Space X

donspeekinglesh · 06-12-2018 1:05am

No, this: https://arstechnica.com/science/2018/12/after-26-straight-successes-spacex-fails-to-land-a-rocket-it-wanted-back/

Though it seems the rocket survived the landing.

Beeker · 06-12-2018 9:15pm

https://www.youtube.com/watch?v=LFdep0qCmYA

josip · 12-02-2019 12:32pm

Raptor engines have begun testing, the grasshopper tests will be interesting.

https://newatlas.com/spacex-mars-raptor-lift-off-power/58432/

Also and not worth a new thread/finding an old thread, Mars One has gone bankrupt.

Capt'n Midnight · 12-02-2019 9:10pm

josip wrote: »

Raptor engines have begun testing,

Pressures higher than the RD-180 :eek:

Serious piece of kit.

Capt'n Midnight · 16-03-2019 10:13pm

NASA admits SLS won't be ready for 2020 lunar test launch so will have to use a pair of commercial launches instead.

So $20Billion give or take later it's an Earth Orbit Rendezvous of the Orion crew capsule and the European service module using off the shelf launchers.

So ULA and or SpaceX will get the gig at a fraction of the cost of an SLS launch.

It's embarrassing and not at all unexpected.

Beeker · 17-03-2019 8:34am

Capt'n Midnight wrote: »

NASA admits SLS won't be ready for 2020 lunar test launch so will have to use a pair of commercial launches instead.

So $20Billion give or take later it's an Earth Orbit Rendezvous of the Orion crew capsule and the European service module using off the shelf launchers.

So ULA and or SpaceX will get the gig at a fraction of the cost of an SLS launch.

It's embarrassing and not at all unexpected.

I agree its the way they should have gone in the first place. SLS is going nowhere with no mission. It was and still is just a jobs program to get Congress on its side.

Leave commercial companies to the launch business and NASA can contract out when ever they want to launch a spacecraft.

Capt'n Midnight · 10-04-2019 10:28pm

2nd Falcon Heavy stream due to start at April 10, 11:30 PM

SpaceX Falcon Heavy Arabsat-6A rocket launch, live stream
https://www.youtube.com/watch?v=ecpUjam6byA

ricimaki · 10-04-2019 10:33pm

Just to clarify the above, the stream starts at 11.30 PM. Lift off is due for roughly 1 AM Irish time.

Here's hoping they recover all 3 boosters this time!

josip · 11-04-2019 12:57am

Scrubbed

josip · 11-04-2019 10:51pm

Weather (and systems) looking ok for launch in 45 mins.

https://www.youtube.com/watch?v=ojvu2u28CIY

Ghost Train · 11-04-2019 11:24pm

Bump

T -11 minutes

josip · 11-04-2019 11:38pm

Maximum dynamic pressure passed

(no idea what that means)

expectationlost · 11-04-2019 11:46pm

seeing the two rockets come down at the same time was great

Ghost Train · 11-04-2019 11:49pm

There's something about seeing two rockets land at once, slightly unreal.
Good job SpaceX

josip · 11-04-2019 11:53pm

I could watch that landing over and over again, all night long.
Let's hope they get 3 from 3 this time.

Capt'n Midnight · 11-04-2019 11:57pm

3 out of 3 ,

and future plans to catch the payload fairings too

BoJack Horseman · 11-04-2019 11:58pm

josip wrote: »

I could watch that landing over and over again, all night long.
Let's hope they get 3 from 3 this time.

They did

Centre-core landed successfully as well

d4fea3aae529c1072308206ab372b41cd4977b36b41dedc1b268f34836316f7a.png

Capt'n Midnight · 12-04-2019 12:03am

Upper stage engine reignition - 5 mins to deployment
https://www.youtube.com/watch?v=vF_2kYAwMGw

Capt'n Midnight · 12-04-2019 12:10am

Job done, Arabsat on it's own.

