#Chang’e2

[scienza-magia]

La Cina sta per essere la prima superpotenza nel Sistema Solare

La Cina prepara ZhengHe, una missione multipla nel sistema solare. L’agenzia spaziale cinese (CNSA) ha aumentato notevolmente le attività spaziali negli ultimi anni e ha grosse ambizioni per il futuro. Sulla Luna è in piena fase operativa la missione Chang’e 4, con un lander e un rover che operano da più di un anno, mentre la sonda Tianwen-1 è in viaggio verso Marte, partita a fine luglio per quella che è la prima missione interplanetaria cinese completamente indipendente. A fine anno dovrebbe partire una nuova missione verso la Luna, che riporterà campioni di suolo a Terra, e dall’anno prossimo inizierà la costruzione della nuova stazione spaziale tutta fatta in casa. Prossimamente, invece, è prevista un’avventura spaziale nuova e un po’ particolare, per certi versi abbastanza unica nel suo genere. Si tratta di ZhengHe (in cinese semplificato 郑和, traslitterato Zhèng Hé), una missione esplorativa nel sistema solare con (almeno) due obiettivi molto distanti tra di loro. Il termine deriva dall’omonimo esploratore cinese, molto famoso nella cultura locale, un ammiraglio che nel XV secolo con più di 300 navi andò in Indonesia, in India, in Arabia e in Africa. A CNSA announcement today makes clear that China has approved a very ambitious asteroid/comet mission. It will collect samples from near-Earth asteroid 2016 HO3 & deliver them to Earth then head to main belt comet 133P via Mars flyby. That profile calls for launch in 2022. pic.twitter.com/SCCBLOSC58 — Read the full article

[interplanetarypodcast]

(The Interplanetary Podcast)

Can artificial miniature magnetospheres be used to protect spacecraft

Ruth Bamford of the Rutherford Appleton laboratory

On earth the radiation hazards that you come across a generally related to the radioactive Decay of heavy elements like radium and uranium and  gamma rays and x-rays etc. However out in space is a completely different story and it's one of the major obstacles to space travel beyond the Earth. The extreme forces at the centre of the Sun, black holes, pulsars, quasars and of Supernova Explosions can accelerate protons, alpha Particles (two protons and two neutrons bound together), and even heavier nuclei like that of Iron, to ridiculous speeds and energies from mega electron volts to hundreds of giga electron volts which are of course extremely bad for you.  Because the energy is so high the nuclei of atoms and the electrons are blasting out into space separately as a form of high energy plasma.

The astronauts at the Apollo era saw these is blinding flashes when one of these high energy particles hit the back of their retina for example however it plays havoc with Electronics solar panels and most importantly human tissue.

So how do we protect ourselves from the galactic cosmic rays and the really highly variable solar particles from solar flares etc which are an ever-present hazard in space.  

In the 1950s especially from Explorer 1 onwards came the study of how the Earth protects itself from these galactic rays via its own magnetosphere something that life on earth would almost be impossible without.  Since this discovery many schemes have been put forward to using “active” shielding of spacecraft much like that of the Earth's magnetic field to deflect these dangerous cosmic rays. But they all seem to be totally impractical expensive and bulky.  

In all these past studies it was assumed that incoming cosmic charged particles were deflected or reflected using simple charged particle dynamics in a vacuum where the charged particles slowdown or accelerated by Electric Fields or bent around magnetic field lines. In this new study they have looked at a far more complicated system and treated the solar winds and cosmic winds as a plasma which is incredibly complicated but has yielded some interesting conclusions, And that the effectiveness of these mini magnetosphere acting as radiation protection Shields needs to be reconsidered and not simply dismissed based on outdated assumptions.

The team have validated there experiments in the laboratory in solar wind tunnels in computer simulations and also there are some interesting validations in space.   There are naturally occurring mini magnetic spheres on the moon and these create an interesting effect where the colour of the regolith is actually maintained over millenia because it is protecting the ground from this solar radiation Data from both the Chinese chang’e2 and the Indian Chhandrayaan 1 have revealed these “Lunar Swirls” in glorious detail, and showing these Relatively weak phenomena to be capable of slowing incoming Particles and providing a tranquil Haven from the solar wind

SLXLM

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 Based on a spacecraft design by Mark G Benton in an AIAA publication from 2011 it could be shown that you would need the requirements of about 20 kilowatts of onboard power being directed The superconducting Magnetic coils weighing about 3000 kilograms including the Cooling.  This would reduce the particle Flux by about 20% but you could greatly enhance this by pumping plasma into the bubble and this would mean 80 to 90% of particles would be excluded and deflected

The scientists have concluded that the use of active deflector shielding for radiation in space may be coming of age. It's a field that may have been ignored because of the over simplistic models used before to work out the power requirements to deflect these dangerous particles.  The study uses and much more complicated interaction but shows to be more efficient, This combined with the great progress in the last 10 years of superconducting technology and liquid deposition and multilayer coated conductor films etc etc May lead to a totally practical construction within the next 10 years Of a fully functioning active deflector shield.

More work is needed to understand the very complex interactions in these plasmas around Magnetic Fields but if humanity is going to go into space we absolutely do need active radiation shielding