1. EERF 6395 Navigation & Communication System for Deep Space Missions
Krishna Prasad Sreenivassa Rao (Satcom RX)
Johns George (Radar RX)
Johny Richards Rosary (Radar TX)
Rohan Kamdar (Satcom TX)

2. Introduction
Deep space missions deal with objectives like reaching celestial bodies that are located far away in space
One such example is the recently accomplished ‘Rosetta’ mission involving Comet ‘capture’ and landing
In this project we consider designing Navigation and Communication system for the Rosetta Mission
Space missions are highly challenging engineering feats apart from giving valuable information required to understand the Universe we live in
Since such missions typically last for a long time and the spacecraft is separated by a huge distance, designing communication modules is highly challenging

3. System Architecture
f = GHz

4. System Design Our system design involves designing a
RADAR based navigation system to avoid space debris during journey in space
Long distance (Satellite communication) system to correspond with the base station located on Earth for receiving command updates and to exchange information
The spacecraft remains dormant for a long time before approaching the comet’s vicinity. Command updates are sent from the base station to ‘awaken’ the spacecraft at the right time
Information includes data about experiments, photographs etc.

5. TOP LEVEL SPECS - RADAR Parameter Specifications Operating Frequency
1.232 GHz
Antenna Type
Parabolic Reflector
Transmission Power
60 dBm
Received Power
-120 dBm
Range
50 km
Radar Cross Section
0.01 m2
Radar Type
Pulse Doppler Radar

6. TOP LEVEL SPECS – SATELLITE COMMUNICATION
Parameter
Specifications
Frequency Band
L Band
Uplink Frequency
2 GHz
Downlink Frequency
1.5 GHz
Transmitter Antenna Gain
26 dB (Spacecraft)
Receiver Antenna Gain
60 dB (Base Station at Earth)
Antenna Type
Parabolic
Range
4.5 x 1011 m

7. Radar Transmitter

8. RADAR BLOCK DIAGRAM Amplifier Mixer Tone Antenna BPF Generator
Circulator
Local Oscillator
Received Signal
BPF
Mixer
Amplifier

9. Schematic

10. Nominal Analysis

13. Yield Analysis

16. Components

17. TONE Generator
Wide Frequency Range
Wide Power Level

18. Low Noise Figure
Wide Frequency range

19. Low Insertion Loss

20. Active Mixer
High Gain Conversion
Good Output IP3

21. Narrow Pass Band
Low Insetion Loss

22. High Gain
High P1dB

23. Radar Antenna
High Gain
Manageable Size

24. Hand Calculations
No -: k=1.38 x , T= 3K , B = 6 MHz (BPF bandwidth) No = x W = dBW Taking SNR to be dB, we get : So = -150 dBW = 1 x W = Receiver Sensitivity = Pmin Transmitter Power = dBm = 1140 W Gain of antenna = 36 dBi = 3981 RCS = 10 cm x 10 cm = 0.01 sq.m Range = 1140 x x 0.24 x 0.01 = m = km (4 π) 3 x EIRP = Pt * Gt = 96 dBm

25. HAND CALCULATIONS (contd)
POWER ADDED EFFICIENCY
Pin = mW + 1 mW = mW
Pout = dBm = W
Pdc = Idc * Vdc = W
PAE = ((Pout – Pin )/ Pdc ) * 100
= (( – )/2521) * 100
PAE = %

26. Doppler Shift vr = 10,000 m/s ft = 1.232 GHz c = 3 x 108 m/s
fd = 2 ft *vr /c
fd = 2 x 1232 x 106 x = kHz
3 x 108
Doppler Shift = kHz

27. Satellite Receiver

28. SATCOMM Block Diagram UPLINK MIXER LPF BPF ANTENNA LOCAL OSCILLATOR
BASEBAND SIGNAL
LPF
BPF
ANTENNA
LOCAL OSCILLATOR
POWER AMPLIFIER
DOWNLINK
LOW NOISE AMPLIFIER
AMPLIFIER
MIXER
BASEBAND SIGNAL
LPF
BPF
ANTENNA
LOCAL OSCILLATOR

29. Satellite Receiver Schematic

30. Nominal Analysis

34. Yield Analysis

38. Components

39. LNA High Gain & P1 dB Low Noise Low Power
Ideal to use as a first stage in a SATCOMM receiver system

40. Narrow Pass band
Low Noise

41. Active Mixer
High Gain Conversion
Good Output IP3

42. Low Loss
High Rejection

43. Flexible tuning
Low Power

44. LNA 1 – 25dB Gain LNA
Good Gain & P1 dB
Low Noise
Low Power

45. LNA 2
Low Noise
High Gain
Low Power

46. Deep Space Communication Network 60 dB – 80 dB Gain 35m Antenna
ESA’s L-BAND Antenna
Redu, Belgium

47. Hand Calculations Pt = 59.09 dBm Gt = 26 dB Gr = 60 dB
R = 4.5 x m
λ = 0.2 m
Pr = dBW dBW
Pr = dBW = dBm
Path Loss = dBm

