space technology lecture notes on satellite

space

1. Terra at 10
The EOS Flagship
Eric Moyer
NASA/Goddard Space Flight Center
Greenbelt, Md. 20771
Photos provided by Al Lampe May 11, 2010
Goddard Space Flight Center

2. The satellite’s name “Terra,”
meaning Earth, was the winning
entry in a nationwide student
essay contest won by a high school
student from St. Louis, Missouri.

3. A Walk down Memory Lane….
What did it take
to build Terra?

4. Primary Structure

5. Communications Equipment Module

6. Power Equipment Module
Batteries

7. Solar Array

8. The equipment modules
were then integrated
on to the
Primary Structure
Power
Equipment
Module
Communications
Equipment
Module
Primary
Structure
The equipment modules were then
integrated on to the Primary Structure

9. Thermal Control Subsystem

10. Guidance
Navigation
and
Control
Subsystem

11. Guidance Navigation and Control Subsystem
Reaction Wheel Assembly
Star Trackers

12. Propulsion Subsystem

13. Flight Software and Simulators

14. Navigation
TDRS On-board Navigation System (TONS)
Performance has exceeded requirements

15. The Instruments

16. ASTER Instrument
METI and ERSDAC, Japan

17. CERES Instrument
Langley Research Center, Virginia

18. MISR Instrument
Jet Propulsion Laboratory, California

19. MODIS Instrument
Goddard Space Flight Center, Maryland

20. MOPITT Instrument
Canadian Space Agency and University of Toronto, Canada

21. So what did it take
to build Terra?
A lot of dedication, technology
and
teamwork!!!

22. View of Terra Equipment Modules
Technology and Teamwork

23. View of Terra Instruments
Technology and Teamwork

24. Terra Spacecraft was built by Lockheed Martin
at the Valley Forge, Pennsylvania facility
and managed by NASA Goddard Space Flight Center
Technology and Teamwork

25. Terra moved to
the launch site in
California

26. Spacecraft on Transporter with Frame

27. Spacecraft on Transporter
bagged for shipment

28. Terra Spacecraft Transportation Container

29. Terra flew on a C-5 aircraft from Dover Air Force Base, Delaware
to Vandenberg Air Force Base, California, where it was
processed and launched.

30. C-5 on Final Approach to Vandenberg

31. The Solid Rocket Boosters arrive at Vandenberg

32. Transportation System outside
Payload Processing Facility at
Vandenberg AFB, California

33. Shipping container entering Payload Processing Facility

34. Removing Shipping Container Cover

35. Removing Frame

36. Terra spacecraft being prepared for installation on its
Three-Axis Positioner (TAP)
TAP

37. Final Check-up/Pre-launch Testing

38. Propulsion Leak Testing

39. Contamination Inspections

40. Inspecting the MODIS instrument lens for dust

41. Inspecting and Cleaning

42. After testing and inspections,
Terra received a
“GO FOR LAUNCH”!

43. Preparing Terra
for positioning on its
Payload Adapter
Terra:
Weight –5190 kg
Diameter –3.5 meters
Length –6.8 meters

44. Terra mounted to its adapter is then installed in a
Launch Vehicle Fairing.
Adapter
Fairing

45. The Fairing was positioned on top of the Atlas rocket
inside the building.

46. Terra Launch
December 18, 1999

47. Terra’s systems and
Instruments were
checked successfully and
declared operational.

48. 5/29/2024
GSFC
48
Terra Today

50. 5/29/2024
GSFC
50
•The Flight Operations Team (FOT):
•evaluates Terra’s health and safety, 24 hours a
day, 7 days a week,
•performs 27-28 contacts thru TDRS daily
•ensures that all the science data are downlinked
(99.05 % data capture)
•maintains Terra’s orbit by doing maneuvers
25 Inclination Maneuvers
58 Drag Make Up Maneuvers
The instrument teams work with the FOT to manage
the operation of the instruments.
Taking Care of Terra

51. Tracking & Data
Relay Satellite
(TDRS)
Instrument Teams
and Science
Investigator-led
Processing System
(SIPS)
Direct Broadcast/
Direct Readout
Stations
Direct
Broadcast
(DB)
EOS Data and
Operations System
(EDOS)
Data Processing
White Sands
Complex
(WSC)
Ground Stations
Internet
(Search,
order,
distribution)
Research
Education
Value-Added
Providers
Interagency
Data Centers
International
Partners
Earth
System Models
Decision Support
Systems
Distribution
and Data
Access
Data Acquisition
Flight Operations,
Data Capture,
Initial Processing,
Backup Archive
Data
Transport
to Data
Centers/
SIPSs
Science Data Processing,
Data Mgmt, Interoperable
Data Archive, &
Distribution
NASA
Integrated
Services
Network
(NISN)
Mission
Services
Mission Operations Science Operations
EOS Operations
Center (EOC)
Mission Control
EOSDIS
Data
Centers
Terra
Spacecraft
ASTER
Team
CERES
Team
MISR
Team
MODIS
Team
MOPITT
Team
Terra Ground System

