SpaceX CRS-4 launch

[sgt_flyer]

Hello,

Edit : today's launch was scrubbed due to bad weather. They will attempt a new launch tomorrow at 01:52 AM EDT ( 05:52 UTC)

http://www.spacex.com/webcast/

so, SpaceX CRS-4 mission is planned for their backup launch date - for a Sunday 21/09 launch - at 05:52 AM UTC (01:52 AM EDT) - here's the current countdown http://spacexstats.com/mission.php?launch=18

Coverage :

Nasa TV did not update their web TV planning yet , but coverage should be avaible here :

http://mobile.nasa.gov/content/watch-nasa-tv

And SpaceX webcast http://www.spacex.com/webcast/

the dragon capsule will be loaded with 5000lb (2250kg) of various supplies and experiments for ISS.

in the payload, they will also have (as the most interesting payloads) :

ISS-Rapidscat (ISS-Quickscat replacement, for monitoring oceans winds, to help in meteo predictions. will be attached to ISS)

SSIKLOPS launcher (for having another sytem for releasing small sats from ISS)

20 Mousetronauts ! (with a Bone Densitometer) the mouses will be part of an experiment on bone density changes in zero-G environments. (imagine one of the rodents escapes inside ISS ^^)

Made in Space's custom 3d printer (modified for Zero-G) - we'll see how useful it can be to be able to manufacture small parts on demand

Planetary resources' Arkyd 3 cubesat (which basically a testbed for the systems of one of Planetary resources upcoming satellite - minus the truly expensive stuff ) - which will be released from ISS's Kibo module.

Spinsat : a satellite for testing atmospheric density, it will also carry DSSP's electric SRB thrusters (those are small solid SRB's, which are controlled electrically - send in electricity, they start burning, stop electricity, they stop burning - and can be built really small, to perform as RCS system for small sats.

the dragon capsule will return with 3800lb of cargo (1700kg).

concerning the launch, they announced they will try to perform a booster reentry of the first stage, but they will have a low probability of success (as they had to use the first stage they prepared for crs-4 on their asiasat 6 launch) so CRS-4 1st stage don't have the legs etc to assist in stabilisation / control during the propulsive return.

Edited September 20, 2014 by sgt_flyer

[sojourner]

The first stage on this launch does not have legs. The previous stage wasn't destroyed by the rocket "tumbling". It landed on the ocean then broke apart when it fell over in the water.

Chance of launching tonight is only %50 due to weather. Massive weather system in the gulf that could move over the state.

http://www.wunderground.com/radar/radblast.asp?ID=TBW

Edited September 19, 2014 by sojourner

[Godot]

... It landed on the ocean then broke apart when it fell over in the water.

...

This reminds me of several landings of my KSP secondary stages (that do reentry with the command capsule but get separated (with their own chutes) before landing) ... lots of cases where they shared this fate

[sgt_flyer]

@Sojourner, yes, that's what i meant by telling it tumbled after landing and yes, effectively, it won't have landing legs (it was confirmed in the prelaunch press briefing)

Edited September 19, 2014 by sgt_flyer

[Scotius]

I hope there will be video of 3D printer in action on board ISS. I want to see future happening

[sojourner]

and yes, effectively, it won't have landing legs (it was confirmed in the prelaunch press briefing)

"Effectively"? It won't have them, period.

[sgt_flyer]

Please Sojourner- try to understand what i wrote . - by effectively, i only meant that you where right that there would be no landing legs... You have a curious way to reply to a person who acknowledged your point - now, this thread isn't the place to be arguing about what meaning we could give to words

Edited September 19, 2014 by sgt_flyer

[magnemoe]

This reminds me of several landings of my KSP secondary stages (that do reentry with the command capsule but get separated (with their own chutes) before landing) ... lots of cases where they shared this fate

Yes even if you do an soft landing in water an high and narrow rocket will tip over, the speed the top has then it hit water breaks it.

In real life this will break open the rocket, might also rupture tanks, you also have waves.

[Streetwind]

Was it confirmed that they will try the propulsive touchdown?

The first stage core for CRS-4 was swapped with one of the Asiasat missions for unknown reasons. The Asiasat missions needed too much fuel, meaning the upgraded core went to waste on it, whereas the CRS-4 mission would have enough fuel but it now has an un-upgraded core that cannot mount landing legs.

The bigger issues than having legs to land on (which isn't important in the ocean) is the fact that the legs are aerodynamically shaped to stabilize the stage during reentry and descent, and the core upgrades for landing also include a beefed-up RCS system. The last time they tried to perform a propulsive landing with an un-upgraded core - which was also the first time they ever tried it - the rocket started spinning during descent, which centrifuged the fuel against the outer walls so that the engines wouldn't start for the landing burn. The stage hit the water at full terminal velocity.

