Landsat 7 End of Life Plans

[Lurker]

On February 7, 2017, the twentieth and final inclination (Delta-I) maneuver of Landsat 7 took place. (Delta-I maneuvers keep the spacecraft in the correct orbital position to ensure it maintains its 10:00 am ± 15 minutes mean local time (MLT) equatorial crossing.)  Landsat 7 reached its peak outermost inclination boundary of 10:14:58 MLT on August 11, 2017.

Landsat 7 is now drifting in its inclination and will fall back to 09:15 am MLT by July 2021. The chart below illustrates the inclination trend from June 2014 to June 2026.

 

The USGS and NASA are planning for Landsat 7 to remain on-station and fulfilling its current science mission until Landsat 9 completes its launch (scheduled for September 16, 2021), on-orbit checkout, and commissioning. Sometime after Landsat 9 is nominally acquiring science mission data, Landsat 7 will exit the constellation and lower its orbit by 8 km to prepare for servicing by NASA’s On-Orbit Servicing, Assembly, and Manufacturing-1 (OSAM-1) mission. The mission - the first of its kind in low Earth orbit - will provide Landsat 7 with the needed fuel for a successful decommissioning.

source:

https://www.usgs.gov/core-science-systems/nli/landsat/landsat-7?qt-science_support_page_related_con=0#qt-science_support_page_related_con

[rahmansunbeam]

Let's say goodbye to Landsat 7 and say hello to Landsat 9 !

Landsat-9 will replace Landsat 7 in its orbit. The new OLI-2 and TIRS-2 sensors of the Landsat 9 will be a slight improvement from its predecessor. According to the overview,

• the spatial and spectral resolution remains the same - moderate spatial resolution—15 m, 30 m, and 100 m depending on spectral band—and the ability to detect the same range in intensity as Landsat 8, or better
• The OLI–2 will capture observa­tions of the Earth’s surface in visible, near-infrared, and shortwave-infrared bands with an improved radiometric precision (14-bit quantization increased from 12 bits for Landsat 8), slightly improving overall signal to noise ratio
• TIRS-2 will measure thermal radiance emitted from the land surface in two thermal infrared bands using the same technology that was used for TIRS on Landsat 8, however TIRS-2 will be an improved version of Landsat 8’s TIRS, both with regards to instrument risk class and design to minimize stray light
• Both OLI–2 and TIRS–2 have a 5-year mission design life, although the spacecraft has 10+ years of consumables

Here are the spectral bands from OLI-2,

• Band 1 Visible (0.43 - 0.45 µm) 30-m
• Band 2 Visible (0.450 - 0.51 µm) 30-m
• Band 3 Visible (0.53 - 0.59 µm) 30-m
• Band 4 Red (0.64 - 0.67 µm) 30-m
• Band 5 Near-Infrared (0.85 - 0.88 µm) 30-m
• Band 6 SWIR 1(1.57 - 1.65 µm) 30-m
• Band 7 SWIR 2 (2.11 - 2.29 µm) 30-m
• Band 8 Panchromatic (PAN) (0.50 - 0.68 µm) 15-m
• Band 9 Cirrus (1.36 - 1.38 µm) 30-m

Two spectral bands from TIRS-2,

• Band 10 TIRS 1 (10.6 - 11.19 µm) 100-m
• Band 11 TIRS 2 (11.5 - 12.51 µm) 100-m

The good thing is Landsat 9 will image the Earth every 16 days in an 8-day offset with Landsat 8, which means increased temporal coverage of observations.

Edited August 4, 2021 by rahmansunbeam