Versions Compared

Old Version 23

changes.mady.by.user Unknown User (janssonm@mit.edu)

Saved on

compared with

New Version 24

changes.mady.by.user Unknown User (janssonm@mit.edu)

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

  • Neglect drogue deployment bag as of right now, we will take this into account on calculations further down the line. Or alternatively, there will likely be enough wiggle room with all the lengths that we don't need to worry about it.
  • 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.
ConstraintDescription
WC,D > RBThe line connecting the top of the main chute canopy to the inside of the deployment bag must be long enough such that the main parachute is not stuck inside the deployment bag upon full line extension.
WA,H > WA,E,F,G + RD + SD + lfcWhen lines between the mission package and fin can are fully extended, the drogue parachute must be within the airstream.
WA,H > lmp + hmp + lfcAssuming full line extension, the mission package and booster section should not hit one another during descent. This neglects the effect of drag on these sections and their respective masses.
WA,E,F,G - lmp > 8.5*FD,D- SDThis constraint reduces the impact of forebody wake on the drogue parachute during drogue descent. Please see the extended note below on the calculation of forebody diameter. We subtract the vertical height of the shroud lines to reach a total canopy distance of ~9 forebody diameters.1
WA,E,F < WA,B + SM + RM + WC,DPrior to firing the tender descender, the load should go through the shorter (TD) path. Note that this is automatically satisfied by virtue of the fact that the main shroud lines alone are significantly longer than the deployment bag. There is no need to check this constraint.
WA,B > lmp + 6*FD,M
 -
Mathinline
body\sqrt{S_{M}^2-(D_{M}/2)^2}
"[T]he parachute should be ejected to a distance equivalent to more than four times–and preferably six times–the forebody diameter" (Knacke, 5.2.2). Please see the extended note below on the calculation of the forebody diameter. We subtract the vertical length of the shroud lines to reach a total canopy distance of ~6 forebody diameters.

...