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Nov 25, 2016

Mars Vehicle "2500" - Part 1 - Basics

This Mars Vehicle (MV), model "2500" is part of the LEAMOR (Light Extended Apollo Mars Orbit Rendezvous) total mission plan. See the article for general ideas about that Mars mission plan.

Figure 1. Mars Vehicle (MV) "2500" with ablative lower part and heat shield above ablative fuel balls.

Figure 1 shows how the Mars Vehicle (MV) model "2500" looks like. It is typically a 150,000 lbs bi propellant standard LM (Apollo Lunar Module) type configuration before Descent Orbit Insertion (DOI). That is the typical maximum mass but the mass could be less if all aerodynamic braking (AB) and best optimal descent trajectories were used. As the Apollo Lunar Module it has also 2 stages: descent and ascent.

As the Apollo LM the LEAMOR MV will also be transported to the Low Mars Orbit and wait there until the manned Mars landing will take place. So it is not meant to carry any large cargo outside the astronauts since those could be sent more direct and less secure routes directly to the Mars surface (using for example so called Mars direct concept).

Here are the basic MV burn calculations repeated again for the descent and ascent with masses. Safety factor 1.3 for propellants. (The Rocket Equation used).

  • MV full 150 t (about max SLS, later maybe more)
  • MV dry 27 t
  • AS full 20 t
  • AS dry 3.5 t (3500 lbs)
  • DS dry 7 t (7000 lbs)
  • Isp both 311 s
  • Results delta-V: MV = 5.2 km/s and AS = 5.3 km/s (~ 1.3 x 4.1 km/s)

Notice that the descent stage is as wide as possible to add much as possible drag when entering Mars thin atmosphere .. on the other hand the ascent stage is slender to help it to reach the required orbital speed through the atmosphere. Lower fuel balls have double skin to help them handle the entry heat and covered with ablative shielding material. Since they a hard enough the landing gears are directly attached to them. Also the descent engine and the small heat shield above it is covered with ablative layer.

This vehicle can ALSO land to the Earth's Moon (and many other places) without any problem (due to much lower gravity than Mars) .. and the ablative layer is not required with the Earth's Moon since it does not have any atmosphere at all.

Figure 2. Some additional details.

Figure 2 shows some additional details like, how the nose cone opens to allow docking and how the fuel lines are installed.

Figure 3. Some usual atmospheric entry forms.

Figure 3 shows some usual re-entry body forms. Since most (or all) of the braking is done by the descent rocket thrust the drag body shape is not important it is there just to give some additional drag and prevent the burning of the surface by hot plasma.

See also:


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