Mars preparation

According to the capability map analyzed in section 4.2.2 (see figure 4.12), some of the capabilities needed for human Mars mission can be achieved only with specific missions to Mars. For this reason, as already introduced, a dedicated concept, called Mars Preparation (MP), is included in the scenario to achieve the missing capabilities. In particular, this concept allows the demonstration of the capabilities listed in table 4.29. The proposed missions have not been analyzed in details, but basic considerations on the main objectives, baseline architectures and elements are provided hereafter.

4. HUMAN SPACE EXPLORATION REFERENCE SCENARIO

Transportation Support-In Space Support - Surface

Operations Operations High speed Earth manned

EDL

In-Space cryogenic fuel manage- ment

Surface cryogenic fuel

management Advanced RvD High capacity cargo trans-

fer In-Space advanced robotics Surface advanced power Long range comms Orbit cargo insertion Surface advanced thermal Medium range comms Orbit manned insertion Surface radiation protec-

tion Short range comms Destination cargo entry Surface advanced robotics Safe in-space elements sep-

aration Destination cargo D&L Atmospheric ISRU

Destination manned D&L Surface mobility Destination cargo ascent

Table 4.29: Mars preparation concept capabilities

Analogously to what done for the previous concepts, the process of analysis of the Mars preparation case for the definition of the missions and the architectures starts from the identification and evaluation (qualitative) of specific “Second-Level Key Decisions” (as previously explained), for which specific options are selected. The key decisions for the Mars preparation concept are summarized in table 4.30, in which the alternative options are shown, as well as the justification of the final choices.

Key decision Options Notes

Mission strategy Orbiter-ERV pre- deployment All-in

Orbiter pre-deployed into Mars or- bit with dedicated mission before the lander one.

Orbiter transfer

propulsion Solar electric

Chemical cryogenic Chemical storable Nuclear thermal

Same propellant used for Mars transfer orbit insertion, mid-term correction and attitude control ma- neuvers.

ERV transfer

propulsion Solar electric

Chemical cryogenic

Chemical storable

Same propellant used for Earth transfer orbit insertion, mid-term correction and attitude control ma- neuvers. Orbiter-ERV Mars insertion strategy Aero-braking Propulsive braking

Rigid aeroshell is used, 9 months ae- rocapture into 500km circular orbit, 45deg inclination. Orbiter operative life Until ERV Earth injection Few years after MRS end Until Mars habitability test (7y) Until Mars unmanned rehearsal (10y)

10-years operative lifetime system in Mars orbit is a valuable demo of Mars relay satellite mission.

Lander transfer

propulsion Solar electric

Chemical cryogenic Chemical storable Nuclear thermal

Same propellant used for MTO in- sertion, mid-term correction and at- titude control maneuvers; Mars di- rect entry trajectory implemented. Surface exploration strategy Only lander Lander + small rover Lander + big rover

Samples collected in two locations by the lander and a small size rover (Spirit and Opportunity class). Descent/Ascent propulsion Pressure-fed hypergolic NTO/MMH Pump-fed cryogenic LOX/LCH4 Pressure-fed cryogenic LOX/LH2 Hybrid

First Mars ascent demonstration supposed to implement the simplest strategy and propulsion system

Table 4.30: Mars preparation “Second-Level Key Decisions”

4.2 Characterization of missions and related architectures

1. Mars sample return phase, during which a sample return mission is envisioned to carry back to Earth at least 500g of samples;

2. Mars Preparation I phase, which includes a Mars habitability test mission to demonstrate some specific capabilities;

3. Mars Preparation II phase, which represents an unmanned rehearsal mission, for the demonstration of additional capabilities and to pre-deploy the Mars relay satellite.

A minimum of four missions is needed for this concept, all classified in only one type: • Unmanned Cargo Delivery Mission, referring to unmanned missions for the demon-

stration of technologies in view of the human mission to Mars as well as for the pre-deployment of robotic assets.

For the mentioned missions, four di↵erent new architectures are identified. The first one refers to the Mars sample return mission and is schematically illustrated in figure 4.38.

Figure 4.38: Mars preparation concept - mission architecture 1

4. HUMAN SPACE EXPLORATION REFERENCE SCENARIO

operations is shown in figure 4.39.

Figure 4.39: Mars preparation concept - mission architecture 2

The third architecture refers to the Mars unmanned rehearsal mission: the sequence of operations is shown in figure 4.40.

The fourth architecture refers to the Mars relay satellite deployment mission: the sequence of operations is shown in figure 4.41.

According to these mission architectures, 22 di↵erent elements are needed to accomplish the Mars preparation concept missions, which are (number of needed units is reported in brackets):

• Transportation Elements – Small aeroshell (two units)

– MSR Mars ascent vehicle (one unit) – Interplanetary space tug (three units) – 2-tons lander (one unit)

– 20-tons lander (one unit)

– Descent/Landing stage (one unit) – Medium aeroshell (one unit)

4.2 Characterization of missions and related architectures

Figure 4.40: Mars preparation concept - mission architecture 3

4. HUMAN SPACE EXPLORATION REFERENCE SCENARIO

– Aeroshell (one unit) – MAV demo (one unit) – LH2 tank (one unit)

– Long term NTR (two units) • In-space elements

– MSR ERV (one unit) – MSR orbiter (one unit) – Mars relay satellite (one unit) • Surface elements

– Atmospheric ISRU demo (one unit) – MSR rover (one unit)

– Utility cart (one unit) – Manipulator (one unit) – SHAB demo (one unit) – FSPS (one unit) – SolPS (one unit)

– Atmospheric ISRU plant (one unit)

Analogously to what done for the precedent concepts, these elements can be further classified as “New Project”, “Upgraded Versions” and “Already Used” elements, with respect to previous steps of exploration (ISS, cis-lunar, Moon and NEA concepts): the pie chart reported in figure 4.42 summarizes the number of elements, highlighting their design status (green, yellow and red colors are used to indicate already used, upgraded version and new project, respectively).

4.2 Characterization of missions and related architectures