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SpaceX lands rocket at sea second time after satellite launch

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Re: SpaceX lands rocket at sea second time after satellite launch

#21

Post by dkbrk »

tigershark wrote: post #19
gpm wrote: post #10

Earlier quoted context omitted.

To expand on this slightly the CRS8 (and OG2, the land landing) landing was done using only 1 engine, which even then was presumably throttled. This landing burn was done using 3 engines so they spend less time below terminal velocity, and thus use less fuel. The total deceleration should be ~40 m/s during the burn.

40 m/s is a velocity, not an acceleration (deceleration). I guess that you mean 40 m/s^2

He did say total deceleration, so I believe he meant the landing burn starts at a velocity of 40 m/s and consequently the total ΔV of the landing burn is 40 m/s.

That said, I have no idea where he got that number, whether 40 m/s or 40 m/s^2; both are incorrect.

The best estimate available for the flight dynamics can be found at flightclub.io, specifically for JCSAT-14: https://flightclub.io/results/?id=eeaf889e-f3d8-4f9b-be98-b7...

This shows the landing burn starting at a velocity of 269 m/s and experiencing a peak deceleration of 12.3g = 121 m/s^2

I don't know how accurate these numbers are, but some fans put quite a bit of effort into getting the flightclub.io profiles as close to reality as possible, so they tend to be pretty good.

Re: SpaceX lands rocket at sea second time after satellite launch

#22

Post by SpaceX_Tech »

agildehaus wrote: post #11
haser_au wrote: post #3

Earlier quoted context omitted.

They said at the beginning of the live stream that they plan to do a test fire on the first recovered first stage "sometime soon".

The first recovered stage, F9-021, has already been static fired and will likely end up as a monument outside of SpaceX HQ as they've filed an FAA request to do so. https://oeaaa.faa.gov/oeaaa/external/searchAction.jsp?action... The second recovered rocket, F9-023, will be relaunched. It has already been static fired with no announced problems. Elon said it'd be a few months before a customer was announced, but the g…

Based on that FAA application it looks like someone will be losing their prime parking spot.

In all seriousness though, I'm not sure how I feel about this monument. It's going to be really crammed next to the main building and I don't think it will have a very strong visual presence with a giant grey wall directly in the background. There isn't really a good vantage point for viewing either. I suppose it will look ok from the opposite corner of Crenshaw.

Re: SpaceX lands rocket at sea second time after satellite launch

#23

Post by kchoudhu »

agildehaus wrote: post #11
haser_au wrote: post #3

Earlier quoted context omitted.

They said at the beginning of the live stream that they plan to do a test fire on the first recovered first stage "sometime soon".

The first recovered stage, F9-021, has already been static fired and will likely end up as a monument outside of SpaceX HQ as they've filed an FAA request to do so. https://oeaaa.faa.gov/oeaaa/external/searchAction.jsp?action... The second recovered rocket, F9-023, will be relaunched. It has already been static fired with no announced problems. Elon said it'd be a few months before a customer was announced, but the g…

Do customers get a discount for launching on a used rocket?

Re: SpaceX lands rocket at sea second time after satellite launch

#24

Post by SpaceX_Tech »

dba7dba wrote: post #18
CamperBob2 wrote: post #12

Earlier quoted context omitted.

Amusing... I was wondering why they needed to get FAA permission to park the rocket, but the application says it'll be 160 feet tall. So they're standing it up, as opposed to the NASA methodology of positioning their monuments horizontally.

There is no open space to park a 160ft long object horizontally anywhere near spacex HQ.

Not sure why your comment was downvoted but this is true, there really isn't much open space around the SpaceX property.

I wish we had a campus like Raytheon or Northrop have in El Segundo/Redondo Beach. The 60's & 70's were certainly the high points in aerospace campus architecture here in SoCal.

Re: SpaceX lands rocket at sea second time after satellite launch

#25

Post by coderdude »

SpaceX_Tech wrote: post #24
dba7dba wrote: post #18

Earlier quoted context omitted.

There is no open space to park a 160ft long object horizontally anywhere near spacex HQ.

Not sure why your comment was downvoted but this is true, there really isn't much open space around the SpaceX property. I wish we had a campus like Raytheon or Northrop have in El Segundo/Redondo Beach. The 60's & 70's were certainly the high points in aerospace campus architecture here in SoCal.

Do you work for SpaceX? You have it in your username and comment like you're part of the company, but also spend your time discussing the merits of the NRA. Do you represent SpaceX or are you just super enthusiastic about them? It's not easy to tell.

Re: SpaceX lands rocket at sea second time after satellite launch

#26

Post by lmm »

kchoudhu wrote: post #23
agildehaus wrote: post #11

Earlier quoted context omitted.

The first recovered stage, F9-021, has already been static fired and will likely end up as a monument outside of SpaceX HQ as they've filed an FAA request to do so. https://oeaaa.faa.gov/oeaaa/external/searchAction.jsp?action... The second recovered rocket, F9-023, will be relaunched. It has already been static fired with no announced problems. Elon said it'd be a few months before a customer was announced, but the g…

Do customers get a discount for launching on a used rocket?

The first one definitely will (unless negotiations break down and they decide to launch without a customer, but that seems unlikely). Eventually when it becomes routine maybe not.

Re: SpaceX lands rocket at sea second time after satellite launch

#27

Post by andygates »

agildehaus wrote: post #11
haser_au wrote: post #3

Earlier quoted context omitted.

They said at the beginning of the live stream that they plan to do a test fire on the first recovered first stage "sometime soon".

The first recovered stage, F9-021, has already been static fired and will likely end up as a monument outside of SpaceX HQ as they've filed an FAA request to do so. https://oeaaa.faa.gov/oeaaa/external/searchAction.jsp?action... The second recovered rocket, F9-023, will be relaunched. It has already been static fired with no announced problems. Elon said it'd be a few months before a customer was announced, but the g…

023 (Fnord) has been fired? I must have missed that. Got a link?

Re: SpaceX lands rocket at sea second time after satellite launch

#29

Post by SpaceX_Tech »

coderdude wrote: post #25
SpaceX_Tech wrote: post #24

Earlier quoted context omitted.

Not sure why your comment was downvoted but this is true, there really isn't much open space around the SpaceX property. I wish we had a campus like Raytheon or Northrop have in El Segundo/Redondo Beach. The 60's & 70's were certainly the high points in aerospace campus architecture here in SoCal.

Do you work for SpaceX? You have it in your username and comment like you're part of the company, but also spend your time discussing the merits of the NRA. Do you represent SpaceX or are you just super enthusiastic about them? It's not easy to tell.

I do work for SpaceX although I'm not in engineering or software dev. I work in the technician/skilled labor side of the house.

I don't think I've posted anything specifically discussing the merits of the NRA, although I have posted on the subject of gun control and self defense. In any case I'm not sure why discussing that topic and working at SpaceX would be mutually exclusive.

Obviously it should be said that I don't represent SpaceX and the views I express here are my own and not the company's.

Re: SpaceX lands rocket at sea second time after satellite launch

#30

Post by JumpCrisscross »

neals wrote: post #28

I always try to watch the webcasts and I can't help but cringe so hard when they start chanting 'USA USA USA', every single time. What is up with that?

It's an American company, hiring American engineers, and successfully competing with the interests of entire nation-states?
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