Mission Manager Update: Kepler’s K2 Mission Begins Campaign 13

Last month the scientific community and the world were delighted with the announcement of a total of seven Earth-size planets orbiting a nearby star called TRAPPIST-1. Data from NASA’s Spitzer space telescope revealed the last four of these neighbors, and as planned, the Kepler space telescope also had an opportunity to look in on this interesting target.

During its observing campaign 12, covering the period of Dec. 15, 2016 to March 4, the Kepler spacecraft, operating as the K2 mission, monitored the brightness of TRAPPIST-1. Earlier this month, we released the raw, uncalibrated data to the scientific community, with the fully calibrated data to follow in the next few months. We are excited to see what these observations have added and will further contribute to the community’s investigation into the TRAPPIST-1 system.

Kepler’s K2 mission is now in its thirteenth observing campaign, monitoring a patch of sky in the direction of the constellation Taurus. During this campaign, the spacecraft will monitor more than 21,000 targets, including the Taurus star-forming region and the nearby Hyades open star cluster. Measurements of 33 galaxies, six asteroids, eight trans-Neptunian objects and one comet are also scheduled.

Kepler's K2 Mission Begins Campaign 13

Over the last year, the team also has been gearing up to deliver the final data products from the Kepler [prime] mission. Today marks an important milestone: the final Kepler Object of Interest (KOI) table has been delivered and made available to the community at the NASA Exoplanet Archive. The KOI table contains a list of notable objects that show evidence of astrophysical transit events. The release of these data will help the community plan follow-up studies while our final analyses are completed. A paper detailing the mission’s final candidate catalog is anticipated this summer.

At this time of year, the original Kepler field of view rises in the night sky allowing scientists to carry out their follow-up studies of these KOIs using ground-based telescopes in the northern hemisphere.

Beginning April 1st, the Kepler/K2 guest observer office will be under the direction of Dr. Geert Barentsen. Geert will lead the team’s efforts to engage and support the broader scientific community using data from the K2 mission. He joined the team in June 2015 and has been instrumental in shaping the diverse portfolio of observation targets for the K2 mission. Geert also organized the first-of-its-kind microlensing experiment for NASA—a collaborative survey between the K2 mission and ground-based observatories around the world. Community engagement and the results of the study serve as a proof of concept for NASA’s Wide-Field Infrared Survey Telescope, to be launched in the mid-2020s. Geert is currently organizing another K2 mission campaign focused on the study of supernovae, which is scheduled to begin in December.

With this new appointment, the team bids farewell to Dr. Tom Barclay, our current director of the Kepler/K2 guest observer office, as he begins a new opportunity as the deputy director of the guest investigator office for NASA’s next planet-hunting mission, the Transiting Exoplanet Survey Satellite. Tom joined the team in March 2011 and was promoted to director in October 2014. He led the efforts to engage the scientific community on a new and unexpected opportunity that would become the K2 mission. In July 2016, his leadership and passion for the search for other worlds was recognized with a NASA Ames Honor Award for his exceptional efforts. We applaud Tom’s enthusiastic and tireless work as the Kepler/K2 guest observer director. He will be missed.

The spacecraft remains healthy and productive–a true explorer as it recently completed its eighth full year in space. It now trails Earth by 84 million miles in its tour around the sun. That’s about 452 light-seconds for those spatially inclined, or 0.9 AU for folks that like smaller numbers.

Regards,

Charlie Sobeck
Kepler and K2 mission manager
NASA’s Ames Research Center

Mission Manager Update: K2 Marching On With Campaign 11

Kepler’s K2 mission is now in the midst of its eleventh campaign, observing a patch of sky in the direction of the constellation Sagittarius. During this campaign, it will observe 14,250 new targets, including the Galactic Center and Saturn’s moons Titan and Enceladus.

Campaign 11 began on Sept. 24, but was interrupted for three days (Oct. 18-20) to make a small pointing correction to accommodate the imbalance that was created by broadcasting data from a different antenna on the other side of the spacecraft. Although the spacecraft is as big and heavy as an SUV, it actually turns slightly when we change the broadcasting antenna. This is like having your car begin to turn from the force of the blinking of your turn signal. Yes, the spacecraft is that delicately balanced! Data collection for Campaign 11 will continue until Dec. 7.

