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SpaceX's Big Falcon Topic 2

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16 hours ago, Spockydog said:

Maybe. Time will tell. I just find it incredulous that a man whom many claim to be such a visionary is flogging a device whose only real purpose is arson, or burning people or animals alive.

 

I can go to any hardware store and buy an industrial version of one of these.  Or I can make one from a can of hairspray and a lighter for under $10.  While Musk's version may not be practical for soldering pipe... it's not much different.  And they are incredibly fun to play with. 

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12 hours ago, SpaceChampion said:

Really getting off-topic here.  Maybe take it to another thread?

Agreed.  Can we accept that Elon Musk is doing visionary things with space flight and quit looking for reasons to nitpick?

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Please tell us a bit more about the Falcon Heavy! 

As I understand it’s essentially 3 Falcon 9’s next to each other, right? Will they try to recover the first stage(s?) after the launch? If so, do the 3 pieces land as one or do they separate in flight and land separately?

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They wanted it as simple as strapping three F9's together, but found the center core needed some considerable reinforcement.  So the center boosters are custom made variant for Falcon Heavy.  The side boosters are from previously flown F9s.  The left one flew to the space station on the CRS-9 mission.  The right one flew the Thaicom satellite into space.  Both are "Block 3", an older design that SpaceX is willing to sacrifice on the F-Heavy demo flight if the whole thing blows up.  The center core is a previously unflown Block 3 version as well.  Once they prove FH with a couple of demo flights, they'll be using Block 5 versions, which is designed for more thrust and a long life of repeated reuse.

Yes, all 3 boosters will land.  The side boosters will separate first and land within seconds of each other on the Cape.  The center core starts with a low thrust to conserve fuel while the side boosters do the heavy work of lifting it at about Mach 10 past Max Q, the point of maximum dynamic pressure & drag on the rocket that it can take without destroying itself.  After the atmosphere thins out some, speed can increase to the Mach 25 or so needed to stay in orbit.  So the side boosters separate after Max Q and the center core goes full thrust, lifting the second stage.  The center core separates when it's down to about 4% fuel remaining and lands on the drone ship Of Course I Still Love You.

After that, the second stage burns to put the payload into its final orbit around the sun (probably a couple of separate burns to adjust trajectories).  It's unclear whether the Tesla Roadster will stay connected to the 2nd stage or separate, but a normal payload would separate just before being placed into its target orbit.  A reason to not separate is the 2nd stage batteries might be used to power cameras for the ride longer than the Tesla's batteries might last.  But I'm sure we'll see some great photos.

This video is similar to what the flight will look like except it wrongly has the center core landing on the Cape.

 

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First: thanks for the detailed explanation of the Falcon Heavy! Sounds like an awesome event. I’ll be glued to my screen.

Second, that’s really cool news about the survived rocket. Can soft landing in water be a potential standard procedure in the future? The accuracy demands will be considerably lower and a slight malfunction doesn’t necessarily need to be catastrophic. 

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3 hours ago, Erik of Hazelfield said:

Second, that’s really cool news about the survived rocket. Can soft landing in water be a potential standard procedure in the future? The accuracy demands will be considerably lower and a slight malfunction doesn’t necessarily need to be catastrophic. 

No, they're already pretty accurate, down to a few feet from the bulls-eye.  Just landed it on water because they weren't sure what would happen with the much higher than normal thrust retroburn, and didn't wanted to risk damaging the drone ship.  They expected it would at least break up a bit and sink.  They don't want water landings because seawater is harsh on the electronics.  It's a Block 3 version so they're not going to reuse it again.  They're only bringing it in because they can't just leave it out there as a hazard, but can take it apart and get good data on the stresses it went through.  The final version, Block 5, was designed after examining in detail the first recovered boosters a few years ago, so anything they learn from this will likely only apply to modifying the software if they find the rocket can treated harsher and still survive hundreds of flights.  How harsh they can treat it determines how much payload they can lift into space.

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On 1/30/2018 at 2:39 PM, Ser Scot A Ellison said:

Agreed.  Can we accept that Elon Musk is doing visionary things with space flight and quit looking for reasons to nitpick?

He's a visionary and he's a genius.

Edited by GAROVORKIN

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11 hours ago, SpaceChampion said:

No, they're already pretty accurate, down to a few feet from the bulls-eye.  Just landed it on water because they weren't sure what would happen with the much higher than normal thrust retroburn, and didn't wanted to risk damaging the drone ship.  They expected it would at least break up a bit and sink.  They don't want water landings because seawater is harsh on the electronics.  It's a Block 3 version so they're not going to reuse it again.  They're only bringing it in because they can't just leave it out there as a hazard, but can take it apart and get good data on the stresses it went through.  The final version, Block 5, was designed after examining in detail the first recovered boosters a few years ago, so anything they learn from this will likely only apply to modifying the software if they find the rocket can treated harsher and still survive hundreds of flights.  How harsh they can treat it determines how much payload they can lift into space.

Didn't they used to land in the water all the time and retrieve the capsules during the early years?

Or are you saying they've learned not to do that?

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30 minutes ago, Pony Queen Jace said:

Didn't they used to land in the water all the time and retrieve the capsules during the early years?

Or are you saying they've learned not to do that?

We're talking about the 1st stage boosters, not the capsules.   Just looked at the record -- only 3 times in 2014 over a 5 month period.  They were just testing the retropulsion landing burn for that, and got the data they wanted in order to begin trying to landing it on the ship.  That was never intended to be an option for the long term.

The capsules are a different story.  They still land the Dragons on water as it is designed for.  They intended to have Dragon 2 (the crew version) land on land, but NASA isn't allowing the placement of the landing legs to pop out through the heat shield (that frightens them because of the Shuttle Columbia's loss due to heat shield damage) so they'll never certify it to fly.  So SpaceX abandoned that idea since the intention to move on to BFR makes that method of landing obsolete.  The BFR's heat shield is on it's side, so it comes down on its belly to present a wide profile to the atmosphere, then spins around for engines down to land on its legs -- good for Mars or Earth.

Edited by SpaceChampion

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7 minutes ago, SpaceChampion said:

Just looked at the record -- only 3 times in 2014 over a 5 month period.  They were just testing the retropulsion landing burn for that, and got the data they wanted in order to begin trying to landing it on the ship.  That was never intended to be an option for the long term.

I meant like the 60's

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Tuesday is going to be interesting - Musk has been pretty vocal about the likelihood of failure.  27 engines and only one needs to have a catastrophic failure for there to be a big failure.  The payload is one of the original Tesla roadsters from his personal collection.  Musk said that so long as the pad isn't destroyed he'll call it a win.  We'll see.  I hope it reaches orbit.

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