52. 5/29/2024
GSFC
As of May 11, 2009,
•Terra continues to perform very well
–Still operating on primary spacecraft
components except for the Direct Access System
(DB) Module (operating on redundant side)
–All the instruments are producing science data
–Anomalies have been successfully
resolved/accommodated
•Terra has traveled approximately 1.54
billion miles (55289 orbits)

53. 5/29/2024
GSFC
53
Terra Data
•Terra has generated 753 terabytes (TB) of data
•1.35 million Level zero data products and 324,000
near real time products
Data Recovery is ~ 99.05%
•5.5 petabytes (PB) of Terra science data have been
distributed to the world (public)
•2.4 PB of Terra data are archived at geographically
distributed data centers located in Colorado,
Virginia, Tennessee, Maryland, South Dakota, and
California

54. •Demand now exceeds 40 million files annually
−From national/international scientists, US
government, educational institutions, commercial
interests
•Direct Broadcast (Realtime MODIS data):
–Over 1000 users at ~ 150 direct broadcast sites world-wide
−Uses include
−Forest fire detection and prevention
−Coastal and fisheries studies and research
−Disaster management
−Natural resources and environmental research
−Agricultural studies and research
−Environmental hazard monitoring
−Meteorological research and monitoring
Terra Data Demand and Distribution

55. EOS Direct Broadcast Sites Worldwide

57. 57
5/29/2024
GSFC
Thank you for your attention.

58. 5/29/2024
GSFC
58
Back-up slides

59. Instrument Status (back-up)
•ASTER
−Continues to operate normally except for SWIR detectors
−SWIR detector temperature rose and caused data saturation
−Cooler recycling attempts failed
−Detectors declared non-operating in January 2009
−VNIR, TIR continue to produce science data
•CERES
−Instruments performing as expected, operating nominally since launch
−Expected to be able to fully support all science goals during the extended mission
with a high probability of success.
•MISR
−Instrument has been performing superbly and reliably since launch
−Stability is maintained with bi-monthly activations of the on-board calibrator.
•MODIS
−Instrument continues to show excellent performance
−MODIS has lost redundancy (power supply, formatter)
−To date, all on-board calibrators continue to function well
•MOPITT
−One of two instrument coolers failed in April 2001
−Led to the loss of 4 of the 8 channels
−CO profiles now done using the remaining 4 channels

60. Instrument Status (back-up)
•ASTER
−Continues to operate normally except for SWIR detectors
−SWIR detector temperature rose and caused data saturation
−Cooler recycling attempts failed
−Detectors declared non-operating in January 2009
−VNIR, TIR continue to produce science data
•CERES
−Instruments performing as expected, operating nominally since launch
−Expected to be able to fully support all science goals during the extended mission
with a high probability of success.
•MISR
−Instrument has been performing superbly and reliably since launch
−Stability is maintained with bi-monthly activations of the on-board calibrator.
•MODIS
−Instrument continues to show excellent performance
−MODIS has lost redundancy (power supply, formatter)
−To date, all on-board calibrators continue to function well
•MOPITT
−One of two instrument coolers failed in April 2001
−Led to the loss of 4 of the 8 channels
−CO profiles now done using the remaining 4 channels

61. Project Overview
Terra Features
•Launch Date: December 18,1999 (Atlas IIAS, VAFB)
•Orbit: 705 km, sun-synchronous polar, 98.2
o
Inclination, 10:30 AM
MLT descending node
•Instrument Payload:
–ASTER (SWIR, TIR & VNIR) -Advanced Spaceborne Thermal
Emission and Reflection Radiometer(Japan)
–CERES (Fore & Aft) -Clouds and the Earth's Radiant Energy
System (USA –Langley)
–MISR -Multi-angle Imaging Spectro-Radiometer (USA –JPL)
–MODIS -Moderate Resolution Imaging Spectroradiometer(USA –
GSFC)
–MOPITT -Measurement of Pollution in the Troposphere
(Canada)
•Project Management: Earth Science Mission Operations (ESMO)
•Spacecraft Flight Operations: Contracted by GSFC to Honeywell /
Lockheed Martin team and supported by NASA TDRSS and EPGN
•Instrument Operations and Science Data processing: Performed at
respective Instrument Locations where developed
•Mission Duration:Successful Prime mission of 5 years. Extended
Operation through 9/2011 has been approved.
•Distributed Active Archive Centers:LP DAAC –MODIS, ASTER;
Langley DAAC –CERES, MISR, MOPITT
Science
•The primary objective of the Terra Mission is to simultaneously study
clouds, water vapor, aerosol, trace gases, land surface and oceanic
properties, as well as the interaction between them and their effect on
the Earth’s energy budget and climate.

