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

[Robotbeat]

Here is a video from a Chinese space club.

Wow, amazing video is amazing.


On a different note, I'd like to ask why there haven't been any attempts to land Grasshopper onto the barge first, ahead of CRS5? Is it mainly because of FAA clearance issues? Isn't a lot being left to chance by trying to land on barge directly from CRS5 on the first go?

Grasshopper is stuck in Texas and has been sitting out in the elements for a while, probably hasn't been maintained at all. F9dev1 blew up, and F9dev2 has yet to fly at all.

It's either try it with this flight, or they throw this first stage away (just like every other flight). Even if it's just a 50% chance of working this time, why throw away a piece of hardware that probably is worth tens of millions of dollars? They're not going to hold up this flight so they can transport Grasshopper ALL the way over from Texas just to try a test when they'd have to get special permission for that test already and they have a HUGE launch backlog. Best to just give it a go with this launch.

[deruch]

Here is a video from a Chinese space club.

Wow, amazing video is amazing.


On a different note, I'd like to ask why there haven't been any attempts to land Grasshopper onto the barge first, ahead of CRS5? Is it mainly because of FAA clearance issues? Isn't a lot being left to chance by trying to land on barge directly from CRS5 on the first go?

Well, first they'd have to get a license to run the test but that's not a huge obstacle.  Then you have all the problems that Robotbeat outlined.  Then there's fact that this may turn out to be a "high risk" test, as far as the rocket is concerned.  Basically, there would be a significant chance that they'd end up crashing the Grasshopper into the ocean and wrecking it.  That would be a total waste since, due to the limitations of its hardware, GH couldn't really approximate most of the flight regions that will cause the biggest problems (boost back, re-entry, high level winds).  They're going to get a large number of free tests with stages that would otherwise be junk.  Better to use them and not risk throwing away the Grasshopper, which will make an excellent addition to the Smithsonian one day.  Especially when the return on the test wouldn't be all that great.

[Robotbeat]

How far away will the launch be visible, if you've got a view down to the horizon? I'm at roughly 620 miles as the crow flies. Wondering if I should bother going to the water to see the launch.

[Comga]

How far away will the launch be visible, if you've got a view down to the horizon? I'm at roughly 620 miles as the crow flies. Wondering if I should bother going to the water to see the launch.

From simple geometric calculations:
If you are 620 miles from the track, it would be visible at ~75 km altitude.  That's second stage flight, IIRC, which is not a particularly bright flame.
If you are north, the distance and altitude could be less, but not much.

[Earendil]

Guys what is (to your expertence) the most reliable source for viewing the launch.. 

Last time I tried to watch  it on livestream, it started breaking up.. interrupting right at T0 .. same was on Nasa Tv..
I am sure thic launch will stress the streming sources even more

Ideas?

[NovaSilisko]

Guys what is (to your expertence) the most reliable source for viewing the launch.. 

Last time I tried to watch  it on livestream, it started breaking up.. interrupting right at T0 .. same was on Nasa Tv..
I am sure thic launch will stress the streming sources even more

Ideas?

I've had good luck with the Youtube streams, they've got the biggest baddest servers of them all and can handle the load.

[docmordrid]

I've never had trouble with Livestream's SpaceX channel, YouTube or NASA TV streaming via their Android app  (which gets Chromecast Screencasted to the 52".)

[PhilW]

[laika_fr]

Msg to SpaceX : if it doesn't work use multiple platforms and spread em.

Now, good luck.

[Jarnis]

Guys what is (to your expertence) the most reliable source for viewing the launch.. 

Last time I tried to watch  it on livestream, it started breaking up.. interrupting right at T0 .. same was on Nasa Tv..
I am sure thic launch will stress the streming sources even more

Ideas?

I've watched NASATV via Ustream

http://www.ustream.tv/nasahdtv/pop-out

...with the spacex webcast (livestream) as backup on the 2nd PC, and Youtube page open but paused on third browser in case one of the two primaries fails. Youtube tends to be many seconds behind the other two, so that's why it is "tertiary". Usually Ustream and SpaceX streams are off each other by 1-2 seconds and I keep audio on for the stream that is closest to real time (both are many seconds behind the action due to long signal path but that matters mostly if you plan on actually viewing the launch on-site)

Redundancy rules.

