In order to develop the space environment, space-based materials will have to be used. It is not cost-effective to launch all the materials necessary to develop Lunar bases, Mars bases, or large deep space habitats using earth only sourced materials.  The availability of  local materials that can be extracted to manufacture space structures, provide breathable gases, produce fuel for space propulsion and energy compels current day space industrial engineers to consider space-based resources.  Although on-orbit assembly of flight vehicle components (or space station components) is not new, the new frontiers of interplanetary space voyages make it necessary to set up manufacturing in space so that indigenous materials may be used.  The IN-SITU Resource Utilisation (ISRU) mission planned by the European Space Administration (ESA)  plans to show that water and oxygen extraction on the moon is feasible by 2025.  Due to the harshness of the space environment (in particular radiation and micro-meteorite impacts) it is recommended that automated  (or robotic) mining and materials processing  equipment should be made. Recent developments in computer hardware and artificial intelligence makes it possible  for robotic mining and manufacturing modules to be launched out to material-rich objects in the solar system.  Mining and manufacturing can be conducted prior to the arrival of the human crew. The final assembly can be overseen by the human crew ensuring safety, efficiency, and quality.


The manufacturing of future interplanetary (manned or unmanned) spacecraft will require cost effective designs that allow for multi-mission capability. Constructing a vehicle to operate on 1 tank of fuel is not a cost effective way to conduct exploration or development missions.  It is proposed that the capability to refuel spacecraft on-orbit or enroute be developed.  This requires establishing propulsion requirements for interplanetary voyages departing from  various orbits (Earth, Moon, Mars, and Venus) and  establishing off world fuel depots. To engineer space based refueling of cryogenic fuels will require the development of  durable and sustainable refueling systems and engine hardware.  A  new set of  design criteria must be created to accomodate these ultra long duration multi-mission requirements. Ground operational testing together with space operational testing should be conducted to ensure all safety and system performance  requirements are met.  Most of the energy expended by launch vehicles is for the purpose of getting to Low Earth Orbit.  Inflight refueling will dramatically  reduce the cost of exploration and development of the solar system since a vehicle can be refueled in space and used multiple times.


Manned interplanetary spaceflight requires that long duration life support technology be created.  Studies conducted onboard the International Space Station (ISS) have indicated that long periods in a microgravity environment can have debilitating effects on astronauts.  Cosmonauts like Valery Polyakov (437 days), and astronauts like Scott Kelly (340 days), Christina Koch (328 days),  Peggy Whitson (289 days) and Andrew Morgan (272 days)  have shown tremendous biological adaptability to the microgravity environment in the relatively safe harbour of low earth orbit where they were protected by the earth’s magnetic field.  Long duration microgravity causes muscle atrophy, skeletal deterioration  (due to bone mineral density loss),  eyesight impairment (likely due to increased intracranial pressure), and serious cardiovascular probems (slowing down of blood flow and  increased blood clotting).  Space travel also exposes  human astronauts to much higher levels of radiation both during transit to Mars, on Mars (with virtually no protective magnetic field and a thin atmosphere), and then on the return trip back to earth. Astronauts will experience increased risks of cancer and genetic damage  due to long duration exposure to radiation. These effects indicate  that the long voyage to Mars (which can take 2 – 3 years round trip to complete),  would degrade the health of the crew sufficiently to jeopardize the success of the mission.  While many of these effects can be reversed after the astronaut returns to earths gravity, crew functionality would be impaired below a minimum acceptable level during the mission .  Engineers should seek spacecraft designs that include artificial gravity and additional shielding from radiation. 


Manned interplanetary voyages require powerplants that can generate energy (electricity & heat) for years.  This means some form of nuclear powerplant is required.  Interplanetary propulsion can be done using an ion rocket, a chemical rocket, a nuclear thermal rocket, (NTR) or by using a variable specific impulse magnetoplasma rocket (e.g. VASIMR).