Therefore I'm not sure if they'll bother trying it. I mean sure, you have the fuel necessary to go through the motions, but it's pretty much guaranteed to fail. Guess you got to weigh the data gathering versus potential negative PR.

The Asiasat missions incidentally also performed first stage relights for a return burn. They fell into the atmosphere without any fuel left, though. Maybe this time they'll do something similar - just practice the relight maneuver, and abandon the stage once it's inside the atmosphere.

[sgt_flyer]

well, from what i read, they will try to do the propulsive landing, but they are not expecting it to work.

[Karriz]

I think it makes sense for them to try a soft splashdown and get as much data as possible, there can't be any negative outcome of it. It'll fall into ocean anyways, so they might as well ignite the engines and see what happens.

Orbcomm 2 next month(?) will be the first barge landing unless I'm mistaken, so they need to do testing whenever they have the opportunity.

[Streetwind]

I heard that the barge landing is expected for CRS-5 later this year. Not sure what Orbcomm-2 will be doing in this regard. And there's of course the possibility that I heard wrong.

[Kryten]

Barge landing currently isn't possible because Blue Origin (Bezos' company) hold a patent for it. Spacex is currently challenging the patent.

[sgt_flyer]

I heard that the barge landing is expected for CRS-5 later this year. Not sure what Orbcomm-2 will be doing in this regard. And there's of course the possibility that I heard wrong.

well, they even plan for a softlanding on actual land for at least one of the two upcoming launches.

http://www.spacex.com/news/2014/07/22/spacex-soft-lands-falcon-9-rocket-first-stage

i don't know if they'll go on with the barge landing though - as SpaceX is engaged in a legal battle with Blue origin (Blue origin patented in 2010 the sea landing concept)

http://www.geekwire.com/2014/elon-musks-spacex-challenges-patent/

edit : kryten beat me about the sea landing patent though the patent system is really weird to allow patenting such 'generic' concepts...

[Reddragon]

SpaceX employees used to introduce the mission details in the webcast before turning to the countdown. I wonder if they are still doing that.

[sojourner]

Barge landing currently isn't possible because Blue Origin (Bezos' company) hold a patent for it. Spacex is currently challenging the patent.

Patent law doesn't work that way. SpaceX can test barge landing all they want. They only run afoul of the patent if they try to make a profit from barge landings.

[Frozen_Heart]

Guess you got to weigh the data gathering versus potential negative PR.

They might try it but just not tell anyone?

[Kryten]

You can't just drop rocket stages into the Atlantic without prior notice. There'd have to be NOTAM's at the very least.

[magnemoe]

Patent law doesn't work that way. SpaceX can test barge landing all they want. They only run afoul of the patent if they try to make a profit from barge landings.

Think you are right as I understand its legal to replicate an patent for testing or performance use, teacher of mine replicated an patented electronic circuit and found that the patent description would not work. Either an bug or planned to make it harder to replicate and put inside an integrated circuit black box.

And yes its an idiotic patent, made more stupid since we have had carriers in 80 years. yes I see that some sub systems like something who catch the landing legs would be patented.

[Scotius]

One day some smart*** will try to get walking patented. It's crazy world.

[Francesco]

as SpaceX is engaged in a legal battle with Blue origin (Blue origin patented in 2010 the sea landing concept)

http://www.geekwire.com/2014/elon-musks-spacex-challenges-patent/

This is just ridiculous.

What are they patenting, exactly?

A barge?

The atmosphere, which slows down the vehicle?

The idea that if something goes up, then it can also come down?

They haven't even attempted it so far, while SpaceX already did.

Blue Origin is cringe-worthy.

[Francesco]

Patent law doesn't work that way. SpaceX can test barge landing all they want. They only run afoul of the patent if they try to make a profit from barge landings.

Which would mean, selling refurbished F9 first stages to the next customer, for a lower launch price?

And Blue Origin would get a cut of that money?

[sojourner]

Or be barred by Blue Origin from doing it. Assuming of course that the patent holds, which it won't.

[Kryten]

Jeff Bezos can afford the best lawyers money can buy. It apple can trademark rounded rectangles, he can patent landing on a barge.

[PakledHostage]

If apple can trademark rounded rectangles, he can patent landing on a barge.

We're getting off topic but some guy in Australia managed to get a patent for the wheel. Admittedly he did it to test the workability of Australia's (at the time) new national patent system, but the point stands.