Index

CHAPTER 3

PERFORMANCE

The launch performance given in this chapter is based on the following assumptions:

The two-stage LM-2C is mainly used for conducting LEO (h<500 km) missions and the LM-2C/CTS for circular LEO (h³ 500 km) and SSO missions. LM-2C takes JSLC as its main launch site, and it can also be launched from XSLC and TSLC. In this Chapter, the launch capabilities of LM-2C launching from JSLC and XSLC are introduced. The launch capabilities vary with different orbital altitudes and inclinations.

3.1 LM-2C Mission Descriptions

3.1.1 Flight Sequence

The typical flight sequence of LM-2C is shown in Table 3-1 and Figure 3-1.

Table 3-1 LM-2C Flight Sequence

Events

Two-stage LM-2C Flight Time (s)

LM-2C/CTS

Flight Time (s)

Liftoff

0.000

0.000

Pitch Over

10.000

10.000

Stage-1 Shutdown

120.270

120.270

Stage-1/Stage-2 Separation

121.770

121.770

Fairing Jettisoning

231.670

231.670

Stage-2 Main Engine Shutdown

305.770

301.184

Stage-2 Vernier Engine Shutdown

566.234

613.333

Stage-2/CTS Separation

/

616.333

CTS Solid Rocket Motor Ignition

/

2888.347

Beginning of Terminal Velocity Adjustment

/

2928.347

SC/LV Separation

569.234

3013.347

CTS Deorbit

/

3213.347

 

3.1.2 LM-2C/CTS Characteristic Parameters

The characteristic parameters of typical LM-2C/CTS trajectory are shown in Table 3-2. The flight acceleration, velocity, Mach numbers and altitude vs. time are shown in Figure 3-2a&b.

Table 3-2 Characteristic Parameters of Typical Trajectory

Event

Relative Velocity (m/s)

Flight Altitude (km)

Ground Distance (km)

Ballistic Inclination (° )

SC projection Latitude (° )

SC projection Longitude(° )

Liftoff

0.2

1.452

0

90

38.661

111.608

Stage-1 Shutdown

2035.853

47.052

61.755

22.765

38.106

111.633

Stage-1/Stage-2 Separation

2043.777

48.257

64.549

22.403

38.081

111.635

Fairing Jettisoning

3698.167

117.618

352.768

4.263

35.490

111.729

Stage-2 Main Engine Shutdown

6379.424

146.895

679.624

-2.540

32.551

111.813

Stage-2 Vernier Engine Shutdown

7917.684

181.142

2825.723

-25.629

13.252

112.076

Stage-2/CTS Separation

7918.657

181.104

2848.800

-25.829

13.045

112.077

CTS SRM Ignition

7402.700

637.804

18860.013

-173.727

-44.220

-80.123

Terminal Velocity Adjustment Ending

7512.356

639.455

18971.228

-177.295

-41.780

-80.001

SC/LV Separation

7520.725

637.611

18983.402

177.366

-36.557

-79.808

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 3-2a LM-2C/CTS Flight Acceleration and Flight Velocity vs. Flight Time

Figure 3-2b LM-2C/CTS Flight Altitude and Mach Numbers vs. Flight Time

3.2 Launch Capacities

3.2.1 Basic Information on Launch Sites

Two-stage LM-2C and LM-2C/CTS conduct LEO and SSO missions from Jiuquan Satellite Launch Center (JSLC), which is located in Gansu Province, China. The geographic coordinates are listed as follows:

Latitude:

40.96° N

Longitude:

100 .29° E

Elevation:

1072m

Two-stage LM-2C and LM-2C/CTS conduct LEO missions from Xichang Satellite Launch Center (XSLC), which is located in Sichuan Province, China. The geographic coordinates are listed as follows:

Latitude:

28.2° N

Longitude:

102.02° E

Elevation:

1826m

 

3.2.2 Two-stage LM-2C Mission Performance

The launch capacity of Two-stage LM-2C for typical LEO mission (h=200km, i=63° ) is 3366kg. The different LEO launch capabilities vs. different inclinations and apogee altitudes are shown in Figure 3-3a,b,c&d.

