advertisement
Forums

The Forum is sponsored by 
 

AAPL stock: Click Here

You are currently viewing the Tips and Deals forum
SpaceX - Missed it by that much...
Posted by: GGD
Date: February 17, 2020 02:50PM
Successful Starlink launch and deploy, but the stage one landing totally missed the drone ship. You can see some smoke/mist in the upper right corner.

[youtu.be]

I do wonder how the booster locates the drone ship during the final descent, shared GPS coordinates, some sort of homing beacon, or cameras and "visual" targeting.

It looks more like it thought the ship was in a different location since it's wasn't even close to the deck at all. Will be interesting to hear what they figure out about what caused this miss.

Haven't seen any word on the fairing recovery for this flight.
Options:  Reply • Quote
Re: SpaceX - Missed it by that much...
Posted by: Ombligo
Date: February 17, 2020 03:18PM
First miss since 2016.



“No persons are more frequently wrong, than those who will not admit they are wrong.”
-- François de La Rochefoucauld

"WE CALL BS!" -- Emma Gonzalez
Options:  Reply • Quote
Re: SpaceX - Missed it by that much...
Posted by: jdc
Date: February 17, 2020 03:33PM




----


Edited 999 time(s). Last edit at 12:08PM by jdc.
Options:  Reply • Quote
Re: SpaceX - Missed it by that much...
Posted by: gabester
Date: February 17, 2020 03:55PM
Would not be surprised to discover there was a nearby Russian submarine engaged in GPS spoofing, although that would likely be detected by the ship too. Or perhaps the booster had accurate GPS and the ship did not due to GPS spoofing, and the landing optimization routine feeds the data from the ship to the booster (which would make sense...)

It will be interesting to find out the why. Don't forget there was a booster last year with an inoperable grid fin which they let dunk in the sea rather than risk a catastrophic pad attempt... and how many times was this booster used prior? I'm guessing 3 or more...
Options:  Reply • Quote
Re: SpaceX - Missed it by that much...
Posted by: Ombligo
Date: February 17, 2020 04:34PM
A number of space junkies are pointing to a cable that broke free and could be seen hitting the booster as it fell away, others are also saying that a landing leg deployed oddly. Some speculation that it may have altered the aerodynamics and balance.

Still, pretty amazing that this is even a discussion compared to just a decade ago.

Finally, compare it to Boeing - they consider getting a booster to just get back to Earth as a successful landing.



“No persons are more frequently wrong, than those who will not admit they are wrong.”
-- François de La Rochefoucauld

"WE CALL BS!" -- Emma Gonzalez
Options:  Reply • Quote
Re: SpaceX - Missed it by that much...
Posted by: ztirffritz
Date: February 17, 2020 04:51PM
From previous misses, I've heard that it has code that has a make or break limit. If location or various sensors are so far off nominal that it can't recover it intentionally steers away from the drone ship. This one made a soft landing and they were able to vent the tanks so they may still recover it, albeit, somewhat water logged. If they use them for Starlink missions, the quality thresholds can be much lower.



**************************************
MacResource User Map: [www.zeemaps.com]#
Options:  Reply • Quote
Re: SpaceX - Missed it by that much...
Posted by: ztirffritz
Date: February 17, 2020 04:52PM
Quote
gabester
Would not be surprised to discover there was a nearby Russian submarine engaged in GPS spoofing, although that would likely be detected by the ship too. Or perhaps the booster had accurate GPS and the ship did not due to GPS spoofing, and the landing optimization routine feeds the data from the ship to the booster (which would make sense...)

It will be interesting to find out the why. Don't forget there was a booster last year with an inoperable grid fin which they let dunk in the sea rather than risk a catastrophic pad attempt... and how many times was this booster used prior? I'm guessing 3 or more...

This was it's 4th launch.



**************************************
MacResource User Map: [www.zeemaps.com]#
Options:  Reply • Quote
Re: SpaceX - Missed it by that much...
Posted by: sekker
Date: February 17, 2020 06:50PM
Odd, nothing on Twitter at all from SpaceX or Musk beyond this was the 80th successful Falcon9 launch.



Edited 1 time(s). Last edit at 02/17/2020 06:50PM by sekker.
Options:  Reply • Quote
Re: SpaceX - Missed it by that much...
Posted by: RAMd®d
Date: February 17, 2020 10:31PM
I wonder if the ship or anybody on land can see the booster's instruments, as Tesla can with the car's instruments.

As in if somebody spoofed GPS coordinates, could the ship see that on the booster?



Silly question - of course they can.




When a good man is hurt,
all who would be called good
must suffer with him.

You and I have memories longer than the road that stretches out ahead.

There is no safety for honest men except
by believing all possible evil of evil men.

We don’t do focus groups. They just ensure that you don’t offend anyone, and produce bland inoffensive products. —Sir Jonathan Ive

Perfection is the enemy of progress. -Winston Churchill

-An armed society is a polite society.
And hope is a lousy defense.

You make me pull, I'll put you down.

Mister, that's a ten-gallon hat on a twenty-gallon head.

I *love* SIGs. It's Glocks I hate.




Edited 1 time(s). Last edit at 02/17/2020 10:41PM by RAMd®d.
Options:  Reply • Quote
Re: SpaceX - Missed it by that much...
Posted by: gabester
Date: February 18, 2020 01:18AM
Quote
ztirffritz
From previous misses, I've heard that it has code that has a make or break limit. If location or various sensors are so far off nominal that it can't recover it intentionally steers away from the drone ship. This one made a soft landing and they were able to vent the tanks so they may still recover it, albeit, somewhat water logged. If they use them for Starlink missions, the quality thresholds can be much lower.

This is, of course, much more sensible that my paranoid exclamation "OMGz itz the Russkiiz!"
Options:  Reply • Quote
Re: SpaceX - Missed it by that much...
Posted by: Buzz
Date: February 18, 2020 08:14PM
I'm kinda surprised they don't use an airborne drone/plane with a laser guidance beam like used for guiding smart bombs.... at least to guide the booster close enough to the landing ship so that the automatic stuff can take over. Although they've had a pretty good run without it the last few years, maybe just as a redundant backup system?
==
Options:  Reply • Quote
Re: SpaceX - Missed it by that much...
Posted by: Paul F.
Date: February 19, 2020 01:30PM
Regarding guidance;
The booster is 100% autonomous... it aims for it’s pre-programmed spot in the ocean. It neither knows nor cares if the drone ship is actually there. The drone ships job is to be exactly on that spot when the booster comes in... also not knowing or caring where the booster is.

As for last moment “abort to sploosh”... the booster makes a last moment poll of its position, attitude, altitude, systems check (fuel state, landing legs, tank pressures, etc), and decides “ Go to land”, or “ Abort 300 meters off programmed landing spot”.
I haven’t read much about this mission (been out of town with limited internet), so I assume some parameter was off enough for the boosters “barge destruction avoidance system” to be activated.

Still, fourth flight of that booster, and 60 satellites delivered to orbit... not a failure.



Paul F.
-----
A sword never kills anybody; it is a tool in the killer's hand. - Lucius Annaeus Seneca c. 5 BC - 65 AD
----
Good is the enemy of Excellent. Talent is not necessary for Excellence.
Persistence is necessary for Excellence. And Persistence is a Decision.

--

--

--
Eureka, CA
Options:  Reply • Quote
Sorry, only registered users may post in this forum.

Click here to login

Online Users

Guests: 112
Record Number of Users: 186 on February 20, 2020
Record Number of Guests: 2330 on October 25, 2018