Planetary Travel and solar flares

[Jimmyboy]

Space trips to say Mars are deemed as hazardous as solar flares can erupt from the sun and could be directed at a potential spacecraft heading to Mars..

The Earths Magnetoshpere does not seem to be that strong, I read it is approx between 30-60 micro teslas which is very weak, but it manages to protect us from the particles from the sun. Wouldnt it be a good idea to have an electromagnet on board creating a weak flux around the space craft to protect from solar rays?? Could the same be applied to satellites too?

 

[Shpaget]

Earth's magnetic field is fairly weak in intensity but it extends many kilometers out.
An electromagnet placed on board a spaceship would, despite its intense field in proximity have very short range.

Magnetic field exerts a force on solar wind and even a small force is enough to divert it if you can apply it long enough as it is the case in Earth's magnetosphere.
On the other side, an artificial field would exert its force for a significantly shorter period of time and, unless extremely strong, be insufficient.

 

[Jimmyboy]

Why do you say the electromagnet would only be able to create a field for a short time? It could be created for as long a you want with sufficient fuel????

 

[Mee_n_Mac]

One article to whet your appetite ...

http://www.thespacereview.com/article/308/1

The concept of magnetic shielding is not new. As Hoffman says, “The Earth has been doing it for billions of years!” Earth’s magnetic field deflects cosmic rays, and an added measure of protection comes from our atmosphere which absorbs any cosmic radiation that makes its way through the magnetic field. Using magnetic shielding for spacecraft was first proposed in the late 1960’s and early 1970’s, but was not actively pursued when plans for long-duration spaceflight fell by the wayside.

However, the technology for creating superconducting magnets that can generate strong fields to shield spacecraft from cosmic radiation has only recently been developed. Superconducting magnet systems are desirable because they can create intense magnetic fields with little or no electrical power input, and with proper temperatures they can maintain a stable magnetic field for long periods of time. One challenge, however, is developing a system that can create a magnetic field large enough to protect a bus-sized, habitable spacecraft. Another challenge is keeping the system at temperatures near absolute zero, which gives the materials their superconductive properties. However, recent advances in superconducting technology and materials permit superconductive properties to exist at temperatures higher than 120 kelvin (−153° C).

There are two types of radiation that need to be addressed for long-duration human spaceflight, says William S. Higgins, an engineering physicist who works on radiation safety at Fermilab, the particle accelerator near Chicago. The first are solar flare protons, which would come in bursts following a solar flare event, such as those seen last week. The second are galactic cosmic rays, which, although not as lethal as solar flares, represent a continuous background radiation to which the crew would be exposed. In an unshielded spacecraft, both types of radiation would result in significant health problems, or death, to the crew.

And ....

http://physicsworld.com/cws/article/news/36558

This idea was first put forward in the 1960s, but was considered unworkable because it was reckoned that a volume of space more than 100 km across would have to be shielded. Extending a field over this distance would require magnets with strengths of tens or even hundreds of Teslas, which could not be transported into space.

However, according to Bamford, these previous calculations are inaccurate because they assume that the solar-wind plasma flows like a normal fluid. Decades of research on nuclear fusion have instead shown that plasmas are subject to all sorts of turbulent behaviour not seen in normal fluids, and that, furthermore, this turbulence can occur on roughly human scales.


The researchers believe it is possible to exploit this knowledge of turbulence to create a much smaller protective bubble, and have confirmed this belief — first through computer simulations, and then in a laboratory experiment. The latter involved injecting a supersonic plasma into a 1.5 m long vacuum vessel lined with magnetic coils, with a target magnet placed at the far end of the vessel. Using both optical imaging and an electromagnetic probe, Bamford’s team showed that the target magnet deflected the plasma such that the volume of space surrounding the magnet was almost entirely free of plasma particles (Plasma Phys. Control. Fusion 50 124025).

Bamford and colleagues say these results show that a spacecraft could in fact be protected using a bubble just some 100–200 m across. This, they say, would correspond to a magnet of about 1 Tesla, which would be light enough to be transported into space

 

[Gravity_Ray]

I dont want to answer for Shpaget. But what I think he means by "shorter period of time" doesnt apply to turning the field on and then turning it off! I think he means since the EM field around your space ship is weak and small the particles will travel through it very fast and it just isnt big enough to deflect the particles in the short period of time the particles will take to travel through your field.

The answer is in the first paragraph. Any artificial EM field will have a smaller radius around the ship than the EM field around the planet. The EM field is created by Earth's core which is rather large (anyway much larger than anything we can put in a space ship). Also the EM field around the planet doesnt actually deflect ALL the particles, but most of them.

The EM field around a ship will not be large enough to deflect particles as they travel through the EM field. So the field will have be exceptionally strong. So it has to be either weak and very big, or very strong and very small.

The idea is sound though. So you can always build your space ship with the water needed for the mission in tanks around the "living" quarters AND you can add to that an EM field around your space ship. You can not have too much protection from solar flares.

 

[Shpaget]

I dont want to answer for Shpaget. But what I think he means by "shorter period of time" doesnt apply to turning the field on and then turning it off! I think he means since the EM field around your space ship is weak and small the particles will travel through it very fast and it just isnt big enough to deflect the particles in the short period of time the particles will take to travel through your field.

The EM field around a ship will not be large enough to deflect particles as they travel through the EM field. So the field will have be exceptionally strong. So it has to be either weak and very big, or very strong and very small.

Yep, that's exactly what I meant.
I thought I was clear enough.

 

[Jimmyboy]

Your too clever Shpaget :shock:

Thanks Mee & Mac, Interesting idea, The energy requirments wouldnt be that much I would envisage, you could have the system at a low intensity or none at all with no threat and high when there is a threat.

But as you pointed out it looks like there on to it, so good luck to them...!!!