|
|
|
Thread Tools | Display Modes |
|
#1
|
|||
|
|||
Falcon 9 Delivers Dragon Into Orbit, Flubs Landing
Falcon 9 Delivers Dragon Into Orbit, Flubs Landing http://aviationweek.com/space/falcon...n-orbit-flubs- landing Note that's not my title, that's Aviation Week & Space Technology's title. I LOL-ed because why don't they use this headline with every Atlas V, Delta IV, Ariane V, Soyuz, Proton, and etc. launch? Because every single one of them never even attempts to recover the firs stage. Now obviously there was a failure. Musk tweeted that a grid fin pump failed. You could see in the live stream video that the grid fin on the right side of the camera's frame kept tilting to the right, but never tilted back to the left. That triggered the stage's automatic abort system, which kept the landing trajectory on a spot on the ocean instead of redirecting towards the landing pad. That worked well. They do this on every landing, including on the autonomous drone ship, so that if anything goes wrong, it's not going to damage the landing facility (be it fixed or floating). That happened to the core stage of the Falcon Heavy on its first flight. It ran out of "starting fluid" for its engines and splashed down hard instead of hitting the autonomous drone ship. Also, the stage managed to land very well on the ocean (as can be seen in a video posted by an observer on social media). SpaceX also released the on board camera footage from the stage which showed that once the landing burn started, the engines were able to negate the roll caused by the stuck grid fin. All in all it landed very well (just in the ocean). After the ocean landing, Musk Tweeted, "Appears to be undamaged and is transmitting data. Recovery ship dispatched." Last I heard on Twitter last night, they had the stage secured to at least one ship and they were waiting for daylight (today) to resume recovery operations. I'm not sure this is something they've planned for in great detail, so how they get the stage back into port will be interesting. Luckily, they're not very far away from port. I still think it's funny that people focus so much on the landing when that's gravy for SpaceX. The primary customer (this time NASA) doesn't care if the landing succeeds or not, just that the payload (this time Dragon) gets into the correct orbit. By all accounts, this was yet another successful *launch* of Falcon 9. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
#2
|
|||
|
|||
Falcon 9 Delivers Dragon Into Orbit, Flubs Landing
I wonder if it's useful to add a backup pump since this has never happened
before in almost 40 landings. They should first find the root cause of the failure, maybe it's something minor and the pump itself. I doubt if a pump system would fail if it was properly manufactured and installed over the liftime of the stage. "Jeff Findley" wrote in message ... Falcon 9 Delivers Dragon Into Orbit, Flubs Landing http://aviationweek.com/space/falcon...n-orbit-flubs- landing Note that's not my title, that's Aviation Week & Space Technology's title. I LOL-ed because why don't they use this headline with every Atlas V, Delta IV, Ariane V, Soyuz, Proton, and etc. launch? Because every single one of them never even attempts to recover the firs stage. Now obviously there was a failure. Musk tweeted that a grid fin pump failed. You could see in the live stream video that the grid fin on the right side of the camera's frame kept tilting to the right, but never tilted back to the left. That triggered the stage's automatic abort system, which kept the landing trajectory on a spot on the ocean instead of redirecting towards the landing pad. That worked well. They do this on every landing, including on the autonomous drone ship, so that if anything goes wrong, it's not going to damage the landing facility (be it fixed or floating). That happened to the core stage of the Falcon Heavy on its first flight. It ran out of "starting fluid" for its engines and splashed down hard instead of hitting the autonomous drone ship. Also, the stage managed to land very well on the ocean (as can be seen in a video posted by an observer on social media). SpaceX also released the on board camera footage from the stage which showed that once the landing burn started, the engines were able to negate the roll caused by the stuck grid fin. All in all it landed very well (just in the ocean). After the ocean landing, Musk Tweeted, "Appears to be undamaged and is transmitting data. Recovery ship dispatched." Last I heard on Twitter last night, they had the stage secured to at least one ship and they were waiting for daylight (today) to resume recovery operations. I'm not sure this is something they've planned for in great detail, so how they get the stage back into port will be interesting. Luckily, they're not very far away from port. I still think it's funny that people focus so much on the landing when that's gravy for SpaceX. The primary customer (this time NASA) doesn't care if the landing succeeds or not, just that the payload (this time Dragon) gets into the correct orbit. By all accounts, this was yet another successful *launch* of Falcon 9. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
#3
|
|||
|
|||
Falcon 9 Delivers Dragon Into Orbit, Flubs Landing
"Rocket Man" wrote on Thu, 6 Dec 2018
