A hit Hollywood film often leads to a sequel. Sometimes those movies do well, but rarely will they eclipse the original. Undaunted by those odds, NASA is set to reboot a successful study of Earth’s lightning from space — this time from the unique vantage point of the International Space Station (ISS).
A team of Earth scientists at NASA’s Marshall Space Flight Center in Huntsville, Alabama, and the University of Alabama in Huntsville have high hopes for a follow-up mission for the agency’s Lightning Imaging Sensor (LIS) first launched into space in the late-1990s. Now, an identical LIS — built as a back-up — is headed to the space station for a two-year mission to probe the mysteries of lightning and its connections to other atmospheric phenomena.
The LIS is a sophisticated lightning research instrument designed to measure the amount, rate and optical characteristics of lightning over Earth. Mounted externally on the station in an Earth-viewing position, the spare LIS will build on the foundation of space-based lightning observations begun by its predecessor.
The original LIS was launched in 1997 as part of the Tropical Rainfall Measuring Mission (TRMM). LIS on TRMM was an outstanding success, delivering an impressive 17 years of lightning observations. But the TRMM satellite’s orbit only carried LIS over locations on Earth between 35 degrees north and 35 degrees south latitudes. So it gave lots of data for the tropics, but it could not observe far enough toward the poles to cover the more temperate zones, including more heavily populated areas away from the equator.
“The LIS used in this follow-on mission is an exact duplicate of the sensor used on TRMM,” said Richard Blakeslee, science lead for the LIS at NASA Marshall. “But it will sample lightning over a wider geographical area.”
The orbiting laboratory’s higher inclination provides the opportunity to observe farther into the Northern and Southern hemispheres — all the area between 56 degrees north and 56 degrees south latitude.
Another advantage of using the space station for LIS observations is the capability to get lightning data downlinked in real-time and into the hands of scientists and other interested users. This data can be used for research or operational applications in data-sparse regions — over the oceans, for example — to provide situational awareness for weather forecasts, advisories and warnings. The real-time LIS data will be directly accessible to users around the world through a partnership with NASA’s Short Term Prediction Research and Transition (SPoRT) Center in Huntsville.
LIS on the space station will also provide important cross-sensor calibrations, especially for the new Geostationary Lightning Mapper, an instrument based on LIS design heritage that is flying on NOAA’s recently launched GOES-16 satellite. Cross-calibrating LIS data with other space-based lightning and weather instruments may create a longer lightning data record to improve our knowledge of severe weather formation and long-term changes in lightning distributions.
The idea for the original version of the sensor was the result of a meeting of atmospheric scientists convened by NASA in 1979. They were exploring the idea of using lightning observations from space as a remote-sensing tool to study weather and climate. TRMM was the first mission that documented a detailed global lightning climatology for the tropics from space.
“The space-based vantage point allows us to observe all forms of lightning over land and sea, 24 hours a day,” said Blakeslee. “The orbit of the space station will allow LIS to look at lightning distributions over different times of the day, further enhancing our knowledge of the complicated dynamics of lightning.”
Data from LIS will also help scientists examine the relationship between lightning and severe weather. Understanding the processes that cause lightning and the connections between lightning and subsequent severe weather events like convective storms and tornadoes is a key to improving weather predictions and saving life and property, in this country and around the globe.
The LIS is scheduled for launch to the space station this month on the tenth SpaceX cargo resupply mission. The sensor will fly as hosted payload on the U.S. Department of Defense Space Test Program-Houston 5 (STP-H5) mission. STP-H5 is integrated and flown under the management and direction of the DOD’s STP.
From the pioneering scientists who ushered in a new era of space-based lightning detection, this is one sequel that just may be scientific box-office gold.