Skimming gas giants

[Blue Ghost]

Well, that probably won't change much till the Juno mission spacecraft arrival some 3 years from now! See: http://missionjuno.swri.edu/

Got to hold one of the actual flight instruments in my grubby little paws (well, gloved in a clean room) before it departed.

There was lots of specialized shielding and fabrication involved in the Juno probe due exclusively to the extreme environment - dad spent weeks designing and precisely fitting exotic metal interlocking shielding plates in the instrument he fabbed - which was not a requirement for the similar instruments he had made for Cassini, New Horizons, Rosetta, nor LRO missions. The coatings and conductor routing on the Juno mission are also unique - and yet the mission life is still expected to be shortened appreciably. I was involved in several discussions with the design team of a very large Faraday cage for one of the test chambers that had to be specially constructed.

As for direct lethality of EMF - that is something on the order of a billion G (Gauss), IIRC - so no, not from Jupiter. However, the indirect effect of Jupiter's strong rotating magnetic field certainly creates an environment quite lethal to humans without extensive protection.

Very very cool, BytePro. I'm jealous

As for the EMF, wow. Someone's got some numbers out there, but billion Gauss is kind of up there. Could a starship even survive that, let alone the crew?

 

[HG_B]

Could a starship even survive that, let alone the crew?

Without even noticing it. Based on damage taken off from direct nuke weapon hits.

 

[Blue Ghost]

Are you sure about that? I think the only starship that can take a nuke are mainline navy vessels.

 

[HG_B]

Are you sure about that? I think the only starship that can take a nuke are mainline navy vessels.

I didn't say without damage. Smaller ships can take them without being totaled.
MgT being the latest version with this. So yes, based that, the fields around these GG's are next to nothing for a Trav star ship. The energy level difference across the EM spectrum is many orders of magnitude different. The damage taken by a Trav ship is primarily from the insanely high heat & intense gamma, neutron & X-ray.

 

[BytePro]

Very very cool, BytePro. I'm jealous

As for the EMF, wow. Someone's got some numbers out there, but billion Gauss is kind of up there. Could a starship even survive that, let alone the crew?

My recollections are from EMF safety research (and both my memory and the sources could be wrong...).

The 10^9 figure is related to cellular life, and quite theoretical, since its well above current practical lab thresholds... but, there's no evidence I've heard of that the EMF directly is going to be short term 'lethal' at the levels encountered as we currently know them. Of course, we've really barely scratched the surface in terms of research. As to damage to non-living material - well, the surface of a neutron star would exhibit 1,000 to 10,000 times higher Gauss.

Regulatory agencies do provide safety information regarding EMF. Prior to cellular disruption, there have been other noticed effects - IIRC, around 10^2 Gauss reportedly can cause visual issues. And ELF associated with power transmission is suspected of carcinogenic effects. Overall, speaking of EMF without being specific is not actually very useful - generally something else will be lethal in any environ supporting directly lethal EMF...

As to lighting, plasmas and high voltage/current discharge - as an artifact related to EMF - those can most certainly cause damage. The objective will be to mitigate the effects - just like we do with aircraft and spacecraft today in a variety of ways.

BTW: On of the objectives of the Juno mission is to do the first magnetic mapping of Jupiter.

 

[Blue Ghost]

I didn't say without damage. Smaller ships can take them without being totaled.
MgT being the latest version with this. So yes, based that, the fields around these GG's are next to nothing for a Trav star ship. The energy level difference across the EM spectrum is many orders of magnitude different. The damage taken by a Trav ship is primarily from the insanely high heat & intense gamma, neutron & X-ray.

My first group rarely did starship combat, when they did it was standard 1d6 missiles, and 1 pt LASERS. Laser weapons, if you reverse engineer Snapshot rules, do a thousand points of damage (that actually may be written down somewhere), which implies that starship missiles to 1000 to 6000 points of damage. As big as that is compared to a Laser rifle (5d6?...I can't remember), it's not a nuke.

I've heard nukes bandied around before on other threads, but I'm highly iffy that point. If it's official in the rules, well, maybe I'll drop the game.

 

[Blue Ghost]

My recollections are from EMF safety research (and both my memory and the sources could be wrong...).

