1. Launch vehicle
The vehicle of choice is the Falcon Heavy rocket, which SpaceX has designed to carry about 30,000 pounds to the vicinity of Mars. The Falcon Heavy’s first demonstration flight is planned for later this year.
NBF – The Mars mission can also use two or more launches of smaller rockets which already exist. Using more smaller rockets would increase cost and complexity
2. Crew life support system
Paragon Space Development Corporation is contracted to build a prototype this year. The system — like the one on the International Space Station — will convert exhaled carbon dioxide into oxygen, recycle water from urine and feces, filter the cabin air, and maintain its temperature and pressure.
But unlike the more automated ISS system, Inspiration’s smaller life support will be run by the crew themselves – making it simpler, quicker and cheaper to build, and less likely to break.
3. Cosmic rays / Radiation
A magnetosphere protects earthlings and even ISS astronauts, but there’s no natural radiation shield for the Mars voyage.
NASA has a Water Walls project. The nuclei in atoms block cosmic rays; and water molecules, made of three small atoms, contain more nuclei per volume than even metal. Water in polyethylene bags could create a 15-inch thick shield. But when NASA tested the system in 2011, they found it was not as efficient in orbit.
Water Walls provides four principal functions of processing cells in four different types plus the common function of radiation shielding:
1. Gray water processing for urine and wash water,
2. Black water processing for solid waste,
3. Air processing for CO2 removal and O2 revitalization,
4. Food growth using green algae, and
5. Provide radiation protection to the crew habitat (all cells).
The spacecraft’s walls can also be lined with dehydrated feces, urine, and food. Like water, the hydrocarbons in excrement and food are rich in nuclei. After the feces is dehydrated by the cabin’s water recycling system, it can be bagged up and fixed to the walls.
4. Higher speed (about 30,000 mph) earth re-entry than ever before
As a result of its slingshot, the spacecraft will be traveling so fast it’ll need to spend 10 days in orbit just to lose speed. After that, it’ll still be traveling at a record 14 kilometers (about 8 miles) per second when it hits Earth’s atmosphere – a higher velocity than anything manmade has ever had during re-entry. NASA will help design the re-entry path and heat shields to protect Inspiration’s astronauts.
A normal conservative approach for validating a man rated system (after all the mockups and simulations) would be to have several full scale live tests. Full scale high speed tests of earth re-entry would be expensive to perform. It seems to actually perform a full scale test you would need to launch something that would slingshot around the moon and then have more rockets and fuel to increase speed before re-entry.