Patrol 4x4 - Nissan Patrol Forum banner
6161 - 6177 of 6177 Posts

·
Registered
2003 GU PATROL
Joined
·
20,888 Posts
I don't think it's over yet unfortunately.
 

·
Premium Member
nissan
Joined
·
7,566 Posts
However my (rather basic) understanding of Lagrange points suggests that whilst L4 and L5 are stable, L1,2 and 3 are not, (in the way that a ping pong ball perched upon a basketball is not stable), so it will require regular small adjustments to maintain its position.

As this will be ongoing through its expected lifespan, and it surely does not have enough propellant to facilitate this beyond initial positioning, where will the energy come from to maneuver it in years to come?
I think you are overestimating the magnitude of the corrections that will be needed. Thrusters are usually quite small and their typical burn times are of short duration so the fuel lasts a long time. You are correct that the L2 location is inherintly unstable but these instabilities are quite weak. No doubt if left unchecked they will lead to the satelite eventually being lost but if the position of the satelite is adjusted regularly then it takes very little energy to correct it. NASA is saying that with the fuel left after initial positioning, they should be able to keep Webb stable for at least its minimum planned life which is 10 years. I expect it will last as long as Hubble which was more like 30 years. By then they will either have sorted out something better or worked out how to maintain it and resupply it.

Think about the pingpong ball on top of the basket ball you mentioned before. If the pingpong ball moves slightly off centre and you correct it straight away you will only have a small velocity and short distance to deal with. If you don't correct it immediately you will have to deal with an item that has moved much further and is moving in the wrong direction much faster which obviously requires much more energy to correct. As long as their corrections are done early enough they should not require much energy at all.

"The Webb team has analyzed its initial trajectory and determined the observatory should have enough propellant to allow support of science operations in orbit for significantly more than a 10-year science lifetime," NASA officials wrote in a statement posted Wednesday (Dec. 29)."
 

·
Every dog has his day
2005 TD42 GU IV
Joined
·
18,882 Posts
Awesome, thanks @Overboard I never found that info. I’d also expect it to last a lot longer than 10 years.

Thsnks again 👍👍👍
 

·
Administrator
Y2KGUII ZD Wgn
Joined
·
50,753 Posts
Sitting at my mates place and on the roof above us are 8 green frogs, a couple are hidden around the corner but this shows 6
Wood Gas Tints and shades Bird Darkness
 

·
Registered
1998 2.8GU wagon
Joined
·
3,279 Posts
We get a few of the big green tree frogs, whereas our neighbour 100m or so away gets heaps of them. We get lots of other different types all around the house & yard. In wet weather we have to be careful where we tread, so we don't step on them.
 
  • Like
Reactions: rgren2

·
I Have Imaginary Friends
Patrol Hybrid.
Joined
·
18,192 Posts
You also have a cat, they decimate them. You’ll hear a terrifying scream, cat killing frog.
 

·
Administrator
Y2KGUII ZD Wgn
Joined
·
50,753 Posts
Djokovic finally ordered to piss off, about bloody time, you self important moron who doesn't give a rats bum about anyone else but himself.
 

·
just a good guy.
2009 gu ute
Joined
·
10,003 Posts
Home made meat lovers pizza and pototo cubes in the air fryer . Fat free cooking is the best.
 
  • Like
Reactions: Foo

·
I Have Imaginary Friends
Patrol Hybrid.
Joined
·
18,192 Posts
This came from another site, there could be tax claims. 🤔 He’s not all bad, very me,me.
Smile Sleeve Collar Font Happy
 

·
Every dog has his day
2005 TD42 GU IV
Joined
·
18,882 Posts
It seems some lads have a sense of humour at my new job…

Two of the blokes had to go for a random D&A one morning. They were a straight down the line fella about my age, and a young lad, a big fella but in the gym junkie way not the GBFC way.

No probs there, but before returning to the plant they made old mate (who was very reluctant) ring their supervisor and straight faced say one had failed on cocaine and the young fella had steroids and the superintendent would have to be called.

Supervisor almost hit the roof but cottoned on before he got too excited lol

Then we have one of the geo/greenie/look after animals and indigenous sites etc types… pretty hare brained and I don’t even know her actual title or job.

Anyway someone found a dead bird and put it on her desk with an out of service tag around it’s neck.

Hehehe

No idea who but shlt hit the fan and they’re leaving no tern unstoned (see what I did there) to find the culprit.

Seems to be a few rascals in my midst… I like it 😇
 

·
Premium Member
Triton n Lovin it.
Joined
·
27,664 Posts
Seeing my mate that had the massive stroke, moved from the Intensive Care ward for stroke survivors to a hospital in Ipswich for his rehabilitation. He has regained movement in his left arm and hand is sitting up okay. 🙂

Foo
 

·
Premium Member
Triton n Lovin it.
Joined
·
27,664 Posts
Walking into Aldi and seeing that they have the 20v batteries and chargers in, now I can use my blower that I got before Christmas. 😁 👏

Foo
 

·
Registered
1998 2.8GU wagon
Joined
·
3,279 Posts
Had an old drill press that the previous owner left in the garage, that I never used. Gave it a clean up & put it on Facebook. Had about 6 enquiries straight away, but the first guy never showed up, so contacted the next one. He jumped in his van & drove 1/2 hour here, paid my asking price & gave me a $25 voucher for his gelato shop.
 

·
Premium Member
Triton n Lovin it.
Joined
·
27,664 Posts
Had an old drill press that the previous owner left in the garage, that I never used. Gave it a clean up & put it on Facebook. Had about 6 enquiries straight away, but the first guy never showed up, so contacted the next one. He jumped in his van & drove 1/2 hour here, paid my asking price & gave me a $25 voucher for his gelato shop.
I'd have driven down there and given you $25 if I'd have known that! :unsure: ;)😇

Foo
 
6161 - 6177 of 6177 Posts
Top