Juno Arrival This Year!

[Emperor of the Titan Squid]

Woohoo!!!!!!!!!!!!!!! It got there ! we finally have a Jupiter orbiter!

[lajoswinkler]

58 minutes ago, Plusck said:

I'm getting more annoyed with the NASA Juno "press kit".

According to my KSP orbital spreadsheet, modified to use Jupiter's data (radius 71492000m, mass 1.8986x10²⁷kg) and with a Pe of 4200 km and Ap of 10 million km, velocity at Pe is 57.65 km/s. JOI is a 35-minute burn which, according to the press pack, imparts a "mean change in velocity" (whatever the hell that means*) of 542 m/s. Therefore, on arrival at Pe it could not be going faster than 58.2 km/s, or 210,000 km/h or 130,000 mph relative to Jupiter.

The press kit gives Juno's maximum speed as being 165,000 mph. That is 73.3 km/s. In other words, that is the combined right-angle sum of vectors of its Jupiter-relative velocity at Pe plus the relative velocity difference of 43 km/s when Earth and Jupiter are on opposite sides of the Sun. It's artificial and pretty meaningless (any satellite on the other side of the Sun from us gets an automatic 60km/s "speed boost" if you look at it like that).

Oh and of course, just after saying it'll be going at over 150,000 mph, the press pack says the spacecraft "slams on the brakes" when it reaches Jupiter. And "after slowing down, Juno can then enter Jupiter orbit". It's a particularly retarded way of describing the process, mixing Earth-relative speeds with Jupiter-relative braking, and suggesting that getting into orbit is something you do "after" braking.

And to top it all off, those last couple of lines are accompanied by an infographic that gives a top speed for a bicycle at "70 mph" !?! This is just another meaningless figure (top bicycle sprint speeds are typically 50mph), especially compared to the meaningless human "15mph" (athletes do much better) and car "100mph" (which all but the most underpowered cars can easily exceed).

 

*(unless they expect Juno to explode in the process, in which case a "mean change in velocity" might actually mean something)

What do you expect from the public relationship department which constantly feeds the general public with false claims about what planetary bodies really look like? They've imprinted the sight of Venus as an orange ball with yellowish veins (false colored radar image), Pluto as a carnie colored ball (false color + high saturation), Martian surface has blue rocks (enhanced false color), etc.

 

And all it takes is a caption, a one sentence explanation.

[PB666]

http://scienceveda.com/a-creepy-sound-recorded-at-jupiter-by-the-juno-spacecraft/

[PB666]

https://en.wikipedia.org/wiki/LEROS
318 sec Hydrazine / mixed oxides of nitrogen.

The burn of Juno’s 645-Newton Leros-1b main engine began on time at 8:18 p.m. PDT (11:18 p.m. EDT), decreasing the spacecraft’s velocity by 1,212 mph (542 meters per second) and allowing Juno to be captured in orbit around Jupiter. Soon after the burn was completed, Juno turned so that the sun’s rays could once again reach the 18,698 individual solar cells that give Juno its energy.

 

[Vanamonde]

Juno threads have been merged so that the discussion doesn't become scattered and repetitive. 

[r4pt0r]

Hijacking this thread.


So when can I see some neato pics from Juno? Im looking for a new desktop wallpaper.

[Camacha]

On 05/07/2016 at 4:49 PM, lajoswinkler said:

What do you expect from the public relationship department which constantly feeds the general public with false claims about what planetary bodies really look like? They've imprinted the sight of Venus as an orange ball with yellowish veins (false colored radar image), Pluto as a carnie colored ball (false color + high saturation), Martian surface has blue rocks (enhanced false color), etc.

And all it takes is a caption, a one sentence explanation.

Talk to NASA, they are the only people that can fix this supposed problem.

Edited July 7, 2016 by Val
Removed derailing

[Wjolcz]

2 hours ago, r4pt0r said:

Hijacking this thread.


So when can I see some neato pics from Juno? Im looking for a new desktop wallpaper.

Same.

[CatastrophicFailure]

4 hours ago, r4pt0r said:

Hijacking this thread.


So when can I see some neato pics from Juno? Im looking for a new desktop wallpaper.

