SpaceX Tuesday...

TOPIC CLOSED
TOPIC CLOSED
Author
Discussion

Beati Dogu

8,892 posts

139 months

Thursday 20th September 2018
quotequote all
Eric Mc said:
This pop star even sang about it -

https://www.youtube.com/watch?v=gWPYmSRP110

WARNING - this could be the creepiest video ever posted on PH.
And we're back to pedo cave divers again. wink

Or this...

https://www.youtube.com/watch?v=eyiVSBAq2Nw

Kccv23highliftcam

1,783 posts

75 months

Friday 21st September 2018
quotequote all
Eric Mc said:
Is this supposed to be the first circumlunar flight with this spacecraft? Would there be an unmanned test flight first - or a flight undertaken with a test crew only?

In aviation and space it has long been axiomatic that in the early stages of development of an aircraft or spacecraft, you only risk the lives of the professional people involved in the project i.e. the test pilots and test crew (if a crew is required).

As with a lot of Musk "propaganda", the nitty gritty detail is missing.
Perhaps the fact that it's a commercial operation Eric......

MartG

20,678 posts

204 months

Friday 21st September 2018
quotequote all

Caruso

7,436 posts

256 months

Friday 21st September 2018
quotequote all
MartG said:
https://spacenews.com/commercial-crew-providers-be...
"A key issue in the development of Boeing’s CST-100 Starliner and SpaceX’s Crew Dragon has been their ability to meet a “loss-of-crew” requirement — a measure of the probability of death or permanent disability of one or more people on a spacecraft during a mission — of 1 in 270. The companies have faced problems meeting that requirement, significantly more stringent than that of the space shuttle."
1 in 270, not sure I'd like those odds!

MartG

20,678 posts

204 months

Friday 21st September 2018
quotequote all
Caruso said:
MartG said:
https://spacenews.com/commercial-crew-providers-be...
"A key issue in the development of Boeing’s CST-100 Starliner and SpaceX’s Crew Dragon has been their ability to meet a “loss-of-crew” requirement — a measure of the probability of death or permanent disability of one or more people on a spacecraft during a mission — of 1 in 270. The companies have faced problems meeting that requirement, significantly more stringent than that of the space shuttle."
1 in 270, not sure I'd like those odds!
Way better odds than on the Shuttle

anonymous-user

54 months

Friday 21st September 2018
quotequote all
MartG said:
Caruso said:
MartG said:
https://spacenews.com/commercial-crew-providers-be...
"A key issue in the development of Boeing’s CST-100 Starliner and SpaceX’s Crew Dragon has been their ability to meet a “loss-of-crew” requirement — a measure of the probability of death or permanent disability of one or more people on a spacecraft during a mission — of 1 in 270. The companies have faced problems meeting that requirement, significantly more stringent than that of the space shuttle."
1 in 270, not sure I'd like those odds!
Way better odds than on the Shuttle
I bet there is some serious maths involved in that probability calculation.

Toaster

2,939 posts

193 months

Friday 21st September 2018
quotequote all
MartG said:
Way better odds than on the Shuttle
Given that space flight engineering has vigorous standards possibly more so than passenger aircraft for which being killed in a crash is 11million to one if your an Astronaut I think you need to be afraid.....very afraid

Polite M135 driver

1,853 posts

84 months

Friday 21st September 2018
quotequote all
Caruso said:
MartG said:
https://spacenews.com/commercial-crew-providers-be...
"A key issue in the development of Boeing’s CST-100 Starliner and SpaceX’s Crew Dragon has been their ability to meet a “loss-of-crew” requirement — a measure of the probability of death or permanent disability of one or more people on a spacecraft during a mission — of 1 in 270. The companies have faced problems meeting that requirement, significantly more stringent than that of the space shuttle."
1 in 270, not sure I'd like those odds!
they should just promise to launch every second one empty.

Warmfuzzies

3,984 posts

253 months

Friday 21st September 2018
quotequote all
Toaster said:
Given that space flight engineering has vigorous standards possibly more so than passenger aircraft for which being killed in a crash is 11million to one if your an Astronaut I think you need to be afraid.....very afraid
Understand probability ?

Toaster

2,939 posts

193 months

Friday 21st September 2018
quotequote all
Warmfuzzies said:
Understand probability ?
I do actually along with baseysien statistics so if you fancy a chat over a pint I’d be more than happy to discuss

Einion Yrth

19,575 posts

244 months

Friday 21st September 2018
quotequote all
Toaster said:
I do actually along with baseysien statistics so if you fancy a chat over a pint I’d be more than happy to discuss
Not so hot on spelling or capitalisation, mind...

Warmfuzzies

3,984 posts

253 months

Friday 21st September 2018
quotequote all
Toaster said:
Warmfuzzies said:
Understand probability ?
I do actually along with baseysien statistics so if you fancy a chat over a pint I’d be more than happy to discuss
Fab, I’m outside Colchester, let me know when nearby and we can talk semantics, and conditional probabilities.

Beati Dogu

8,892 posts

139 months

Friday 21st September 2018
quotequote all
They've refitted Pad 39a's emergency egress basket system. As seen here in 2012:

https://www.youtube.com/watch?v=TGMWdtQYkbc

For Falcon 9 use, they've mounted it about 60 feet higher than for the Shuttle program. So even more of a wild ride.


The one for the much taller Saturn V must have been something else. eek

RobDickinson

31,343 posts

254 months

Friday 21st September 2018
quotequote all
Good article on the pressure days of the falcon 1

https://arstechnica.com/science/2018/09/inside-the...

Beati Dogu

8,892 posts

139 months

Saturday 22nd September 2018
quotequote all
And the rendering of the Mars base has been updated....




Previously...



rovermorris999

5,202 posts

189 months

Saturday 22nd September 2018
quotequote all
It's all getting a bit Dan Dare.

anonymous-user

54 months

Saturday 22nd September 2018
quotequote all
rovermorris999 said:
It's all getting a bit Dan Dare.
But still possible ....


Eric Mc

122,032 posts

265 months

Saturday 22nd September 2018
quotequote all
Landing large heavy objects on the surface of Mars is a very, very difficult nut to crack. The largest object so far that has been safely landed on the surface is the Curiosity Rover which weighed about the same as a VW Golf.

The problem is that their isn't enough atmosphere to provide sufficient aerodynamic braking but enough to cause heating. You still need rocket power to gently put down. Because the atmosphere is so thin, the reliance on rocket thrust to land is greater so more fuel is needed to slow down compared to earth.

Building a spacecraft that is capable of both entering earth's atmosphere and landing and one that can do the same on Mars is not going to be easy. I wonder what techniques SpaceX have come up with. They haven't divulged that type of detail yet, as far as I am aware.

Beati Dogu

8,892 posts

139 months

Saturday 22nd September 2018
quotequote all
It the presentation last year Elon said they expect to be able to scrub off over 99% of the velocity aerodynamically. As you say, it'll be coming in hot (7.5 km/s initially), so there will be some ablation of the heat shield compared to an Earth re-entry.

We know they plan to in-space-refuel the Mars-bound BFS first with up to three dedicated BFS tanker flights each (depending on the payload). So it will have the fuel for a propulsive landing.

Mars also has 38% lower gravity than the Earth , so that's a help. It won't need the BFR booster to get back off Mars either.

Einion Yrth

19,575 posts

244 months

Saturday 22nd September 2018
quotequote all
Beati Dogu said:
It won't need the BFR booster to get back off Mars either.
But will need locally produced methane; it's certainly a tough nut to crack, but SpaceX have good engineers, so I wouldn't bet against them.

TOPIC CLOSED
TOPIC CLOSED