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Mars Requirements

Missions to Mars may be designated Category III, IVa, IVb, or IVc for planetary protection purposes, depending on their aims.

Category III missions to Mars (flybys and orbiters), as well as cruise stages, as stated in Section 5.3.1.2 of NPR 8020.12D, shall avoid Mars impact at a probability no less than 0.99 for 20 years after launch and a probability no less than 0.95 for the period 20-50 years after launch.

All Category IV missions to Mars shall meet the following bioburden constraints, as deemed appropriate given the mission type and needs, and as approved by the NASA PPO.

The following table provides the bioburden values for Mars Category IVa, IVb, and IVc missions.

Table is adapted from Frick, A. F., Mogul, R., Stabekis, P., Conley, C. A., Ehrenfreund, P. Overview of Current Capabilities and Research and Technology Developments for Planetary Protection. Adv. Space Res. 54, 221-240.

  • Table of Category IV Bioburden Constraints in pdf format.



     

    Category

    Soft-Landed Hardwarea (SL)

    Hard-Impacting Hardwareb

    Total Spacecraftc

     

    Sub-Category

     

    Type

     

    System Level

     

    Surface Bioburdend

    (sBbSL)

     

    Surface Bioburden Densityd (ρsBbSL)

     

    Hard-Impacting Bioburdene

     

    Accountable Bioburdenf

     

    Enclosed Bioburden Densityg

     

    Total Bioburdenh

     

     

     

    (spores)

    (spores/m2)

    (spores)

    (spores)

    (spores/m2)

    (spores)

    IVa

    No Life Detection

    Full-System

    < 3×105

    < 300

    5×105sBbSL

    < 5×105

    1000

    IVb

    Life Detection

    Full-System

    < 30

    < 0.03

    5×105sBbSL

    < 5×105

    1000

     

    Life Detection

    Sub-System

     

    < 30 subsystem

     

    < 0.03 subsystem

    5×105 – Total sBbSL

    < 5×105

    1000

    < 3×105 Total sBbSL

    < 300 Total ρsBbSL

     

    Life Detection

    Full-System

    Bioburden levels or other values are dependent upon experimental needs.

    Sub-System

    IVc

    Special Region is Within the Landing Ellipse

    Full-System

    < 30

    < 0.03

    1.5×104sBbSL

    0.1

    < 1.5×104

     

    Special Region is Outside or Sub-Surface to the Landing Ellipse

    Full Systemi

    < 30

    < 0.03

    1.5×104sBbSL

    0.1

    < 1.5×104

     

    Special Region is Outside or Sub-Surface to the Landing Ellipse

    Sub-Systemj

     

    < 30 subsystem

     

    < 0.03 subsystem

    5×105 – Total sBbSL

    < 5×105

    1000

    < 3×105 Total sBbSL

    < 300 Total ρsBbSL

     

    Missions that May Induce or Create a Special Region

    Full-Systemk

     

     

    Bioburden levels or other values are dependent upon experimental needs.

     

     

    Sub-Systeml

    a.  For all missions, the soft-landed hardware must be protected from recontamination due to the hard-impacting hardware and other components of the spacecraft.

    b.  Includes only hard-impacting hardware that is within 3 σ of the landing ellipse.

    c.  Includes all hardware (soft-landed and hard-impacting hardware) that is within 3 σ of the landing ellipse.

    d.  Includes only accessible or exposed surfaces.

    e.  Includes all surfaces and encapsulated and mated materials of the hard-impacting hardware.

    f.    Includes components of the spacecraft that may release spores into the environment, including the accessible surfaces of the soft-landed hardware and all components of the hard-impacting hardware.

    g.  Includes all non-accessible surfaces of the soft-landed hardware.

    h.  Includes all surfaces and encapsulated and mated materials of the soft-landed and hard-impacting hardware.

    i.    Full-system option will be employed if the spacecraft carries a long-term heat source (e.g., plutonium) or failure modes analysis of the landing event indicates that debris field could contaminate a special region at a probability >1%.

    j.    Sub-system option may be employed if failure modes analysis of the landing event indicates that debris field would not contaminate a special region at a probability >1%.

    k.   Full-system option will be employed if failure modes analysis of the landing event indicates that debris field could create a special region at a probability >1%.

    l.    Sub-system option may be employed if failure modes analysis of the landing event indicates that debris field will not create a special region.