there are currently 5 satellites in the “a-train”: aqua, cloudsat, calipso, parasol, and aura

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• There are currently 5 satellites in the “A-Train”: Aqua, CloudSat, CALIPSO, PARASOL, and Aura.

• OCO and Glory missions will launch in January and June 2009, respectively

The Afternoon Constellation(A-Train)

01_Kelly_MOWG_Rev.ppt – page 6

Mission MLT

Aqua 01:37:24

CloudSat 01:46:13

CALIPSO 01:46:24

PARASOL 01:36:22

Aura 01:46:00

As of October 22, 2008

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2002Afternoon Constellation Evolution

akelly_trainstatus2.ppt – page 4

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Afternoon Constellation EvolutionAura and PARASOL joined in 2004


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CloudSat and CALIPSO joined in 2006Afternoon Constellation Evolution


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Glory and OCO to be launched in late 2008Afternoon Constellation Evolution


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The Afternoon Constellation

MODIS/ CERES

IR Properties of Clouds

AIRS Temperature and

H2O Sounding

OCO - CO2

Aqua

1:30 PM

PARASOL

Aura

OMI - Cloud heights

OMI & HIRLDS – Aerosols

MLS& TES - H2O & temp profiles

MLS & HIRDLS – Cirrus clouds

1:38 PM

OCO

1:15 PM

Glory

VIIRS - Clouds & AerosolsCrIS/ATMS- Temperature and H2O SoundingOMPS - Ozone

NPP

CALIPSO- Aerosol and cloud heights

Cloudsat - cloud droplets

PARASOL - aerosol and cloud

polarization

CALIPSO Cloudsat

pres_frascati_new_missions_gleason.ppt – page 2

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Morning and Afternoon Constellations

SAC-C

EO-1

Terra

Landsat

In contrast, the Earth Science Constellation satellites orbit in close proximity so that observations occur at about the same time over approximately the same region.

Due to the relative closeness of the satellites (as small as 10 seconds), safety is an issue.

Most constellations are spaced around the Earth to provide instantaneous, global coverage (e.g., GPS, communications, satellite radio, weather).

GPS Constellation

Earth Observing Constellations Unique Challenges

55165.ppt – page 11

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Earth Observing ConstellationsWhy Fly Constellations?

Constellations provide the opportunity to make coincident,

co-registered, and nearly simultaneous science measurements

from a range of instruments.

– The satellites are aligned in their orbital positions so their instrument fields of views overlap.

– Earth science data from one satellite’s instrument can be correlated with data from another.

The whole is greater than the sum of its parts

The Earth science community has long advocated placing numerous instruments in space to study the Earth and its environment.


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13.5 km AIRS IR; AMSU & HSB

wave

13.5 km AIRS IR; AMSU & HSB

wave

Washington DCUSGS Map

5.3 x 8.5 km TES 5.3 x 8.5 km TES

0.09 km CALIPSO0.09 km CALIPSO

0.5 km MODIS Band 3-70.5 km MODIS Band 3-7

1. 4 km Cloudsat1. 4 km Cloudsat

OCO1x1.5 km

The Afternoon Constellation observational “footprints” vary greatly

2.3 km AIRS 0.4-1 2.3 km AIRS 0.4-1

55165.ppt – page 10 & A-train3.ppt – page 9

6x7 km POLDER 6x7 km POLDER

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Now for a closer look


First up, Aqua …

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Purpose

Investigates the Earth's water cycle, including evaporation from the oceans, water vapor in the atmosphere, clouds, precipitation, soil moisture, sea ice, land ice, and snow cover on the land and ice.

Instruments• AIRS: Atmospheric Infrared Sounder – Obtains highly accurate temperature profiles within the

atmosphere

• AMSU-A: Advanced Microwave Sounding Unit – Obtains temperature profiles in the upper atmosphere (especially the stratosphere) and provides a cloud-filtering capability for tropospheric temperature observations

• HSB: Humidity Sounder for Brazil – 4-channel microwave sounder aimed at obtaining humidity profiles throughout the atmosphere.

• AMSR-E: Advanced Microwave Scanning Radiometer for EOS – Uses a twelve-channel, six-frequency, microwave radiometer system to measures precipitation rate, cloud water, water vapor, sea surface winds, sea surface temperature, ice, snow, and soil moisture

• MODIS: Moderate Resolution Imaging Spectroradiometer – Similar to Terra

• CERES: Clouds and the Earth's Radiant Energy System – Similar to Terra

EOS Aqua


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Instrumental Background : MODIS

– NASA, Terra & Aqua• launched 1999, 2002• 705 km polar orbits, descending (10:30

a.m.) & ascending (1:30 p.m.)

