RocketLab Discussion Thread

[tater]

 

[tater]

 

[PakledHostage]

I see that their second stage jettisons its batteries about mid burn. It's on a trajectory that takes it south over Antarctica from New Zealand.  I hope debris from the batteries doesn't survive reentry to litter the ice? Not cool, if so... Does anyone know where the batteries re-enter? Maybe they overfly Antarctica and land in the Indian or Atlantic Oceans on the other side?

[darthgently]

49 minutes ago, PakledHostage said:

I see that their second stage jettisons its batteries about mid burn. It's on a trajectory that takes it south over Antarctica from New Zealand.  I hope debris from the batteries doesn't survive reentry to litter the ice? Not cool, if so... Does anyone know where the batteries re-enter? Maybe they overfly Antarctica and land in the Indian or Atlantic Oceans on the other side?

I remember hearing in an interview (maybe?) that given the materials and velocities involved it all ends up as smoke practically speaking.  It is annoying that you or I could technically get fined for disposing of tiny Li coin cell batteries by burning them, but it's ok to burn what I'm guessing are batteries at least the size of shoe boxes

Edited January 31, 2024 by darthgently

[PakledHostage]

Antarctica is delicate and there is pressure (and some acceptance, internationally) that it be set aside as an ecological and scientific preserve. I'd hope that Rocket Lab (and anyone else) would ensure that they aren't re-entering debris over it. To paraphrase the meme: all your base are not belong to us... There are parts of the world we should leave alone. 

[CatastrophicFailure]

1 hour ago, PakledHostage said:

Antarctica is delicate and there is pressure (and some acceptance, internationally) that it be set aside as an ecological and scientific preserve. I'd hope that Rocket Lab (and anyone else) would ensure that they aren't re-entering debris over it. To paraphrase the meme: all your base are not belong to us... There are parts of the world we should leave alone. 

Here’s a paper from RocketLab about exactly that. There is zero risk to Antarctica, short of perhaps an upper-stage failure, which they want to avoid as much as anyone. 
 

https://www.rocketlabusa.com/assets/Uploads/RL-publicviewingrestrictions-F2.pdf
 

2 hours ago, darthgently said:

I remember hearing in an interview (maybe?) that given the materials and velocities involved it all ends up as smoke practically speaking.  It is annoying that you or I could technically get fined for disposing of tiny Li coin cell batteries by burning them, but it's ok to burn what I'm guessing are batteries at least the size of shoe boxes

You or I have reasonable options for disposing of said batteries.  And if we did just set to burning them, between all the yous and Is our toasty button cells would rapidly exceed RL’s shoeboxes, likely by orders of magnitude. 
 

Another reason why so many players, RL included, are moving towards reusability. . 

[darthgently]

20 minutes ago, CatastrophicFailure said:

Here’s a paper from RocketLab about exactly that. There is zero risk to Antarctica, short of perhaps an upper-stage failure, which they want to avoid as much as anyone. 
 

https://www.rocketlabusa.com/assets/Uploads/RL-publicviewingrestrictions-F2.pdf
 

You or I have reasonable options for disposing of said batteries.  And if we did just set to burning them, between all the yous and Is our toasty button cells would rapidly exceed RL’s shoeboxes, likely by orders of magnitude. 
 

Another reason why so many players, RL included, are moving towards reusability. . 

Yeah, I chose the word "annoying" over "enraging" to be precise.  Throwaway batteries of any size are a great annoyance high green ideals notwithstanding 

[PakledHostage]

38 minutes ago, CatastrophicFailure said:

Here’s a paper from RocketLab about exactly that. There is zero risk to Antarctica, short of perhaps an upper-stage failure, which they want to avoid as much as anyone. 
 

https://www.rocketlabusa.com/assets/Uploads/RL-publicviewingrestrictions-F2.pdf
 

Did you post the wrong link? That paper says nothing about any such thing?

[CatastrophicFailure]

5 minutes ago, PakledHostage said:

Did you post the wrong link? That paper says nothing about any such thing?

It’s right there on the second page, the maritime exclusion zone. That’s the only debris risk short of a failure. 

[mikegarrison]

21 minutes ago, CatastrophicFailure said:

It’s right there on the second page, the maritime exclusion zone. That’s the only debris risk short of a failure. 

I strongly doubt that zone applies to the second stage, and specifically the battery drop.