Since my last update, our investigation into the cause of the spacecraft’s photometer—the onboard camera—being powered off in July during Campaign 10, confirms that that science detector Module 4 failed. The likely cause was a random part failure that resulted in a high electric current in the circuitry, which blew the protection fuse, disabling the detector but preventing the problem from propagating to other detectors. As part of the fault protection response, the photometer was powered off.

Eighteen of the 21 science detector modules remain fully operational. Two science modules had failed previously: Module 7 in January 2014 and Module 3 in January 2010. These are not unexpected events as the spacecraft ages in the harsh environment of space.

Kepler photometer modules
The comparison of two full frame images from the Kepler spacecraft show two black squares (Modules 3 and 7) and 19 red squares on the left. On the right, there are three black squares (Modules 3, 4 and 7) and 18 red squares. A red square indicates that data is being collected by the photometer and a black square indicates no data is being collected and that the module is no longer functional. Eighteen of the 21 science detector modules remain fully operational.
Credits: NASA Ames/W. Stenzel

In September, the spacecraft had a unique opportunity to provide a ‘wide-angle’ view of comet 67P/Churyumov–Gerasimenko, making observations of its core and tail. These observations complement the close-in study of the comet provided by the European Space Agency’s Rosetta spacecraft during the final month of its mission. These and the remainder of Campaign 10 data have been downlinked to the ground and are being processed for release at the public archive later this month.

We’ve also made changes with the Kepler and K2 project scientist personnel.

Natalie Batalha, astrophysicist and project scientist for NASA's Kepler mission
Natalie Batalha, astrophysicist and project scientist for NASA’s Kepler mission

On Aug. 15,Natalie Batalha, project scientist for NASA’s Kepler mission Natalie Batalha was appointed as the project scientist for the Kepler mission. Since 1999, Dr. Batalha has served in numerous leadership roles throughout the mission including deputy principal investigator and science team lead. In addition to her responsibilities with the Kepler mission, Natalie is a co-lead of NASA’s Nexus for Exoplanet System Science Coalition, and serves on the James Webb Space Telescope Advisory Committee. She also serves as a member of the NASA Advisory Council’s Astrophysics Subcommittee, and, in 2013, participated on the task force to define NASA’s 30-year Astrophysics RoadmapEnduring Quests, Daring Visions: NASA Astrophysics in the Next Three Decades.

Jessie Dotson, project scientist for NASA's K2 mission
Jessie Dotson, astrophysicist and project scientist for NASA’s K2 mission

On Sept. 6, Jessie Dotson assumed the role of project scientist for the K2 mission. Dr. Dotson was formerly the deputy science office director for Kepler and, in 2008, established the Kepler Guest Observer Office. Most recently, she served as astrophysics branch chief in the Space Science and Astrobiology Division at NASA Ames. In 2014, Jessie helped formulate the Asteroid Threat Assessment Project (ATAP) at NASA Ames to quantify the risk to Earth of an asteroid impact. She currently leads the ATAP asteroid characterization team. In 2016, Jessie was awarded a NASA Outstanding Leadership Medal for her work as the astrophysics branch chief at Ames.

Together, Natalie and Jessie replace Steve Howell who served as Kepler project scientist since 2010 and K2 project scientist since mission conception in 2013. In that role, Steve oversaw Kepler science operations through the end of its prime mission, the recovery from the reaction wheel failure that nearly ended the mission, and the development and implementation of the K2 mission that gave Kepler a new lease on life. We commend Steve for his work as the Kepler/K2 project scientist, with notable leadership in catalyzing the science community to support Kepler’s extended mission called K2.

In August, the team gathered for the annual year-in-review of spacecraft operations with Ball Aerospace, the designer, manufacturer and flight controller of Kepler. A topic of high interest is the on-board fuel reserve, which is expected to last into the spring of 2018.

At last count, Kepler has identified more than 5,100 planet candidates. Of these, more than 2,500 have been verified as bona fide planets. NASA’s next planet-hunting mission, the Transiting Exoplanet Survey Satellite (TESS), is scheduled to launch no later than June 2018. TESS will build upon Kepler’s success and search for exoplanets around the stars closest to the own solar system.