48. Summary

49. Compliance Matrix (SATCOM)
PARAMETER
DESIRED
SPECS
PROJECTED
PERFORMANCE
COMPLIANT
OPERATING FREQUENCY
1.5 GHz Y
TRANSMITTER OUTPUT POWER
58.5 dBm
59.09 dBm
TRANSMITTER GAIN
88.5 dB
89.08 dB
RECEIVER GAIN
124 dB
124.5 dB
RECEIVER NOISE FIGURE
1.5 dB
1.7 dB
RANGE
4.5 x 1011 m
5 x 1011 m

50. Compliance Matrix (RADAR)
PARAMETER
DESIRED
SPECS
PROJECTED
PERFORMANCE
COMPLIANT
OPERATING FREQUENCY
1 GHz
1.232 GHz (modified) Y
TRANSMITTER OUTPUT POWER
60 dBm
60.57 dBm
TRANSMITTER GAIN
60 dB
71.61 dB
RECEIVER NOISE FIGURE
2 dB
1.636 dB
RECEIVER GAIN
120 dB
123.1 dB
RANGE (in km) 50
48.152

51. Health, Environment and Consumer Issues
According to IEEE Standard C recommendation, a distance of about 400 m should be maintained to avoid exposure to high power, Electromagnetic waves.
Typically, Antennas intended for Deep Space communication are located in remote places.

52. Production Schedule

53. Trade-Offs
In our project, the distance considered is very large and the RCS assumed for space debris is very small. To satisfy both the requirements, heavy power consumption becomes necessary
Such high power consuming components are present on the spacecraft
Thus specialized power sources like the RTGs apart from conventional Solar panels
With all such measures taken, the cost of the project shoots up drastically!
The assumed velocity of space debris is 5 km/s and the spacecraft is also 5 km/s. Detecting debris of higher velocity correlates to lesser reaction time.
To give us more reaction time, the Radar range has to be increased, again resulting in higher power consumption!

54. Project Cost Component Cost Radar Transmitter (1.2 GHz) $0.25 million
Radar Receiver (1.2 GHz)
Transceiver (2 GHz)
$1.5 million
Transceiver (1.5 GHz)
System Implementation
$20000
TOTAL
$ 4.02 million

55. Summary
The proposed project is a one-of-a-kind system that ‘captures’ a comet, ejects a lander on its surface and sends back collected results of scientific experiments carried out on the comet.
The Radar and Communication system for which the specifications were presented, ensures that the space probes navigates to the comet avoiding debris that the probe may encounter during the journey, carries out its experiments successfully and sends back collected result.
Power required to navigate, perform experiments and send data can be high and suitable arrangements to generate power have to be made, which ultimately raises the cost of the project.
Sufficient care is taken to ensure that the proposed requirements are met with adequate accuracy as space missions are very expensive.

56. Thank you!

57. Appendix

58. RADAR RECEIVER

59. Radar Receiver Schematic

60. Nominal Analysis

64. Yield Analysis

68. Low Noise Amplifier High Gain & P1 dB Low Noise Low Power
Ideal to use as a first stage in a RADAR receiver system

69. Band Pass Filter
Narrow Passband – 6 MHz

70. 1100 MHz VCO
Flexible tuning
Low Power

71. MIXER
Active Mixer
High Gain Conversion
Good Output IP3

72. 200 MHz LPF
Low Loss
High Rejection

73. Low Noise Amplifier - 1
Low Noise
High Gain
Low Power

74. Low Noise Amplifier - 2
High Gain
Low Power Consumption

75. Hand Calculations
No -: k=1.38 x , T= 3K , B = 6 MHz (BPF bandwidth) No = x W = dBW Transmitted Power = dBm = W Gain of antenna = 36 dBi = 3981 Range = m RCS = 10 cm x 10 cm = 0.01 sq.m Pmin = x x x 0.01 = 1 x = -150 dBW = -120 dBm (4 π) 3 x Pmin is above Noise by dB

76. Satellite Transmitter

77. Schematic

78. Hand Calculations

79. When Pr = Pmin = -124 dbm,
Pt = Pmin = dbm, f = 1.5 GHz, Gt = 26 dB, Gr = 60 dB (Deep Space Network)
Rmax = 794 x 400 x 106 x 0.04 = 5 x 1011 m
(4 π)2 x 3.16 x 10-16
EIRP = Pt * Gt = dBm

80. Power Added Efficiency
Pin = mW + 1 mW = mW
Pout = dBm = 811 W
Pdc = Idc * Vdc = W
PAE = ((Pout – Pin )/ Pdc ) * 100
= ((811 – )/2521) * 100
PAE = %

81. Nominal Analysis

84. Yield Analysis

87. TONE Generator

88. Gain = 33 db
NF = 1.2 db
P1dB = 21 dbm

90. Active Mixer
High Gain Conversion
Good Output IP3

91. Low Insertion Loss

92. Power Amplifier
High Gain
High P1dB

93. High Gain

94. References http://www.everythingrf.com/
acts.htm