Habitat/Descent Stage Mass Properties Version 1.0

Name                          Weight  X Station  Y of CG  Z of CG    Ixx       Iyy       Izz
                                       of CG

                                (lb)    (ft)      (ft)     (ft)   (sl ft2)  (sl ft2)   (sl ft2)
Airlock                        600.00   5.00      0.00    -0.50    168.00    239.00    239.00
Habitat                     15,000.00  25.00      0.00    -1.00 10,621.00 22,794.00 22,794.00

  Total Habitat             15,600.00  24.23      0.00    -0.98

Other Stuff                    595.00  45.00      0.00     0.00      7.00      7.00      7.00
RL-10 Engine                   305.00  50.00      0.00    -0.50      9.50     33.20     33.20

  Total Descent Stage          900.00  46.69      0.00    -0.17

  Total Habitat/Desc Stage  16,500.00  25.46      0.00    -0.94 10,828.96 43,771.52 43,748.07

Release Notes:

This is the initial release of the Habitat and Descent Stage Mass Properties sheet. It has been put together to serve primarily as a seed for my spreadsheet. As such, all values contained in this sheet are to be treated as extremely preliminary. Unless otherwise noted, consider all quantities are assumed to have a very high degree of uncertainty. Please see the Habitat and Descent Stage Mass Properties Coordinate System page for a description of the coordinate system in which the Centers of Gravity and Moments of Inertia are represented.

1. Weights: The weights for the airlock and an RL-10A-3-3A engine are reasonably well-known quantities. The other weights have been added merely to make the Habitat and Descent Stage weights add up to previously published data. Treat these other weights with a high degree of uncertainty.

2. X CG location: The X coordinate of each component's center of gravity has been based upon a crude estimate of where the geometric center of each component will be located. The Hab/Desc total makes use of each of these locations.

3. Y CG location: The Habitat and Descent Stage have been assumed to have a plane of symmetry in the X-Z plane. Consequently, the Y coordinates of all center of gravity locations are zero.

4. Z CG location: The Z coordinate of each component's center of gravity has been based upon a crude estimate of where the geometric center of each component will be located. The Hab/Desc total makes use of each of these locations.

5. Component Moments of Inertia: The component moments of inertia, where given, have largely been based upon approximating each component as a cylindrical shell.

6. Overall LTV Moments of Inertia: The overall moments of inertia take into account the CG locations of each component, in addition to making use of the available component moments of inertia.

Planned enhancements to this page include:

• Increased and improved component weight definition
• Increased and improved component CG location definition
• Increased and improved component moment of inertia definition
• Addition of cross products of inertia