NASA - National Aeronautics and Space Administration

The Launch Blog was activated on Feb. 16, 2007 at 3:45 p.m. The Launch Blog was deactivated at 6:01 p.m. + View Launch Videos All times are Eastern Standard Time (EST) unless otherwise stated.

6:01 p.m. - Scrub. The final weather balloon came back "red" for upper-level winds. The team is preparing for a 24-hour turnaround. Please check the THEMIS Web site for the very latest.
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5:54 p.m. - NASA Launch Manager Chuck Dovale has polled the launch team, and all team members have given the "go" for launch. Upper-level winds are "green" for the moment and are expected to remain that way to allow a liftoff in just a few minutes. All spacecraft are on internal power, and are reported go for launch.

5:51 p.m. - T-4 minutes and holding for 10 minutes. This is the final built-in hold in tonight's countdown. The launch team is continuing to monitor upper-level winds, which are currently showing "green" once again. Otherwise, there are no issues in work and the countdown is progressing very smoothly toward a liftoff at 6:05 p.m.

Did You Know?
A payload fairing is used to surround the spacecraft and protect it from temperature, humidity, contamination and wind as the rocket ascends toward orbit.

5:40 p.m. - T-15 minutes and counting. The countdown clock will pause once more for the last built-in hold at the T-4 minute mark. That hold is planned for 10 minutes.

5:32 p.m. - The team is monitoring the upper-level winds, which are "red" at the moment, meaning they are outside of launch constraints. In the meantime, though, the countdown will proceed as planned.

5:28 p.m. - In about four minutes, we'll hear NASA Launch Manager Chuck Dovale poll the launch team to confirm that everyone is "go" to proceed with the countdown. At 5:40, the clock will resume counting down from the T-15 minute mark.

5:20 p.m. - T-15 minutes and holding. This is a 20-minute built-in hold.

5:15 p.m. - Launch Weather Officer Joel Tumbiolo just provided another weather update, and the good forecast is unchanged. The main concern at this point is upper-level wind shear above 10,000 feet. But the weather remains "green."

"The radar is clean," Tumbiolo reported. "We're still sitting in good shape."

5:09 p.m. - At T-26 minutes and counting, steering checks called "slew checks" are under way. During this eight-minute test, the first- and second-stage engine nozzles are put through a programmed series of movements to verify they'll be able to steer the vehicle properly during the climb to space. The second-stage engine is tested first, followed by the first-stage engine.

5:00 p.m. - T-35 minutes and counting. The countdown is still proceeding very smoothly, with no issues in work. Launch of THEMIS aboard the Delta II rocket remains set for 6:05 p.m., a little over an hour from now.

4:47 p.m. - Loading of super-cold liquid oxygen into the rocket's first stage is complete. During the remainder of the countdown, puffs of oxygen can be seen venting from the first stage as small amounts of the propellant are boiled off and replenished. This is a preventive measure to keep the pressure from building up inside the tank.

Did You Know?
Delta rockets have been built and launched since 1960. Delta's origins go back to the Thor, a single-stage, liquid-fueled rocket, which later evolved into the Delta II.

Interview with Dr. Vassilis Angelopoulos, THEMIS Principal Investigator
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4:35 p.m. - THEMIS stands for Time History of Events and Macroscale Interactions during Substorms. It's a long name, but a fascinating mission: The set of five probes will investigate what causes the auroras in the atmosphere to change from slowly shimmering waves of light to wildly shifting streaks of color. With this information, scientists may better understand why and how certain components of space storms disturb satellites, power grids and communications systems here on Earth.

Interview with Garrett Skrobot, NASA Mission Manager
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4:25 p.m. - As liquid oxygen loading continues, engine heaters help stabilize the vehicle as the super-cold propellant flows into the tank.

4:20 p.m. - At T-75 minutes and counting, liquid oxygen is flowing in the rocket's first stage.

4:15 p.m. - The countdown clock is at T-80 minutes and counting, and the blast danger area has been cleared. Final preparations are under way for liquid oxygen loading. That should begin in just under 5 minutes.

Did You Know?
THEMIS will be launching aboard a Delta II rocket with three stages, nine strap-on boosters and a protective 10-foot fairing.

4:08 p.m. - Loading of liquid oxygen into the Delta II's first stage will begin in just over 10 minutes. NASA Launch Manager Chuck Dovale just conducted his poll, and the team is ready to go ahead with tanking.

4:05 p.m. - The T-95 minute weather briefing brought good news to the launch team. Temperatures are warmer than expected, in the low 50s, and although ground winds remain a concern, they're still expected to stay below the limit.

"We're green on all constraints," Tumbiolo summarized.
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3:55 p.m. - The countdown is proceeding very smoothly this afternoon, and there are no issues with the Delta II launch vehicle or the five THEMIS spacecraft. The launch team is preparing for "cryo tanking," the process of filling the first stage with about 15,000 gallons of cryogenic liquid oxygen chilled to -300 degrees Fahrenheit. NASA Launch Manager Chuck Dovale will poll the launch team shortly to verify that all is ready for tanking.

In just a few minutes, Launch Weather Officer Joel Tumbiolo will provide an update on tonight's forecast.

3:45 p.m. - Good afternoon, and thanks for turning to NASA's Launch Blog. The five THEMIS spacecraft are set to lift off this evening aboard a Delta II rocket from Launch Pad 17-B at Cape Canaveral Air Force Station in Florida. Launch is targeted for the opening of tonight's window, which extends from 6:05 p.m. until 6:23 p.m.

A successful liftoff tonight will be a new record for NASA, with the largest number of scientific satellites the agency has ever launched aboard a single rocket. + View Image

It's been a busy day for the launch team. At about 10:00 this morning, the gantry-like mobile service tower was rolled away from the Delta II. The terminal countdown began at 3:05 p.m., counting down from the T-150 mark. First stage nitrogen and helium chilldown and pressurization were complete at 3:23 p.m., and loading of about 10,000 gallons of RP-1 fuel into the rocket's first stage began about 15 minutes ago.

Weather for this evening is looking great so far. The forecast has been upgraded to a 90-percent chance of favorable conditions for launch.

Launch Blog Team
Live Updates/Layout Anna Heiney (InDyne, Inc.)	Video Uploads/Captions Elaine Marconi (InDyne, Inc.)
Quality Control/Publishing Cheryl L. Mansfield (InDyne, Inc.)	Video Production Aly Lee (InDyne, Inc.)
Video Capture/Editing Chris Chamberland, Gianni Woods and Michael Chambers (InDyne, Inc.)