There are currently 20 NASA Earth observing missions circling our world, either as singular flagship spacecraft or as constellations of small sats that work together to do their science. These missions collectively observe everything from the chemistry of our atmosphere, to the flux of solar radiation on our world, to the planet’s thermal behavior and changing sea levels. Together, these spacecraft provide continuous monitoring of out evolving world over time.
Unfortunately, many of these missions are already working on borrowed time.
Ace, CYGNSS, Jason03, Landsat 7 & 8, and SMAP all beyond their proposed end dates, and Aqua, Aura, DISCOVR, GRACE, and OCO-2 all slated to end next year. And not all can just keep working with additional funding.
And we’re going to talk about what this means.
The trio missions – Terra, Aqua, Aura – are environmental science satellites.
TERRA is a flagship mission of the US, Japan, and Canada, and it is working to study our world’s atmospheric composition, thermal behavior, and changing air, land and water using a suite of imagers and spectrographs. Launched in 1999, this mission helped us understand how air flights drive cloud formation after 9/11. It has brought us spectacular images of hurricanes , dust storms, wildfires and more.
TERRA is in a Sun-Synchronous Polar Orbit, allowing it to get image after image of our world with similar lighting. Located in Low Earth Orbit, TERRA is subject to drag from the earth’s extremely thin atmosphere, and as much as we might want to, we can’t keep it going forever. Current plans are to deorbit the bus sized spacecraft sometime later this year or next year.
And there is nothing planned to replace it.
This story also applies with some slight plot twists to Aqua and Aura.
Aqua launched in 2002, and its instruments are focused on Earth’s water, with systems designed to monitor clouds, atmospheric temperature and humidity, land and sea temperature, and more. Slated for a 5 year mission, it’s still going 23 years later, but it has long run out of fuel, and current models suggest drag will deorbit it sometime in 2026.
Aura, the third of these sun synchronous polar orbiters, launched in 2004, and is a collaboration with the European Space Agency. It is focused on our atmosphere, and lets us know everything from the status of the Ozone hole to the effects of rockets and burning up satellites on the atmosphere.
And guess what – it too will likely deorbit in 2026. These missions all caught the attention of the media, with outlets ranging from the New York Times to Politico to Scientific America all speaking out about the loss to science this will cause. Of immediate concern, we will be losing the information they capture on how ash from volcanoes, smoke from fires, dust, and pollution all move through our atmosphere and affect the air quality and weather patterns around the world. Longer term, they monitor the no-longer-healing Ozone hole. While we can hope to launch missions to collect data in the future, without overlapping data from the current and future instruments, figuring out how to calibrate their data for long term studies will be next to impossible. As researchers, we’re kind of expected to do the next to impossible every day – this is how we end up with still working 25 year old spacecraft that were originally launched on 5 year missions, but it would be a whole lot easier to understand our world if we had continuity between Earth Observing missions.
And what is concerning to me and so many others is Terra, Aqua, and Aura were major missions from the golden era of NASA getting back into the science game. These Earth observers were worked on at the same time that NASA was building the great observatories and the follow-up missions of Chandra, Fermi, and JWST. There is currently nothing planned to replace any of these flagship missions of the 80s, 90s, and early 2000s, and while I love those eras of music, I like my missions a bit more modern.
NASA currently shows 3 smaller missions in the planning stages, and none of them will replace these Earth observing capabilities.
But Terra, Aqua, & AURA are just 3 of the 9 that are nearing end of life. The Deep Space Climate Observatory, or DSCOVR, is another earth observer. Launched in 2015 on a 5 year mission, it is still going strong 10 years in. Placed in the L1 Lagrange point, its data aids in weather forcasting and space weather prediction – that’s the stuff that tells us when aurora may be visible. We don’t have to worry about it falling out of orbit, and it should be able to carry on its mission as long as its computers work, which could mean decades. But are we going to keep relying on decades old space craft when most of us don’t like to trust even 5 year old phones?
I could keep going, keep telling you about GRACE, and OCO-2, and Landsat 7 & 8 and all the other aged missions still doing their jobs because engineers building for NASA like to build things that last.
And I am so grateful that our science, for now, will continue because of that over engineering.
But we are in a situation where it takes years to decades to develop, build, and launch satellites and we don’t have replacements currently being planned. Instead, as we discussed last week, we have massive slashes coming to NASA, and the possibility that nearly complete space missions, like the Roman Space Telescope, will be cancelled. As long as they don’t take the missions apart, cancelled doesn’t have to mean forever – DISCOVR was actually cancelled under the 2nd bush administration, and pulled out of storage in the Obama administration.
But can we, as a planet, afford a gap in data right now? Each year the ocean temperatures are driving more rapidly growing hurricanes and more powerful storms. Changes in rain patterns are driving fires with continent-covering smoke. We are seeing dust storms from Africa laying sand over Europe.
And it is the Earth observing missions that allow us to see in detail what is happening.
We currently use a multi-pronged data collection process. DSCOVR, out at L1, can image the Sunlit side of our planet, over and over, giving a picture of our world. From their low earth orbits, TERRA, AQUA, and AURA are getting detailed images of stripes of our planet, with repeat images being taken roughly every couple weeks. And, with airplanes, drones, and ground stations, we get the most detailed measurements moment by moment. All this data is needed in our weather models to produce the more or less accurate storm predictions we have today. As someone living in tornado alley, I appreciate the heads up on when I need to be ready to hide in the basement, and when it is fine to go on a four-hour bike ride. It turns out that the blue skies of 9:00 AM can quickly be erased by severe weather, and these kinds of forecasts are necessary not just for safety, but also for the economy, as they are used to guide planting, shipping, air travel, and so much more.
And we are going to start losing this data either later this year, or next year. This will be one more thing negatively impacting our economy and our safety that we need to be aware of.
Folks, I don’t know what happened 20 to 30 years ago politically that led to so much money going to science missions. It was a drop in the bucket compared to the 60s, but it was enough to set us up for the science guided world we live on. In this age where tourist flights above the atmosphere are possible, it feels like getting more science missions shouldn’t be so impossible.
But – right now, as we watch more rockets going up than at any point in history, we aren’t launching all that many science missions.
This is our reality, There is no easy way to summarize this segment. We are nearing the end of an era and soon we will see missions failing, from Hubble looking out to TERRA and company looking down, and our ability to keep up our current pace of science will falter.