SpaceX FH : Falcon Heavy Demo : Feb 6, 2018 : Discussion Thread 2

[Semmel]

Caught this during Gwynne Shotwell's TED presentation, FH being lifted up before being placed on the TEL.

The most powerful active rocket in the world AND a recovered first stage in one photo?
How can that not be a favorite?
Thanks for snagging it!

Well.. three recovered first stages really..

[oiorionsbelt]

Caught this during Gwynne Shotwell's TED presentation, FH being lifted up before being placed on the TEL.

The most powerful active rocket in the world AND a recovered first stage in one photo?
How can that not be a favorite?
Thanks for snagging it!

Well.. three recovered first stages really..

The current most powerful rocket is made from reused parts.

[lamid]

aphelion Tesla Roadster with Starman 9 nov 2018 12:33 UTC
248 892 569 km

source
Horizons, Tesla Roadster (spacecraft) 143205 (solution #10)

[speedevil]

aphelion Tesla Roadster with Starman 9 nov 2018 12:33 UTC
248 892 569 km

source
Horizons, Tesla Roadster (spacecraft) 143205 (solution #10)

For the same source, this gives the velocity on 2018-Feb-11 19:00  at 0.01006AU from earth (around edge of hill sphere) as  3.50463km/s.
Shortly earlier, a few minutes before 2018-Feb-08 04:00  it crossed the distance of the moon, at  0.002580AU traveling    3.736km/s.

[lamid]

Just a little.
In the picture of Tesla Roadster Spaceman it looks like the aphelion is a lot behind the orbit of Mars.
Only the Mars orbit has an eccentricity of 0.0934, that is, 1.382x1.666 au.
If Tesla Roadster Spaceman flew to the opposite side, it would fly tight,
99.86% to Mars aphelion
would miss 337000 km, 0.135%.

   Mars   SpaceX Roadster   
ecentricity   0.0934   0.256   
Inclination   1.850   1.077   °
Omega   49.558   317.1   °
Aphelion   1.666   1.663745   au
Aphelion   249,230,052   248,892,746 km
Perihelion   1.382   0.986   au

[oiorionsbelt]

While rewatching the FH demo launch video I noticed something for the first time.
 @ 3:46 in the video the commentator describes the FH 2nd stage this way.
 

the 2nd stage is exactly the same as any other F9 flight, except we've added a bit more helium onto it this time.

Why do they need more He in the 2nd stage of FH as compared to F9?
 
Sorry if this has been answered but I have not see it referenced.

[Lars-J]

It could have something to do with long coast of that stage before the TMI burn.

[meekGee]

Or needing higher pressure.  Remember the pressure carries a bug chunk of the compressive load.

-----
ABCD: Always Be Counting Down

[LouScheffer]

It could have something to do with long coast of that stage before the TMI burn.

You would expect a long coast to need almost twice as much helium.  They heat the helium with the engines, so it takes less mass to fill the volume at the pressure they need.  So during boost, the tank is filled with hot helium.  During a long coast, the helium already in the tank will cool.  Say they inject it at 400 K (just a guess).  In the LOX tank, it will drop to about 100K, and hence provide only 1/4 the pressure after the long coast.  Since the tank is almost empty, it will take roughly 3/4 the original amount of hot helium to pressurize it again.  The fuel tank will not cool as much, so maybe need 1/2 the original helium more.

[kessdawg]

National Geographic documentary about Falcon Heavy demo flight.  Includes interesting behind the scenes discussions.  Even snippets of a discussion about frequency ranges to avoid damage to the vehicle during static fire.

https://www.nationalgeographic.com/tv/watch/12e413e68c538ba79a298f709efc1607/

[atsf90east]

National Geographic documentary about Falcon Heavy demo flight.  Includes interesting behind the scenes discussions.  Even snippets of a discussion about frequency ranges to avoid damage to the vehicle during static fire.

https://www.nationalgeographic.com/tv/watch/12e413e68c538ba79a298f709efc1607/

Watching this launch again with all of the behind the scenes looks made it just as exciting and emotional as watching it live earlier this year. 

[jak Kennedy]

National Geographic documentary about Falcon Heavy demo flight.  Includes interesting behind the scenes discussions.  Even snippets of a discussion about frequency ranges to avoid damage to the vehicle during static fire.

https://www.nationalgeographic.com/tv/watch/12e413e68c538ba79a298f709efc1607/

Damn, “Geograpic restriction” when I try to play it, WTFalcon. Not so “National”!

[russianhalo117]

National Geographic documentary about Falcon Heavy demo flight.  Includes interesting behind the scenes discussions.  Even snippets of a discussion about frequency ranges to avoid damage to the vehicle during static fire.

https://www.nationalgeographic.com/tv/watch/12e413e68c538ba79a298f709efc1607/

Damn, “Geograpic restriction” when I try to play it, WTFalcon. Not so “National”!

use a VPN in the US and will not be an issue.

[matthewkantar]

Was that new Falcon 1 blooper reel material I saw?

[ZachS09]

National Geographic documentary about Falcon Heavy demo flight.  Includes interesting behind the scenes discussions.  Even snippets of a discussion about frequency ranges to avoid damage to the vehicle during static fire.

https://www.nationalgeographic.com/tv/watch/12e413e68c538ba79a298f709efc1607/

Watching this launch again with all of the behind the scenes looks made it just as exciting and emotional as watching it live earlier this year. 

I saw it as well, and while I was pleased to relive the side core landings at Cape Canaveral, I'm surprised that they didn't cover the center core landing failure near the drone ship.

[CorvusCorax]

I posted this link in the discussion thread a month ago.  It is the same video, although region locked for USA I believe.

https://www.nationalgeographic.com/tv/watch/12e413e68c538ba79a298f709efc1607/

I believe this is a version of the same video which isn't region locked. Looks like a re-upload of a version that was broadcasted on TV somewhere in the world. Guess there's no way to tell if and how long it'll stay up unless you're a international copyright law expert

[catdlr]

I posted this link in the discussion thread a month ago.  It is the same video, although region locked for USA I believe.

https://www.nationalgeographic.com/tv/watch/12e413e68c538ba79a298f709efc1607/

I believe this is a version of the same video which isn't region locked. Looks like a re-upload of a version that was broadcasted on TV somewhere in the world. Guess there's no way to tell if and how long it'll stay up unless you're a international copyright law expert

Not available anymore.....

[theinternetftw]

I posted this in a different thread, but since the same discussion is going on here:

This is a US amazon link to buy the show for $3: https://www.amazon.com/Mars-Inside-SpaceX/dp/B07KFZPD1N

It might be on your region's amazon, too, if you search for the title there.

[Norm38]

Can't quote from locked threads, but in the update thread FST posted:

twitter.com/flcnhvy/status/1163015383663677440
Btw, any chance SpaceX could launch a small spacecraft that could catch up to Starman & take some pics? Would be super interesting to see what Roadster & its passenger look like these days

https://twitter.com/elonmusk/status/1163015575699779584

In a few years

Last week I happened to be talking to the CEO of a motorcycle company.  We were in his showroom where he had the 1st cycle off the line for each model they'd built.  He pointed to one and talked about how he had sold it, regretted it so much that he tracked it down and paid 4 times what it was worth to get it back.

We joked that we wouldn't be surprised if one day Elon sent a starship after his Roadster to get it back.

[Slothman]

Roadster and starman have now completed their first lap around the sun