Transcript C/NOFS - ViRBO

The PECOS Low Earth Orbit
Space Weather Satellites
NSF Small Sat Conference 15 - 17 May 2007
O. de La Beaujardière, F. J. Rich, D. A. Cooke, J. Mozer,
Space Weather Center of Excellence
Air Force Research Laboratory, Space Vehicles Directorate
L. C. Gentile
Boston College Institute for Scientific Research
PECOS: Small LEO SWx Sats
Overview
• Introduction / rationale
• DMSP / POES / NPOESS status
• Proposed LEO constellation
DMSP
NPOESS
– Polar and Equatorial Comm/nav Outage
Satellites (PECOS) for SWx needs in
ionosphere and neutral atmosphere
– Notional architecture based on small
satellites in 3 different types of orbits
• Mission study and challenge to
science community
• Conclusion
C/NOFS
2
Introduction
•
Looming crisis in U.S. space weather capabilities
•
Space Environment Sensor Suite (SESS) no longer on NPOESS
•
Last DMSP launch ~2012
•
AF Space Command, AFRL and others developing comprehensive plan to
specify and forecast natural space environment in post-DMSP era
•
Recommendation: PECOS (Polar & Equatorial Comm/nav Outage Satellites)
small LEO satellites to meet ionosphere / thermosphere SWx requirements
and ensure continuity of DMSP capability
Actual
Position
Predicted
Position
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Rationale
• Air Force is responsible for DoD space weather
• Understanding and forecasting space weather are key
to ensuring SWx mission success
• AF Space Command seeking funding in 2010 as ‘capability
disconnect’
• Objectives of proposed PECOS mission
– Nowcast and forecast of ionosphere and thermosphere conditions
• Provide tools for DoD and civilian systems for
communication, navigation, surveillance
• Coordinated effort by DoD and civilian agencies
to meet U.S. space weather requirements
• Transition from DMSP era to 21st century provides exciting
opportunities for new technology development
– Smaller satellites
– Lighter payloads
– Flexible launch options
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PECOS
Small Sats for SWx
Polar Cap
Scintillation
Polar Ionospheric
Disturbances
AFSATCOM
Mid-latitude
Scint & TEC
GPS
Equatorial
Ionospheric
Disturbances
Equatorial
Storm Effects
Scintillation
Forecasts
Magnetic
Equator
Satellite
Drag
UFO & FLTSATCOM
PECOS provides capability to specify and forecast ionospheric and
thermospheric impacts on satellite systems.
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Present Capability
DMSP Orbits
F15, 2112 LTAN
F16, 2003 LTAN
DMSP
F14, 1926 LTAN
F13, 1828 LTAN
F17, 1736 LTAN
Primary
4 or 5 DMSP
satellites on orbit
at any time
Back-Up
LTAN = Local Time of
Ascending Node @ Launch
As of Feb 07
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DMSP and POES
Current SWx Sensors in Polar Orbit
DMSP Block 5D-3 (F16-20)
TED
DPU
MEPED
Space Environment
Monitor (SEM-2)
Thermal Plasma
Sensor
Magnetometer
Auroral
Particle
Detector
POES
Ultraviolet
Limb Imager
Ultraviolet
Disc
Imager
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Nunn-McCurdy Impact
TED
DPU
MEPED
Space Environment
Monitor (SEM)
Thermal Plasma
Sensor
Magnetometer
Back
Side
SEM is the only
Post-Nunn-McCurdy
NPOESS SWx sensor
Auroral
Particle
Detector
Ultraviolet
Disc
Imager
Ultraviolet
Limb Imager
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PECOS
A Proposed Solution for SWx
PECOS is LEO mini-satellite constellation, 3 types of orbits
• PECOS High -- Polar orbit, altitude ~ 800 km, sun synchronous
• PECOS Low -- Polar orbit, low altitude < 350 km
• PECOS Equator -- Equatorial orbit, low altitude
Objectives
Large TEC plume disrupts
nav, comm, and
surveillance systems
– Meet DoD priority requirements in ionospheric
density, scintillation, and satellite drag
– Meet NPOESS IORD I space environment
Environmental Data Records (EDRs)
– Maintain current DMSP capability
to ensure long-term continuity of space
environmental monitoring
– Leverage new technology development for
future operational systems
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PECOS High -1
•
DMSP-type polar orbit:
~ 700 to 900 km altitude
Nominal 2-satellite constellation
at ~ 14:30, 21:30 LT
Objective: achieve DMSP functions
Instruments:
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GUVI
Mini-UV spectrograph / imager(s)
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Electron density
Neutral atmosphere composition (O/N2)
Auroral precipitation
Equatorial scintillation
Thermal plasma suite
•
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Drift velocity, electric field
Temperatures Ti, Te
Electron density and density fluctuations
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PECOS High - 2
•
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Instruments (continued)
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Magnetometer on short boom
Currents
Total electromagnetic energy
Penetration electric fields
Particle detectors
20 eV - 10 MeV for electrons
20 eV - 300 MeV for protons
Scintillation (DORIS)
and GPS receiver
Electron density profile
Scintillation, comm/nav outages
Possible launch scenario:
2 satellites on same Minotaur
Desired LT orbits reached after time
and altitude change
Considering topside sounder
on separate satellite (Tacsat 5)
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PECOS Low
•
Polar orbit ~300 km perigee
–
•
Elliptical (apogee ~400)
Primary objective:
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Critical parameters for satellite drag
