TABLE 5-2 Recommended Notional GMD-E KV Mass Properties Statement

Liquid Midcourse KV with 30 cm 45-kg Sensor Segment or Subassembly Mass (kg) Notes

DACS

 

Adjusted for 4 g

Pressure regulator

0.50

Assumes 4 divert thrusters

Divert thrusters

4.60

ACS required assumed = 0.1 × divert

ACS thrusters

0.46

Closing velocity = 8-10 km/sec

Value drivers

Included

Maximum total time of KV operational = 1,100 sec

Manifold

Included

Sized for 4 g in last 10 sec

Seeker less IMU including cooling

45.00

 

Contingency for FPA shielding

1.00

 

IMU

1.00

 

Avionicsa

10.00

 

Separation system

0.50

 

Ordnance initiate lines

0.25

 

Kill enhancement device

5.00

Rough estimate

KV primary battery

5.00

Estimate based on other programs

KV basic structure and install

8.00

Tanks used as load-carrying structure but Kevlar epoxy composite structure for high axial and lateral acceleration

Total KV dry weight less tank
Useful fuel and oxidizer

81.31

Total ∆V in m/sec + 10% ACS

ACS and press fraction of useful, 10%

19.30

Added ACS fuel at 10% of divert

ACS and pressurization fuel, 10% Unusable propellant fraction, 3%

1.93

Propellant trapped in system 20% of fuel load

Unusable propellant

0.58

Conventional pressure tanks

Tankage

3.98

Account for ACS/pressure fuel used but not effective for thrust

Subtotal of KV wet

106.52

 

Isp of propellant (sec)

300

 

Isp (effective) after ACS and pressurization fuel

285

 

∆V from rocket equation

602

 

∆V desired in m/sec (input)

600

 

KV mass with 15% fuel remaining

88.47

 

Thrust for 4 g at 15% fuel load g at full fuel load

3,468

Based on 4 g

  3.32  

NOTE: ACS, altitude control system; IMU, inertial measurement unit; FPA, focal plan array; FTS, flight termination system; TM, telemetry.

aAvionics includes guidance/control computer, tactical communications transponder, KV electronic safe arm, FTS antenna (nontactical), FTS battery, command destruction recovery signal, X-band antennas, X-band TM, power divider/hybrid coupler, J Box, control module, logic.



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