CAS-7B(BP-1B) Satellite

CAMSAT News Release20190601

CAS-7B ( BP-1B ) amateur radio satellite is now ready for launch
CAS-7B ( BP-1B ) satellite is an amateur radio satellite combined with educational. Chinese Amateur
Satellite Group ( CAMSAT ) is working the project with Beijing Institute of Technology ( BIT ), one of
the most famous aerospace universities in China. The university provides support in launch of thesatellite, there are many teachers and students from this university are participating in thedevelopment and testing of the satellite. With the help of CAMSAT, the university has established anamateur radio club (call sign: BI1LG), many students are the members, they are learning amateur
radio satellite communication and experience endless fun.
Because of the orbital apogee and the size and mass of the satellite, the orbital life of the satellite is
expected to be only one week, up to a maximum of one month, which will also provide with anopportunity for hams to track and monitor satellite entering the atmosphere.
The CAS-7B ( BP-1B ) is scheduled to be launched at the end of June this year. The launch will use a
new launch vehicle from a small commercial rocket company. This is the first launch of this launchvehicle, and there is a large possibility of failure, if the launch fails, we will have another launch later
this year.

CAS-7B/BP-1B Satellite schematic diagram1

CAS-7B(BP-1B) Satellite

CAS-7B/BP-1B was undergoing thermal vacuum test

CAS-7B/BP-1B was undergoing test2

CAS-7B(BP-1B) Satellite● Satellite Name: CAS-7B/BP-1B● Architecture: 1.5U Cube-satellite with flexible film ball
● Dimensions: 263Lx140Wx105H mm with 500 mm diameter flexible film ball
● Mass: 3kg● Stabilization: Pneumatic resistance sail passive control● Orbit:● Orbit type :LEO
● Apogee :300km Circular orbit● Inclination :42.7º● Period :90.6min● Payload:● VHF Antenna: one 1/4λ monopole antenna with max.0dBi gain is located at +Y side
● UHF Antenna: two 1/4λ monopole antennas with max.0dBi gain are located at –Z and +Z side
● CW Telemetry Beacon:
435.715MHz
20dBm● V/U FM Transponder Downlink:
435.690MHz
20dBm, 16kHz bandwidth● V/U FM Transponder Uplink:
145.900MHz
16kHz bandwidth● CAS-7B ( BP-1B ) Satellites CW Telemetry Beacon Encoding Format

1、Telemetry beacon transmission timing：

Transmit a frame

5 sec., no transmission

next frame

2、Telemetry modulation and encoding：（1）Modulation: CW；（2）Encoding: Morse Code；（3）Transmitting speed: 22wps；（4）Numeric telemetry data encoding：
NumeralEncoding

0T

1

A

2

U

3V

445E
3

CAS-7B(BP-1B) Satellite
667B8D9N

3、Content of a telemetry frame
Transmission
Sequence

Content of Transmission

NoteEncoding1CAS7B

Satellite Identifier

Standard Morse Code2

BP1B

Start Identifier

Standard Morse Code3

BP1B

Start Identifier

Standard Morse Code4 - 35

CH1 – CH32

Telemetry Data Channel 1-32

Encoded Morse Code36

CAMSAT

Stop Identifier

Standard Morse Code37

CAMSAT

Stop Identifier

Standard Morse Code

4、Content of telemetry data channel
ChannelName of Parameter

Data Range

Type

N(min)N(max)

Description and Equation
the counter is incremented by one after aCH1

Telemetry frames transmitted counter

Data000999

CW telemetry frame is sent. Restart fromzero after the counter is full.
the counter is incremented by one after aCH2

Executed remote command counter

Data000

999

remote command is executed. Restartfrom zero after the counter is full.

CH3

Current operating mode

Status

001

110

①

CH4

Sail ball inflatable control

Status

050

591

②

CH5

Payload Status

Status

000

111

③

CH6

Battery voltage

Data000

999

V=N/100（V）

CH7

Primary power supply voltage

Data000

999

V=N/10（V）

CH8

DC / DC converter output voltage

Data000

999

V=N/100（V）

CH9OBC power supply voltage

Data000

999

V=N/100（V）

CH10

Solar cell array total current

Data000

999

I=N（mA）

CH11+X Solar cell array current

Data000

999

I=N（mA）

CH12-X Solar cell array current

Data000

999

I=N（mA）

CH13+Y Solar cell array current

Data000

999

I=N（mA）

CH14-Y Solar cell array current

Data000

999

I=N（mA）

CH15+Z Solar cell array current

Data000

999

I=N（mA）

CH16-Z Solar cell array current

Data000

999

I=N（mA）

4

CAS-7B(BP-1B) Satellite
CH17Power supply total output current

Data000

999

I=N（mA）

CH18

OBC current

Data000

999

I=N（mA）

CH19CW beacon current

Data000

999

I=N（mA）

CH20

FM transponder current

Data000

999

I=N（mA）

CH21

OBC temperature

Data000

999

④CH22

Battery 1 temperature

Data000

999

④CH23

Battery 2 temperature

Data000

999

④CH24

CW beacon temperature

Data000

999

④CH25

FM transponder temperature

Data000

999

④CH26

Sail ball surface temperature 1

Data000

999

④CH27

Sail ball surface temperature 2

Data000

999

④CH28

Sail ball surface temperature 3

Data000

999

④CH29

Satellite X-axis attitude angle

Data000

999

⑤CH30

Satellite Y-axis attitude angleData000

999⑤CH31

Satellite Z-axis attitude angle

Data000999⑤CH32

Sail ball internal pressure

Data000999

Note：（1）CH3 Current operating mode：

001:Mode 1（Sleeping）
010:Mode 2（CW Beacon，transmit per 5 minutes）
011:Mode 3（CW Beacon Continuously）
100:Mode 4（CW Beacon + FM Transponder）
101:Mode 5（CW Beacon + FM Transponder + Heater 1）
110:Mode 6（CW Beacon + FM Transponder + Heater 1+Heater 2 ）（2）CH4 Sail ball inflatable control：ABCA and B: Pressure sensor measurement delay, 05-59 seconds
C: Sail ball inflatable primary switcher status, 0 = OFF, 1 = ON

（3）CH5 Payload Status：ABC

A: CW Beacon, 0 = OFF, 1 = ON
B: FM Transponder, 0 = OFF, 1 = ON
C: Sail ball inflatable secondary switcher status, 0 = OFF,（4）Temperature：ABC
A: 0 – 2 , Temperature = ABC ℃
A: ≥3 , Temperature = - (A-3)BC ℃（5）Satellite attitude angle：ABCAttitude angle
0°～ 99°100°～ 180°

A01

B
0 - 90 - 9

C0 - 90 - 9
51 = ON

PV= Nx3 ( mV )⑥

CAS-7B(BP-1B) Satellite-0°～ -99°-100°～ -180°

890 - 9
0 - 9

0 - 9
0 - 9

（6）Sail ball internal pressure:
Sail ball internal pressure
（Pa）

PV
（mV）

1

101300

2388

2

2000

2366

3

1900

2365

4

1800

2366

5

1700

2332

6

1600

2272

7

1500

2222

8

1400

2159

9

1300

2076

10

1200

1948

11

1100

1863

12

1000

1761

13

900

1596

14

800

1398

15700

1301

16600

1153

17500

982

18400

779

19300

571

20

200

367

21

100

212

22

80

155

23

60

121

24

40

84

25

20

47

26

5

12

27

1

28
29

3-2

0-3

0

1×10
1×106