Secondary objectives:
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Electron density profile
Scintillation
Instruments
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•
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Neutral wind monitor
Accelerometer
~12800 LEO objects in catalog
Actual
Position
Predicted
Position
Thermospheric density
Mass spectrometer
Thermospheric composition
Thermal plasma suite
Drift velocity, electric field
Temperatures Ti, Te
Electron density and density fluctuations
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PECOS Equator
•
Equatorial orbit (~13° inclination)
–
•
Apogee: ~700 km, Perigee: ~350 to 400 km
Objective: Forecast low-latitude comm / nav outages
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•
C/NOFS follow-on
Instruments
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Thermal plasma suite
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Drift velocity
Temperatures Ti, Te
Electron density and density fluctuations
Neutral wind monitor
Planar Langmuir probe
•
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C/NOFS
Electron density, in situ irregularities
Scintillation (DORIS) and GPS receivers
•
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Electron density
Scintillation, comm/nav outages
Electric and magnetic field suite
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Electric field
Wave spectra
Plasma irregularities
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Space Environment Monitoring
Concerns and Options
Input from SWx community needed to optimize
notional PECOS configuration
– Constellation, orbit, payload (< 100 kg)
– New instrument designs
• Smaller in size, weight, power
• Higher resolution measurements
for more accurate specification
• Operational systems must be based on proven technology
• Need to demonstrate technology readiness
– Standard small-sat bus and interface
recommended for all PECOS spacecraft
• AFRL Plug & Play satellites
• Ball Aerospace SIV sats for STP
• Other options
– Adaptable launch configuration
• ESPA ring
• Minotaur
• Other
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PECOS
Proposed Design Study
End-to-end assessment of requirements: from space environment
parameters to mission application
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Systematic analysis of requirements and options to meet them
Operational analysis a critical component
Interagency team
Integrated approach leveraging data from other U.S. sources
Determine best strategy for operational and S & T development
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Opportunity to demonstrate viability of new small-sat technologies
Proven technology required for operational systems
GUVI
EPBs
15
Concluding Remarks
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AF is the responsible entity for DoD Space Weather
AFRL SWx CoE is taking a leadership role to resolve crisis
PECOS small sat system will meet DoD priority SWx requirements
in ionosphere, scintillation and satellite drag
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AFRL & AF Space Command studying possible architecture
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2 to 4 sats on PECOS HI orbit (DMSP type) (primary for ionosphere, secondary for thermosphere)
1 or 2 sats on PECOS Low orbit (primary for thermosphere, secondary for ionosphere)
1 sat on PECOS equator (C/NOFS follow on) (primary for scintillation, secondary for iono and thermo)
Mission development plan will define optimal configuration of orbits, instruments, models
Provides opportunity to leverage new technology development
for sensors, spacecraft, launch options
Collaboration with NPOESS still needed
–
NPOESS ground segment will be a great asset
Interagency coordination and collaboration are essential
Plan urgently needed to ensure continuity of
SWx monitoring in post-DMSP era
If nothing is done soon, U.S. risks loss of capability
to build and maintain space environment instruments
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Back-up Material
Jicamarca Radar, Peru – Oct 22, 1996
GUVI
DMSP
C/NOFS
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DMSP & PECOS Notional Timeline
DMSP
FY
07
FY
08
FY
09
FY
10
FY
11
FY
12
FY
13
FY
14
FY
15
FY
16
FY
17
FY
18
FY
19
FY
20
FY
21
F13
F14
F15
F16
F17
F18
F19
F20
C/NOFS
PECOS
C/NOFS ResOps
Lab Dev / SPO
PECOS-Eq-a
PECOS-Hi-a
PECOS-Lo-a
PECOS-Eq-b
PECOS-Hi-b
PECOS-Lo-b
Op S/C
Extended-Op S/C
Demo S/C
SPO
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NPOESS and PECOS
•
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Space Environment Sensor Suite (SESS) will not fly on NPOESS
(outcome of Nunn-McCurdy review)
AF Space Command seeking funding in 2010 as ‘capability disconnect’
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•
•
Concerns with re-incorporating two sensors on NPOESS
– Integration costs might not be borne by NPOESS IPO
– NPOESS survival not assured
– Does not meet SWx requirements and warfighter needs
– Space weather is not prime concern for NPOESS
Pre-Nunn-McCurdy SESS did not meet DoD SWx requirements
–
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•
2130 orbit, required for ionospheric scintillation, eliminated
Scintillation and magnetic field requirements not met
Electron density profile and neutral density profile marginal
Collaboration with NPOESS still needed
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•
