A NASA-funded OU mission is gearing up for a critical design review of its instrument, which is intended to measure carbon emissions in the Americas every day for three years.
The Geostationary Carbon Cycle Observatory (GeoCarb) team has spent the last two years designing, testing, building and reviewing the satellite observatory — its hopeful launch date is summer 2022.
The GeoCarb team and its consultants are spread across the globe, with a small team of OU researchers based in Norman. Lockheed Martin, an aerospace, defense, security, and advanced technologies company that first envisioned the idea for GeoCarb, is building the instrument in Palo Alto, California.
In July 2017, NASA awarded OU a $166 million grant to move forward with the proposal for GeoCarb. The observatory is designed to attach to a “host” satellite, likely one owned by the company SES, and will be in geostationary orbit to observe daily carbon dioxide, methane and carbon monoxide in the Americas over the span of three years.
At around 22,000 miles away from the Earth, GeoCarb will give scientists a thorough look at greenhouse gases from the Hudson Bay to the southern tip of South America — a first in climate change research. It will also “monitor plant health and vegetation stress,” according to the website.
The GeoCarb project is now in “Phase C,” said Shelly Finley, deputy program manager.
“Right now we're full steam ahead with putting the instrument together,” Finley said. “And the critical design review is the final step to sign off to say, ‘Yes, your designs, your plans for putting the instrument together all look solid. Move forward.’ And so that's what Phase C is all about.”
Phase C will end when the instrument has been completely finished and tested, according to a GeoCarb timeline available on OU’s website. Phase D will prepare the observatory to attach to the satellite and then launch it, and Phase E will analyze the data GeoCarb provides.
Sean Crowell, deputy principal investigator and project scientist, said a principal part of the process so far has been for Lockheed Martin’s team to build “engineering models” of GeoCarb. Testing ensures they fully understand how the device will work and save money when it’s time to put the real thing together, Crowell said.
“The thing that you build and actually put into space is really expensive,” Crowell said. “And so what they do is, they build these sort of intermediate systems … and so those have pretty much all been tested, vetted. There should be fewer surprises once they start testing the smaller parts of the system and putting it together.”
Exciting moments come for the OU team when they receive pictures and videos of different parts of the system working, even if it’s just a door swinging open, Crowell said.
As they prepare for the upcoming review, which will take place Jan. 29-31 in Palo Alto, Finley said she feels confident that everything is ready to go and the team will be given the green light to move forward with the mission.
And Finley said finishing the instrument isn’t the only work left to be done.
“It's a mission and not an instrument — we tend to focus on the instrument, and NASA tends to remind us not to just focus on the instrument,” Finley said. “We are still maturing things like ground systems. So you're going to pull data off the satellite, and that data has to be translated to all the different parties, it has to be calibrated … and has to be processed and reprocessed.”
Crowell and Finley are part of about 15 people involved with GeoCarb at OU. This team includes Berrien Moore, principal investigator and dean of the College of Atmospheric and Geographic Sciences, along with program managers, a staff assistant, two undergraduate students and two graduate students.
Jeff Nivitanont, a mathematics graduate student, has been part of the GeoCarb team for two years and his research has focused on the performance of the instrument.
“What I do is, I characterize how the instrument is going to perform when observing very specific scenes,” Nivitanont said. “This is called the uncertainty quantification. So basically, I'm trying to predict what are the biggest errors in measurement that we should expect.”
Nivitanont performs these studies using radiative transfer models that simulate the data GeoCarb will be collecting, and then running that data through the algorithms that will be used on the actual data. Because of the GeoCarb’s uniqueness, few have done the type of characterization he is doing, Nivitanont said.
“So it's something that I can see having to take more time,” Nivitanont said. “And future space-based remote sensing instruments are going to have to do this quantification I've been doing for the past two years.”
Because GeoCarb has so many partners around the globe, Nivitanont said the team will most likely consult on future remote sensing space missions. And though he is graduating in May, Nivitanont expects that his involvement with GeoCarb won’t be over.
After spending two years researching and gaining the knowledge required, he likely will be asked to help or advise in future studies, Nivitanont said.
Each member of the team has gained something from being part of GeoCarb. Finley said her management and people skills have increased. While Crowell has gained management skills as well, he said seeing students learn and mature as scientists has been one of the most rewarding things. Nivitanont said his communication skills have improved greatly, and he has gained a tremendous amount of knowledge during his research.
But the biggest reason he wanted to be involved with GeoCarb is so he could be a part of something impactful and useful.
“I think the questions that we're trying to get at are extremely difficult, but also very important,” Nivitanont said. “Anytime there's ever been a very difficult problem (humankind) faced, there has always been a huge collective effort toward solving that problem. So, GeoCarb is just one part of the large effort that is going toward this huge problem with climate change.”
