For the Hermes Pathfinder vehicle, the relevant dimensions are:
| Variable | Length (in inches) | Description |
|---|---|---|
| hmp | 57.4 | Height of the mission package from nose cone tip to the end of the airframe |
| lmp | 14.5 | Depth into the cup |
| lfc | 7.6 | Depth of booster coupling section |
| hfc | 86.23 | Total height of booster including coupling section. |
| RB | 7.5 | Height of the main deployment bag, not including flaps (should make sure there is enough margin on relevant constraint(s)). |
| DM | 114 (9.5 ft) | Diameter of the main parachute |
| RM | 80.6 | Height of the main parachute (found using 0.707 aspect ratio): RM = DM*0.707 |
| SM | 126 | Length of shroud lines on the main parachute (may change when we update the main) |
| RD | 31 | Height of the drogue parachute (measured 2/15/2018) |
| SD | 100 | Vertical length (accounts for confluence angle) of the drogue shroud lines. Taken from the DGB parameters spreadsheet. |
Constraints and Calculations v2.0
These calculations and constraints are only a preliminary estimation, with the following assumptions:
- Neglect drogue deployment bag as of right now, we will take this into account on calculations further down the line.
- Vehicle dimensions are subject to change
- Main parachute shroud line length are subject to change–I also don't think this value accounts for the confluence angle, so it will actually be a little lower than advertised.