The Delta II rocket with the THEMIS spacecraft atop sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station in this aerial view of the launch complex area as the mobile service tower begins to move away. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m.

In this aerial view, the Delta II rocket with the THEMIS spacecraft sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station, as the mobile service tower moves away from the pad. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m.

In this close-up aerial view, the Delta II rocket with the THEMIS spacecraft atop sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m.

In this close-up aerial view, the Delta II rocket with the THEMIS spacecraft atop sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station as the mobile service tower moves away from the pad. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m.

In this close-up aerial view, the Delta II rocket with the THEMIS spacecraft atop sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station as the mobile service tower begins to move away. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m.

At Cape Canaveral Air Force Station, clouds of smoke form around the Delta II rocket with NASA's THEMIS spacecraft aboard as it blasts off Pad 17-B at 6:01 p.m. EST. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color.

At Cape Canaveral Air Force Station, the Delta II rocket with NASA's THEMIS spacecraft aboard begins its ascent from Pad 17-B, in sight of the Atlantic Ocean, at 6:01 p.m. EST. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color.

At Cape Canaveral Air Force Station, clouds of smoke encompass the Delta II rocket with NASA's THEMIS spacecraft aboard as it blasts off Pad 17-B, in sight of the Atlantic Ocean, at 6:01 p.m. EST. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color.

Amid billows of smoke, the Delta II rocket with NASA's THEMIS spacecraft aboard blasts off Pad 17-B at Cape Canaveral Air Force Station at 6:01 p.m. EST. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color.

Clouds of smoke encompass the Delta II rocket with NASA's THEMIS spacecraft aboard as it blasts off Pad 17-B at Cape Canaveral Air Force Station at 6:01 p.m. EST. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color

At Cape Canaveral Air Force Station, clouds of smoke envelop the Delta II rocket with NASA's THEMIS spacecraft aboard as it blasts off Pad 17-B at 6:01 p.m. EST. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color.

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket with the THEMIS spacecraft atop sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station in this aerial view of the launch complex area as the mobile service tower begins to move away. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket with the THEMIS spacecraft atop sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station after the mobile service tower moves away from the pad. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- In this close-up aerial view, the Delta II rocket with the THEMIS spacecraft atop sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station as the mobile service tower moves away from the pad. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. -- At Launch Pad 17-B at Cape Canaveral Air Force Station, an unusual view of the Delta II rocket with the THEMIS spacecraft atop gives the solid rocket boosters a "larger than life" appearance as the mobile service tower moves away. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket with the THEMIS spacecraft atop sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station after the mobile service tower moves away from the pad. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- At Launch Pad 17-B at Cape Canaveral Air Force Station, the mobile service tower surrounds the Delta II rocket with the THEMIS spacecraft atop. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket with the THEMIS spacecraft atop sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station after the mobile service tower moves away from the pad. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- In this close-up aerial view, the Delta II rocket with the THEMIS spacecraft atop sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. -- At Launch Pad 17-B at Cape Canaveral Air Force Station, the mobile service tower moves away from the Delta II rocket with the THEMIS spacecraft atop. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- In this close-up aerial view, the Delta II rocket with the THEMIS spacecraft atop sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station as the mobile service tower begins to move away. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. -- In this aerial view, the Delta II rocket with the THEMIS spacecraft sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station, as the mobile service tower moves away from the pad. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m. Photo credit: NASA/George Shelton

A radiosonde, an instrument that transmits measurements on atmospheric pressure, humidity, temperature and winds, is prepared for use on a weather balloon at the Cape Canaveral Air Force Station weather station. The data it returns will be used to determine if conditions are acceptable for the launch of NASA's THEMIS mission. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is planned from Pad 17-B in a window that extends from 6:01 to 6:19 p.m. EST.

A worker releases a weather balloon at the Cape Canaveral Air Force Station weather station. The balloon is equipped with a radiosonde, an instrument that transmits measurements on atmospheric pressure, humidity, temperature and winds as it ascends. The data will be used to determine if conditions are acceptable for the launch of NASA's THEMIS mission. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is planned from Pad 17-B in a window that extends from 6:01 to 6:19 p.m. EST.

A worker releases a weather balloon at the Cape Canaveral Air Force Station weather station. The balloon is equipped with a radiosonde, an instrument that transmits measurements on atmospheric pressure, humidity, temperature and winds as it ascends. The data will be used to determine if conditions are acceptable for the launch of NASA's THEMIS mission. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is planned from Pad 17-B in a window that extends from 6:01 to 6:19 p.m. EST.

