Satellite Safety

Missions


AFTERNOON CONSTELLATION

The Afternoon Constellation is a group of Earth orbiting satellites with synergistic science objectives in similar sun-synchronous orbits all with their ascending node equator crossings near 13:30 hours Mean Local Time (MLT). This Constellation is also known as the "A-Train".

 Aqua

Aqua is a synergistic instrument package measuring at visible, infrared, and microwave frequencies allows comprehensive studies of water in the Earth/atmosphere system, including its solid, liquid and gaseous forms, plus studies of vegetation, both on the land and in the ocean. [More]

  • Instruments : AMSR-E, AIRS, AMSU-A, HSB, CERES, MODIS
  • Responsible Organization: NASA/GSFC
  • Launch: 05/04/02
  • Design Lifetime 6 years
  • Altitude 705 km
  • Inclination 98.2 degrees
  • Orbit Type : Sun-synchronous frozen
  • Nominal Equator Crossing Time wrt: 0.0
  • Required MLT at the ascending node : 13:30 - 13:45
  • Operational MLT at the ascending node: 13:30 - 13:45Beta angle limited
  • Ground-track Reference WRS-2
  • Ground-track Control ± 10 km as measured at the descending node.
  • Coincident Observation: N/A
  • Buffer to closest Control Box: 30 seconds to front of CALIPSO box (Note 3)
 Aura

Observations from Aura's limb sounding and nadir imaging allow studies of the horizontal and vertical distribution of key atmospheric pollutants and greenhouse gases and how these distributions evolve and change with time. [More]

  • Instruments : HDRLS, MLS, TES, OMI
  • Responsible Organization: NASA/GSFC
  • Launch: 07/15/04
  • Design Lifetime : 6 years
  • Altitude : 705 km
  • Inclination 98.2 degrees
  • Orbit Type : Sun-synchronous frozen
  • Nominal Equator Crossing Time wrt Nominal Aqua: ~8 minutes
  • Required MLT at the ascending node : 13:30-14:00
  • Operational MLT at the ascending node: 8 minutes later than Aqua
  • Ground-track Reference: -18.0 (East) of Aqua
  • Ground-track Control: ± 20 km as measured at the descending node
  • Coincident Observation: N/A
  • Buffer to closest Control Box: 30 seconds to front of CALIPSO box (Note 3)
 CALIPSO

Observations from CALIPSO's space-borne lidar, combined with passive imagery, will lead to improved understanding of the role aerosols and clouds play in regulating the Earth's climate. [More]

  • Instruments : CALIOP, IIR, WFC
  • Responsible Organization: NASA/GSFC, NASA/LaRC, CNES
  • Launch: 04/28/2006
  • Design Lifetime: 3 years
  • Altitude 705 km
  • Inclination 98.2 degrees
  • Orbit Type : Sun-synchronous frozen
  • Nominal Equator Crossing Time wrt Nominal Aqua: 73 seconds
  • Required MLT at the ascending node: 9 minutes later than Aqua
  • Operational MLT at the ascending node: 9 minutes later than Aqua
  • Ground-track Reference: 215 km East of Aqua WRS-2
  • Ground-track Control: ± 10 km as measured at the ascending node.
  • Coincident Observation: Aqua MODIS based on ground-track reference
  • Buffer to closest Control Box: 30 seconds to the back of the Aqua box and to the front of the CloudSat box
 CloudSat

CloudSat's Cloud Profiling Radar will allow for the most detailed study of clouds to date and should better characterize the role clouds play in regulating the Earth's climate. [More]

  • Instruments : CPR
  • Responsible Organization: NASA/GSFC, NASA/JPL
  • Launch: 04/28/2006
  • Design Lifetime: 2 years
  • Altitude: 705 km
  • Inclination 98.2 degrees
  • Orbit Type : Sun-synchronous frozen
  • Nominal Equator Crossing Time wrt Nominal Aqua: 176 seconds
  • Required MLT at the ascending node : 108 seconds later than CALIPSO's MLTAN
  • Operational MLT at the ascending node: 108 seconds later than CALIPSO's MLTAN
  • Ground-track Reference: 215 km East of Aqua WRS-2
  • Ground-track Control: ± 10 km as measured at the ascending node.
  • Coincident Observation: Maintain position behind CALIPSO for lidar and Aqua MODIS
  • Buffer to closest Control Box: 60 seconds to the back of the CALIPSO box
 GCOM-W1

The Global Change Observation Mission 1st-Water (GCOM-W1) observations of water circulation changes. Specifically it will observe precipitation, vapor amounts, wind velocity above the ocean, sea water temperature, water levels on land areas, and snow depths. [More]

  • Instruments : AMSR2
  • Responsible Organization:JAXA
  • Launch: 05/18/2012
  • Design Lifetime: 5 years
  • Altitude : 705 km
  • Inclination 98.2 degrees
  • Orbit Type : Sun-synchronous frozen
  • Nominal Equator Crossing Time wrt Nominal Aqua: 259.5 seconds (in front)
  • Required MLT at the ascending node : 13:15 - 13:45
  • Operational MLT at the ascending node: 259.5 seconds earlier than Aqua
  • Ground-track Reference: WRS-2
  • Ground-track Control : ±20 km as measured at the descending node
  • Coincident Observation: 10 minutes in from of Aqua
  • Buffer to closest Control Box: 195 seconds to the front of the Aqua box
 OCO

