Re: [Starlink] saving ship 20

[Dave Taht <dave.taht@gmail.com>]

thx all. I still think that attempting re-entry with a known-busted
heatshield is kind of a waste, but...

btw, the alt.space mailing list I had been on for a decade or three
(on one of my retired accounts) is "arocket", which has participants
such as henry spencer (https://en.wikipedia.org/wiki/Henry_Spencer),
the original founder of the L5 society, and a few other notables.

https://www.freelists.org/post/arocket/FW-NASA-HQ-News-NASA-Awards-Artemis-Contract-for-Future-Mega-Moon-Rocket-Boosters,3

Just spent an enjoyable hour catching up there.

On Sat, Feb 12, 2022 at 2:04 PM David Lang <david@lang.hm> wrote:
>
> On Sat, 12 Feb 2022, Dave Taht wrote:
>
> > Having a pause to inspect the lost tiles, and assess the damage before
> > even attempting re-entry strikes me as a good idea. I hope they've
> > lined up some good telescopes this time to take a peek at it. Always
> > sad we didn't get that done for columbia.
>
> for this first flight, they are deliberatly not going into an orbit that would
> clear the ground (they are going high enough, and fast enough, but not round
> enough), so that they don't need to deal with the complications of a zero-g
> restart (settling the fuel, etc)
>
> They have lined up the NASA aircraft that has a big telescope on it to watch it
> during reentry, and unlike everyone else, they put lots of cameras on and in
> their rockets (spectacular PR and very useful to figure out what went wrong)
>
> Odds are that something will go wrong before reentry on the first flight, but
> they have the timeline go all the way to a landing burn above the ocean, but I
> don't think anyone is expecting it to be intact by the time it spashes down. It
> would be an absolutly spectacular win if it does survive to that point.
>
> > Developing the capability to do on-orbit repair, also is a good goal.
> >
> > A small robot to do external inspection?
> >
> > It seems pointless to attempt re-entry if you determined it was going to
> > fail and seems better to plan on exploring other options.
>
> until we have a lot more access to space, people are more afraid of 'space junk'
> than interested in accumulating resources in space.
>
> Even if they end up missing some tiles and get a burn-through during reentry,
> it's worth doing the reentry to learn how the skydiver approach works compared
> to what every other spacecraft has done. There has never been anything close to
> this big that's attempted reentry, they don't know how well the computer models
> actually match reality. Given that it will be years before there is manned
> flight that would be able to use it if they left it up there, odds are good that
> it would come down first anyway, just in an uncontrolled fashion.
>
> I'll point out that the bigelow inflatable module on the ISS is only being used
> for storage, NASA doesn't trust inflatables.
>
> >>
> >> And, as we have seen many times, getting back in one piece is the hardest
> >> part to get right.
> >
> > So why not have a plan B involving staying in orbit, rather than burning up?
>
> if you never attempt reentry, you can never succeed.
>
> >>
> >> > Do they not have enough thrust, even with an empty payload bay, to
> >> > stay up there?
> >>
> >> I'm sure they do, but to stay up they would need a course corrction
> >> or two.
> >
> > testing restart seems smart.
>
> these are gen-1 raptor engines, given how much more complicated they are than
> the gen-2 raptors, how useful would it be? and it would add a LOT of
> complication. Also, unless you boosted it up above the ISS, it will deorbit
> fairly quickly. Starlinks are higher and denser, and they have a lifetime of 5
> years or so without reboost.
>
> David Lang



-- 
I tried to build a better future, a few times:
https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org

Dave Täht CEO, TekLibre, LLC