A weather balloon takes flight from the Cape Canaveral Air Force Station weather station. The balloon is equipped with a radiosonde, an instrument that transmits measurements on atmospheric pressure, humidity, temperature and winds as it ascends. The data will be used to determine if conditions are acceptable for the launch of NASA's THEMIS mission. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is planned from Pad 17-B in a window that extends from 6:01 to 6:19 p.m. EST.

A weather balloon is prepared for release at the Cape Canaveral Air Force Station weather station. The balloon is equipped with a radiosonde, an instrument that transmits measurements on atmospheric pressure, humidity, temperature and winds as it ascends. The data will be used to determine if conditions are acceptable for the launch of NASA's THEMIS mission. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is planned from Pad 17-B in a window that extends from 6:01 to 6:19 p.m. EST.

KENNEDY SPACE CENTER, FLA. -- With all lower panels of the transportation canister in place around the THEMIS spacecraft and upper stage booster, workers at left prepare to move the overhead crane above them to the cylindrical upper canister and place it over THEMIS. When THEMIS is completely enclosed, it will be transported to Launch Complex 17-B for mating with its launch vehicle. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Pad 17-B at Cape Canaveral Air Force Station aboard a Boeing Delta II rocket managed by the United Launch Alliance. Photo credit: NASA/Troy Cryder

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the THEMIS spacecraft is lifted up alongside the mobile service tower. Once inside, THEMIS will be encapsulated and mated with the third stage of the Delta II rocket. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- In the upper level of the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, workers wait for the THEMIS spacecraft (background) to be lifted and moved inside. THEMIS will then be encapsulated and mated with the third stage of the Delta II rocket. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- In the upper level of the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, workers help maneuver the THEMIS spacecraft inside. THEMIS will then be encapsulated and mated with the third stage of the Delta II rocket. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the THEMIS spacecraft is lifted up alongside the mobile service tower. Once inside, THEMIS will be encapsulated and mated with the third stage of the Delta II rocket. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

At Astrotech Space Operations, workers look over the integrated THEMIS spacecraft before spin-balance testing. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

At Astrotech Space Operations, the media are dressed in clean room, or bunny, suits to photograph the integrated THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

At Astrotech Space Operations, the integrated THEMIS spacecraft is ready for spin-balance testing. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

At Astrotech Space Operations, workers prepare the integrated THEMIS spacecraft for spin-balance testing. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

At Astrotech Space Operations, the integrated THEMIS spacecraft is on ready for spin-balance testing. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

At Astrotech Space Operations, the media are dressed in clean room, or bunny, suits to photograph the integrated THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

At Astrotech Space Operations, the integrated THEMIS spacecraft is spinning on the spin table, part of spin-balance testing. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

In the Hazardous Processing Facility at Astrotech Space Operations, a worker checks data on the integrated THEMIS spacecraft sitting on the spin table. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

KENNEDY SPACE CENTER, FLA. -- In the high bay at Astrotech Space Operations, workers prepare to join the upper cylindrical canister to the lower panels already in place around the THEMIS spacecraft and upper stage booster. When completely enclosed, THEMIS will be transported to Launch Complex 17-B for mating with its launch vehicle. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Pad 17-B at Cape Canaveral Air Force Station aboard a Boeing Delta II rocket managed by the United Launch Alliance. Photo credit: NASA/Troy Cryder

KENNEDY SPACE CENTER, FLA. -- In the high bay at Astrotech Space Operations, workers guide the suspended upper canister toward the THEMIS spacecraft and upper stage booster at right. When the upper and lower canisters are joined, the THEMIS will be completely enclosed and will be transported to Launch Complex 17-B for mating with its launch vehicle. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Pad 17-B at Cape Canaveral Air Force Station aboard a Boeing Delta II rocket managed by the United Launch Alliance. Photo credit: NASA/Troy Cryder

KENNEDY SPACE CENTER, FLA. -- In the high bay at Astrotech Space Operations, workers secure the upper cylindrical canister to the lower panels already in place around the THEMIS spacecraft and upper stage booster. When completely enclosed, THEMIS will be transported to Launch Complex 17-B for mating with its launch vehicle. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Pad 17-B at Cape Canaveral Air Force Station aboard a Boeing Delta II rocket managed by the United Launch Alliance. Photo credit: NASA/Troy Cryder