PECOS small satellites would cost less than NPOESS SESS
NPOESS ground segment will be a great asset
PECOS mission maintains long-term continuity of space environment
monitoring for DoD SWx mission in post-DMSP era
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Scintillation and Ionospheric
Specification for Comm/Nav/Surveillance
• Ionospheric density and irregularities
affect DoD SSA mission
• Accurate forecast and specification
of ionospheric parameters needed for:
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Communication
GPS Navigation
Surveillance
Geolocation
HF communication
Missile defense
Scintillation
Plasma Density
AF Goal: 72-120 hour
space weather forecast
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Satellite Drag and
Precision Orbit Determination
• Thermosphere (non-ionized part of upper atmosphere)
affects satellite drag and reentry
• Accurate nowcast and forecast of thermospheric
parameters needed for:
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Precise satellite orbit determination
Avoidance of collisions with space debris
Satellite reentry prediction
Maintenance of space objects catalog (12800 objects)
Prediction of satellite positions
Actual
Predicted
Position
Position
Mission planning support
• Design of space systems for
long-term operations
• End-of-life plans
• Fuel and station-keeping
– AFSPC Goal, 90 - 500 km: 5% drag error,
500 - 700 km: 10% error
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Drivers for Satellite Drag/Neutral Density
• Satellite drag is significant
below 600 km
•Thermospheric neutral density
controlled by:
Solar Wind
Interaction
• Solar EUV heating
• Auroral heating (particles
and electromagnetic energy)
• Upward propagating waves from
troposphere
Density variability at 400 km
• Solar cycle: factor of 10 variation
with EUV over 11 yr cycle
• Day-to-day: ~10% variability
• Storm events: Factor of 6 increase in
a few hours
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Present Capability
DMSP SWx Instruments and Measurements
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•
•
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Precipitating Particle Sensor (SSJ5) – 30 eV to 30 keV
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Auroral Boundaries and Energy Deposition
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Electron Density Profile
Thermal Plasma Monitor (SSIES)
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In Situ Electric Field
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In Situ Plasma Density and Temperature
Magnetometer (SSM)
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In Situ Field-Aligned Current  of Joule Heat Obs.
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Global Geomagnetic Disturbance  Proxy for Dst Index
Extreme Ultraviolet Scanners / Photometers
(SSUSI and SSULI)
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Plasma Density (~200 to 600 km)
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Auroral Energy Deposition & Auroral Boundary
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Neutral Atmosphere Density and Composition
AFRL responsible for all DMSP SWx instruments, except SSULI
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Present Capability
DMSP Schedule
• DMSP F20 launch ~ 2012
FY07
FY08
FY09
FY10
FY11
FY12
FY13
FY14
FY15
FY16
FY17
FY18
F15
F16
Expected Life
Guaranteed Life
F17
F18
F19
•
•
NPOESS: 2013 for C1 launch
MetOp: A in 2006, B in 2010 (?)
F20
FY15 is critical time to have new operational system
in place; program planning should start in FY08
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Complementary Space Instruments
• Satellites / sensors presently on orbit
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MetOp with SEM particle detector
JASON provides TEC above oceans
DMSP SWx sensors (while it lasts)
GRACE accelerometer
CHAMP accelerometer (while it lasts)
COSMIC
DMSP
• Planned satellite missions
– NPOESS
• Only SEM particle detectors (POES heritage) on one orbit
– SWARM
• 3-satellite constellation for solid Earth magnetic field
measurements, but no SSA contribution
• Proposed Missions
– UV Imager at GEO orbit
– COSMIC II with GPS, mini-UV and DORIS Rx
COSMIC
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Complementary Ground-Based
Instruments
SCINDA Ground Stations (2008 plan)
30N
• SCINDA sites
• Coherent radars
0
on a 24 / 7 basis
30S
• Ionosondes
60E
90E
120E 150E
210E 240E 270E 300E 330E 0
30E
• All-sky cameras
Backbone Sites Supporting Sites United Nations IHY Sites
• GPS Rx
DORIS UHF/S-Band Beacons at Ground Sites
• DORIS Tx
• Ground magnetometers
• Fabry-Perot
Interferometers
• Incoherent Scatter
Radars for campaigns
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PECOS
Development Issues
• Important technology progress expected in spacecraft
design, instrumentation, interface, launch options
• Community input needed to assess
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Spacecraft design / size
Instrument miniaturization
Standard interface options
Optimum orbits
Life time on orbit
Launch options
Telemetry / Real-time data need
Software, models
Impact on warfighter needs
• Balance cost / schedule / performance / technical risk
• SWx requirements tied directly to mission applications
– Systematic analysis from SWx measurements to operations
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DMSP
C/NOFS
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