This section requires further editing to include all previous efforts.

Repository of Working Models

Minimalist Transportation Concept

How do we transport crew and cargo to the Martian surface using 25 mt launch vehicles?
- 25 mt is “worst-case scenario”
- Larger payload capabilities would facilitate transportation and also lead to scaling benefits
Specific challenges:
- Launch and LEO orbit assembly
- Mars aerocapture and EDL
  - Ballistic coefficient (entry body mass, diameter, shape)
  - Altitude at Mach 3 / aeroshell separation
- Propulsive descent (800 m/s assumed for now)
- Final landing GN&C, landing error reduction
- Hazard avoidance
Falcon 9 Heavy assumed as reference LV
- ~28 mt to 300 km LEO
- ~4 m x ~10 m cylinder of usable volume in shroud

Entry vehicle is based on conic blunted body
- 20 degree side-wall angle
- Drag coefficient: ~1.6
- L/D: ~0.3
Total mass is 12 mt, leading to a ballistic coefficient of around 600 kg/m2
- Mach 3 altitude ~ 5 km
Final descent propulsion based on MMH / N2O4
- Isp = 320 s
- 8 tanks (4 fuel, 4 oxidizer)
Cargo to surface: ca. 5 mt

Transportation concept based on dual blunt-shaped entry bodies
- Reduces ballistic coefficient per entry body (~ 600 kg/m2)
- Allows for simple blunt-body shape
Entry bodies are launched together with additional cruise systems
- Solar arrays, batteries, radiators
- Entry bodies separate prior to aerocapture and aeroentry
2 Earth departure stages are launched after the entry bodies
- Stages dock to entry bodies for dual burn Earth departure
Initial analysis indicates that ~25 mt can be injected towards Mars using LOX / kerosene stages
- ~10 mt useful cargo mass on Mars surface (~ 5 mt per entry body)
Crew transportation with entry body (cargo) and additional transit habitat
- 2 sets of solar arrays, batteries, and radiators
- Transit habitat is jettisoned prior to aerocapture
2 Earth departure stages are launched separately and docked
- Dual burn Earth departure
- LOX / kerosene propulsion
Initial analysis indicates that 2-3 crew can be delivered to Mars surface this way
- Crew can be sustained for 30+ days on surface after landing
- Unpressurized mobility delivered with crew

4-6 crew can be transported to Mars with 6 Falcon 9 heavy launches
- Launch cost of ca. $ 600 Mn (ca. $ 100 Mn per launch)
3 Falcon 9 heavy launches can deliver a minimum of 10 mt of useful mass to the Martian surface
- Equivalent to 26-month consumables demand for 4 crew
Forward work:
- More detailed design of aeroshell and descent stage
- More detailed design of Earth departure propulsion
  - Including propellant type trade
- Investigation of different entry body shapes

Previous transportation strategy was based on use of ~12 mt aeroshells with diameters around 5 m
This leads to a significantly increased number of aeroshells that need to be built, as well as to reduced maximum volume of items that can be transported to Mars
Analysis was carried out to determine whether it is possible to use a single ~24 mt aeroshell

Basic shape is blunted cone with 20-degree side-wall angle
Achieves L/D of 0.3 at 18.5-degree angle of attack
Drag coefficient of ~1.5 at 18.5-degree angle of attack
Shape is similar to SpaceX Dragon capsule
- May be possible to utilize aerodynamic database from Dragon
- Possibly use Dragon derivative?

Falcon 9 Heavy [FY 2008 $]
- $ 94.5 Mn per shot for LEO mission
Lander costs [FY 2004 $]
- Dry mass: 2453 kg
- Development: $ 1482 Mn
- Production (1st unit): $ 112 Mn
Aeroshell costs [FY 2004 $]
- Dry mass: 8000 kg
- Development: $ 2839 Mn
- Production (1st unit): $ 245 Mn
TMI stage [FY 2004 $]
- Dry mass: ~5000 kg
- Development: $ 560 Mn
- Production (1st unit): $ 32 Mn
Approximate marginal cost for transporting 10 mt to the surface of Mars:
- (3 x 94.5 + 2 x 32 + 112 + 245)*1.2 = 845.4
- $ 84540 / kg on the surface of Mars

“2 mt case”: integrated payloads of no more than 2 mt can be landed on the surface of Mars; extension of current Mars EDL technology
Cargo transportation
- All cargo packages are landed on the surface of Mars using scaled-up MSL-type vehicles
- Each cargo package and the associated cruise stage and EDL system is launched and injected towards Mars using an EELV-class launch vehicle (Falcon 9 heavy, Delta IV heavy, Atlas V heavy, etc.)
Crew transportation
- Similar approach as for 10 mt case, but different hab / EDL design
- Mars Transfer Vehicle is assembled in LEO out of 3 payloads of ~25 mt
  - 1st payload: habitat + Mars entry vehicle (same entry vehicle as for cargo)
  - 2nd and 3rd payloads: each one ~25 mt propulsion stage for TMI
- 2 crew are transported using this transfer vehicle