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1. FD3SA+(OP)[view] [source] 2014-04-18 16:30:52
Elon has just confirmed [1] that they will be attempting to recover the first stage. This is the first flight with the landing leg module attached to the first stage. The landing legs will be deployed over sea for a soft landing in preparation for a land-based recovery.

This will be a historic moment if the recovery succeeds, ushering in a new era of space travel due to the massively reduced operating costs of recoverable engines.

1. https://twitter.com/elonmusk

replies(2): >>joezyd+S >>FD3SA+ep
2. joezyd+S[view] [source] 2014-04-18 16:40:57
>>FD3SA+(OP)
Is Musk planning to have his drones watch the landing? I'm guessing that's what the "recovery ship" would be doing, although his twitter feed is saying that heavy seas might make that difficult.
replies(2): >>Brando+A8 >>toomuc+bs
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3. Brando+A8[view] [source] [discussion] 2014-04-18 18:00:49
>>joezyd+S
That would be awesome. I was astounded the first time I saw one of their McGregor, Texas rocket tests from the point-of-view of a hexacopter flying near the rocket's flightpath.

https://www.youtube.com/watch?v=9ZDkItO-0a4

In this video, the copter is actually HOVERING ABOVE the rocket as the rocket descends back down to the launchpad. The only time I've ever seen something like that before was Hollywood (Apollo 13, and then when the footage was re-used in Austin Powers 2).

4. FD3SA+ep[view] [source] 2014-04-18 21:24:15
>>FD3SA+(OP)
Update from Elon [1]:

"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!)"

So it appears it may be a failure, we'll find out soon what went wrong this time. More from Elon regarding what success would be, telemetry wise:

"Rocket boost stage reaching 0 m/s in one piece :) Will know soon. Odds not high." [1]

Regardless, they've demonstrated that the landing-leg module can survive the stresses of liftoff and fully powered flight, particularly at Max Q. This is quite an achievement, and vital for future tests.

1. https://twitter.com/elonmusk/with_replies

replies(2): >>mikeyo+ts >>lutorm+Cv
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5. toomuc+bs[view] [source] [discussion] 2014-04-18 22:06:41
>>joezyd+S
Quadcopters don't have the endurance to hover in the recovery zone, unless one of the SpaceX recovery ships were to deploy them.

Ideally, you'd use something like a Predator or Reaper with long endurance and stabilized optics. At $4MM per drone (new), that's not outside the realm of possibility.

replies(1): >>SEJeff+vv
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6. mikeyo+ts[view] [source] [discussion] 2014-04-18 22:10:11
>>FD3SA+ep
I think you're reading more into his comment than he intended. The first tweet,

    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!)
Was a very upbeat message in the context of their previous attempts.

This rocket was only doing 360 m/s, but importantly, wasn't rolling at all -- Their last 'test' failed when the rocket started rolling at a very high rate of speed and they lost engine power.

Musk was then asked:

    if anything could go better, what would it be?
To which he replied:

    Rocket boost stage reaching 0 m/s in one piece :)
    Will know soon. Odds not high.
The first line is just a joke that the test would go better if the rocket got to the surface in 1 piece. I think his 'odds not high' statement is just to dampen excitement a bit, since they went into this with a ~40% chance of success for the landing stage.
replies(2): >>Johnny+lw >>FD3SA+vy
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7. SEJeff+vv[view] [source] [discussion] 2014-04-18 23:05:39
>>toomuc+bs
You don't buy a single predator, you buy a set of them, along with all of the support gear including the ground control station, and support from the manufacturer. - former shadow 200 military drone pilot
replies(1): >>toomuc+zx
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8. lutorm+Cv[view] [source] [discussion] 2014-04-18 23:08:15
>>FD3SA+ep
They said during the press conference that the 8.5km altitude is when they lost telemetry from the cape due to the stage going below the horizon. Further data will come from the plane, but they didn't have those data yet. So the end of data at that point does not imply a failure.
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9. Johnny+lw[view] [source] [discussion] 2014-04-18 23:22:45
>>mikeyo+ts
I believe the 0 m/s refers to the boost stage's speed after a successful landing.
replies(1): >>nardi+JB
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10. toomuc+zx[view] [source] [discussion] 2014-04-18 23:50:46
>>SEJeff+vv
Can you rent time from a non-military agency? I know NASA has at least one Global Hawk.
replies(2): >>toomuc+fF >>SEJeff+mZ
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11. FD3SA+vy[view] [source] [discussion] 2014-04-19 00:11:43
>>mikeyo+ts
Agreed, it appears I was unnecessarily pessimistic. Seems like SpaceX has pulled it off [1]:

"Data upload from tracking plane shows landing in Atlantic was good! Several boats enroute through heavy seas."

