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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

by FD3SA 12y ago

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 https://twitter.com/elonmusk/with_replies

mikeyouse 12y ago
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.
- JohnnyBrown 12y ago
  I believe the 0 m/s refers to the boost stage's speed after a successful landing.
  - nardi 12y ago
    Since this is over the ocean, I interpreted this to mean reaching a state of stable hover.
    - lutorm 12y ago
      It does, but the hover is at sea level... ;-)
- FD3SA 12y ago
  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 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.
  - mikeyouse 12y ago
    Woooooooo! I was probably unnecessarily optimistic, but I'm so glad they are making this much progress so quickly!
  - jval 12y ago
    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.
    - yock 12y ago
      The F9R would be the first sub-orbital booster to return to Earth and land vertically under its own engine thrust.
    - pbreit 12y ago
      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_development_program#Economic_issues http://en.wikipedia.org/wiki/SpaceX_reusable_launch_system_d...
lutorm 12y ago
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.

by FD3SA 12y ago

mikeyouse 12y ago

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.

JohnnyBrown 12y ago
I believe the 0 m/s refers to the boost stage's speed after a successful landing.
- nardi 12y ago
  Since this is over the ocean, I interpreted this to mean reaching a state of stable hover.
  - lutorm 12y ago
    It does, but the hover is at sea level... ;-)
FD3SA 12y ago
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 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.
- mikeyouse 12y ago
  Woooooooo! I was probably unnecessarily optimistic, but I'm so glad they are making this much progress so quickly!
- jval 12y ago
  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.
  - yock 12y ago
    The F9R would be the first sub-orbital booster to return to Earth and land vertically under its own engine thrust.
  - pbreit 12y ago
    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_development_program#Economic_issues http://en.wikipedia.org/wiki/SpaceX_reusable_launch_system_d...

lutorm 12y ago

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.