Regards,

Charlie Sobeck
Kepler and K2 mission manager
NASA’s Ames Research Center

Mission Manager Update: Photometer Update

As reported in last week’s update, the Kepler spacecraft’s photometer—the onboard camera—was commanded to return to science after being found to be off during a routine contact on Thursday, July 28. Yesterday, the team confirmed that the photometer responded as expected and began collecting data again on Tuesday, Aug. 2.

Yesterday’s scheduled contact with the spacecraft was made using the 70-meter dish at NASA’s Deep Space Network (DSN) at Goldstone, California. The large dish provided the necessary communications link with the spacecraft to confirm Kepler was back doing science.

The Kepler focal plane
The Kepler focal plane is approximately one foot square. It’s composed of 25 individually mounted modules. The four corner modules are used for fine guiding and the other 21 modules are used for science observing.
Credits: NASA Ames and Ball Aerospace

Our investigation of the cause centered on the focal plane detector modules. The signature of the recorded faults surrounding the anomaly was reminiscent of an event in January 2014, when one of the science detector modules (Module 7) failed. In that case, we concluded that the most likely cause was a random part failure that resulted in a high electric current in the circuitry, which blew the protection fuse, disabling the detector but preventing the problem from propagating to other detectors. As part of the fault protection response, the photometer was powered off. Thus, it seemed likely that this most recent anomaly might be the result of another random detector failure—something to be expected as we continue to extend the spacecraft’s mission.

Analysis of the temperature data from the focal plane seems to bear out this hypothesis, and points suspicion to science detector Module 4, as the likely culprit. When we turned the photometer back on, all the other modules warmed up at a consistent rate, while Module 4 reacted more slowly, and never reached full operating temperature before the DSN contact ended.

As part of our standard contact procedures yesterday, we brought down a few pixels from the focal plane to verify the precise pointing of the spacecraft, and some of these pixels were from the suspect Module 4. The data from these pixels failed to register its assigned target star, while pixels from other modules produced the expected signals from their assigned target stars. Therefore we are relatively certain that this detector has indeed failed.

For the K2 mission’s current Campaign 10, the targets that were assigned to Module 4 will yield no further science results. For the campaigns going forward, we will select targets which fall on the remaining operational detectors, which will have little to no impact to the upcoming science.

Such hardware failures were foreseen in the initial mission planning, and the system design is robust and compartmentalized to minimize the impacts. After more than seven years in the harsh conditions of space, 85 percent of Kepler’s original detectors are still operating. Module 4 will be the third of the 21 science modules to have failed in-flight.

Kepler’s primary mission ended in 2013 but exoplanet and astrophysics observations continue with the K2 mission, which began in 2014. In June, NASA Headquarters announced that Kepler is to continue science operations through the end of the FY19, by which time the on-board fuel is expected to be fully depleted.

To-date, Kepler has identified more than 5,100 planet candidates, of which 2,454 have been verified as bona fide planets. NASA’s Transiting Exoplanet Survey Satellite, scheduled to launch in 2017 or 2018, will continue Kepler’s success and search for exoplanets closer to our own solar system.

Regards,

Charlie Sobeck
Kepler and K2 mission manager
NASA’s Ames Research Center

Mission Manager Update: K2 Campaign 10

During a scheduled contact with NASA’s Kepler space telescope on Thursday, July 28, the team found the photometer—the camera onboard the spacecraft—powered off. The photometer was turned on again and the flight system returned to autonomous science operations on Monday, Aug. 1. We will confirm that science operations have been resumed within a week. The team is currently investigating the cause; the spacecraft is otherwise operating normally.

The Kepler spacecraft is currently in the tenth observing campaign of its second mission, called K2. Kepler’s primary mission ended in 2013 but more exoplanet and astrophysics observations continue with the K2 mission, which began in 2014. To-date, the K2 mission has identified more than 450 new planet candidates, of which 128 have been verified as bona fide planets.

In June, NASA Headquarters announced that the K2 mission is to continue science operations through the end of the FY19, by which time the on-board fuel is expected to be fully depleted.

