Appendix 8.0

Randy Andersen

Systems

The arrangement of the floors was based on the following test cases. Table A8-1 lists the mass of each level, along with its height, original starting point, and original center of gravity location.

Mass (kg) / Height (m) / Or. St. Z (m) / Y (m) / Z (m) / X (m)
Garage / 12,644 / 2 / 0 / -0.5 / 0.6 / 0.9
Ejection Level / 3,113 / 1.5 / 2.5 / -0.2 / 0.7 / 3.2
Kitchen Level / 4,277 / 2.5 / 4.5 / -1.8 / -1.1 / 5.6
Sleeping Level / 1,747 / 2.5 / 7.5 / 0.1 / 0.9 / 8.3
Hemisphere / 13,837 / 6.5 / 10 / 1.3 / 0.1 / 10.7
Total / 35618
Each Floor = 0.3 m thick

Table A8-1: Level Mass, Height, and Center of Gravity Location

Table A8-2 on the next page shows the six test cases of rearranging the levels. The hemisphere and the garage are always left at the top and bottom respectively. But the other levels were free to move. Case 5 provides the highest center of gravity at approximately 6.28 m from the base. This was chosen as the floor arrangement because the total system center of gravity for the HAB was specified to be no lower than 6.50 m from the base. I felt that this arrangement provided the best opportunity to obtain a workable model.

Level / Mass (kg) / Height of CM (m)
Case 1: / Hemisphere / 13,837 / 10.7 / CG(m)= / 5.899829
Sleeping / 1,747 / 8
Kitchen / 4,277 / 5.5
Ejection / 3,113 / 3.3
Garage / 12,644 / 1.2
External / 525 / -1.64
Case 2: / Hemisphere / 13,837 / 10.7 / CG (m) = / 6.084836
Ejection / 3,113 / 8.9
Sleeping / 1,747 / 6.2
Kitchen / 4,277 / 3.7
Garage / 12,644 / 1.2
External / 525 / -1.64
Case 3: / Hemisphere / 13,837 / 10.7 / CG (m)= / 6.255149
Kitchen / 4,277 / 8.3
Ejection / 3,113 / 6.1
Sleeping / 1,747 / 3.4
Garage / 12,644 / 1.2
External / 525 / -1.64
Case 4: / Hemisphere / 13,837 / 10.7 / CG (m) = / 5.928404
Sleeping / 1,747 / 8
Ejection / 3,113 / 6.1
Kitchen / 4,277 / 3.7
Garage / 12,644 / 1.2
External / 525 / -1.64
Case 5: / Hemisphere / 13,837 / 10.7 / CG (m) = / 6.283725
Ejection / 3,113 / 8.9
Kitchen / 4,277 / 6.5
Sleeping / 1,747 / 3.4
Garage / 12,644 / 1.2
External / 525 / -1.64
Case 6: / Hemisphere / 13,837 / 10.7 / CG (m) = / 6.098717
Kitchen / 4,277 / 8.3
Sleeping / 1,747 / 5.2
Ejection / 3,113 / 3.3
Garage / 12,644 / 1.2
External / 525 / -1.64

Table A8-2: Level Arrangement Spreadsheet - Center of Gravity Location

13 Meter Diameter Case

This case is presented as a comparison to our final design. It is not as complete because work was stopped short on this case when we found that the 9 meter case would work. The 9 meter case would obviously be lower in mass, so it was chosen. Several areas that need more work are as follows: no room was left for structural and TPS placement on the outside of the cylinder, and the support pillar was often entered with the incorrect diameter of 4m instead of 2m.

Garage Level

The garage level of the 13 m case is similar to that of the 9 m final design. The mass change of 6 kilograms to 12,650 kg is again due to rounding error. See Figure A8-1 for a schematic.

Figure A8-1: 13 Meter Case Garage Level

Sleeping Level

The sleeping level of the 13 m case is similar to that of the 9 m final design. The mass change of 1 kilogram to 1,746 kg is due to rounding error. The components are just allowed more room to spread out here. See Figure A8-2 for a schematic.

Figure A8-2: 13 Meter Case Sleeping Level

Kitchen Level

The kitchen level of the 13 m case is similar to that of the 9 m final design. There is no mass change from 4,277 kg. See Figure A8-3 for a schematic.

Figure A8-3: 13 Meter Case Kitchen Level

Ejection Level

The ejection level of the 13 m case is similar to that of the 9 m final design. There is no mass change from 3113. See Figure A8-4 for a schematic.

Figure A8-4: 13 Meter Case Ejection Level

Hemisphere Level

The hemisphere level of the 13 m case is similar to that of the 9 m final design. The change from 13,837 kg to14,724 kg is due to higher propellant and parachute masses. See Figure A8-5 for a schematic.

Figure A8-5: 13 Meter Case Hemisphere Level

Total HAB Interior

The total component mass of the HAB is 34,896 kg. See Figure A8-6 for a schematic.

Figure A8-6: 13 Meter HAB Levels

Total HAB

Here again, the more cumbersome components are supplied. Table A8-3

Note that in this early model the comm. antenna is not included and the RCS engines were included in the CGMOI code as part of the retro engine.

CG Loaction (m)
Mass (kg) / Y / Z / X
CGMOI / 34,896 / -0.1 / 0.2 / 4.9
Structure / 14,100 / 0 / 0 / 6.6
TPS - Hemisphere / 3,700 / 0 / 0 / 12.44
TPS - Cylinder / 1,050 / 0 / 0 / 5
Air / 941 / 0 / 0 / 8.25
System / 54,687 / -0.06381 / 0.127620824 / 5.908016

Table A8-3: Final Total Mass and Center of Gravity Location

This rough case calculates a total mass of 54,687 kg for the HAB. This is significantly heavier, 16.25 %, than the 9 m case of 47,042.7 kg. Also, the center of gravity of approximately 5.91 m from the base is lower than the minimum of 6.5 m.

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