8
$\begingroup$

This answer reminded me that the Electron rocket drops one of it's batteries when it is mostly spent. We might call that "micro-staging".

This answer quotes Spaceflight 101:

With a low auto-ignition temperature of only 150°C, the second stage batteries will burn up in their entirety during re-entry while the first stage batteries are also likely to be incinerated to some extent during their sub-orbital re-entry.

The phrase "...likely to be incinerated to some extent..." is a bit vague and half-hearted.

Is there any further information on this? Do they hit the water in burning lithium and plastic flames, or do they dissipate before impact?

$\endgroup$
  • 2
    $\begingroup$ New Zealand changed or at least assessed it's law to allow for rocketlab launches: Regulatory Impact Statement: Regulation of deposit of jettisoned material from space vehicle launches under the Exclusive Economic Zone and Continental Shelf (Environmental Effects) Act2012. It also mentions batteries impact on the ocean. Citation: "Information from Rocket Lab notes that lithium batteries are expected to burn up completely during descent rather than be deposited.". $\endgroup$ – Christoph Apr 17 '19 at 6:40
  • 2
    $\begingroup$ @Christoph thanks for that! "...expected to burn up completely..." is definitely different than "...likely to be incinerated to some extent..." Hmm... I wonder if they are telling different stories to different people!? $\endgroup$ – uhoh Apr 17 '19 at 15:03
  • 1
    $\begingroup$ @uhoh It seems impossible that the first-stage batteries burn up during their descent. By definition, they're jettinosed well before MECO. In this launch: youtube.com/watch?v=SNuauG1Gvr8, at MECO the Electron rocket was at an altitude of 77.8 km; jettisoning must have happened well before that. This article spaceflight101.com/spacerockets/electron states that the used batteries have an auto-ignition temperature of 150° C; it seems not sure at all that this temperature is reached, by atmospheric friction, during a fall from some tens of kilometers. $\endgroup$ – Jan van Oort Aug 24 '19 at 12:30
  • $\begingroup$ @JanvanOort thanks, but I think you are mostly just reiterating the content of the question. $\endgroup$ – uhoh Aug 24 '19 at 12:48
  • 1
    $\begingroup$ @uhoh you're completely right; that's a second-stage (at T+6:25 it can't be but that). $\endgroup$ – Jan van Oort Aug 24 '19 at 13:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.