SpaceX Updates (Thread 8)

By DocM
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IsItPluggedIn

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Posted
3 hours ago, DocM said:

FYI, Paragon SDC has won the NASA contract for a new water recovery system on ISS. They developed the Commercial Crew ECLSS used in Starliner and Dragon 2 and have a long history with NASA, Boeing, SpaceX and ISS. 

 

http://www.nasa.gov/press-release/nasa-awards-contract-to-increase-water-recovery-on-space-station

 

http://www.paragonsdc.com/paragon-iwp/

 

 

 

 

 

I went to the "Mars Live Experience" last night and Jason Crusan was talking about this being tested on the ISS for future deployment on Mars. 

Grand Master

DocM

Posted
  • Author
Posted (edited)

SpaceX timeline.

 

FH and F9 development end in about 16 months with Block 5. ITS spaceship testing starts in Q3-Q4 2018.  Booster testing in mid-2019, orbital tests in 2020.

 

From the final ITS presentation pdf.

 

ITS-Timeline-1280.jpg

 

 

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SarK0Y

Posted
Posted

probability of next explosion is very high -- Musk et Co must stop gambling on deeply cryogenic propellants ==>> DCP needs the brand new EXPENDABLE rocket. DCP is extremely tricky Beast:

 

1. fuel easily goes 3-stated at once  (it's partially solid, partially liquid & partially gaseous) + fluctuates through that states.

2. material becomes fragile.

3. very limited time to keep fuel stable.

4. chemical surprise (like cool fire) can takeover at any Place, at any Time. 

=====================

Don't gamble with that Beast ==>> There never has mercy. :)

Grand Master

DocM

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Posted (edited)

Better tell that to Russia since sub-chilled LOX is required on the Russian engined Antares and Soyuz 2-1v.

 

Sub-chilled LOX at 66°K is liquid, not partially solid (54.6°K) and certainly not partially gas because it's well below its 90.188°K boiling point.

 

Something abnormal in the prop and He loads chilled the LOX enough to solidify it (likely γ-phase) inside the COPV overwrap winding, nowhere else. This has been reproduced, with a loud bang, so preventing it from happening again shouldn't be an issue. 

Edited by DocM
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SarK0Y

Posted
Posted
17 hours ago, DocM said:

Better tell that to Russia since sub-chilled LOX is required on the Russian engined Antares and Soyuz 2-1v.

 

Sub-chilled LOX at 66°K is liquid, not partially solid (54.6°K) and certainly not partially gas because it's well below its 90.188°K boiling point.

i think they have followed only well-proven process -- if No, Musk-like stories (Boom, baby, Boom) shall become their fate too.

17 hours ago, DocM said:

certainly not partially gas because it's well below its 90.188°K boiling point.

gaseous state may instantly appear in some locations. solid state in a classical form doesn't exist within the over-chilled medium -- super electrical conductivity + other quantum odds make a material transparent for super cooled Atoms/Molecules.

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SarK0Y

Posted
Posted (edited)
Quote

SpaceX chief Elon Musk called the problem surprising and said it had never been encountered in the history of rocketry.

But it's not completely unexpected. A panel of highly respected aerospace experts told NASA eight months before the accident that the lack of a re-circulation pump aboard the Falcon rocket could be a safety problem.

RELATED: Dramatic Video Shows Moment of SpaceX Explosion

"We are concerned that there may be insufficient pre-cooling of the tank and plumbing with (SpaceX's) current planned oxidizer fill scenario," former astronaut Thomas Stafford and members of the International Space Station Advisory Committee wrote in a December 2015 letter to NASA.

The letter was released on Friday.

"Without re-circulation there may be stratification of oxidizer temperature that will cause a variation in the input conditions to the oxidizer pump," the letter said.

NASA's space shuttles, for example, used a re-circulation system and pressure lines to help keep liquid oxygen temperatures consistent, Mike Leinbach, former shuttle launch director, told Seeker.

"That's key," said Leinbach.

NASA also has a bit of history with liquid oxygen behaving badly with a composite fuel tank, which was developed as part of the experimental X-33 spaceship in the 1990s.

RELATED: SpaceX Rocket, Israeli Satellite Destroyed

"The composite tank experienced cracks when fueled in development tests. Composite was used to save weight. Never could overcome it technically, and contributed a lot to the program demise," Leinbach wrote in an email.

http://www.seeker.com/spacex-elon-musk-falcon-rocket-explosion-launch-pad-accident-2083614822.html

 

Grand Master

BetaguyGZT

Posted
Posted

In all fairness we'll call this lesson learned. SpaceX will adapt, and the data gathered on this mishap can be used to prevent occurrences like this one in the future; be it Russia or anyone else. Better that it happen before these rockets have Crews on top of them -- in any Space Program. Don't want any loss of life, injury, or setbacks over something that could have been prevented. (Y) 

 

This is another example of how difficult Space is. 

Grand Master

DocM

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Posted (edited)

And LOX stratification in a full tank over time wasn't the issue. The tank was only part full. 