Congrats to the SpaceX team if this is the case. I've been glued to my laptop since the launch. I can finally say we've made a significant breakthrough in aerospace during my lifetime.

The last time a breakthrough of this magnitude occurred was during the Apollo program.

1. https://twitter.com/elonmusk/status/457307742495993856

UPDATE: Further confirmation.

"Flight computers continued transmitting for 8 seconds after reaching the water. Stopped when booster went horizontal."

It appears that we've witnessed history today ladies and gentlemen.

replies(2): >>mikeyo+IB >>jval+bJ
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12. mikeyo+IB[view] [source] [discussion] 2014-04-19 01:27:32
>>FD3SA+vy
Woooooooo!

I was probably unnecessarily optimistic, but I'm so glad they are making this much progress so quickly!

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13. nardi+JB[view] [source] [discussion] 2014-04-19 01:27:33
>>Johnny+lw
Since this is over the ocean, I interpreted this to mean reaching a state of stable hover.
replies(1): >>lutorm+8D
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14. lutorm+8D[view] [source] [discussion] 2014-04-19 02:01:33
>>nardi+JB
It does, but the hover is at sea level... ;-)
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15. toomuc+fF[view] [source] [discussion] 2014-04-19 02:43:58
>>toomuc+zx
Addition/Edit: They own at least two: http://www.nasa.gov/centers/armstrong/aircraft/GlobalHawk/in...
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16. jval+bJ[view] [source] [discussion] 2014-04-19 05:02:07
>>FD3SA+vy
Wow, I had no idea this was such a breakthrough. I'm not in the industry and I barely know anything about this, but can you explain what it is about recovering the booster that is such a huge breakthrough? Haven't we had recoverable space equipment for ages (e.g. space shuttle?) Forgive what is surely an ignorant question.
replies(4): >>yock+cK >>pbreit+uK >>HenryM+zT >>andrew+m41
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17. yock+cK[view] [source] [discussion] 2014-04-19 05:44:18
>>jval+bJ
The F9R would be the first sub-orbital booster to return to Earth and land vertically under its own engine thrust.
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18. pbreit+uK[view] [source] [discussion] 2014-04-19 05:58:41
>>jval+bJ
SpaceX suggested that the boosters account for upwards of 75% if the rocket's cost so reuse is a huge economic benefit. SpaceX estimated that it could reduce a launch from $60m to under $10m.

The space shuttle did have recoverable boosters but the refurbishing process offered much less cost savings.

I believe no other rockets provide for booster recovery.

http://en.wikipedia.org/wiki/SpaceX_reusable_launch_system_d...

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19. HenryM+zT[view] [source] [discussion] 2014-04-19 12:40:21
>>jval+bJ
The Space Shuttle was only partially recoverable. There were three main parts to the system.

1. The shuttle itself - this needed extensive maintenance work done to it after each flight.

2. The big orange fuel tank - this couldn't be reused

3. The solid rocket boosters on either side - these had to be completely rebuilt after they splashed down in the ocean (it is easier to splash them down in the ocean than the Falcon 9 first stage, as they separate at a lover altitude).

Overall this didn't save much on costs, with the average cost of a flight (inclusive of development costs) being about US$1.5 billion.

replies(1): >>hga+pW
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20. hga+pW[view] [source] [discussion] 2014-04-19 14:12:49
>>HenryM+zT
"The shuttle itself - this needed extensive maintenance work done to it after each flight."

Including complete rebuilds for the three Space Shuttle Main Engines (SSMEs), they were I gather somewhat needlessly too high performance/sports car types of devices.

In general, the Space Shuttle design was twisted by various unnecessary requirements (e.g. while the Air Force didn't want it, it could originally do a single polar orbit mission, which required extreme heat shield technology to land back at the same location while the earth turned underneath it. This was later mitigated by replacing a lot of those tiles with a ... glass fiber mat???), and to minimize development costs. Solid fuel booster you can't turn off were formerly considered to be unacceptably dangerous for manned missions, but they were the cheapest to develop.

Operating costs? Well, NASA post-Apollo makes the most sense if you view it as a public works project.... Low launch rates, especially post-Challenger after more people realized what an abomination it was, plus a huge fixed work force made it very expensive to operate.

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21. SEJeff+mZ[view] [source] [discussion] 2014-04-19 15:31:53
>>toomuc+zx
Highly unlikely, the big UAVs tend to contain top secret avionics and we don't always want the world to know the capabilities of their payloads. It might be possible, but it would be a lot easier to call IAI or Northrop and ask if they would rent it to you.
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22. andrew+m41[view] [source] [discussion] 2014-04-19 17:09:27
>>jval+bJ
The key engineering problem that they solved is related to fuel and weight. They need more fuel for the landing, but more fuel adds more weight, which requires more fuel for lift off.
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