62. Subsystem Component DesignCurrentCapability Comments
Solar Array 24 Shunts23 Shunts96%
Degradation is minimal. Fully capable of supporting
mission through 2020 unless future failures occur.
Batteries 108 Cells107 Cells99.1%
1 Cell failed on 10/13/09. Multiple heater groups failed
simultaneously (4 of 9).
MODIS CPHTS 2 2 FullPerformance is nominal
MOPITT CPHTS 2 2 FullPerformance is nominal
SWIR CPHTS 2 2 FullPerformance is nominal
SCC SCC 2 2 FullPerformance is nominal
HGA 2 2 Full
MDA BITE failures occur 2-3/week due to SEU.
Recoverable
X-Band 2 1 75%
DAS Modulator 1 failed (50%). Solid State Power
Amplifier redundancy still available (100%).
CTIU 2 2 FullPerformance is nominal
OMNI 2 2 FullPerformance is nominal
MO 2 2 FullPerformance is nominal
SFE 2 2 FullSFE SEU occur 1-2/year. Recoverable
SSR 59 PWA51 PWA 86.4%Recycle of DMU likely to recover all PWAs
IRU 3 3 FullPerformance is nominal. 2 for 3 redundancy
TAM 2 2 FullPerformance is nominal
SSST 2 2 FullPerformance is nominal
CSS 2 2 FullPerformance is nominal
ESA 2 2 FullPerformance is nominal
FSS 1 1 FullPerformance is nominal. Not currently used
RWA 4 4 FullPerformance is nominal. 3 for 4 redundancy
MTR 3 3 FullPerformance is nominal
Prop REAs 16 16 FullPerformance is nominal
GNC
EPS
TCS
COMM
CDH

63. Description Status
Hex Bay Battery Anomaly
•Cell 50 and multiple Heater Groups failed on
10/13/09
•Power is stable.
•Capable of additional cell failures before impacting Nominal
Operations.
•Limited Heater Control capabilities
SSR PWA Anomaly
•7 PWAs are currently offline as a result of
over-current protection.
•Re-allocated Buffers to maximize use.
•Capable of losing a few more supersets before operations require
reducing science collection for MODIS and MISR. ASTER will
reduce data collection if their buffer is effected.
•Recycle of Data Memory Unit likely to recover all failed supersets.
DAS Modulator Hardware Failure
•EPC-1 Voltage not being regulated to 5 V on
5/29/08.
•EPC-1 Current was decreasing as well.
•Manually turned off DASM-1 on 6/1/08.
•DASM-1 EPC-1 failure occurred.
•Switched to DAS Modulator Side 2 cross-strapped with Solid State
Power Amplifier Side 1 (SSPA-1) on 6/13/08
•No additional DAS Modulator redundancy. Only remaining
redundancy in X-Band is limited to switch for SSPA-2.
SA Performance
•Shunt #10 failed to transmit on 9/10/00.
•Reduces maximum available Solar Array
Power by 1/24.
•Array continues to provide excess power for nominal operations.
•Still operating array with 15-25
o
offset to minimize power
generation.
•Capable of losing 2 more circuits before impacting Nominal
Operations
•Degradation is less than originally expected.

64. Terra Hardware Anomalies (1 of 3)
Date Incident Cause Response
12/18/1999Solar Array Blanket Box
A-side Failed to indicate
Open during deployment.
Redundant side indicated open. Cause of
failure unknown.
Able to deploy mast anyway. Blanket Box was
separated. Telemetry failed to indicate so. Component
is turned off and never planned to be used again.
1/4/2000 PMEA Load Resistor Box
(LRB) Circuit 1B Failed
(1) LRB 1 or harness would require 2
failures to produce observed signature
(2) PMEA 1 PWB has single wiring runs to
and from LRB circuit relay and potential
single point failure at plated through hole for
relay pin
Evaluated EPC operational range. Determined nominal
operations can exist at reduced load.
9/24/2000 Solar Array Shunt 10
failed
Cause Unknown. Unsuccessful in identifying
a single cause of the anomaly and digging
further will require addressing multiple
failures.
Nominal operations was able to continue. Reviewed
impact to propulsive maneuvers and continue to watch.
5/7/2001 MOPITT Displacer B
failed
Cause Unknown. The compression wave created by the coolers moves the
free floating displacer. This side of the compressor
needs to continue operating for counterbalance.
Operating at a reduced compression to provide some
counterbalance but to prevent the free floating displacer
from hitting it's stop causing so-called "Ringing Effect".
The failed side does not provide valid science data.
6/15/2001 MODIS Power Supply 2
failed
Power Supply Shutdown caused by a
thermal runaway condition in one of the two
Down Regulator FETs. Suspect a High
Energy Particle was the cause of the thermal
runaway condition damaging the FET
Switched to Power Supply 1.
8/4/2001 MOPITT Chopper Motor
3 failed
The anomaly likely caused a fuse to blow
resulting in a permanent failed chopper
motor. Transistor Drive Circuit is likely
cause.
This corrupts the science data on channels 5 & 6. Note:
Channels 5-8 are the only channels which provided good
science data since the Displacer B Anomaly.
Fortunately, Chopper 3 stopped at an open or partially
open position allowing data to be captured minimizing
the impact to the science data.