– Sensor Characteristics• 36 spectral bands ranging from 0.41 to

14.385 µm• cross-track scan mirror with 2330 km

swath width• Spatial resolutions:

– 250 m (bands 1 - 2)– 500 m (bands 3 - 7)– 1000 m (bands 8 - 36)

• 2% reflectance calibration accuracy• onboard solar diffuser & solar diffuser

stability monitor

AMS2006_Riedi_et_al.ppt – page 3

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GEYSER, CAA fast-moving wildfire burned in northern California’s Sonoma wine country on Friday, September 3, 2004. It rapidly grew to several thousand acres, threatening homes and vineyards. Smoke billowed out over the Pacific Ocean for nearly 200 miles.

MODIS_FireImages.ppt – page 3

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Next up, Aura …

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Purpose

Researches the composition, chemistry, and dynamics of the Earth’s atmosphere as well as study the ozone, air quality, and climate.

Instruments• HIRDLS: High Resolution Dynamics Limb Sounder – Observes global distribution of

temperature and composition of the upper troposphere, stratosphere, and mesosphere

• MLS: Microwave Limb Sounder – Uses microwave emission to measure stratospheric temperature and upper tropospheric constituents

• OMI : Ozone Monitoring Instrument – Distinguishes between aerosol types, such as smoke, dust, and sulfates. Measure cloud pressure and coverage, which provide data to derive tropospheric ozone.

• TES: Tropospheric Emission Spectrometer – High-resolution infrared-imaging Fourier transform spectrometer that offers a line-width-limited discrimination of essentially all radiatively active molecular species in the Earth's lower atmosphere.

EOS Aura


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• At the request of the Aura Project Scientist, Aura was moved from its current location (15 minutes behind Aqua) to ~ 8 minutes behind Aqua—completed on May 8, 2008

• Aura is now on a different ground track than Aqua (+18 kilometer (East) offset of Aqua’s WRS-2 path) to enable MLS/CloudSat viewing goal

• Aura FOT is maintaining the Control Box to ±10 km (±20 km requirement)

Aura Rephasing (1 of 2)

A-Train Control Box Configuration


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Ground track(WRS Paths)

Equator

CloudSat ground track

Orbit PlaneMLTAN – 13:35 13:44

Aqua

PARASOL

MLS

AIRS +/- 825 km

MODIS +/- 1150 km

OMI +/- 1300 km

N

MLS Limb track

Aura

CloudSat CALIPSO

Aura MLS now sees the same air mass as CloudSat and CALIPSO

~7 min 10 sec8 min

7 min

Aura Rephasing (2 of 2)


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0

25

50

75

100

125

150

175

200

225

250

Date

Fu

el R

emai

nin

g (

kg)

Definitive Fuel Use Predicted Fuel Use

Aura Fuel Usage: (Actual & Predicted)

Fall 2006 Delta-i

Maneuvers

Fall 2004 Delta-i

Maneuvers

Spring 2007 Delta-i

Maneuvers

Spring 2009 Delta-i

Maneuvers

Annual Delta-i

Maneuvers

02_Guit_SpacecraftStatus.ppt – page 15

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Next PARASOL …

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PARASOL

Instrument

POLDER: Improve the microphysical and radiative property characterization of clouds and aerosols for model improvement.

Source: CNES


Purpose

Studies the role of clouds and aerosols using Polarization and Anisotropy of Reflectances for Atmospheric Science coupled with Observations from a LIDAR.

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Instrumental Background : POLDER

– CNES/LOA instrument, Parasol launched 2005• ~ 705 km polar orbits, ascending (13:30 a.m.)

