Structures Sybsystem Progress Report 11/10/95 - A&M

Structures Sybsystem Progress Report 11/10/95 - A&M

This week was spent investigating the possibility of jettisoning the propulsion system prior to landing. An initial configuration had the entire primary propulsion system (XLR-132 main engine and propellant tanks) being jettisoned prior to landing. This gave the best results in terms of minimizing landing weight and reduced landing gear length and payload deployment distance. However, this configuration required the 3 auxiliary thrusters be located near the center of the vehicle above the main engine. Since there are certain mission phases which require the auxiliary thrusters to be fired while the main engine is still attached, this option was rejected. The alternative to this is to simply decouple the main engine from the rest of the propulsion system and structure and jettison it only. This will still offer a reduced landing gear length and payload deployment distance (although not quite as much) as well as reduced landing weight. The figure below shows this new configuration as it would appear after landing. The three auxiliary thrusters (MR-107) are located on the base of the vehicle on a diameter of 186 cm at 120 degree intervals.

The vehicle at landing has the following inertial properties (vehicle axes shown below)

Ixx = 177 kg*m^2
Iyy = 161 kg*m^2
Izz = 151 kg*m^2

CG is 70.3 cm up from the base of the vehicle

The vehicle shown below has the following properties just prior to main engine jettison:

Ixx = 181 kg*m^2
Iyy = 165 kg*m^2
Izz = 152 kg*m^2

CG is 29.2 cm up from the base of the vehicle

The fueled vehicle has the following properties:

Ixx = 538 kg*m^2
Iyy = 473 kg*m^2
Izz = 555 kg*m^2

CG is 23.4 cm up from the base of the vehicle
(assumes 220 kg landing weight option)

Next week:

Our focus next week will be on defining the structural interface for the landing gear as will as baselining the designs for the deployment mechanisms. The following week will consist of finalizing the preliminary analysis and drawings.


Buttons

Wednesday, 31-Dec-1969 18:00:00 CST
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