Regards,

Charlie Sobeck
Kepler and K2 mission manager
NASA’s Ames Research Center

Mission Manager Update: K2 Marches On

The K2 mission, the two-wheel operation mode of the Kepler spacecraft observing in the ecliptic, is exhibiting no discernible ill effects since the recent Emergency Mode, other than the extra fuel usage. K2 is now in the second half of the special microlensing campaign called Campaign 9. The first half of the campaign was shortened by two weeks as a result of the emergency, and the data acquired have made public. The microlensing team has already been searching for the telltale events that indicate an object passing in front of a background star, identifying approximately two-dozen of these lensing events. Thus far, the experiment seems to be a smashing success!

While we are still dotting the i’s and crossing the t’s on the cause of the emergency, all the signs are pointing towards a single bit that changed state in the memory of an electronic chip that controls the internal command and data bus onboard the spacecraft. The memory was designed to be highly resistant to upset but if a high-energy cosmic ray hit in just the wrong place or at the wrong time in a write cycle an upset can occur. In this case, the upset caused a disruption in the internal data stream, passing invalid data sets to the flight computer, setting off several fault responses including the shutdown of critical heaters on the spacecraft. After a couple of hours, propellant froze in the propulsion system effectively disabling pointing control. Without pointing control, the spacecraft slowly drifted until the sun got too close to a “forbidden zone” around the optical axis of the telescope, causing the Emergency Mode to kick in and protect the telescope. While we have an excellent fault protection system onboard, no amount of pre-planning is going to work if we get multiple, random faults, which is why we have the Emergency Mode in the first place. And it worked beautifully!

The spacecraft emergency provided an opportunity to highlight the important role that engineering plays behind the scenes in the development and operation of a mission. Last month the engineers from NASA Ames, Ball Aerospace and the Laboratory for Atmosphere and Space Physics at the University of Colorado, both located in Boulder, who all worked on the recovery of the spacecraft, participated in a Reddit “Ask Me Anything.” The team had a fantastic time responding to the online community’s questions about the steps in the recovery and the experience of working through a high-pressure, high-visibility situation. We were encouraged by the level of interest and look forward to welcoming more problem solvers to the field of engineering. You can learn more about managing the recovery of a spacecraft 75 million miles from Earth in a recent question and answer feature.

Meanwhile the scientific results from the missions keep rolling out. Last month Dr. Timothy Morton of Princeton University announced that his analysis of the Kepler data was able to validate planethood for 1,284 more of Kepler planet candidates. The Kepler verified planet count currently stands at 2,327.

Now in its ninth observing campaign, K2 continues to produce a bounty of data for the scientific community to continue the search for exoplanets and to study planet and star formation, as well as the explosive death of red giant stars, commonly known as supernovae. The K2 planet count continues to climb, reaching more than 250 candidates, of which nearly 50 have been verified as bona fide planets.

NASA has also announced today that K2 is to continue science operations through the end of the FY19, by which time the on-board fuel is expected to be fully depleted. The mission extension, based on a recommendation from NASA’s Astrophysics Division’s 2016 Senior Review of operating missions, provides two additional years of funding for K2 to continue exoplanet discovery, and the study of notable star clusters, young and old stars, active galaxies and supernovae. For more details about the recommendation and for a listing of other missions approved for extension, see the 2016 Senior Review report.

With the emergency behind us, and fuel to last us into the summer of 2018 or beyond, the news of the two-year mission extension was a welcomed vote of confidence in the team. This news comes just a week after K2 completed two years of operations, celebrating its second “birthday.”

Regards,

Charlie Sobeck
Kepler and K2 mission manager
NASA’s Ames Research Center

Mission Manager Update

While analysis of the Kepler mission data proceeds, we continue to operate the spacecraft for the K2 mission. In the Mission Manager updates, I’ll provide periodic posts on the spacecraft operation, the team and the latest science results from the Kepler and K2 data. In this blog I’ll give you a view of the work we’re doing, and the various issues that we have to consider.Charlie Sobeck, Kepler and K2 mission manager

Charlie Sobeck
Kepler and K2 mission manager
NASA’s Ames Research Center