 

As to prop and crew loading...

 

1) you load crew first. The rocket is empty so both the flight crew and ground crew are safe. During fueling the flight crew is buttoned up in a capsule surrounded by thermal protection materials, which is also equipped with a powerful launch escape system looking for an excuse to bug out.

 

It would have easily outrun the AMOS-6 event, as fast an event as one can imagime.

 

2) you fuel first, and expose both the flight crew and ground crew to a rocket filled with 500t of propellants looking for an excuse to go boom. If anything goes wrong both crews are SOL; the launch escape system can't fire and the NASA required zip lines are a joke. Puh-lease. Call the coroner.

 

I'll take door #1.

 

How the NAC avoids common sense sometimes amazes me.

 

 

Edited by DocM
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SarK0Y

Posted
Posted
38 minutes ago, DocM said:

As to prop and crew loading...

much better to use Soyuz-like scheme w/ no DCP as well. other schemes could be adopted to crew vehicle, if they have showed due success rate in cargo flights.

 

46 minutes ago, DocM said:

1) you load crew first. The rocket is empty so both the flight crew and ground crew are safe. During fueling the flight crew is buttoned up in a capsule surrounded by thermal protection materials, which is also equipped with a powerful launch escape system looking for an excuse to bug out.

i've had some doubts about escape system of Dragon ==>> engines of capsule must be as far from 2nd stage as possible, otherwise rocket explosion could affect them.

Grand Master

BetaguyGZT

Posted
Posted
5 minutes ago, SarK0Y said:

second moment, solid boosters work faster, it's better for escape tower.

Why, when the Dragon 2's propulsion system, at full power, can do the same job at the same response time and speed with less weight? No need for an escape tower that potentially can strike the spacecraft (not to mention add additional weight)?

 

Nah, we like the SuperDraco engines. A lot. :yes: 

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SarK0Y

Posted
Posted
43 minutes ago, Unobscured Vision said:

Why, when the Dragon 2's propulsion system, at full power

perhaps theoretically, practically Musk's "optimizations" have proven self unsafe. i remember how Musk's supporters were blackmailing Shuttle. But in practice Shuttle was more reliable/safe & even more cheap as well.

Grand Master

DocM

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1 hour ago, SarK0Y said:

much better to use Soyuz-like scheme w/ no DCP as well. other schemes could be adopted to crew vehicle, if they have showed due success rate in cargo flights.

Guess you missed the part about other launchers using chilled LOX. If Shuttle had continued it's quite likely it too would have used sub-chilled propellants, NASA was exploring it and saw no deal breakers, and the required pumps are commercially available. In short, quit the FUD.

 

Quote

 

i've had some doubts about escape system of Dragon ==>> engines of capsule must be as far from 2nd stage as possible, otherwise rocket explosion could affect them.

Dragon 2 pad abort test overlaid on AMOS-6 explosion, timed so the SuperDraco ignition happens after the event started. FYI, the SuperDracos reach 100% throttle in 90-100 milliseconds.

 

 

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SarK0Y

Posted
Posted
5 minutes ago, DocM said:

Guess you missed the part about other launchers using chilled LOX. If Shuttle had continued it's quite likely it too would have used sub-chilled propellants, NASA was exploring it and saw no deal breakers, and the required pumps are commercially available. In short, quit the FUD.

Yes, it'd be used WELL-PROVEN PROCESS & RD180-like engines for its boosters :rolleyes:

 

10 minutes ago, DocM said:

the SuperDracos reach 100% throttle in 90-100 milliseconds

your pic just shows how engines of Dragon could be affected by such explosion -- normal escape tower stays safe at any scenario.

Grand Master

DocM

Posted
  • Author
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Guess you missed the part about RD-180 not being used for govt launches after Vulcan flies. Atlas V then needs to be commercially viable, which it will have a problem doing - too many NON-Russian engined options. 

 

The SuperDraco nozzles are covered by pop-off panels before they fire, and so are protected. After they fire their exhaust velocity is fast and voluminous enough to handle thrusting during a hypersonic re-entry for landing on Mars, so a piddling subsonic fireball is nothing. Try harder.

Grand Master

Draggendrop Veteran

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Just a heads up guys, we can't use the "troll" word without getting a warning.

 

We must agree to disagree and move on with our usual thorough science.

 

You guys are smart and know what to do.

 

Thanks much.    :s

Grand Master

Draggendrop Veteran

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Posted
14 minutes ago, DocM said:

I could get very creative quoting that first line DD, but I'll restrain myself.

I'm having one of those days where I feel like a bag of hammers, shouldn't be near a keyboard.....:s

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SarK0Y

Posted
Posted
5 hours ago, DocM said:

Guess you missed the part about RD-180 not being used for govt launches after Vulcan flies. Atlas V then needs to be commercially viable, which it will have a problem doing - too many NON-Russian engined options. 

vulcan.png

planned:rofl: i'd like to share you some inside -- this rocket will go nowhere or will have RD yet again :) well, mid-12.16?:)

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