SpaceX Falcon 9 v1.1 - Dragon - CRS-5/SpX-5 -Jan. 10, 2015 - DISCUSSION

[Star One]

Yeh I agree with the UK media coverage.  BBC first had headlines of "SpaceX Failure" and then changed it to "crash" but the article still comes across as emphasising the failure unless you read further down.

I suppose with the instantaneous fixed launched windows SpaceX had no choice with the lack of daylight and weather conditions at the barge site however wondering if the weather conditions at the barge site could effect the timings of a non-ISS launch to improve their chances.

The UK coverage was awful, Sky News thought the first stage didn't land for a month after launch, confusing it with  Dragon.

I'm surprised I didn't see Kay Burley on a boat trying to force the barge into an exclusive interview.

All the reporting I heard was without context or nuance.

[samoo]

Elisabeth III which should be towing barge will enter Jacksonville approximately in 2.5 hours, I hope we will get at least some view of barge via webcams in port.

http://www.vesselfinder.com/?mmsi=367017460

[te_atl]

From Elon

@elonmusk: Didn't get good landing/impact video. Pitch dark and foggy. Will piece it together from telemetry and ... actual pieces.

Another explosion, another missing video.  What are the odds? 

But I see these landing experiments as an interesting side-show.  The real news continues to be the repetitive success of this launch vehicle.

 - Ed Kyle

What Ed said. "It was pitch dark" Except for the blazing rocket engine. Which cranks out a lot of lumens.

Pitch dark and fog with a high power light source make for really crappy visibility.  The fog refracts the light all over the freakin place.   Try driving in a heavy fog with your high beams on and you'll get a low power example.  Just warn me before you do.  I don't want to be anywhere near anyone crazy enough to try that stunt.

[Karloss12]

Yeh I agree with the UK media coverage.  BBC first had headlines of "SpaceX Failure" and then changed it to "crash" but the article still comes across as emphasising the failure unless you read further down.

BBC doesn't have a clue about SpaceX.  When F9R-D1 exploded, the BBC headline was "Falcon 9 Rocket Explodes".  When I e-mailed BBC to explain that it was not a F9 rocket as it was absent of much of its safety systems and engines and it was a reussability "test" they improved the headline slightly to "Falcon 9 Rocket Explodes during test".

And the BBC Science Correspondent seems to be very over worked or uninterested in aerospace as he seems to rely allot on advise from old space experts for his blogs.  According to him it is going to be a challenge convincing customer to launch there satellites on a second hand rocket.  Given the choice between catching a airliner flight on an aircraft that has rolled straight out of the workshop or has been in service for 6 months, I think the choice is simple.

True. BBC science reports about space are extremely amateur. How do you like the name for of the article about most recent launch: "Spacex rocket test ends in crash" ?
BBC science is more concentrated on "global warming" spam propaganda, that is the only "science" for them

The latest BBC headline is "SpaceX launches cargo ship but rocket recovery test ends in crash".  This is allot better.  Someone at BBC is obviously educating themselves about aerospace as they go along.  The article has improved allot as well.

[kevin-rf]

But I see these landing experiments as an interesting side-show.  The real news continues to be the repetitive success of this launch vehicle.

 - Ed Kyle

Wait, did Ed just tally this as a success?

[Zpoxy]

Hydraulic fluid doesn't get used up unless there's a leak.

Or unless they decided to used an open system in which the hydraulic fluid is simply dumped downstream of the actuator, which makes for a simpler system and eliminates the mass of a collection tank and associated plumbing.

And will get you the opportunity to explain yourself to the EPA.

??  open system hydraulics have been used on numerous aerospace vehicles (see Conestoga LV, for example).

The first Delta III launch failed for this very reason. Three of the nine solid rocket motors had TVC provided by this type of hydraulic system. Guidance system issues caused a roll oscillation, which in turn drove unplanned roll control commands on the three SRMs, causing the system to run out of fluid prematurely. This in turn led to loss of the vehicle when the remaining systems couldn't cope with the SRM TVC failure. See Boeing's summary here:

http://boeing.mediaroom.com/1998-10-15-Boeing-Changes-Delta-III-Control-Software

[rcoppola]

(My one allocated off-topic post per thread)

Regarding Media Coverage. At least in the States, the vast majority of headlines are quite good. Some headlines play off Elon's "Close but no cigar." quote. Or successful launch, failed landing. Most articles refer to what happened as a test that it is an historic effort and they came "This"...close. There are exceptions as with all things but for the most part, everyone seems to be having a lot of fun with it.

