? It has a lower ISP than hydrogen but higher energy density,
to simplify somewhat, and is easier (possible even) to store on long flights.

~~~
nickik
Methane also avoids the hydrogen embitterment problems that long term use of
hydrogen would cause your engine.

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nigrioid
Interesting timing... it coincides nicely with the bad press about the
layoffs.

~~~
jaimex2
Thats Tesla, not SpaceX?

~~~
oneweekwonder
I believe you are right. But that is what you going to get from the general
public if you use the same face to drive/promote a enterprise/brand.

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Overtonwindow
Ol' Musky

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m3kw9
The potential of what a human brain is able to achieve..

~~~
m3kw9
Don’t be jealous guys

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na85
Well, if the moderators are enforcing "on-topic" questions in an __Ask Me
_Anything_ __, then it seems reddit 's transformation into a marketing and
brand promotion platform seems complete.

~~~
cromwellian
I don't feel that at all. If Musk is having an AMA on a topic, like the BFR, I
feel that is better than an open ended AMA, since the signal to noise ratio
will be better and I can go there to read about exactly the topic I'm
interested in. I'm not particularly interested, for example, in questions
about Musk's divorce or dating habits.

Perhaps they need to change the name of these on-topic AMAs, but Musk isn't
selling BFR rockets to consumers, generally geeks are interested in SpaceX
from a hobby interest point of view, and so the idea of marketing and brand
promotion seems a little divorced from reality.

SpaceX isn't going to increase their launch contracts by entertaining AMA
questions. My guess is, Musk likes engaging people and talking about the cool
shit he's working on.

~~~
dogma1138
I think this has less to do about signal to noise and more to do with crowd
control.

BFR as a project is out of touch with the current affairs at Tesla and SpaceX
which means that there is basically no negative sentiment that can be
generated from asking questions about the topic or their answers.

A general AMA however will likely touch about things like the failure to
support Autopilot 2.0 hardware on schedule, Model 3 delivery delays, Falcon
Heavy delays, and those are just the light stuff.

One does have to wonder why is there an AMA on the only detached and
"universally rosie" subject just as Tesla announced layoffs.

While I don't think it was planned, I do have a strong suspicion that the AMA
was intentionally focused and the mods were asked to enforce question rules
(and looks like more strictly than usual even based on previous Musk AMAs).

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mikeash
How does it make the slightest bit of sense that an AMA on a space forum would
be intended as a deflection from firings at a totally different company in a
different field? A bunch of space enthusiasts asking about Mars isn’t going to
change public perception of Tesla in the slightest. Not everything is a vast
PR conspiracy.

You say you have a strong suspicion that it was intentionally focused. Did the
fact that it says “about BFR” in the title give it away? Of course it’s
focused.