[PhilW]

Msg to SpaceX : if it doesn't work use multiple platforms and spread em.

Now, good luck.

Multiple return / landing pads is good!

[darkenfast]

The propulsion system must only be used for station keeping as barge is being pushed by a tug.

That was never in doubt for most of us - except for a vocal minority here.

Hey, you could've been wrong.

No one who knows marine vessels ever thought differently. This platform is much more barge than ship. Now that we've seen new pictures it appears modifications are minimal. Only whats needed to be a stable base for initial landings and not much else. Very much in the SpaceX style of doing business.

Getting back to this issue of the question of whether the propulsion system would only be used for station-keeping, it looks like we have a better answer:

https://twitter.com/elonmusk/status/552182273865699328
"Drone spaceport ship heads to its hold position in the Atlantic to prepare for a rocket landing" (@elonmusk) (emphasis mine)

...I just want to say... "Neener"

Um, the vessel tracking information clearly shows that the ASDS was delivered to its position by tug.

No one is doubting that a tug was used. The issue was whether the on-board thrusters would (or actually, could) be only used for position-keeping. And unless Musk is a liar, we know that the on-board thrusters were not just used for position-keeping.

...From the tracks, the amount of untowed propulsive sailing by the ASDS was under 5km (which is the distance the support ships appear to be standing off from the target touch down location).

Oh, totally true, I'm sure! But still counts as a (childish) Neener.

Actually, from the bow wave that the barge is throwing, I'd bet that it was under tow at the time of the picture.  You just can't see the cables (I believe they run from both forward quarters), against the water.  It takes a lot of low-rpm, big-thrust power to move that kind of barge at anything faster than a snail's pace, and that's just what a tug is good at.

[PhilW]

Don't really care how it gets there. Only important objective it is under F9 as it touches down.

[mtakala24]

Did someone catch the weather briefer's name? He has a Finnish-sounding surname, but not sure when pronounced by Americans.

edit: Nevermind, found out. Its Mike McAleenan. It sounded like Mäkeläinen to me

[laika_fr]

looked like someone was monitoring the platform at sea ( secondary control room, last row)
wasn't quick enough to take a screencap

[sdsds]

So we're 50 minutes into the NASA coverage. Is there perhaps some little piece of this flight that George Diller hasn't yet mentioned? Plenty of talk about science aboard Dragon... but nothing at all about a drone ship holding position offshore!

[Llian Rhydderch]

So we're 50 minutes into the NASA coverage. Is there perhaps some little piece of this flight that George Diller hasn't yet mentioned? Plenty of talk about science aboard Dragon... but nothing at all about a drone ship holding position offshore!

We've discussed this a few times now. 

NASA bought a launch from SpaceX to transport cargo to the ISS.  That's NASA' interest.

SpaceX is taking the booster stage they own, AFTER they have completed the first stage transport job for NASA to accelerate the booster on an orbital trajectory, and running some privately-funded controlled-descent flight tests.

It is is NASA's interest to focus on their mission.

It is SpaceX's business to choose how much of any information to release about the proprietary test flight back to the surface of the ocean with an attempt to land on the ASDS.

[RotoSequence]

Perhaps there was some sort of problem with the second stage O2 tank? It looks like it was venting pretty heavily before they called the hold.

[NovaSilisko]

Perhaps there was some sort of problem with the second stage O2 tank? It looks like it was venting pretty heavily before they called the hold.

It was an actuator for thrust vectoring (hasn't this happened a few times in a row?)

Genuine question: How's this stuff only get found literally minutes before launch? Especially with such a long time since the previous launch...

[rpapo]

Perhaps there was some sort of problem with the second stage O2 tank? It looks like it was venting pretty heavily before they called the hold.

It was an actuator for thrust vectoring (hasn't this happened a few times in a row?)

Genuine question: How's this stuff only get found literally minutes before launch? Especially with such a long time since the previous launch...

My guess: the engine chill-down affects the actuators somehow.