Besides, it doesn't really matter. When they do succeed, possibly as soon as next month, headlines and pictures will be broadcast all over the world and everything that came before will be forgotten, except when the NOVA documentary comes out retelling the epic tale of how it was achieved.

[mr. mark]

But I see these landing experiments as an interesting side-show.  The real news continues to be the repetitive success of this launch vehicle.

 - Ed Kyle

Wait, did Ed just tally this as a success?

Well that's 9 successful v1.1 launches in a row. 81 Merlin 1D engines (not including VAC) running without a failure. Speaks well of the new engine design.

[savuporo]

The latest BBC headline is "SpaceX launches cargo ship but rocket recovery test ends in crash"..

Accompanied by pictures of a an autonomous barge ship, and a crashed rocket, respectively
They'll get it right, eventually.

[ChrisC]

Elisabeth III which should be towing barge will enter Jacksonville approximately in 2.5 hours, I hope we will get at least some view of barge via webcams in port.
http://www.vesselfinder.com/?mmsi=367017460

Thanks for that tracking link.  Before I start Googling, do we already have some links to port webcams?  I checked the last few pages of this discussion thread and the update thread.

[samoo]

here's one nice webcam, http://thesurfersview.com/cams/florida-marina/mayport.php

EDIT: webcam is located here https://goo.gl/maps/mfipA

[Jet Black]

Yeh I agree with the UK media coverage.  BBC first had headlines of "SpaceX Failure" and then changed it to "crash" but the article still comes across as emphasising the failure unless you read further down.

BBC doesn't have a clue about SpaceX.  When F9R-D1 exploded, the BBC headline was "Falcon 9 Rocket Explodes".  When I e-mailed BBC to explain that it was not a F9 rocket as it was absent of much of its safety systems and engines and it was a reussability "test" they improved the headline slightly to "Falcon 9 Rocket Explodes during test".

And the BBC Science Correspondent seems to be very over worked or uninterested in aerospace as he seems to rely allot on advise from old space experts for his blogs.  According to him it is going to be a challenge convincing customer to launch there satellites on a second hand rocket.  Given the choice between catching a airliner flight on an aircraft that has rolled straight out of the workshop or has been in service for 6 months, I think the choice is simple.

True. BBC science reports about space are extremely amateur. How do you like the name for of the article about most recent launch: "Spacex rocket test ends in crash" ?
BBC science is more concentrated on "global warming" spam propaganda, that is the only "science" for them

The latest BBC headline is "SpaceX launches cargo ship but rocket recovery test ends in crash".  This is allot better.  Someone at BBC is obviously educating themselves about aerospace as they go along.  The article has improved allot as well.

The Guardian's article on this continues to be terrible.

[kevinof]

or 81 Merlin engines that could be re-used and flown again! 

But I see these landing experiments as an interesting side-show.  The real news continues to be the repetitive success of this launch vehicle.

 - Ed Kyle

Wait, did Ed just tally this as a success?

Well that's 9 successful v1.1 launches in a row. 81 Merlin 1D engines (not including VAC) running without a failure. Speaks well of the new engine design.

[ChrisC]

Thanks samoo!  Posted to updates thread.

EDIT: there is an ASDS updates thread where progress is being logged.

http://forum.nasaspaceflight.com/index.php?topic=36167.20

[edkyle99]

But I see these landing experiments as an interesting side-show.  The real news continues to be the repetitive success of this launch vehicle.

 - Ed Kyle

Wait, did Ed just tally this as a success?

Of course it was a launch success.  The first stage landing experiment was a side-show.  It very much remains to be seen if these experiments will lead to an operational system, but successfully launching that rocket over and over again during its first 1.5 years of service is the real deal.  Not many launch vehicles have met that mark.

 - Ed Kyle

[winkhomewinkhome]

Huh?  If the vehicle has more thrust than weight, then it follows that it WOULD be able to hover.  Just not for very long, because the available fuel, I'd imagine, is quite low.