The 10^9 figure is related to cellular life, and quite theoretical, since its well above current practical lab thresholds... but, there's no evidence I've heard of that the EMF directly is going to be short term 'lethal' at the levels encountered as we currently know them. Of course, we've really barely scratched the surface in terms of research. As to damage to non-living material - well, the surface of a neutron star would exhibit 1,000 to 10,000 times higher Gauss.

Regulatory agencies do provide safety information regarding EMF. Prior to cellular disruption, there have been other noticed effects - IIRC, around 10^2 Gauss reportedly can cause visual issues. And ELF associated with power transmission is suspected of carcinogenic effects. Overall, speaking of EMF without being specific is not actually very useful - generally something else will be lethal in any environ supporting directly lethal EMF...

As to lighting, plasmas and high voltage/current discharge - as an artifact related to EMF - those can most certainly cause damage. The objective will be to mitigate the effects - just like we do with aircraft and spacecraft today in a variety of ways.

BTW: On of the objectives of the Juno mission is to do the first magnetic mapping of Jupiter.

Incredible stuff. As for mapping, that will be interesting. I constantly read and hear how there's no solid surface on either gas gas giant, and that as one descends you gradually find yourself in a thicker mixture of atoms (hydrogen?) until you're crushed. I then hear allusions to "the surface of Jupiter", which just makes me scratch my head even more ---> Surface?

All in all I think gas giants are fascinating structures; huge, vast, violent, colossal skies that dwarf our imaginations, it would be one rocking place to visit assuming you had the means to survive the trip.

 

[BytePro]

In scientific discussions, the 'surface' is where the pressure of the atmosphere is 1 bar - i.e. standard atmospheric pressure at Earth’s surface.

The core of Jupiter might be some type of rock/solid, or metallic liquid hydrogen, etc.

We've a lot of theory and sensory observation, but we don't yet know much with any certainty, really, about the composition of the other planets in our system (and our own planet still holds mysteries). Every new space probe drastically increases our knowledge, and several have resulted in some fundamental changes in prior theories. On the few occasions I had conversations with Scott (P.I. for the Juno mission), he was fond of the phrase 'rewriting the books'...

EDIT: Here's an article I found some time back re: possible solid core for Jupiter - http://iopscience.iop.org/1538-4357/688/1/L45

 

[HG_B]

If it's official in the rules, well, maybe I'll drop the game.

It is.

 

[Blue Ghost]

It is.

Well, I think more correctly there are two types; nuclear and conventional, stated in book 5. I'm more referring to what a civvie of any kind might carry. I have a real hard time believing that a 100 ton scout, even though it's as big as a 737 with thick metal bulkhead, is going to survive the area of incineration of a nuke.

I think it would have problems dealing with a massive gas giant lightening strike.

 

[HG_B]

Well, I think more correctly there are two types; nuclear and conventional, stated in book 5. I'm more referring to what a civvie of any kind might carry. I have a real hard time believing that a 100 ton scout, even though it's as big as a 737 with thick metal bulkhead, is going to survive the area of incineration of a nuke.

I think it would have problems dealing with a massive gas giant lightening strike.

Different types of energy altogether. All I can say is study physics or electrical Eng. Electrical discharge is not difficult to handle...

 

[Blue Ghost]

In scientific discussions, the 'surface' is where the pressure of the atmosphere is 1 bar - i.e. standard atmospheric pressure at Earth’s surface.

The core of Jupiter might be some type of rock/solid, or metallic liquid hydrogen, etc.

We've a lot of theory and sensory observation, but we don't yet know much with any certainty, really, about the composition of the other planets in our system (and our own planet still holds mysteries). Every new space probe drastically increases our knowledge, and several have resulted in some fundamental changes in prior theories. On the few occasions I had conversations with Scott (P.I. for the Juno mission), he was fond of the phrase 'rewriting the books'...

EDIT: Here's an article I found some time back re: possible solid core for Jupiter - http://iopscience.iop.org/1538-4357/688/1/L45

Ah, very interesting, and very cool

 

[Blue Ghost]

Different types of energy altogether. All I can say is study physics or electrical Eng. Electrical discharge is not difficult to handle...

