SpaceX Tuesday...

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Beati Dogu

8,862 posts

138 months

Tuesday 10th September 2019
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You should go over to the Bahamas and tell them that. I'm sure they'd appreciate it.

Art0ir

9,401 posts

169 months

Wednesday 11th September 2019
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Beati Dogu said:
You should go over to the Bahamas and tell them that. I'm sure they'd appreciate it.
Big difference in gale force winds and what the Bahamas experienced. I’m sure you knew that though, so curious as to why you’d try to compare the two.


Flooble

5,565 posts

99 months

Saturday 14th September 2019
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Has anyone been following the construction of the two Starship prototypes?

They are working weekends on them and really ramming through the process, it's feels like sort of pace you would see in a "World War" type newsreel, with prototypes thrown together in a matter of months.

The SLS project makes a big deal about "we rotated the engine section through 180 degrees" as their only news for weeks; in the same time SpaceX seem to have welded together half a rocket.


Zad

12,695 posts

235 months

Sunday 15th September 2019
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Not dissimilar to how the pair of Mars rovers were built for NASA. Built by competent engineers who were essentially just left to get on with it. No messing around having to develop whole new technologies or go through long expensive tendering processes, only to be told politics has got involved and you need to start again.

Beati Dogu

8,862 posts

138 months

Sunday 15th September 2019
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Talking of which, here's the next Mars rover being spin tested to determine its center of gravity.

https://www.jpl.nasa.gov/news/news.php?feature=749...

Like balancing a tyre, they add weights to even it out.



Meanwhile, SpaceX have launched 10 times this year and aim to launch 7-8 more before the year is out. Including their first manned flight - they hope. They've finally caught up with the backlog of launches delayed after the Falcon 9 pad explosion it seems.

Next year may see as many as 24 launches according to Gwynne Shotwell. Many of them Starlink.


Flooble

5,565 posts

99 months

Sunday 15th September 2019
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Beati Dogu said:
Talking of which, here's the next Mars rover being spin tested to determine its center of gravity.

https://www.jpl.nasa.gov/news/news.php?feature=749...

Like balancing a tyre, they add weights to even it out.



Meanwhile, SpaceX have launched 10 times this year and aim to launch 7-8 more before the year is out. Including their first manned flight - they hope. They've finally caught up with the backlog of launches delayed after the Falcon 9 pad explosion it seems.

Next year may see as many as 24 launches according to Gwynne Shotwell. Many of them Starlink.
Wow, 20kg of dead weight - when you calculate cost to orbit that's nearly half a million dollars gone!

MartG

20,622 posts

203 months

Sunday 15th September 2019
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Flooble said:
Beati Dogu said:
Talking of which, here's the next Mars rover being spin tested to determine its center of gravity.

https://www.jpl.nasa.gov/news/news.php?feature=749...

Like balancing a tyre, they add weights to even it out.



Meanwhile, SpaceX have launched 10 times this year and aim to launch 7-8 more before the year is out. Including their first manned flight - they hope. They've finally caught up with the backlog of launches delayed after the Falcon 9 pad explosion it seems.

Next year may see as many as 24 launches according to Gwynne Shotwell. Many of them Starlink.
Wow, 20kg of dead weight - when you calculate cost to orbit that's nearly half a million dollars gone!
And 20kg which could have been used for something useful - could it not be designed in such a way that some equipment could be moved to adjust the CG instead of adding dead weight ?

ReallyReallyGood

1,620 posts

129 months

Sunday 15th September 2019
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I’m guessing they’ve thought of that

loudlashadjuster

5,082 posts

183 months

Sunday 15th September 2019
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ReallyReallyGood said:
I’m guessing they’ve thought of that
Yeah, it's hardly rocket science...

MartG

20,622 posts

203 months

Sunday 15th September 2019
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Fake, but cool smile


Beati Dogu

8,862 posts

138 months

Monday 16th September 2019
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MartG said:
And 20kg which could have been used for something useful - could it not be designed in such a way that some equipment could be moved to adjust the CG instead of adding dead weight ?
I suppose that since it's going anyway and there's no other payload, the extra 20 Kg is neither here nor there really.