[CatastrophicFailure]

31 minutes ago, mikegarrison said:

I strongly doubt that zone applies to the second stage, and specifically the battery drop.

 

31 minutes ago, mikegarrison said:

I strongly doubt that zone applies to the second stage, and specifically the battery drop.

It’s the area where debris is a significant risk in the event of a complete failure. If the whole rocket going splodey poses an insignificant debris risk beyond that corridor, then a couple of batteries are even less so.  Antarctica is around 3500km from Mahia, more, depending on trajectory. Battery jettison happens around halfway thru the second stage burn at over 4 km/s, almost Mach 12. There’s no way any of that is surviving reentry, let alone making it to Antarctica. Someone with more time could plug a launch into RSS for a better visual, but I highly doubt the trajectory even intersects the coast of Antarctica at that point. 

The risk of any real damage is, as @tater says, just noise. 

[mikegarrison]

I'm not saying that I think discarding a few batteries is major problem. I'm just saying that the chart that shows a marine exclusion zone doesn't tell you where the batteries would fall (which was the claim when the chart was introduced into the discussion).

In general, I tend to think the "it all burns up in the atmosphere" thing is a (probably deliberate) oversimplification that just sweeps the debris issue under the rug. Stuff seems to survive re-entry from space fairly frequently. But mostly it just falls into the ocean or into some remote area on the land.

[CatastrophicFailure]

No. What I said was, and what the linked paper shows, is that there is no danger to Antarctica. The chart shows, very clearly, where the actual danger zone is, which is nowhere near there. 

[tater]

Just checked the vid. Swap was at almost 202 km altitude, and >4km/s.

[tater]

 

[tater]

 

[AckSed]

I wonder if it's Australia's aviation authorities taking on this, or they've finally convinced the FAA to drop it, so to speak.

[tater]

T-6 min:

 

Edited February 18, 2024 by tater

[JoeSchmuckatelli]

When they dump a battery pack on the way to a 500km pe... Doesn't that leave a fairly small, fairly heavy bit of debris hurtling about? 

(I know they're dumping a stage, too - but its surface area makes it easier to track and degrade) 

Have they ever talked about this? 

[darthgently]

40 minutes ago, JoeSchmuckatelli said:

When they dump a battery pack on the way to a 500km pe... Doesn't that leave a fairly small, fairly heavy bit of debris hurtling about? 

(I know they're dumping a stage, too - but its surface area makes it easier to track and degrade) 

Have they ever talked about this? 

They are still suborbital at that point, iirc, so the battery pack will re-enter?  Pretty sure

[magnemoe]

4 hours ago, darthgently said:

They are still suborbital at that point, iirc, so the battery pack will re-enter?  Pretty sure

Yes it will reenter, as I understand its designed to break up. Cells probably contained in an plastic box or wrapper. 

[darthgently]

What is up with the "fireworks" in Electron's plume?  "Sparks" and erratic flare-ups from both the first stage and second stage.  Don't get me wrong, it works, but just wondering.  Maybe many others look like this and it is just a camera exposure thing in this case but it just looks like they are running a bit less than smoothly

[CatastrophicFailure]

4 hours ago, darthgently said:

What is up with the "fireworks" in Electron's plume?  "Sparks" and erratic flare-ups from both the first stage and second stage.  Don't get me wrong, it works, but just wondering.  Maybe many others look like this and it is just a camera exposure thing in this case but it just looks like they are running a bit less than smoothly

I think it’s come up before, basically it’s just little bits of soot still glowing hot from film cooling, I thinks. 

[darthgently]

1 hour ago, CatastrophicFailure said:

I think it’s come up before, basically it’s just little bits of soot still glowing hot from film cooling, I thinks. 

That makes sense.  It still seems strange that the film cooling would be so erratic.  Saturn V's F1 ran rich for cooling but it was a less chunky.  It seems suboptimal for soot to build up that much before breaking free if the goal is cooling via a fresh film layer

[Geonovast]

6 hours ago, darthgently said:

That makes sense.  It still seems strange that the film cooling would be so erratic.  Saturn V's F1 ran rich for cooling but it was a less chunky.  It seems suboptimal for soot to build up that much before breaking free if the goal is cooling via a fresh film layer

F1 had rich gas generator and used the exhaust from that for film cooling.

No gas generators here.  Pretty sure the only things the F1 and Rutherford have in common is they both run on Kerolox and make rockets go zoom.