anyone who gardens on Earth knows how unpredictable it is, here where we think we know everything and have big (though variable) supplies of what plants need.
Mary Roach wrote 'Packing for Mars' and covers some of the logistics in getting humans in space, a fun and interesting book
There are unknown scientific breakthroughs, but there is the sheer physics of transporting to Mars everything is currently NOT there. Water is key, yet even here on one planet, water is scarce and fought over in some places.
How are those geodesic self contained domes doing?