Plus it makes it simpler & easier to design, thus saving costs at that end. They do it for quite large objects too, including whole satellites. This is the OSIRIS-REx spacecraft being spin tested:

https://www.youtube.com/watch?v=zi6wZj2bFI4

It was launched in 2016 and it currently orbiting the asteroid, Bennu.


They do all sorts of other separate tests before launch. Like rattling their teeth out on shaker tables, putting them in a giant centrifuge & bombarding them with loud noise, all to simulate launch conditions.

annodomini2

6,860 posts

250 months

Monday 16th September 2019
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MartG said:
Flooble said:
Beati Dogu said:
Talking of which, here's the next Mars rover being spin tested to determine its center of gravity.

https://www.jpl.nasa.gov/news/news.php?feature=749...

Like balancing a tyre, they add weights to even it out.



Meanwhile, SpaceX have launched 10 times this year and aim to launch 7-8 more before the year is out. Including their first manned flight - they hope. They've finally caught up with the backlog of launches delayed after the Falcon 9 pad explosion it seems.

Next year may see as many as 24 launches according to Gwynne Shotwell. Many of them Starlink.
Wow, 20kg of dead weight - when you calculate cost to orbit that's nearly half a million dollars gone!
And 20kg which could have been used for something useful - could it not be designed in such a way that some equipment could be moved to adjust the CG instead of adding dead weight ?
They'll have pre-agreed the launch price with a weight limit, it probably costs a lot more than $500k to redesign, rebuild and retest the space craft to save a bit of weight that offers them no financial saving.

MartG

20,622 posts

203 months

Monday 16th September 2019
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annodomini2 said:
MartG said:
Flooble said:
Beati Dogu said:
Talking of which, here's the next Mars rover being spin tested to determine its center of gravity.

https://www.jpl.nasa.gov/news/news.php?feature=749...

Like balancing a tyre, they add weights to even it out.



Meanwhile, SpaceX have launched 10 times this year and aim to launch 7-8 more before the year is out. Including their first manned flight - they hope. They've finally caught up with the backlog of launches delayed after the Falcon 9 pad explosion it seems.

Next year may see as many as 24 launches according to Gwynne Shotwell. Many of them Starlink.
Wow, 20kg of dead weight - when you calculate cost to orbit that's nearly half a million dollars gone!
And 20kg which could have been used for something useful - could it not be designed in such a way that some equipment could be moved to adjust the CG instead of adding dead weight ?
They'll have pre-agreed the launch price with a weight limit, it probably costs a lot more than $500k to redesign, rebuild and retest the space craft to save a bit of weight that offers them no financial saving.
A bit annoying though if you have an experiment which masses less than 20kg but hasn't been approved due to weight limitations of the spacecraft

Eric Mc

121,779 posts

264 months

Monday 16th September 2019
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MartG said:
A bit annoying though if you have an experiment which masses less than 20kg but hasn't been approved due to weight limitations of the spacecraft
Not a big deal if you know there is another SpaceX launch due any day now now. They are a bit like tube trains these days,
- miss one, there'll be another along in a few weeks.

MartG

20,622 posts

203 months

Monday 16th September 2019
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Eric Mc said:
MartG said:
A bit annoying though if you have an experiment which masses less than 20kg but hasn't been approved due to weight limitations of the spacecraft
Not a big deal if you know there is another SpaceX launch due any day now now. They are a bit like tube trains these days,
- miss one, there'll be another along in a few weeks.
Errr - we were talking about the Mars rover...

Eric Mc

121,779 posts

264 months

Monday 16th September 2019
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Did someone not mention SpaceX?

If not - my mistake.

Do you know that EVERY Space Shuttle launch carried ballast up to orbit and back down again?

RobDickinson

31,343 posts

253 months

Monday 16th September 2019
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Those things are complicated engineering with a whole bunch of compromises so no surprise it needs balancing.

Adjusting the whole to no need balancing might have been a much bigger task and compromise more things, or take another 2 years and $billions...

Caruso

7,422 posts

255 months

Monday 16th September 2019
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The rover weighs about 1,000kg I think, making 20kg only 2% of it's mass That's not bad for balance really.

Beati Dogu

8,862 posts

138 months

Tuesday 17th September 2019
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"Droid Junkyard, Tatooine" - Elon Musk


Flooble

5,565 posts

99 months

Tuesday 17th September 2019
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I feel sorry for all the guys who were working there ... having their efforts described as a junkyard!
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