The *minimum* thrust is still greater than the weight.  So once the stage hovers, it can only go up after that point --- until the engines are cut (or run out of fuel) and then it's gravity who's in charge.

And no, the stage can't toggle on and off rapidly.

There is a minimum thrust limit because the rocket combustion is unstable at low fuel pressures.

Some of this Thrust to Weight Ratio discussion has left me rather confused.  The Merlin engine is able to be throttled - yes.
Ratio >1, Falcon goes up - thus throttle up - Falcon up (Grasshopper did)
Ratio < 1 Falcon goes down - thus throttle back - Falcon down (Grasshopper did)
Ratio = 1 Falcon stabilizes vertical momentum +/- thus Falcon hovers (fairly certain Grasshopper did along with horizontal transitions)

Am I missing some thing here?

To say that only a +1 TWR exists would basically translate into what we have seen with Grasshopper was a figment of our imagination...

[R.Simko]

Yeh I agree with the UK media coverage.  BBC first had headlines of "SpaceX Failure" and then changed it to "crash" but the article still comes across as emphasising the failure unless you read further down.

I suppose with the instantaneous fixed launched windows SpaceX had no choice with the lack of daylight and weather conditions at the barge site however wondering if the weather conditions at the barge site could effect the timings of a non-ISS launch to improve their chances.

The UK coverage was awful, Sky News thought the first stage didn't land for a month after launch, confusing it with  Dragon.

I'm surprised I didn't see Kay Burley on a boat trying to force the barge into an exclusive interview.

Chris, I'm surprised  the news agencies arn't beating your door down, to get the REAL space news stories.

[edkyle99]

Am I missing some thing here?

To say that only a +1 TWR exists would basically translate into what we have seen with Grasshopper was a figment of our imagination...

With Grasshopper, propellant loadings can be carefully arranged to provide the needed T/W ratios, allowing Merlin to throttle down enough to fall toward earth.  The Falcon 9 first stage is presumably nearly empty by the time it attempts to land.

 - Ed Kyle

[Herb Schaltegger]

Some of this Thrust to Weight Ratio discussion has left me rather confused.  The Merlin engine is able to be throttled - yes.
Ratio >1, Falcon goes up - thus throttle up - Falcon up (Grasshopper did)
Ratio < 1 Falcon goes down - thus throttle back - Falcon down (Grasshopper did)
Ratio = 1 Falcon stabilizes vertical momentum +/- thus Falcon hovers (fairly certain Grasshopper did along with horizontal transitions)

Am I missing some thing here?

To say that only a +1 TWR exists would basically translate into what we have seen with Grasshopper was a figment of our imagination...

You're missing the fact that T/W is NEVER exactly equal to 1.0, except perhaps for an instant as fuel is consumed and mass goes down. That, plus the fact that (unlike in, say Kerbal Space Program) real world Merlin engines are not infinitely and precisely throttleable, and do not start up and shut down instantly, means that the rocket cannot hover.

[llanitedave]

Huh?  If the vehicle has more thrust than weight, then it follows that it WOULD be able to hover.  Just not for very long, because the available fuel, I'd imagine, is quite low.

The *minimum* thrust is still greater than the weight.  So once the stage hovers, it can only go up after that point --- until the engines are cut (or run out of fuel) and then it's gravity who's in charge.

And no, the stage can't toggle on and off rapidly.

There is a minimum thrust limit because the rocket combustion is unstable at low fuel pressures.

Some of this Thrust to Weight Ratio discussion has left me rather confused.  The Merlin engine is able to be throttled - yes.
Ratio >1, Falcon goes up - thus throttle up - Falcon up (Grasshopper did)
Ratio < 1 Falcon goes down - thus throttle back - Falcon down (Grasshopper did)
Ratio = 1 Falcon stabilizes vertical momentum +/- thus Falcon hovers (fairly certain Grasshopper did along with horizontal transitions)

Am I missing some thing here?

To say that only a +1 TWR exists would basically translate into what we have seen with Grasshopper was a figment of our imagination...

Grasshopper carried more fuel, weighed more, and thus had enough weight to allow a <1 or =1 Thrust/weight ratio.  F9 first stage on return is at the ragged edge of dry.