SpaceX/Dragon Arrives at the Space Station
On July 20, two days after its launch from the Complex 40 at Cape Canaveral - Air Force Station (CCAFS) in Florida, the SpaceX Dragon cargo spacecraft arrived at the ISS, carrying science research, crew supplies and hardware in support to the station’s Expedition 48 and 49 crews. Credit: NASA


The atmosphere of another planet may not be compatible with our basic survival requirements of oxygen, carbon dioxide and nitrogen. In all likelihood, any astronauts stepping foot onto this new world need some form of space suit to enable them to function. Many of these risks can be mitigated by understanding in advance the many worlds and moons of our own Solar System. Then there is the journey itself to get to this new world. This will involve traveling across vast distances of space, not depending on any rescue parties and avoiding asteroids or dust particles as they approach with large kinetic energies. Even a single particle can present a significant collision risk if the vehicle is traveling at high speed. This is due to the fact that kinetic energy is proportional to the velocity squared, so the faster the ship or particle is going, the higher the collision energy involved. There is also the risk from bombardment of cosmic rays en route, which may cause cancer. If an artificial gravity field is not created then astronauts should expect significant calcium loss and bone decay.
Soyuz rendezvous and docking explained
Soyuz undocking, reentry and landing explained