14:59:44 +0100: I wonder if it's useful to add a backup pump since this has never happened before in almost 40 landings. No and I doubt anyone is even considering that. They should first find the root cause of the failure, maybe it's something minor and the pump itself. I doubt if a pump system would fail if it was properly manufactured and installed over the liftime of the stage. You figure out what sort of failure the pump had. If it's something other than a 'one off' failure, you make the pump more robust against that type of failure. -- "Insisting on perfect safety is for people who don't have the balls to live in the real world." -- Mary Shafer, NASA Dryden |
#4
|
|||
|
|||
Falcon 9 Delivers Dragon Into Orbit, Flubs Landing
|
#5
|
|||
|
|||
Falcon 9 Delivers Dragon Into Orbit, Flubs Landing
|
#6
|
|||
|
|||
Falcon 9 Delivers Dragon Into Orbit, Flubs Landing
On 18-12-06 13:06 , Jeff Findley wrote:
Also, the stage managed to land very well on the ocean (as can be seen in a video posted by an observer on social media). SpaceX also released the on board camera footage from the stage which showed that once the landing burn started, the engines were able to negate the roll caused by the stuck grid fin. I thought the landing uses only one engine, therefore probably the center engine -- then how can the engine control roll? I don't understand. In the videos it seems that the roll rate does not decrease much during the landing burn, until just before and mainly after the landing legs are deployed. Deploying the legs moves mass out from the roll axis and therefore decreases roll rate, independently of the engines. All in all it landed very well (just in the ocean). It was significantly tilted at touch-down. Perhaps one or two legs would have crushed their crushables if it had been a hard surface. But I'm impressed that it managed to land at all with that roll rate. Before the entry burn, at about 29:45 in the SpaceX launch video, a white, spiky ring of some sort came off the area around the left-hand grid-fin in the on-board video. Commentators described it as some frozen condensation, but it looked curiously regular for that... I haven't seens anything like that in earlier launches. By all accounts, this was yet another successful *launch* of Falcon 9. Yes indeed. -- Niklas Holsti Tidorum Ltd niklas holsti tidorum fi . @ . |
#7
|
|||
|
|||
Falcon 9 Delivers Dragon Into Orbit, Flubs Landing
Niklas Holsti wrote on Thu, 6 Dec 2018
19:01:58 +0200: On 18-12-06 13:06 , Jeff Findley wrote: Also, the stage managed to land very well on the ocean (as can be seen in a video posted by an observer on social media). SpaceX also released the on board camera footage from the stage which showed that once the landing burn started, the engines were able to negate the roll caused by the stuck grid fin. I thought the landing uses only one engine, therefore probably the center engine -- then how can the engine control roll? I don't understand. The same way any other single engine booster controls roll, I would think. The engine gimbals. -- "Insisting on perfect safety is for people who don't have the balls to live in the real world." -- Mary Shafer, NASA Dryden |
#8
|
|||
|
|||
Falcon 9 Delivers Dragon Into Orbit, Flubs Landing
|
#9
|
|||
|
|||
Falcon 9 Delivers Dragon Into Orbit, Flubs Landing
Jeff Findley wrote on Fri, 7 Dec 2018
07:17:04 -0500: In article , says... Niklas Holsti wrote on Thu, 6 Dec 2018 19:01:58 +0200: On 18-12-06 13:06 , Jeff Findley wrote: Also, the stage managed to land very well on the ocean (as can be seen in a video posted by an observer on social media). SpaceX also released the on board camera footage from the stage which showed that once the landing burn started, the engines were able to negate the roll caused by the stuck grid fin. I thought the landing uses only one engine, therefore probably the center engine -- then how can the engine control roll? I don't understand. The same way any other single engine booster controls roll, I would think. The engine gimbals. That would be a neat trick. Or not. On Falcon 1, that version of Merlin had a gimbal on the turbo-pump exhaust for roll control. As far as I know, they deleted that feature on Merlins used for Falcon 9 since the extra complexity wasn't needed anymore. Wiki indicates that the ability to gimbal was removed as of the Merlin 1C engine. Everything else I find, including the Payload User's Guide, indicates that the Merlin 1D engines on a Falcon 9 do indeed still have the ability to gimbal and gimballing is used to control pitch, yaw, and roll for the first stage. -- "Now I'm hiding in Honduras. I'm a desperate man. Send lawyers, guns and money. The **** has hit the fan." -- "Send Lawyers, Guns, and Money", Warren Zevon |
#10
|
|||
|
|||
Falcon 9 Delivers Dragon Into Orbit, Flubs Landing
|
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
SpaceX video showing Falcon 9 stages and Dragon performing avertical landing | David Spain | Policy | 14 | October 15th 11 09:51 PM |
SpaceX video showing Falcon 9 stages and Dragon performing avertical landing | Space Cadet[_1_] | Policy | 7 | October 6th 11 09:00 PM |
Dragon/Falcon 9 Update | [email protected] | Policy | 16 | October 7th 09 04:42 PM |
No escape tower on Dragon / Falcon 9 | [email protected] | Policy | 0 | September 30th 08 03:43 PM |
ESA flubs Titan Landing show | Ken | Amateur Astronomy | 36 | January 19th 05 08:00 PM |