“That’s the best launch I’ve ever heard.”
A marine layer settled over the viewing area for the launch of NASA’s Orbital Carbon Observatory-2 satellite, creating a thick fog and making visibility difficult for people who came out to Vandenberg Air Force Base in California yesterday morning to witness the launch. A few seconds after launch, spectators heard and felt the roar of the Delta II rocket as it lifted off carrying the satellite, but viewers at the launch site failed to see the rocket take off because of the thick shroud of fog. One official supervising the visitor section just off the base said this launch is the first time in her 14 years of witnessing launches that the orange glow from the rocket wasn’t visible from the viewing area.
The visibility issue was the last thing on the minds of specialists who worked on the Orbiting Carbon Observatory project for months and years, especially after enduring a failed launch of the first OCO in 2009 and a last-minute launch scrub yesterday morning. Today’s textbook launch went off without a hitch as the satellite ended up in orbit successfully within the A-train satellite constellation, and followers breathed a sigh of relief once the satellite deployed its solar panels and began transmitting data one hour after launch.
Monitoring carbon dioxide in the atmosphere
The Orbiting Carbon Observatory-2’s launch seeks to answer important questions about how the Earth absorbs carbon dioxide present in the atmosphere. Currently, ground-based observations exist to monitor carbon dioxide absorption in some parts of the world, but it’s difficult for scientists to monitor those sources in remote terrestrial and ocean-based carbon dioxide-absorption areas, known as sinks.
While the planet creates a natural balance by absorbing the similar amounts of carbon dioxide in natural sinks as what is emitted naturally, the introduction of carbon dioxide emissions from human sources generates questions about how those processes work. While scientists used ground-based sensors to estimate that the amount of carbon dioxide in the atmosphere rose from 320 parts per million to over 400 parts per million by 2013, one big question involved the changes in natural carbon dioxide absorption year to year. Current instruments show that, while carbon dioxide levels are rising, the levels of absorption from the atmosphere can change drastically in different years. Annmarie Eldering, deputy project scientist for OCO-2, said she hopes by reading the data about carbon sinks from OCO-2 and combining findings with data from other satellites such as those on the A-train monitoring the planet, human beings can better predict what will happen and make changes from there.
“If we can better understand the natural cycles, we can better predict the future,” Eldering said. “Someone’s going to throw that stuff together and tell me something I haven’t thought of.”
Recovering from a failed launch five years ago
The original Orbiting Carbon Observatory mission failed on launch in 2009 as the Taurus XL rocket carrying the satellite into orbit failed to separate, causing the payload to crash near Antarctica. Between getting approval and budgeting for the mission as well as making changes to the launch vehicle used, it proved no easy feat to start again on a project that took years to build.
While the team submitted an application to restart the project just days after the launch, budgeting issues pushed the project start date into 2010. NASA planned a launch of the OCO-2 project last year, but the space agency made the decision to switch the launch vehicle to the Delta II rocket. While the Delta II has a history of being a workhorse rocket that has been used in 42 missions at Vandenberg alone, the change meant a delay into 2014.
The space agency targeted a launch date and time in July to allow OCO-2 to merge with other satellites along the A-train, a constellation of satellites taking scientific measurements of the planet. The grouping of the satellites in a constellation allows different diagnostic tools to take measurements of the same areas at the same time, giving greater ability to combine the data. To place the satellite into the A-train, NASA had to launch the satellite within a 30-second window, which Project Architect Randy Pollack described as “merging with traffic going 17,000 MPH.”
The original OCO’s failure came as a surprise to many who worked on the project as news of the launch separation issue came after many of the individuals working on the project left viewing areas to head home thinking the satellite made it into space. For this launch, Mic Woltman, senior vehicle systems engineer for the Launch Services Program, said the OCO-2 team would be paying close attention to every aspect of this launch until the satellite was safely in orbit.
“Launch team will relax once the solar arrays are deployed and they report that they’re charging and getting a good signal back,” Woltman said.
Yesterday's launch took about an hour before teams on the ground received news that the solar arrays deployed and the satellite transmitted data for the first time.
Once the team calibrates the satellite's systems and verifies that measurements match those of existing ground-based instruments, the satellite will begin compiling data and transmitting to teams on the ground. OCO-2 Program Scientist Ken Jucks said the satellite needs to take a good deal of measurements to be effective. At the same time, NASA will need to combine the readings from OCO-2 with ground-based instruments as well as the 17 other satellites studying the Earth’s atmosphere.
“To fully understand your system, you need a lot of data,” Jucks said. “We need a lot of data to fully understand what’s going on in the Earth’s system.”
Jucks said he expects data from OCO-2 to be available to scientists working on the project as well as the general public by the end of the year, along with papers coming out with data from OCO-2 over the next decade.
Earth Right Now
In 2014, NASA plans to carry out five Earth-monitoring instruments, with more missions studying Earth this year than any other year over the last decade.
NASA’s initiative to send up satellites to measure Earth this year, nicknamed by the space agency as Earth Right Now, began with the launch of the Global Precipitation Management satellite earlier this year to measure rainfall, snowfall and precipitation cycles across the planet. OCO-2’s launch yesterday represents the second launched satellite in this year's Earth Right Now initiative, and the space agency will carry out three more missions later this year. Other missions scheduled include a satellite to study soil moisture and two instruments on the International Space Station to measure global wind patterns and cloud/aerosol patterns.
Along with NASA’s own instruments, data will be combined with readings from satellites launched by other countries to paint a more complete picture about the planet. Expected collaborations include combining data with already-deployed satellites like Japan’s Greenhouse Gases Observing Satellite launched in 2009 as well as the European Space Agency’s methane-measuring TROPOMI satellite launching in the next few months. Future projects could include a third generation of OCO as an instrument on the International Space Station.
With all the ground-based and satellite instruments measuring the planet, scientists will have a greater picture than ever about the long-term effects of a changing climate. Eldering said the data is not meant to prove climate change to skeptics, specifically those working in Congress, but rather to show the consequences of human activity on the planet’s natural cycles.
“Our mission isn’t going to be the right kind of data to sell [Congress] on things they don’t know already,” Eldering said. “The data will tell you more about this response: What’s 2050 going to look like? What’s 2100 going to look like?”