SpaceX And/Or Rocketry In General

AgentB
AgentB
Joined: 17 Mar 12
Posts: 915
Credit: 513211304
RAC: 0

Over at redit therre is quite

Over at redit therre is quite a discussion on COPVs. 

The helium in the COPVs is under a lot of pressure - possibly 5000psi or more, but still a gas.   Its primary function is to pressurize the tanks in flight.  I seem to recall reading the cost of the helium is more than the (cheap) LOX!

Putting the COPVs in the LOX (i don't know if this is done elsewhere) has the advantage on being able get more gas in the bottle, and plumbing simplicity but one challenge is a warm carbon fibre wrapped aluminium bottle being dunked in a LOX bath during fuelling must lead to some thermal stresses.  I'm sure fuelling / de-fuelling these things has a very time critical what goes in at what rate.

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6588
Credit: 317360831
RAC: 366383

Here's a shot of the recent

Here's a shot of the recent Raptor testing :

raptor.jpg

Which is designed for vacuum work.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

Anonymous

Mike Hewson wrote:Here's a

Mike Hewson wrote:

Here's a shot of the recent Raptor testing :

raptor.jpg

Which is designed for vacuum work.

Cheers, Mike.

Dyson, be afraid.  Be very afraid.

Alex
Alex
Joined: 1 Mar 05
Posts: 451
Credit: 507128262
RAC: 80408

Rosetta is about to make its

Rosetta is about to make its final crash into a comet - watch it happen LIVE

http://www.sciencealert.com/rosetta-is-about-to-make-its-final-crash-into-a-comet-watch-it-happen-live

 

David S
David S
Joined: 6 Dec 05
Posts: 2473
Credit: 22936222
RAC: 0

Elon announces plan to move

Elon announces plan to move 100 people at a time to Mars, likens it to building the Union Pacific Railroad.

In response, Union Pacific calls dibs on the first Martian railway.

David

Miserable old git
Patiently waiting for the asteroid with my name on it.

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6588
Credit: 317360831
RAC: 366383

If only one out of three

If only one out of three things that Elon envisages come to fruition then he will still be epic IMHO. It's a strange thing happening though. Cynicism is so deep now .... I think Elon has hinted a few times that he reckons there will be a de-population happening here on Earth, soon ? If so I tend to agree. Too many rabbits in the warren as it were. That won't sustain especially for a species that has competition as a baseline biological urge. So the idea is to get off the planet while there are the cooperative social structures available to achieve that.

{ Liquid cryo tanks are/is stirred in order to give correct quantity readings from gauges. Not applicable here. } 

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

David S
David S
Joined: 6 Dec 05
Posts: 2473
Credit: 22936222
RAC: 0

Happy Sputnik day. We've

Happy Sputnik day. We've really come a long way in 59 years.

David

Miserable old git
Patiently waiting for the asteroid with my name on it.

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6588
Credit: 317360831
RAC: 366383

I am so sorry AgentB I was

I am so sorry AgentB I was replying to your comment and deleted it instead ! Epic Fail .... ;-(

You were saying how Elon acknowledged that if he didn't succeed then at least he would assist subsequent generations to.
edit: and some Raptor engine info.  https://www.nasaspaceflight.com/2016/10/its-propulsion-evolution-raptor-engine/ 

 

Elon said after the recent successful test fire that he fully expected it to blow up. As the NASA article indicates the Raptor follows from the superior design that the USSR ran with for a while, but it is a bitch to debug. So if you think the Merlin's are good then these are [awesome]! :-)

Very Stupid Mike.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

AgentB
AgentB
Joined: 17 Mar 12
Posts: 915
Credit: 513211304
RAC: 0

Mike Hewson wrote:I am so

Mike Hewson wrote:
I am so sorry AgentB I was replying to your comment and deleted it instead ! Epic Fail .... ;-(

 

I'm not entirely sure i remember ... I actually just returned to pick up and watch the  Ariane - but it has been delayed 24 hours. http://www.arianespace.com/mission/ariane-flight-va231/

Lots of interesting things on the Raptor you can see it designed to be simple in many ways - only two liquids reservoirs needed, and a different method of restarting. 

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6588
Credit: 317360831
RAC: 366383

AgentB wrote:Mike Hewson

AgentB wrote:

Mike Hewson wrote:
I am so sorry AgentB I was replying to your comment and deleted it instead ! Epic Fail .... ;-(
 

I'm not entirely sure i remember ... I actually just returned to pick up and watch the  Ariane - but it has been delayed 24 hours. http://www.arianespace.com/mission/ariane-flight-va231/ 

You are too kind .... :-)

Quote:
Lots of interesting things on the Raptor you can see it designed to be simple in many ways - only two liquids reservoirs needed, and a different method of restarting.

What I find the biggest boggle here is the aim to have it throttle down to 25%, in such a highly non-linear design ( the mixing problem ). Anyway the fact that it didn't blow up is a testament to SpaceX's design skills and the simulations especially.

I've been researching the Atlas program ( ICBM development from the late 50's ) and note how sensitive progress can be to apparent minutiae. Thus, for instance, inertial guidance is so easy to describe and yet there are more than a few traps for new players that lead to flaming balls of debris. This reminds me of a comment made by a auto race team manager who said he could easily spend half the budget on trials that yields the lifetime of components ie. you must know the fail points of each and every piece of the gadget.

{ One professional driver notably complained about poor testing and was told they'd be happy to do more, but only if his fee wasn't so high. He shut and drove the car as is after that .... }

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.