The Orbiting Carbon Observatory-2 (OCO-2) three grating spectrometers will make global, space-based observations of the column-integrated concentration of CO2, a critical greenhouse gas. [More]

  • Instruments : Three grating spectrometers
  • Responsible Organization: NASA/GSFC NASA/JPL
  • Launch: 07.02.2014
  • Design Lifetime: 2 years
  • Altitude: 705 km
  • Inclination: 98.2 degrees
  • Orbit Type: Sun-synchronous frozen
  • Nominal Equator Crossing Time wrt Nominal Aqua: 195 seconds (in front)
  • Required MLT at the ascending node : 13:21:21
  • Operational MLT at the ascending node: 180.5 - 360.5 seconds earlier than Aqua
  • Ground-track Reference: WRS-2
  • Ground-track Control: ±20 km as measured at the descending node
  • Coincident Observation: Plans to use CloudSat, CALIPSO, and MODIS observations
  • Buffer to closest Control Box: Minimum 15 seconds to front of the GCOM-W1 box

MORNING CONSTELLATION

 Landsat-7

Landsat 7 provides global coverage, and spectral characteristics to allow comparisons for global and regional change detection and image data to various international users throughout the world during times of sudden global changes (e.g., earthquakes or floods). [More]

  • Instruments : ETM+
  • Responsible Organization: USGS/NASA
  • Launch: 04/15/1999
  • Design Lifetime: 5 years
  • Altitude: 705 km
  • Inclination 98.2 degrees
  • Orbit Type : Sun-synchronous frozen
  • Required MLT at the ascending node : 10:00 ± 15 minutes
  • Operational MLT at the ascending node: 10:00 ± 15 minutes
  • Ground-track Reference: WRS-2
  • Ground-track Control : ± 5 km as measured at the descending node.
 Terra

Terra is a multi-national, multi-disciplinary mission that will help us to understand how the complex coupled Earth system of air, land, water and life is linked. [More]

  • Instruments : MISR, CERES, MOPITT, ASTER, MODIS
  • Responsible Organization: NASA/GSFC
  • Launch: 12/18/1999
  • Design Lifetime: 6 years
  • Altitude 705 km
  • Inclination 98.2 degrees
  • Orbit Type : Sun-synchronous frozen
  • Required MLT at the ascending node : 10:30 ± 15 minutes
  • Operational MLT at the ascending node: 10:30 ± 1 minute
  • Ground-track Reference: WRS-2
  • Ground-track Control: ± 20 km as measured at the descending node
EO-1

Earth Observing-1 (EO-1) was developed and validated a number of instrument and spacecraft bus breakthrough technologies designed to enable the development of future earth imaging observatories that will have a significant increase in performance while also having reduced cost and mass. [More]

  • Instruments : ALI, Hyperion
  • Responsible Organization: NASA/GSFC
  • Launch: 11/21/2000
  • Design Lifetime: 1 year
  • Altitude : Less than 705 km (fuel limited)
  • Inclination 98.2 degrees
  • Orbit Type : Sun-synchronous frozen
  • Required MLT at the ascending node : 10:01*
  • Operational MLT at the ascending node: See Note*
  • Ground-track Reference: WRS-2*
  • Ground-track Control: ± 10 km as measured at the ascending node. *

  • * Note: The table lists the original EO-1 requirements. The spacecraft no longer performs orbital maneuvers to maintain its altitude or MLT.
Landsat-8

The Landsat 8 mission provides moderate-resolution measurements of the Earth's terrestrial and polar regions in the visible, near-infrared, short wave infrared, and thermal infrared. Landsat 8 will provide continuity with the 38-year long Landsat land imaging data set. [More]

  • Instruments : OLI, TIRS
  • Responsible Organization: USGS/NASA
  • Launch: 02/11/2013
  • Design Lifetime: 5 years
  • Altitude: 705 km
  • Inclination 98.2 degrees
  • Orbit Type : Sun-synchronous frozen
  • Required MLT at the ascending node : 10:00 ± 15 minutes
  • Operational MLT at the ascending node: 10:10 - 10:15
  • Ground-track Reference : WRS-2
  • Ground-track Control : 5 km as measured at the descending node

FREE-FLYER SATELLITE

 GPM

Global Precipitation Measurement (GPM) helps advance our understanding of Earth's water and energy cycles, improve the forecasting of extreme events that cause natural disasters, and extend current capabilities of using satellite precipitation information to directly benefit society. [More]

  • Instruments : GMI, DPR
  • Responsible Organization: NASA/JAXA
  • Launch: February 27, 2013
  • Design Lifetime: 3 years
  • Altitude : 407 km
  • Inclination 65 degrees