KENNEDY SPACE CENTER, FLA. -- In the high bay at Astrotech Space Operations, the upper cylindrical canister is lowered toward the THEMIS spacecraft and upper stage booster below. When the upper and lower canisters are joined, the THEMIS will be completely enclosed and will be transported to Launch Complex 17-B for mating with its launch vehicle. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Pad 17-B at Cape Canaveral Air Force Station aboard a Boeing Delta II rocket managed by the United Launch Alliance. Photo credit: NASA/Troy Cryder

KENNEDY SPACE CENTER, FLA. -- In the high bay at Astrotech Space Operations, workers guide the upper canister toward the THEMIS spacecraft and upper stage booster below. The upper canister will be joined to the lower panels already in place. Then, THEMIS will be transported to Launch Complex 17-B for mating with its launch vehicle. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Pad 17-B at Cape Canaveral Air Force Station aboard a Boeing Delta II rocket managed by the United Launch Alliance. Photo credit: NASA/Troy Cryder

KENNEDY SPACE CENTER, FLA. -- A worker in the high bay at Astrotech Space Operations places a lower panel of the transportation canister around the THEMIS spacecraft and upper stage booster. When THEMIS is completely enclosed, it will be transported to Launch Complex 17-B for mating with its launch vehicle. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Pad 17-B at Cape Canaveral Air Force Station aboard a Boeing Delta II rocket managed by the United Launch Alliance. Photo credit: NASA/Troy Cryder

KENNEDY SPACE CENTER, FLA. -- Solid rocket boosters are clustered around the base of the United Launch Alliance Delta II rocket in the mobile service tower. A total of nine will assist in the launch of the THEMIS integrated spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. -- Solid rocket boosters left and right are being added to those already clustered around the base of the United Launch Alliance Delta II rocket. A total of nine will assist in the launch of the THEMIS integrated spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. -- Solid rocket boosters are clustered around the base of the United Launch Alliance Delta II rocket. A total of nine will assist in the launch of the THEMIS integrated spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. -- Solid rocket boosters are clustered around the base of the United Launch Alliance Delta II rocket. A total of nine will assist in the launch of the THEMIS integrated spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. -- The covered THEMIS spacecraft is transported to Launch Complex 17 on Cape Canaveral Air Force Station. On Launch Pad 17-B, the spacecraft will be mated with the third stage of the Delta II rocket. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- A transport vehicle moves the covered THEMIS spacecraft away from Astrotech Space Operations in Titusville, Fla., on the start of its journey to Launch Complex 17 on Cape Canaveral Air Force Station. On Launch Pad 17-B, the spacecraft will be mated with the third stage of the Delta II rocket. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., the THEMIS spacecraft is secure inside a protective cover for its transfer to Launch Complex 17 on Cape Canaveral Air Force Station. On Launch Pad 17-B, the spacecraft will be mated with the third stage of the Delta II rocket. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., an overhead crane is in position to lift the crate from one of the components of the recently arrived THEMIS spacecraft. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. -- Workers at Astrotech Space Operations in Titusville, Fla., wipe down the crates containing the probes of the THEMIS spacecraft. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. -- The truck carrying the THEMIS spacecraft arrives at Astrotech Space Operations in Titusville, Fla. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

VANDENBERG AIR FORCE BASE, CALIF. -- The probe carrier assembly on the THEMIS spacecraft undergoes a vibration test (Z-axis). THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Oct. 19 from Cape Canaveral Air Force Station in Florida.

KENNEDY SPACE CENTER, FLA. -- One of several crates containing the components of the THEMIS spacecraft is moved into Astrotech Space Operations in Titusville, Fla. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. -- Workers at Astrotech Space Operations in Titusville, Fla., wipe down the crates containing the probes of the THEMIS spacecraft. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., one of the probes of the THEMIS spacecraft is revealed after the crate and cover were removed. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

VANDENBERG AIR FORCE BASE, CALIF. -- The probe carrier assembly on the THEMIS spacecraft undergoes a vibration test (Z-axis). THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Oct. 19 from Cape Canaveral Air Force Station in Florida.

