Did you notice that our two launch times are of an hour?
You wrote 4:43 Eastern Standard Time - The launch time I copied in says 4:43 p.m. Eastern Daylight Time
If DST happend to you then using EST is incorrect and will results in incorrect converting results because your timezone hast switched to EDT.
Using EST in summer is only correct if you happen to be in places like Jamaica or Haiti. Confusing as hell…
That’s why most timezone converters offer you to enter city names instead of time-zones, cities usually stay where they are no matter what happens around them…
I already posted this in the awesomes of the internets thread
Yes because I never take notice if I say EST or EDT or PST or PDT. I think daylight savings is a thing of the past and it’s unimportant to differentiate the two at this point because, in general, devices(be it mobile phones or computers) decide local time for you.
“…Following stage separation, the first stage of the Falcon 9 will attempt an experimental landing on the “Of Course I Still Love You” droneship in the Atlantic Ocean.”
As of first typing this post, there is about 3.5 hours until launch(with 2 minutes to spare) with weather at 90% go. Everyone is invited! Even @LucasFIN as long as he agrees not to touch anything…
I might have to leave early for a work meeting but I told them rockets are launching and that it’s more important so we’ll see how that works out…
Edit2: Yes you are right! I forgot to mention that they will be attempting a droneship landing on OCISLY roughly 300km offshore. Why not a return to landing site(RTLS) you might ask? Orbcomm did it why can’t dragon? Great question! While I haven’t run the numbers myself, dragon is a pretty light payload and it’s only going to LEO. This leaves a lot of extra performance and it should be capable of RTLS. However, the rumormill is running full steam(combustion) ahead and the standard speculation is that SpaceX really wants to nail the barge landings.
Why??? You are surely asking…this is because Falcon Heavy is set to debut later this year. For those not in the know: FH is basically a falcon 9, with 2 more falcon 9 first stages strapped to the sides so it’s basically 3 falcon9 cores with a second stage. The boosters will run 100%, while the center core throttled down so the boosters separate first, and will RTLS. However, the center core will be going much faster and much farther downrange when MECO occurs, forcing the center core to land on a barge. Hence, the necessity to nail barge landings before they start flying FH so that SpaceX can stop wasting cores.
It’s a really funny concept, wasting cores, because until now it was business as usual.
I couldn’t watch it live this time around either, I was traveling. But I kept refreshing the spacex subreddit via mobile internet so I at least got the events in a somewhat timely manner. Really cool that they pulled it off, now the next really new thing to look forward to is when the 2 boosters of Falcon Heavy return side by side.
Loved the new cameras they had on the second stage.
I was still holding my breath for some time after touchdown hoping it wouldn’t just slowly tip over from the swells, but the ship seems to do a remarkable job of maintaining relative stability. Plus it simply looks more unstable than it really is, the legs are quite wide and Elon mentioned that it would probably take an angle of about 8-10 degrees to tip it over. Someone estimated under ideal conditions (no wind or choppy water) that the first stage could theoretically tip to about 23 degrees without falling over (though it would be one hell of a balancing act). See that answer on space.stackexchange: http://space.stackexchange.com/a/9199/10736
I’m sure a lot of us were doing that. I certainly was. It looks terribly ungainly, perched upright like that, but all the weight was at the bottom, so I doubt there was much chance of a tipover. I wonder if it tends to slide around at all…
Here’s a guy’s speculative answer to the question of tipover angles. Note how low the center of gravity is located - and how far over the thing would have to tip. I suspect the landing struts would collapse before it tilted 23 degrees.
I would not allow myself to place a bet on sliding vs tipping over
Steel will not slide on steel if the angel is below 8,5°
If they added something else on the bottom to prevent sliding that angel can rise beyond 20°
But if you don’t allow it to slide it will tip faster.
That 23° tipping point in that sketch is the point where it tips in a static environment.
Boots are not static. If I get it right the guy that made that sketch used the 23° as base for his calculations on how strong winds the rocket can “absorb” before it gets blown over.
But I think the force that will tip over the rocket first is the ships movement.
Elon guessed 10° is max.
And i guess if the boat really moves more than 10 degrees up and then falls back again to go 10 degrees into the other side that movement will accelerate the rocket strong enough so that its inertia will carry it beyond those 23 degrees.
There is a reason why they rush in to weld the landing shoes onto the deck after a successful landing - it’s stable, but not very stable
Don’t forget that there water so it’s on a slick deck. I don’t know if you ever been out on a boat and walked around on a slick deck, but it’s not easy. Even less so with you have metal on metal…the rule of thumb is stuff wants to slide on a boat and it’s up to you to secure it first. I can easily see it sliding when hitting a larger swell, especially if it hasn’t vented all the fuel yet when adds not only a higher CoM, but additional inertia within the rocket once the fuel slams into the other side of the rocket.
I would argue that sliding is the single largest threat to the rocket, statistically speaking.