I know a little about the subject, but I'm iffy on how much juice a starship can take.

 

[BytePro]

Its the effects of plasma that are the main issue... conductive hull properly designed (Faraday cage) along with shielding and filtering for internal electronics will take care of the electrical issues.

Modern aircraft take lightning strikes all the time. The main artifact is a scorched hull (though in the '60s a fuel tank supposedly blew due to a melt through). But that is not for sustained durations, and Jupiter can produce multi-million volt and amp strikes... (research the Io plasma tube - which Voyager was supposed to fly through - and the Jovian auroras).

For the most part it would be a non issue, but some discharges might be not unlike taking a hit from an energy weapon. Its important to note that a ship would normally very easily avoid such areas - planets don't move unexpectedly and fields are relatively fixed within a certain error metric. Of course, they might knowingly enter such regions...

 

[Blue Ghost]

*snip*
For the most part it would be a non issue, but some discharges might be not unlike taking a hit from an energy weapon. Its important to note that a ship would normally very easily avoid such areas - planets don't move unexpectedly and fields are relatively fixed within a certain error metric. Of course, they might knowingly enter such regions...

Which is kind of what I'm getting at :smirk:

 

[HG_B]

I know a little about the subject, but I'm iffy on how much juice a starship can take.

Well, lightening would not be noticed at all. The hull would become charged to the point where it wouldn't be a ground. Electricity flows for a reason.

 

[Drakon]

Well, lightening would not be noticed at all. The hull would become charged to the point where it wouldn't be a ground. Electricity flows for a reason.

True, however that isn't an issue until you land. All you need is a relative voltage between two points. If both points are 5 thousand volts above some other point, as long as those two points are isolated, it is not an issue.

Ask anyone that has had to do helo ops at sea.

 

[Blue Ghost]

I don't think so. A strike of the order of Saturn would be nearly catastrophic just because of the sheer orders of magnitude of energy on the material. There's also the fact that there is no "ground" on either gas giant, so the electricity isn't passing over the surface to get to the ground, but trying to discharge. It may arc through the ship from cloud to cloud, but even then I'm skeptical purely because of the numbers involved.

 

[Spinward Scout]

EDIT: Here's an article I found some time back re: possible solid core for Jupiter - http://iopscience.iop.org/1538-4357/688/1/L45

I like Arthur C. Clarke's take on it that the core of Jupiter is carbon (i.e. heavier than hydrogen and helium and therefore precipitates out) and that the core is so highly compressed that it becomes a diamond. He explains it in 2061: Odyssey Three.

 

[Carlobrand]

True, however that isn't an issue until you land. All you need is a relative voltage between two points. If both points are 5 thousand volts above some other point, as long as those two points are isolated, it is not an issue.

Ask anyone that has had to do helo ops at sea.

That used to be a serious problem with dirigibles. If they didn't ground fully before the ground crew grabbed the lines, some poor schnook got the shock of his life. :devil:

I don't think so. A strike of the order of Saturn would be nearly catastrophic just because of the sheer orders of magnitude of energy on the material. There's also the fact that there is no "ground" on either gas giant, so the electricity isn't passing over the surface to get to the ground, but trying to discharge. It may arc through the ship from cloud to cloud, but even then I'm skeptical purely because of the numbers involved.

Electrical phenomena are reasonably well understood now, though the order of magnitude is quite a bit lower. Our aircraft are showing hits, but they aren't crashing. One presumes that the culture that has been doing gas giant refueling for the past few thousand years has a pretty good understanding of the physics at that order of magnitude and how to construct ships to avoid serious damage.

As near as I can tell, we're addressing several different phenomena:

magnetic fields, which while intense are not directly dangerous to human physiology (except maybe for some of those debates about long-term effects);

radiation from charged particles trapped by the magnetic field, which can be quite deadly but can be countered by the ship's hull;

and electrostatic discharges, a.k.a. lightning, that the ship happens to get caught up in while flying through the atmosphere collecting hydrogen - and there seems to be some disagreement over what altitude those occur at and what altitude the ship is flying at for hydrogen collection.