– Sensor Characteristics• 10 spectral bands ranging from 0.443 to 1.020 µm• 3 polarised channels•Wide FOV CCD Camera with 1800 km swath

width• +/- 43 degrees cross track• +/- 51degrees along track•Multidirectionnal observations (up to 16 directions)• Spatial resolution : 6x7 km•No onboard calibration system - Inflight vicarious

calibration : – 2-3% absolute calibration accuracy– 1% interband – 0.1% interpixel over clouds

AMS2006_Riedi_et_al.ppt – page 4

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Next CloudSat and CALIPSO …

23d314_calipso-cloudsat.pdf – page 7

Delta II 7420 Launch Vehicle – 10 ft Fairing

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705 km

Aqua

CALIPSO-CloudSat Coordinated Ascent Overview

CALIPSO

CloudSat

690 km

PreliminaryBurns

OrbitRaises 1

OrbitRaises 2

PARASOL

54809.ppt – page 17Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations

Final Trim

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CloudSat

Cloud Profiling Radar


Purpose

Will advance our understanding of cloud abundance, distribution, structure, and radiative properties. First satellite-based millimeter-wavelength cloud radar 1000 times more sensitive than existing ground weather radars Able to detect the much smaller particles of liquid water and ice (ground-based weather radars use centimeter wavelengths)

Instrument

Cloud Profiling Radar (CPR) instrument, a 94-GHz nadir-looking radar. Measures the power backscattered by clouds as a function of distance from the radar. Developed jointly by NASA’s Jet Propulsion Laboratory (JPL) and the Canadian Space Agency (CSA).

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CALIPSO


Instruments

Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP): Two wavelength polarization-sensitive Lidar that provides high-resolution vertical profiles of aerosols and clouds

Wide Field Camera (WFC): Fixed, nadir-viewing imager with a single spectral channel covering the 620-670 nm region

Imaging Infrared Radiometer (IIR): Nadir-viewing, non-scanning imager

Purpose

Determine the distribution of aerosols and thin clouds around the world and will help scientists develop never-before-seen views of Earth’s atmospheric structure and behavior1.

1 -http://www.nasa.gov/mission_pages/calipso/multimedia/cloud_calip_mm.html

27akelly_trainstatus2.ppt – page 7


Final two, OCO and Glory …

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Future Missions

Two more missions are set to join the A-Train after they launch in late 2008:

• The Orbiting Carbon Observatory (OCO) will– Provide space-based observations

of atmospheric carbon dioxide (CO2), the principal human-initiated driver of climate change.

• The Glory mission will– Collect data on the chemical,

microphysical, and optical properties, and spatial and temporal distributions of aerosols, and

– Continue collection of total solar irradiance data for the long-term climate record.

Glory

OCO


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The Afternoon ConstellationIs an International Undertaking


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Principal Investigators/Project Scientists andInternational Partners for Constellation Missions


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Backup Charts

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Morning and Afternoon Constellation Phasing

Tracking Station Key:AGS – Alaska Ground StationSGS – Svalbard Ground StationLGS – Landsat Ground StationTDRSW – TDRS-WEST (geo-synchronous)

kelly_613_409_final.ppt – page 7

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Earth Science Morning Constellation

• SAC-C is staying 2 km above Landsat-7 & Terra

Mission MLTTerra 10:30:03EO-1 09:59:56Landsat-7 10:01:03SAC-C 08:14:41

Original Morning Constellation configuration

• EO-1 is currently 15 km below Landsat-7 & Terra

Operating on a 2-year extension through 2009

Has enough propellant to last through 2011

• Terra and LandSat-7 are continuing operations at

705 km.


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Debris Avoidance

• On average, one object comes closeWithin 5 km of each constellation

mission each dayWithin 2 km of each constellation

mission once or twice a week.• ESMO has a task with the DOD’s

Joint Space Operations Center (JSpOC) to screen all A-Train and Morning Constellation missions to ensure their safety.

• A number of missions are in a 705 km sun-synchronous polar orbit.• 55 other objects reside in orbits with mean altitudes of 705 +/- 5 km,

including, A-Train missions, Terra, EO-1, Landsat-5 and -7, and six Iridium satellites.

• More than 1500 cataloged objects pass through this regime each day.


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• Aura performed a 2-second burn on June 26, 2008 to avoid a piece of well-tracked debris from a U.S. satellite.

• CloudSat performed two small maneuvers on July 20 and 22, 2008 to avoid debris from a Delta I LV.

• PARASOL performed an early drag make-up maneuver on October 20, 2008 to avoid a space object.

• PARASOL is planning a possible avoidance maneuver on October 27

• Terra is evaluating a debris avoidance maneuver this week

Debris Avoidance Maneuvers During June 2007 – July 2008


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INDOCHINA

Image captured on March 10, 2006 from the MODIS instrument on the Aqua satellite. Widespread fires throughout Myanmar (Burma), Thailand and Laos.

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Afternoon ConstellationControl Center Coordination

kelly_613_409_final.ppt – page 15

there are currently 5 satellites in the “a-train”: aqua, cloudsat, calipso, parasol, and aura

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