LIVE: SpaceX Falcon 9 v1.1 - CRS-3 Dragon - ATTEMPT 2 UPDATES

[Helodriver]

Too bad that they couldn't delay for a better sea state. Oh well, primary mission comes first.

Makes me wonder if any shuttle missions were ever delayed for the benefit of SRB recovery.

[mto]

Please keep this thread to updates only.

[Chris Bergin]

So the first stage did what Shuttle boosters have been doing for decades. Big deal.

^^^^^ That was on twitter!

What he meant to say was So the first stage did what Shuttle boosters have been doing for decades, except this one flipped over, restarted, entered stable, didn't use any parachutes, fired again for a soft touchdown. Oh and it deployed its own legs. That is a big deal.

Now we demand video!

[Chris Bergin]

Please keep this thread to updates only.

We do that for the primary part of the mission. After that, it's relaxed somewhat, providing its on topic of what happened during the primary part of the coverage.

[yg1968]

Here is a video of Dragon by Thierry Legault (a well known astro-imager) filmed 25 minutes after launch:

[ChrisWilson68]

Just a thought....

Could returning rocket booster stages one day be fitted with a black box to enable/facilitate data recovery by ocean-going crews?

They're supposed to be coming back to touch down on land.  Ending up in the ocean is just a transitional thing.

Or did you mean in case there was an accident and the stage crashed into the ocean?  Maybe, but maybe not.  First of, all, the returning stage doesn't have anyone on board, so if it's lost, it's not that big a deal -- not like an airliner going down with people on board.  Secondly, the stage is transmitting telemetry continuously during flight, so all the data that would be in the black box is likely to be transmitted anyway.  And finally a low empty weight of the stage is very important, so the hit from weight of a black box is significant.  The combination of those three things suggests to me that the case for a black box on a first stage is much less compelling than for an airliner.

[mmeijeri]

What he meant to say was So the first stage did what Shuttle boosters have been doing for decades, except this one flipped over, restarted, entered stable, didn't use any parachutes, fired again for a soft touchdown. Oh and it deployed its own legs. That is a big deal.

Also, it reentered at twice the velocity and wasn't a massive steel casing but a lightweight aluminium-lithium first stage.

[LouScheffer]

‏@elonmusk  1m
Last known state for rocket boost stage is 360 m/s, Mach 1.1, 8.5 km altitude and roll rate close to zero (v important!)

Hard to imagine a soft touchdown, this time anyway, if the last known state had the F9 at 28,000' going straight down at over Mach 1. Still, the very low roll rate is encouraging, and one can't wait to see yesterday's "Grasshopper II" video recreated after a live F9 launch.

Actually this looks encouraging to me. From that altitude and speed, the first stage would need to decelerate at less than 2 gees to reach simultaneous zero altitude and velocity.

I calculate 45 seconds to zero altitude and velocity at 8m/s/s, or 0.8g

And quite a bit of that deceleration should be provided for free by the atmosphere.  At sea level, the atmosphere is 3 times denser than at 8.5 km, so the terminal velocity should be 1/sqrt(3) times the speed, or only 200 m/s or so.

[drsnooker]

Lars Blackmore ‏@larsblackmore 13m
(Guidance, Navigation and Control team leader for SpaceX's Grasshopper rocket)

We landed the rocket softly in the ocean! One (small) step toward reusable rockets!

[drsnooker]

Huh.... I think Rachel Maddow is about to talk about SpaceX..

Yeah, the Rooskies have the Nikolay Chiker (underwater salvage ship) just off the coast

[dcporter]

All the spacex tweeters are flipping out pretty awesomely.

[LouScheffer]

Falcon 9 stage 2 will be deorbited SW of Australia shortly; first time the second stage has been deorbited on an F9 flight

I wonder whether this is being driven more by orbital debris considerations, wanting to practice relights on the second stage (building up experience for GTO missions), or if they're trying to use it to start gathering data for F9R upper stage reuse, or something else entirely.

If the burn is to depletion it gives a data point on what total vehicle performance really is.

No surprise, but Antares nails it.

0.15% prop residuals at lox depletion, if I picked up correctly. [Edit: pretty much in line with expectations.]

Cheers, Martin

Elon said the stage ran for "a few seconds".  The acceleration at the end of the second stage burn is about 5 Gs, or about 50 m/s, so if "a few" seconds is 3, then they had about 150 m/s to spare.

[pagheca]

something that really amazed me in the livestream of the launch, was to see people actually keeping WORKING in the SpaceX factory, while the Falcon 9 was still ascending. And other people to leave the crowd behind the glass enclosing the tidy and minimalistic control room well before MECO, like if there was something else more important to do. Can you imagine that? I can't.

[Jim]

something that really amazed me in the livestream of the launch, was to see people actually keeping WORKING in the SpaceX factory, while the Falcon 9 was still ascending. And other people to leave the crowd behind the glass enclosing the tidy and minimalistic control room well before MECO, like if there was something else more important to do. Can you imagine that? I can't.

I can.  I have slept through some of the launches I worked on (because I was up for 36-48 hrs) and if there was a scrub, I would have to do it again.

[mgfitter]

Elon said the stage ran for "a few seconds".  The acceleration at the end of the second stage burn is about 5 Gs, or about 50 m/s, so if "a few" seconds is 3, then they had about 150 m/s to spare.

5g with payload mass.

Without payload, the acceleration will be a lot higher than that.

-MG.

[watermod]

Elon Musk ‏@elonmusk  1h
Flight computers continued transmitting for 8 seconds after reaching the water. Stopped when booster went horizontal.

So 8 seconds max instead of 3?

[LouScheffer]

Elon said the stage ran for "a few seconds".  The acceleration at the end of the second stage burn is about 5 Gs, or about 50 m/s, so if "a few" seconds is 3, then they had about 150 m/s to spare.

5g with payload mass.

Without payload, the acceleration will be a lot higher than that.

-MG.

Agreed, but when you are figuring mission margin you need the number you would get with the payload attached, not the higher number the second stage actually got since it had no payload.

[ChrisWilson68]

Elon Musk ‏@elonmusk  1h
Flight computers continued transmitting for 8 seconds after reaching the water. Stopped when booster went horizontal.

So 8 seconds max instead of 3?

The 3 second number was for the de-orbit burn of the upper stage.  The 8 seconds was for the first stage, after it landed on the water.  They are unrelated numbers.

[corrodedNut]

Just a thought....

Could returning rocket booster stages one day be fitted with a black box to enable/facilitate data recovery by ocean-going crews?

It has before, Musk called it the "Talon Pod"

[TrevorMonty]

Congratulations SpaceX on a successful launch and soft landing.
Here's hoping for a successful dragon docking.

Just a thought....

Could returning rocket booster stages one day be fitted with a black box to enable/facilitate data recovery by ocean-going crews?

I suspect recovery ship is being overly cautious until the booster has proven it can land precisely. Wouldn't do have recovery ship taken out by returning booster. Ship should be lot closer in future landings.