Propulsion Group Progress report 11/03/95

Propulsion Group 11/03/95

Britney Sandell

Current Mass: 500
Current Power: N/A

                   Table of Masses         Original Conceptual Design

Data:           Gravity =       9.8     kg/m^2          Lander Mass =   220        kg
                                                      Payload Mass  =   674.9852   kg

Rocketdyne XLR-132                      MR-107                          
Mass =  54      kg              Mass =  0.885   kg              
Isp =   340     sec             Isp =   220     sec             
Vpt-a = 10974.15m/sec                                           
Vp =    12000   m/sec           Vpt-a = 10974.147m/sec          
Delta V1 =-1025.85m/sec         Vp =    12000   m/sec           

Mission                 Delta V              Final           Prop    
Phase                   (m/sec)             Mass(kg)        Mass(kg)        
                      Actual   20% SF                                     
Last Descent               20      24       222.655           2.4923808       
First Descent            1665    1998       279.14738       229.30916
De-Orbit Burn              20      24       508.45654         5.6916186
TCM #5                     20      24       514.14816         5.7553301
Lunar Orbit Insertion     825     990       519.90349       179.87374
TCM #4                     20      24       699.77723         7.8332459
TCM #3                     20      24       707.61048         7.9209306
TCM #2                     20      24       715.53141         8.0095968
TCM #1                     20      24       723.541           8.0992555
Earth Departure Burn -1025.85   -1231.02    731.64026         0


Total Prop Mass for XLR-132                 409.1829                                
Total Prop Mass for MR-107                   45.80236                                

Total Prop Mass Used                        454.985                         
Max Lander Mass =                           455 kg



                        Table of Masses         (Not Jettisoning the XLR-132)                   

Data:           Gravity =       9.8     kg/m^2          Lander Mass =   220     kg
                                                      Payload Mass  =   764.1026kg

Rocketdyne XLR-132                              MR-107                          
Mass =  54      kg              Mass =  0.885   kg              
Isp =   340     sec             Isp =   220     sec             
Vpt-a = 10974.15m/sec                                           
Vp =    12000   m/sec           Vpt-a = 10974.147m/sec          
Delta V1 =-1025.85m/sec         Vp =    12000   m/sec           

Mission                 Delta V           Final              Prop    
Phase                   (m/sec)          Mass(kg)           Mass(kg)        
                        Actual  20% SF                                  
Last Descent               20      24    276.655           3.0968522       
First Descent            1665    1998    333.75185       274.1647
De-Orbit Burn              20      24    607.91655         6.8049653
TCM #5                     20      24    614.72151         6.8811395
Lunar Orbit Insertion     825     990    621.60265       215.05914
TCM #4                     20      24    836.66179         9.3655198
TCM #3                     20      24    846.02731         9.4703566
TCM #2                     20      24    855.49767         9.576367
TCM #1                     20      24    865.07403         9.683564
Earth Departure Burn -1025.85 -1231.02   874.7576          0


Total Prop Mass for XLR-132                     489.2238                                
Total Prop Mass for MR-107                      54.87876                                

Total Prop Mass Used                            544.103                         
Max Lander mass = 420 kg
                        



                         Table of Masses                (No Aux. Thrusters)                     

Data:           Gravity =       9.8     kg/m^2          Lander Mass =   220     kg
                                                      Payload Mass  =   652.48854kg

Rocketdyne XLR-132                              MR-107                          
Mass =  54      kg              Mass =  0.885   kg              
Isp =   340     sec             Isp =   220     sec             
Vpt-a = 10974.15m/sec                                           
Vp =    12000   m/sec           Vpt-a = 10974.147m/sec          
Delta V1 =-1025.85m/sec         Vp =    12000   m/sec           

Mission                 Delta V         Final              Prop    
Phase                   (m/sec)         Mass(kg)          Mass(kg)        
                        Actual    20% SF                                  
Last Descent               20      24      274             1.9807143       
First Descent            1665    1998      275.98071     226.70786
De-Orbit Burn              20      24      502.68858       3.6338775
TCM #5                     20      24      506.32245       3.6601464
Lunar Orbit Insertion     825     990      509.9826      176.44136
TCM #4                     20      24      686.42396       4.9620794
TCM #3                     20      24      691.38604       4.9979497
TCM #2                     20      24      696.38399       5.0340793
TCM #1                     20      24      701.41807       5.0704701
Earth Departure Burn -1025.85 -1231.02     706.48854       0


Total Prop Mass for XLR-132                     482.03                          
Total Prop Mass for MR-107                      34.69                           

Total Prop Mass Used                            516.72                          
Max Lander mass = 435 kg

  1. Fuel Requirements
    1. Type
      1. XLR-132 Monomethyl Hydrazine
      2. MR-107 Hydrazine
    2. Masses
      1. See charts above for different cases.
      2. See charts above for different cases.
    3. Volumes
      1. Using the masses stated above and the densities, the volume can be calculated.
      2. Same as above.

  2. Oxidizer Requirements
    1. Type
      1. XLR-132 Nitrogen Textroxide
      2. MR-107

The Charts above were run for three different cases:

  1. Original Design of one main engine, XLR-132, which is used for the three main engine burns, and three aux. thrusters, MR-107, which are responsible for the TCM's and the last phase of Descent.
  2. Same Original Design but not jettisoning the XLR-132
  3. One engine, the XLR, to accomplish all manuevers

In each case a test was run to check the maximum lander mass that would still satisfy the maximum payload of 2000 kg for the launcher. These values are listed in each chart of the different cases.

RCS (Gary Rhodes)

Since last week, we have realized that our initial methods for calculating the thrusts needed from the RCS were incorrect. We used the formula, Force = mass * ang.acc.* radius. The formulas that should have been used were, Force * radius = I * ang.acc., and ang.vel.(final) = ang.vel.(initial) + ang.acc. * time. I have begun to use the equations, along with a maximum angular velocity of 6 deg/sec^2 and a minimum of 0.6 deg/sec^2 (per Ken Rock) to see which thrusters will suffice for our needs.

So far a few monopropellant Hydrazine Thrusters look sufficient. These include the MRE-0.1. Due to its low thrust range (0.3 to 0.9N) it may not be able to accept a severe load. It would require too great a burn time. The MRE-1, MRE-4, and MRE-5/GRO appear to be contenders.

The current plan does not include coupling these thrusters. However, that is still an option. It is believed that single thrusters will not cause a detrimental translation. This would result in six thrusters, one for each direction for each axis. Coupled thrusters would require twelve thrusters.

Questions

Next Week

Hopefully, thrusters will be chosen for the RCS, along with their fuel and oxidizer requirements. We also hope to have feedback from A&M Structures to hear whether it will be detrimental to their design to use the 9-1/2 ft. Delta II-7925, rather than the 10 ft.

Other than that we hope to continue on with our schedule that was submitted as an earlier progress report.


Buttons

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