Figure 3-3a Two-stage LM-2Cís Capability for Circular Orbit Missions

(From JSLC)

Figure 3-3b Two-stage LM-2Cís Capability for Elliptical Orbit Missions

(From JSLC)

Figure 3-3c Two-stage LM-2Cís Capability for Elliptical Orbit Missions

(From XSLC)

Figure 3-3d LM-2Cís Capability for Large Elliptical Orbit Missions

Note: For this kind of mission, LM-2C works as follows: After Two-stage LM-2C reach the parking orbit (a LEO), it will release a solid upper stage and spin it up according to required direction. Then the upper stage will go into the large elliptical transit orbit by ignition at the pre-determined time. The method is suitable for GTO or Earth escape missions. The solid upper stage for orbit maneuvering can be made according to userís specific requirements.

3.2.3 LM-2C/CTS Mission Performance

The launch capacity of LM-2C/CTS for typical LEO mission (h=500 km, i=50° ) is 3000 kg. The different LEO and SSO launch capabilities vs. different inclinations and apogee altitudes are shown in Figure 3-4a&b.

Figure 3-4a LM-2C/CTSís Capability for Circular Orbit Missions (From JSLC)

 

 

 

 

 

 

 

Figure 3-4b LM-2C/CTSís Capability for Circular Orbit Missions (From XSLC)

 

3.3 Injection Accuracy

3.3.1 Two-stage LM-2C Injection Accuracy

The injection accuracy is different for the different missions. The injection accuracy for elliptical LEO (hp=200km, ha=400km) mission is shown in Table 3-3 and Table 3-4.

Table 3-3 Injection Accuracy for LEO Mission

(hp=200km, ha=400km)

Symbol

Parameters

Deviation (1s)

Da

Semi-major Axis

1.1 km

De

Eccentricity

0.00022

Di

Inclination

0.045 deg.

DW

Right Ascension of Ascending Node

0.055 deg.

Dw

Perigee Argument

1.67 deg.

Table 3-4 Covariance Matrix of Injection for LEO Mission

(hp=200km, ha=400km)

 

a

e

i

Ω

ω

a

1.210

1.154E-4

-8.821E-3

2.202E-2

6.319E-1

e

 

4.840E-8

-3.086E-6

9.622E-6

1.564E-4

i

   

2.025E-3

-3.044E-4

7.823E-3

Ω

     

3.025E-3

2.172E-2

ω

       

2.789

3.3.2 LM-2C/CTS Injection Accuracy

The injection accuracy for the circular orbit mission (h=630km) is shown in Table 3-5.

Table 3-5 Injection Accuracy for Circular Orbit Mission (h=630km)

Symbol

Parameters

Deviation (1s)

Dh

Orbital Altitude

6 km

Di

Inclination

0.05 deg.

DW

Right Ascension of Ascending Node

0.06 deg.

3.4 Separation Accuracy

3.4.1 Two-stage LM-2C Separation Accuracy

The separation accuracy of Two-stage LM-2C is shown in Table 3-6.

Table 3-6 Two-stage LM-2C Separation Accuracy (1s)

Items

Separation Accuracy

Roll Angular Rates wx

<0.5° /s

Yaw Angular Rates wy

<1.1° /s

Pitch Angular Rates wz

<1.1° /s

Pitch

<3.2°

Yaw

<3.2°

Roll

<1.5°

3.4.2 LM-2C/CTS Separation Accuracy

The separation accuracy of LM-2C/CTS is shown in Table 3-7.

Table 3-7 LM-2C/CTS Separation Accuracy (1s)

Items

Separation Accuracy

Roll Angular Rates wx

<0.3° /s

Yaw Angular Rates wy

<0.3° /s

Pitch Angular Rates wz

<0.3° /s

Pitch

<0.6°

Yaw

<0.6°

Roll

<0.6°

3.5 Launch Windows

LM-2C adopts automatic timing ignition, and it can be launched in zero-launch window.