Another 50 days, give or take, once it swings back to perijove. The camera actually isn't all that great, it was literally an afterthought. The primary science package is mostly non-visual, magnetometers & such. 

[lajoswinkler]

9 hours ago, CatastrophicFailure said:

Another 50 days, give or take, once it swings back to perijove. The camera actually isn't all that great, it was literally an afterthought. The primary science package is mostly non-visual, magnetometers & such. 

Again, NASA fails to remember that their funding comes from the general public, indirectly. Business as usual, eh. 

[CatastrophicFailure]

8 minutes ago, lajoswinkler said:

Again, NASA fails to remember that their funding comes from the general public, indirectly. Business as usual, eh. 

Actually, the camera was added specifically to engage the general public. 

[PB666]

11 minutes ago, CatastrophicFailure said:

Actually, the camera was added specifically to engage the general public. 

Where's my ring, man there are cheap. Engaging people but too stingy to buy a ring and then too ashamed to tell the engaged about the whole thing. 

[kerbiloid]

6 hours ago, CatastrophicFailure said:

Actually, the camera was added specifically to engage the general public. 

The cheapest way for space tourists. As Google Earth for terrestrial.

Thirty years later you will ask your grandchild: "Do you want to the Mars?" And hear in return: "What I haven't yet seen there?"

Edited July 8, 2016 by kerbiloid

[lajoswinkler]

6 hours ago, CatastrophicFailure said:

Actually, the camera was added specifically to engage the general public. 

I was referring to the "literally an afterthought". These things should never be an afterthought. They're equally important as magnetometers or radiometers.

[Wjolcz]

Is there like a site with a poll where people can vote on what should they take pictures of? I think I saw something like that somewhere on NASA's official facebook page once.

[PB666]

48 minutes ago, Veeltch said:

Is there like a site with a poll where people can vote on what should they take pictures of? I think I saw something like that somewhere on NASA's official facebook page once.

They should take pictures of Neptune or how about moony McMoonface, the next named moon of the jovian system. Public facebook advice sourcing is about as reliable as a screen door on a submarine. 

 

Edited July 8, 2016 by PB666

[UmbralRaptor]

Meh on engagement -- large sections of the public only care if there are people in the spacecraft. and/or it is searching for life.

1 hour ago, Veeltch said:

Is there like a site with a poll where people can vote on what should they take pictures of? I think I saw something like that somewhere on NASA's official facebook page once.

Voting is apparently coming soon.

Edited July 8, 2016 by UmbralRaptor

[PB666]

1 minute ago, UmbralRaptor said:

Voting is apparently coming soon.

[facepalm]

[Ozymandias_the_Goat]

5 hours ago, PB666 said:

[facepalm]

Did someone say "Facepalm"?

[WinkAllKerb'']

not much to say but i ll keep that one as collector ; )

[Kinglet]

Why did NASA choose to deorbit JUNO after the mission duration?

[insert_name]

7 minutes ago, Kinglet said:

Why did NASA choose to deorbit JUNO after the mission duration?

Planetary protection for Europa 

[Camacha]

On 08/07/2016 at 2:04 PM, PB666 said:

as reliable as a screen door on a submarine. 

Whoa, you did not set your parameters there. A screen door could be perfectly reliable keeping the seaweed out, of flies, or camels, especially when it is on the inside of the submarine.

[Wjolcz]

10 hours ago, Kinglet said:

Why did NASA choose to deorbit JUNO after the mission duration?

Because who wouldn't want to have a proper, fiery viking funeral?

AFAIK the probe has a "life time". If it stays in the high radiation environment for too long it might lose the ability to communicate. When that happens the ground crew won't be able to control it and there's a chance it might encounter one of the moons eventually. Since there's a chance it's not 100% sterile, it may crash on one of them and contribute to a thing called panspermia.

[PB666]

3 hours ago, Veeltch said:

Because who wouldn't want to have a proper, fiery viking funeral?

AFAIK the probe has a "life time". If it stays in the high radiation environment for too long it might lose the ability to communicate. When that happens the ground crew won't be able to control it and there's a chance it might encounter one of the moons eventually. Since there's a chance it's not 100% sterile, it may crash on one of them and contribute to a thing called panspermia.

It will deorbit on its own, anyway. Again they can collect a few drops of data going in for the last time.