KENNEDY SPACE CENTER, FLA. -- With workers standing by at Astrotech Space Operations in Titusville, Fla., an overhead crane lifts the crate from one of the components of the recently arrived THEMIS spacecraft. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

VANDENBERG AIR FORCE BASE, CALIF. -- The probe carrier assembly on the THEMIS spacecraft undergoes a vibration test. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Oct. 19 from Cape Canaveral Air Force Station in Florida.

VANDENBERG AIR FORCE BASE, CALIF. -- An overhead crane hoists the probe carrier assembly on the THEMIS spacecraft to the vibration table (Z-axis). THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Oct. 19 from Cape Canaveral Air Force Station in Florida.

VANDENBERG AIR FORCE BASE, CALIF. -- An overhead crane lifts the probe carrier assembly on the THEMIS spacecraft to a dolly. Visible are some of the solar array covers. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Oct. 19 from Cape Canaveral Air Force Station in Florida.

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., a worker removes the protective cover from one of the components of the recently arrived THEMIS spacecraft. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., one of the probes of the THEMIS spacecraft is revealed after the crate and cover were removed. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

VANDENBERG AIR FORCE BASE, CALIF. -- The probe carrier assembly on the THEMIS spacecraft is prepared for a vibration test. The assembly has solar array covers attached. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Oct. 19 from Cape Canaveral Air Force Station in Florida.

KENNEDY SPACE CENTER, FLA. -- One of several crates containing the components of the THEMIS spacecraft is offloaded from a truck at Astrotech Space Operations in Titusville, Fla. THEMIS, which stands for Time History of Events and Macroscale Interactions during Substorms, comprises five identical probes that will study the dynamic and colorful eruptions of auroras. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

Inside the mobile service tower on Pad 17-B at Cape Canaveral Air Force Station, the Delta II second stage is mated with the first stage. The Delta II is the launch vehicle for the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

On Pad 17-B at Cape Canaveral Air Force Station, the Delta II second stage is being lifted alongside the mobile service tower. Once inside, it will be mated with the first stage already in place. The Delta II is the launch vehicle for the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

KENNEDY SPACE CENTER, FLA. -- Inside the mobile service tower on Pad 17-B at Cape Canaveral Air Force Station, the Delta II second stage is mated with the first stage. The Delta II is the launch vehicle for the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

On Pad 17-B at Cape Canaveral Air Force Station, workers attach an overhead crane to the Delta II second stage in order to raise it to vertical. It will be lifted into the mobile service tower and mated with the first stage already in place. The Delta II is the launch vehicle for the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

On Pad 17-B at Cape Canaveral Air Force Station, the Delta II second stage is moved inside level 9 of the tower. It will be mated with the first stage already in place. The Delta II is the launch vehicle for the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

On Pad 17-B at Cape Canaveral Air Force Station, the Delta II second stage is being lowered toward the Delta II first stage, already in place inside the mobile service tower. The Delta II is the launch vehicle for the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

On Pad 17-B at Cape Canaveral Air Force Station, the Delta II second stage is being lowered toward the Delta II first stage, already in place inside the mobile service tower. The Delta II is the launch vehicle for the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

On Pad 17-B at Cape Canaveral Air Force Station, the Delta II second stage is being lifted alongside the mobile service tower. Once inside, it will be mated with the first stage already in place. The Delta II is the launch vehicle for the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

On Pad 17-B at Cape Canaveral Air Force Station, the Delta II second stage is lifted toward the mobile service tower. Once inside, it will be mated with the first stage already in place. The Delta II is the launch vehicle for the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

On Pad 17-B at Cape Canaveral Air Force Station, the Delta II second stage arrives at level 9 of the tower. The second stage will be moved inside and mated with the first stage already in place. The Delta II is the launch vehicle for the THEMIS spacecraft THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.

