Tag: Orbital Changes

From undergoing an orbit lowering to headlining workshops on novel drifting data, Terra has had a big year so far! (And that’s not even accounting for the satellite’s continuous collection of high quality, earth science data, with no unintended interruptions!)

This news post will provide several important updates on recent instrument team meetings, upcoming virtual workshops featuring Terra, and an overview of three early career scientists using Terra data in their research.

Keep checking the website often for more updates and information on all things Terra!

2022 Meetings and Conferences

  • The CERES instrument team participated in the Fall 2022 Earth Radiation Budget Workshop in Hamburg, Germany from October 12 – 14, 2022. More information, including an agenda and presentation slide decks, can be found on the CERES website.
  • Several members of the Terra team participated in the 22nd William T. Pecora Memorial Remote Sensing Symposium in Denver, CO from October 23 – 28, 2022. More information available on the Pecora 22 website.
  • The ASTER instrument team will hold a science and interface meeting in Tokyo, Japan from November 7-9, 2022.
  • The American Geophysical Union (AGU) Fall 2022 meeting will be held in Chicago, IL from December 12 – 16, 2022. For more information and an agenda, visit the AGU Fall Meeting 2022 website.

Upcoming Terra Workshops and Community Forums

Here’s a reminder that it’s your last chance to sign up for the virtual Terra, Aqua, and Aura Drifting Orbits Workshop that starts tomorrow, November 1-2, 2022. For more information and registration, visit the Terra website (or register here!).

On December 8th, 2022 from 12:30 PM – 3:30 PM ET, the Terra team will be hosting a virtual community forum on Terra’s recent orbit lowering maneuvers (that took place October 12th and 18th). See the graphic below for more information and a QR code linking directly to the Webex webinar registration page.

Infographic on upcoming virtual community forum on Terra satellite's new lower orbit.
Information on Terra’s Lower Orbit Community Forum (virtual webinar) scheduled for December 8, 2022, from 12:30 PM to 3:30 PM ET.

Highlighting Two Decades of Terra Talent

Last week, several NASA Early Career researchers presented their current scientific work during the 2022 Early Career Scientist Forum (full agenda linked here).

The Terra Flight Operations Team is planning a set of orbital maneuvers for October 12 and 19 to lower Terra’s orbit by 6 km, as part of an effort to reduce orbital crossings with several other missions currently at Terra’s 705 km altitude. For more information, view the animation and graphic below, which are also available on the Terra website.

Brief animation of Terra’s October Orbital Maneuvers

NASA previously released a Request for Information (RFI) on a Terra, Aqua, and Aura Drifting Orbits Workshop, for which the response date is October 11, 2022

The Terra, Aqua, and Aura Drifting Orbits Workshop will be held virtually on November 1-2, 2022. The Workshop Agenda has been posted on the NSPIRES page for this RFI. To attend please register at https://science.nasa.gov/earth-science/terra-aqua-and-aura-drifting-orbits-workshop-registration, or use the QR code in the image below.

If you’re a frequent user of Terra data, you’re probably somewhat aware of the recent and upcoming changes to Terra’s “traditional” orbit. (If you weren’t aware of these upcoming changes, or if you just want to read an excellent overview of Terra’s legacy and future, click on the link to read Blumenfeld’s article “From Terra to Terra Firma”).

In efforts to get the news out about Terra’s lowering and drift – and to inform users of potential data impacts resulting from these orbit changes — we’ll be posting several new infographics and short animations on the Terra website, as part of a larger campaign to celebrate over two decades of Terra data. Any graphics posted are available for public use and redistribution. (Click on the image for larger resolution and please share with others!)

Here’s an example of the new graphics we’ll be posting on the site:

Drifting: For over 20 years, Terra has shared an orbital path above the earth with a group of other polar-orbiting, earth-watching satellites (aka Terra's satellite constellation). Terra also passes over the equator at the same time every day. But how does Terra maintain its altitude and speed when Earth's gravity is constantly pulling on it? The answer: by burning fuel to counteract the drag! But Terra's also getting older (in satellite years) and is almost out of fuel; so since 2020, the satellite has been drifting, with no burns to counter the drag, causing slight increases in orbit speed and a resulting earlier passover time each day. DATA IMPACTS: Minor. Data is collected <15 minutes earlier each morning. Slight changes to surface shadows and data swath edges.

Constellation Exit: In October 2022, Terra will be lowered about 4 miles out of its constellation group's path (to make room for new missions) BUT will continue drifting and collecting data in an orbit that's closer to Earth. DATA IMPACTS: Slight to minor. Terra will be even closer to earth, so the images will be collected even earlier in the morning (>15 min) and will have more detail, with only slight changes to swath margins.

Passivation: Terra will keep collecting data until HQ begins the passivation process (aka turning off the satellite's power), sometime within the next 3 to 5 years.
Timeline showing important dates and upcoming orbit changes for the Terra satellite.

This infographic gives a simplified overview of Terra’s orbital movements, from its current drift, through the constellation exit this Fall, and finally into a lower, drifting orbit – along with the estimated (minor) effects possible due to these orbital changes. 

Check the Terra website often for additional information on the Celebrating 25 Years of Terra Data campaign and events!