Apparently cosmic ray exposure for months causes brain damage and cognitive decline in some life forms ( https://thenextweb.com/science/2019/08/07/scientists-ask-nasa-to-reconsider-mars-mission-after-studying-effects-of-space-radiation/ ).
Water or ice several feet thick filter out cosmic rays, so moon water or water lifted from Earth aboard a Star-liner to an orbiting space-dock facility would be required to fill a hinged, spherical shield for spacecraft launched to orbit before beginning the journey.
Building a space-dock to orbit Earth where advanced finishing and modifying work could be done on space-ships should be a practical international effort.
Ice-spheres would be very simple. Like an empty bottle filled with water that freezes- hollow in the center with room for a space-ship and its engine exhaust .
An example paradigm from my story ‘Alterwall Objectives’ in my free story collection; Wrangell’d Pulp Fiction. http://www.lulu.com/shop/gary-clifford-gibson/wrangelld-pulp-fiction/ebook/product-23037183.html
“They’ve sunk the Semi-annual reports of most of the mutual funds I’ve invested in. I can invent a hundred new devices a year and not sell one…I can’t keep this micro-world open” Voevoda said looking out the Big Picture window at the Earth spinning in the distance.
The micro-world was a mostly hollow, creation dry-dock for the construction of material objects through a variety of atom adhesion, accretion techniques. Products were invented, down loaded to micro-world cad/cam and robotically assembled. The entire world could come apart on magnetic hinges and allow the birth of an object two-thirds its own size to emerge. Several similar micro-worlds for various purposes were parked in orbit near the Earth-market.
Smaller micro-worlds were sprayed onto magnetic field molds and flash-fused into place. Dozens of instant Void-ships were turned out each day when business was good. The Solar System was strewn with Voevoda’s Diatom brand Cor-Ships. Double hull construction with a fifteen foot thick ice sheet between hulls stopped lethal cosmic ray penetration. The core ships manufactured their own water for ice from universal hydrogen and oxygen from plant photosynthetic respiration.
Cheri removed her static-cling body wrap to place on a one-piece stealth planetfall suit she’d need to reach down to Earth. She stood in back of Patrick, whom was already wearing a similar suit, appearing as a head floating without a body in the green, lush tropical eco-office such were the camouflage waveform properties of the Voevoda model stealth suit.
“I’m ready,” she said.