Itssoeasy · 12-04-2019 12:22am

josip wrote: »

Maximum dynamic pressure passed

(no idea what that means)

It's the maximum stress of the vehicle. If you remember the shuttle launches the main engines throttled down going through it so as to reduce the stress on the shuttle. You could tell when they were passed it, as the capcom would say "shuttle go at throttle up" meaning the shuttle engines could be throttled back up to 105%(I think that's it)

Capt'n Midnight · 12-04-2019 12:37am

The faster it goes the more pressure there is from air resistance.

But the air gets thinner as you get higher so less air resistance.

So at some point you hit maximum air resistance. The choices are to make the whole thing stronger (read heavier) to survive or take the foot off the accelerator for a few seconds.

Westernyelp · 12-04-2019 12:43am

Itssoeasy wrote:

It's the maximum stress of the vehicle. If you remember the shuttle launches the main engines throttled down going through it so as to reduce the stress on the shuttle. You could tell when they were passed it, as the capcom would say "shuttle go at throttle up" meaning the shuttle engines could be throttled back up to 105%(I think that's it)

That was called Max q in the olden days

Itssoeasy · 12-04-2019 2:27pm

Westernyelp wrote: »

That was called Max q in the olden days

Still is isn't it ?

mikhail · 13-04-2019 5:23am

Itssoeasy wrote: »

It's the maximum stress of the vehicle. If you remember the shuttle launches the main engines throttled down going through it so as to reduce the stress on the shuttle. You could tell when they were passed it, as the capcom would say "shuttle go at throttle up" meaning the shuttle engines could be throttled back up to 105%(I think that's it)

Itssoeasy · 23-04-2019 12:01am

Not a great development for space X with the dragon capsule exploding during a test over the weekend. Now the capsule was going to be used for an abort test I think, and isn’t the one that is still scheduled to bring a crew to the ISS in July.

Ghost Train · 23-04-2019 7:41am

Itssoeasy wrote: »

Not a great development for space X with the dragon capsule exploding during a test over the weekend. Now the capsule was going to be used for an abort test I think, and isn’t the one that is still scheduled to bring a crew to the ISS in July.

Looked pretty bad. Calling it an anomaly didnt go down to well when the video came out. Hopefully they can clearly explain what happened. Looked pretty catastrophic, wouldn't want something like that happening the the space station or of course with crew

Beeker · 24-04-2019 6:32pm

Rapid Unscheduled Disassembly

Itssoeasy · 08-05-2019 9:41pm

Another test has failed it seems. This info came about for a congressional committee that a parachute test failed. One of four parachutes was designed to fail to test the others. It didn't pass. Bad news for the spaceX manned flight to the ISS in July which isn't going ahead if I was a betting man. Not a hope NASA green lights that.

josip · 16-07-2019 12:35pm

https://newatlas.com/spacex-leaking-crew-dragon-explosion/60598/

Capt'n Midnight · 16-07-2019 8:58pm

titanium and nitrogen tetroxide

https://spaceflightnow.com/2019/07/15/spacex-points-to-leaky-valve-as-culprit-in-crew-dragon-test-accident/

He added that the result was surprising. Engineers did not expect a titanium, a material commonly used for decades on space vehicles around the world, could react so explosively in such an environment.

Surprising ???

It's on Page 61 of Ignition by John D. Clark which is essential reading for anyone who wants to do anything with liquid rocket propellents.

... it increased the
corrosion rate at tantalum by a factor of 2000 and that of titanium by
one of 8000.

There was a great deal of interest in titanium at that time, and as
many rocket engineers wanted to use it, the question of its resistance
to RFNA couldn't be neglected. But these corrosion studies were
interrupted by a completely unexpected accident. On December 29,
1953, a technician at Edwards Air Force Base was examining a set of
titanium samples immersed in RFNA, when, absolutely without warning, one or more of them detonated, smashing him up, spraying him
with acid and flying glass, and filling the room with NO2. The technician, probably fortunately for him, died of asphyxiation without
regaining consciousness.

...
by 1956 they were fairly clear.
Initial intergranular corrosion produced a fine black powder of
(mainly) metallic titanium. And this, when wet with nitric acid, was
as sensitive as nitroglycerine or mercury fulminate.

Space X

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