Dozens of satellites could feed NOAA’s future weather models
This article originally appeared in the May 6, 2019 issue of SpaceNews magazine.
The U.S. National Oceanic and Atmospheric Administration’s future satellite constellations are likely to look far different from the current ones, particularly in low Earth orbit where small satellites of various sizes could gather targeted observations.
That is one of the conclusions leaders of NOAA’s Satellite and Information Service have reached since releasing the NOAA Satellite Observing System Architecture study in early 2018.
In geostationary orbit, NOAA will need new imagers around 2030, when the last two Geostationary Operational Environmental Satellite-R series near the end of their expected lives. “That’s got to be our near-term focus,” said Karen St. Germain, director of NOAA’s Office of Systems Architecture and Advanced Planning for NOAA’s Satellite and Information Service.
In contrast, the four spacecraft that make up NOAA’s Joint Polar Satellite System (JPSS) in low Earth orbit could provide data into the mid-2030s, St. Germain said at the 35th Space Symposium. Given that “strong backbone of funded, highly capable systems,” NOAA can spend time looking for ways to take advantage of commercial technology and new acquisition approaches to augment data provided by JPSS, she said.
For example, small satellites could provide ocean surface wind and soil moisture measurements through a technique called Global Navigation Satellite System reflectometry or by using cubesats equipped with Ka-band radars could measure precipitation.
“There’s a lot more opportunity at lower cost to add to the constellation in low Earth orbit,” St. Germain said.
That doesn’t mean, however, that NOAA’s future geostationary constellation will look like GOES-R satellites with sophisticated imagers, lightning mappers, space weather sensors and equipment to communicate observations to people on the ground on a single platform.
“There will be many instruments but they may be on many different observing points,” Stephen Volz, assistant administrator for NOAA’s Satellite and Information Services. Historically, NOAA has gathered weather and climate data from GOES East at 75 degrees west longitude and GOES West at 137 degrees west. Over the last year, NOAA has begun acquiring data from “a half dozen” satellites flown by international partners including Japan’s Himawari 8 and India’s Scatterometer Satellite, St. Germain said.
Himawari-8 provides NOAA with observations from a vantage point west of GOES West and European satellites offer observations east of GOES East. “Think about these all working together providing baseline measurements,” Volz said at the Space Symposium.
In addition, NOAA sees opportunities to augment the baseline measurements with unique datasets. South Korea’s National Institute of Environmental Research plans to launch the Geostationary Environment Monitoring Spectrometer built by Ball Aerospace on Geostationary Korea Multipurpose Satellite-2B in 2020. NASA plans to send a similar Ball instrument, Tropospheric Emissions: Monitoring of Pollution into orbit in 2019 as a hosted payload on a commercial communications satellite.
“In GEO, we are starting to see greater capability to do more than just imaging,” Volz said. “Imaging plus sounding plus air quality and the like. I would not expect them on a big platform. GOES is about as big as we want to get.”
If new instruments flew on separate satellites, NOAA could launch each one when its observations were needed and the technology was ready, St. Germain said.
In addition, NOAA could upgrade its space architecture both in low Earth and geostationary orbit as new capabilities become available, St. Germain said, adding, “We don’t want our future architecture to be static.”
In low Earth orbit, NOAA’s future architecture study highlighted the value of gathering imagery in highly elliptical geosynchronous Tundra orbits to improve observation of high-latitude regions.
“Particularly in the high latitudes, we believe we’re going to be seeing more drilling, more fishing, more tourism, more shipping,” St. Germain said. “That’s going to mean we need more situational awareness when it comes to the risks associated with weather and environmental phenomenon. That’s a capability we’re looking at in the future architecture.”
As NOAA anticipates acquiring data from many more government and commercial sensors, the agency is looking to evolve its ground systems. Historically, each NOAA flight program was responsible for its own ground systems for commanding and controlling satellites as well as processing and distributing data.
“If you imagine a constellation that may have 50 or more contributors that becomes untenable,” St. Germain said. “One of the other things we’re doing is building out what we’re calling an enterprise ground capability. That doesn’t mean one monolithic system, but it does mean common physics in our data processing. It does mean moving toward common standards and that sort of thing.”
NOAA also is focusing on ensuring the data it gathers from external sources is clean from a cybersecurity perspective, St. Germain said. “We’ve piloted a secure way to ingest data,” she added.