65. Terra Hardware Anomalies (2 of 3)
Date Incident Cause Response
9/10/2002MODIS Formatter A
Timing Errors corrupting
Science (Degraded
Performance)
Formatter A has had a history of
problems which resulted in processing
errors. The likely cause of the
Formatter Timing Errors is an incorrectly
terminated clock signal. Fixed on Aqua.
9/10/02 MODIS Science data was effected. MODIS
Formatter Swap to Side B was performed on 9/17/02. Since
the switch, no Formatter Errors have been detected and the
data quality is excellent.
5/6/2003MODIS Solar Diffuser
Screen Door Failed to
Open
Areas investigated where: Spring
problem, Disc skipped over the
engagement pin, Screw pull-up due to
door overdrive, Disc damage due to door
overdrive, Pin damage due to door
overdrive and Thermal stress damage
which is the most likely cause.
No fix to anomaly has been determined. Instead, the MODIS
Solar Diffuser Door was opened on July 2nd, 2003. The door
will remain open indefinitely while keeping the Screen door
closed. This allows some calibration activities to occur.
12/24/2003MODIS NADIR Door
Micro-Switch fails to
indicate Opened
Faulty Switch Does not impact Science Data Collection.
11/22/2004MODIS SRCA Lamp #2
Burnt Out
Burnt Out Using Spare: Lamps #1, 3 and 4
See
Comment
SSR Print Wire Assembly
(PWA) Over-Current
Protection
Suspect Over-current protection falsely
tripped during day/night transitions.
Recycling the SSR Data Module Unit
(DMU) is likely to reset PWAs and return
functionality.
PWA-52, DMU-2 (Supersets 102 & 103) occurred on 7/30/03.
PWA-26, DMU-1 (Supersets 50 & 51) occurred on 9/24/03.
PWA-58, DMU-2 (Supersets 114 & 115) occurred on 9/25/03.
PWA-22, DMU-1 (Supersets 42 & 43) occurred on 10/14/03.
PWA-6, DMU-1 (Supersets 10 & 11) occurred on 7/31/04.
PWA-28, DMU-1 (Supersets 54 & 55) occurred on 8/26/05.
PWA-30, DMU-1 (Supersets 58 & 59) occurred on 4/19/07.
PWA-14, DMU-1 (Supersets 26 & 27) occurred on 1/9/10.
On 6/7/07, swapped DMUs to re-allocate buffers. Increased
MODIS and MISR buffers and reduced ASTER Buffer.
3/1/2006MODIS SRCA Lamp #3
Degraded
Degraded Terra SRCA lamp #3 has degraded significantly. Lamp #3
not to be used again. Terra SRCA lamp operation will follow
Aqua SRCA lamp operation --no 30W lamp configuration.
Does not impact Science Data Collection.

66. Terra Hardware Anomalies (3 of 3)
Date Incident Cause Response
9/25/04 ASTER SWIR Detector
Temperature Control
degraded. Total loss of
useable SWIR science
data as of mid June
2008.
Degraded performance. Suspect
temperature gradient within
compressor.
ASTER SWIR Compressor unable to maintain ideal
detector temperature which initially only impacted
capturing bright scenes however, degraded to point
of total loss of useable SWIR science data. Multiple
attempts were made to restart the compressor with
different control temperatures and/or stroke
amplitude. Some had limited success, however,
degradation continued until data declared unusable.
5/29/08 Direct Access System
Modulator Side 1
(DASM)-1 EPC-1 failed.
Continuing to Investigate Attempt to power cycle on 6/4/08 was unsuccessful.
On 6/13/08, Switched to DASM-2 cross-strapped
with Up-Converter-1 and Solid State Power
Amplifier-1. Continue with normal operations.
10/13/09Hex Bay Battery Cell
#50 failed and 4 of 9
battery heater groups
failed
Investigation ongoing. Modified Charge Management and heater duty cycle
to maintain temperatures.