THEMIS Celebrates Five Years of Watching Aurora and Space Weather

People still talk about the launch. It was the first – and so far, only – time NASA has launched five satellites at one time. Carefully balanced inside a Delta II rocket, the five THEMIS (short for Timed History of Events and Macroscale Interactions during Substorms) spacecraft were launched into space from Cape Canaveral at 6:01 p.m. ET on February 17, 2007. The spacecraft were nestled in a ring shape, four around the outside and one on a middle pedestal. A critical sequencing guided how each spacecraft launched into space, first the top one, then the ones on the outside, so the platform would remain balanced and stable.

"The launch of THEMIS was one of the first Explorer missions I oversaw from concept through launch and on-orbit checkout and it still stands out in my mind," says Willis Jenkins, the Program Executive for NASA's Explorers Program, a program that supports less expensive and highly focused missions. "Trying to get five spacecraft together on one rocket was a challenge, but our team came up with unique ways to build and launch them."

Those five satellites working in tandem was crucial for THEMIS' job of tracking energy as it moves through space. Energy and radiation from the sun impacts and changes Earth's magnetic environment, the magnetosphere, and such impacts cause "space weather" that can harm satellites in space. As they orbit around Earth, the THEMIS satellites work together to gather data on how any given space weather event travels through space – something impossible to understand with a single spacecraft, which cannot differentiate between an occurrence that happens throughout space, rather than in a single location. Since 2007, the THEMIS satellites have reinvigorated studies of the magnetosphere, mapping the details of how explosive auroras occur, how the solar wind transfers energy to Earth's space environment, and how chirping waves in space relate to blinking auroras on Earth.

NASA Mars-Bound Rover Begins Research in Space

NASA's car-sized Curiosity rover has begun monitoring space radiation during its 8-month trip from Earth to Mars. The research will aid in planning for future human missions to the Red Planet. Curiosity launched on Nov. 26 from Cape Canaveral, Fla., aboard the Mars Science Laboratory. The rover carries an instrument called the Radiation Assessment Detector (RAD) that monitors high-energy atomic and subatomic particles from the sun, distant supernovas and other sources.

These particles constitute radiation that could be harmful to any microbes or astronauts in space or on Mars. The rover also will monitor radiation on the surface of Mars after its August 2012 landing. "RAD is serving as a proxy for an astronaut inside a spacecraft on the way to Mars," said Don Hassler, RAD's principal investigator from the Southwest Research Institute in Boulder, Colo. "The instrument is deep inside the spacecraft, the way an astronaut would be. Understanding the effects of the spacecraft on the radiation field will be valuable in designing craft for astronauts to travel to Mars."

Previous monitoring of energetic-particle radiation in space has used instruments at or near the surface of various spacecraft. The RAD instrument is on the rover inside the spacecraft and shielded by other components of Mars Science Laboratory, including the aeroshell that will protect the rover during descent through the upper atmosphere of Mars. Spacecraft structures, while providing shielding, also can contribute to secondary particles generated when high-energy particles strike the spacecraft. In some circumstances, secondary particles could be more hazardous than primary ones

Moon Mission Ready to Fly

At the prelaunch news conference Tuesday, the twin moon-bound GRAIL spacecraft and the United Launch Alliance Delta II rocket that will send them on their mission were reported ready to fly, with the late-summer Florida weather presenting the only question for launch day.

Launch Weather Officer Joel Tumbiolo reported that a stationary front that will be parked over the state and plume of tropical moisture will produce anvil clouds and local showers that give the launch team a 40 percent chance of acceptable weather at liftoff time on Thursday. The same conditions will continue on Friday, with an improving weather picture going into the weekend.

Earlier in the day, the final Launch Readiness Review was conducted and the rocket and spacecraft were given a "go" for launch from Cape Canaveral Air Force Station's Space Launch Complex 17B in Florida. There are two instantaneous launch windows at 8:37:06 a.m. and 9:16:12 a.m. EDT.

NASA Moon Mission in Final Preparations for September Launch

NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission to study the moon is in final launch preparations for a scheduled Sept. 8 launch from Cape Canaveral Air Force Station in Florida.

GRAIL's twin spacecraft are tasked for a nine-month mission to explore Earth's nearest neighbor in unprecedented detail. They will determine the structure of the lunar interior from crust to core and advance our understanding of the thermal evolution of the moon.

"Yesterday's final encapsulation of the spacecraft is an important mission milestone," said David Lehman, GRAIL project manager for NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Our two spacecraft are now sitting comfortably inside the payload fairing which will protect them during ascent. Next time the GRAIL twins will see the light of day, they will be about 95 miles up and accelerating."

NASA's GRAIL Moon Twins are Joined to Their Booster

NASA's lunar-bound GRAIL twins were mated to their Delta II launch vehicle at the Cape Canaveral Air Force Station's Launch Complex 17 at 8:45 a.m. EDT (5:45 a.m. PDT) today. The 15-mile (25-kilometer) trip from Astrotech Space Operations in Titusville, Fla., is the last move for GRAIL before it begins its journey to the moon. NASA's dynamic duo will orbit the moon to determine the structure of the lunar interior from crust to core and to advance understanding of the thermal evolution of the moon.

"We are about to finish one chapter in the GRAIL story and open another," said Maria Zuber, GRAIL's principal investigator, based at the Massachusetts Institute of Technology in Cambridge. "Let me assure you this one is a real page-turner. GRAIL will rewrite the book on the formation of the moon and the beginning of us."

Now that the GRAIL spacecraft are atop their rocket, a final flurry of checks and tests can begin to confirm that all is go for launch. The final series of checks begins tomorrow, Aug. 19, with an on-pad functional test. The test is designed to confirm that the spacecraft is healthy after the fueling and transport operations. Next week, among all the upcoming final tests, reviews and closeout operations leading up to liftoff, the GRAIL team will install the launch vehicle fairing around the spacecraft.