KENNEDY SPACE CENTER, FLA. -- Workers inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station help maneuver the upper canister away from the opening. The canister was removed from around the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- Workers inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station watch as the upper canister is lifted away from the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, workers remove the protective cover surrounding the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- Workers inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station maneuver the upper canister away from the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, workers remove the protective cover surrounding the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- In the upper level of the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, workers help maneuver the THEMIS spacecraft into place. They will next remove the protective cover before encapsulating and mating the spacecraft with the third stage of the Delta II rocket. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- In the upper level of the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, workers help maneuver the THEMIS spacecraft into place. They will next remove the protective cover before encapsulating and mating the spacecraft with the third stage of the Delta II rocket. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, workers erect a protective screen above the THEMIS spacecraft to preserve a clean-room environment. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, workers remove the protective cover surrounding the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- Workers inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station prepare to remove the canister surrounding the THEMIS spacecraft. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- A worker inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station examines the Delta II upper stage booster mated to the THEMIS spacecraft above. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- The THEMIS spacecraft arrives on Launch Pad 17-B at Cape Canaveral Air Force Station. The spacecraft will be lifted into the mobile service tower and, after encapsulation, mated with the third stage of the Delta II rocket. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, technicians stand by as the THEMIS spacecraft is lifted off its transporter. The spacecraft will be lifted into the mobile service tower and, after encapsulation, mated with the third stage of the Delta II rocket. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. The THEMIS mission is to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection. THEMIS is scheduled to launch aboard a Delta II rocket on Feb. 15 during a window extending from 6:08 to 6:27 p.m. Photo credit: NASA/Amanda Diller

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Pad 17-B at Cape Canaveral Air Force Station, workers prepare to install the fairing, seen in the background, around the THEMIS spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. THEMIS is an acronym for Time History of Events and Macroscale Interactions during Substorms. THEMIS consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the tantalizing mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch of THEMIS is scheduled for Feb. 15 aboard a Delta II rocket, with the launch service being conducted by the United Launch Alliance. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Pad 17-B at Cape Canaveral Air Force Station, workers prepare to join the two fairing segments around the THEMIS spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. THEMIS is an acronym for Time History of Events and Macroscale Interactions during Substorms. THEMIS consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the tantalizing mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch of THEMIS is scheduled for Feb. 15 aboard a Delta II rocket, with the launch service being conducted by the United Launch Alliance. Photo credit: NASA/George Shelton

In the mobile service tower on Pad 17-B at Cape Canaveral Air Force Station, the two fairing segments come together around the THEMIS spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. THEMIS is an acronym for Time History of Events and Macroscale Interactions during Substorms. THEMIS consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the tantalizing mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch of THEMIS is scheduled for Feb. 15 aboard a Delta II rocket, with the launch service being conducted by the United Launch Alliance.

In the mobile service tower on Pad 17-B at Cape Canaveral Air Force Station, the first half of the fairing is moved into place around the THEMIS spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. THEMIS is an acronym for Time History of Events and Macroscale Interactions during Substorms. THEMIS consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the tantalizing mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch of THEMIS is scheduled for Feb. 15 aboard a Delta II rocket, with the launch service being conducted by the United Launch Alliance.

In the mobile service tower on Pad 17-B at Cape Canaveral Air Force Station, the second half of the fairing, at right, moves toward the waiting THEMIS spacecraft. The first half has already been put in place. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. THEMIS is an acronym for Time History of Events and Macroscale Interactions during Substorms. THEMIS consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the tantalizing mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch of THEMIS is scheduled for Feb. 15 aboard a Delta II rocket, with the launch service being conducted by the United Launch Alliance.

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Pad 17-B at Cape Canaveral Air Force Station, the first half of the fairing is in place around the THEMIS spacecraft and workers turn to wait for the second half. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. THEMIS is an acronym for Time History of Events and Macroscale Interactions during Substorms. THEMIS consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the tantalizing mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch of THEMIS is scheduled for Feb. 15 aboard a Delta II rocket, with the launch service being conducted by the United Launch Alliance. Photo credit: NASA/George Shelton

In the mobile service tower on Pad 17-B at Cape Canaveral Air Force Station, workers prepare to join the two fairing segments around the THEMIS spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. THEMIS is an acronym for Time History of Events and Macroscale Interactions during Substorms. THEMIS consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the tantalizing mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch of THEMIS is scheduled for Feb. 15 aboard a Delta II rocket, with the launch service being conducted by the United Launch Alliance.

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Pad 17-B at Cape Canaveral Air Force Station, the second half of the fairing, at right, moves toward the waiting THEMIS spacecraft. The first half has already been put in place. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. THEMIS is an acronym for Time History of Events and Macroscale Interactions during Substorms. THEMIS consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the tantalizing mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch of THEMIS is scheduled for Feb. 15 aboard a Delta II rocket, with the launch service being conducted by the United Launch Alliance. Photo credit: NASA/George Shelton