Launch Day: Countdown Coverage for NASA's New Horizons Mission
NASA's New Horizons spacecraft launches into space on a mission to the planet Pluto and beyond on Jan. 19, 2006.
Credit: NASA.

It took three attempts is as many days, but NASA's New Horizons spacecraft has successfully launched on its nine-year mission to the planet Pluto.

At 2:00 p.m. EST (1900 GMT) on Jan. 19, 2006, the New Horizons probe launched into space atop a Lockheed Martin-built Atlas 5 rocket, which flung the spacecraft 36,350 miles per hour (58,338 kilometers per hour) on a mission to the outer edges of our solar system.

Poor weather, including winds and severe storms, prevented two earlier launch attempts earlier this week, but the third time proved to be a charm for New Horizons.

Below is a blow-by-blow account of how the day's launch unfolded beginning with the most recent update:


UPDATE: 4:25 p.m. EST

New Horizons principal investigator Alan Stern said that the ashes of the U.S. astronomer who discovered Pluto are accompanying NASA's mission to the distant planet.

"I want to point out what a great honor it is to have Clyde's window [and family] here with us," Stern said of Patsy Tombaugh, whose husband Clyde Tombaugh discovered Pluto in 1930 using the Lowell Observatory in Flagstaff Arizona. "Some of Clyde's ashes are on the way to Pluto today."

Tombaugh died on Jan. 17, 1997, Stern has said.

Glen Fountain, New Horizons project manager at Johns Hopkins University's Applied Physics Laboratory (APL), said plans are in place for two maneuvers - one 10 days after launch and the second 20 days after liftoff - to refine New Horizons' trajectory.

Mission managers will begin planning for the Jupiter encounter in the fall, Fountain said.

This concludes SPACE.com's live coverage of NASA's New Horizons launch. A wrap up story of today's space shot is available here.

UPDATE: 4:10 p.m. EST

NASA's post-launch press conference for its New Horizons mission to Pluto is underway.

"The United States has a spacecraft on its way to Pluto, the Kuiper Belt and on to the stars," said New Horizons principal investigator Alan Stern during the conference. "I have July 14, 2015 emblazoned on my calendar."

New Horizons will spend more than nine years flying toward Pluto and is expected to fly past Jupiter early next year.

Ground stations received the first signals from the spacecraft at about 2:50 p.m. EST (1950 GMT), with all telemetry indicating good health, mission managers said. The probe's radioisotope thermoelectric generator (RTG), which converts heat from decaying plutonium dioxide into power, is generating about 180 watts and will build up to 240 watts soon, they added.

UPDATE: 2:57 p.m. EST

NASA will hold a press conference in about one hour to discuss the successful launch of its New Horizons probe bound for the planet Pluto and beyond.

"The vehicle looks to be right where it needs to be," NASA launch manager Omar Baez, said after the launch. "It was Mother Nature that was holding us back earlier, but we got through it."

Today's launch marked the third attempt by NASA to loft New Horizons toward Pluto.

High wind speeds at the probe's launch pad at Complex 41 of the Cape Canaveral Air Force Station in Florida forced launch officials to call off a space shot just minutes before liftoff on Tuesday. Nature revealed its ugly side again on Wednesday, when severe storms in Maryland prevented a Florida launch when they knocked out power at New Horizons' mission control center at Johns Hopkins University's Applied Physics Laboratory. The laboratory is managing the mission for NASA.

About the size of a grand piano, New Horizons is the first spacecraft ever destined to visit the planet Pluto. The probe should fly past the Moon at about 11:00 p.m. EST (0800 Jan. 20 GMT) before heading toward a Jupiter flyby in early 2007.

Check back here for live coverage of NASA's post-launch press conference. A wrap up story of today's launch is available here.

UPDATE: 2:45 p.m. EST

NASA's New Horizons spacecraft has successfully separated from its third stage booster and begun the nine-year trek to the planet Pluto.

Flying at a speed of about 36,000 miles per hour, New Horizons is NASA's fastest mission launched to date. The probe should pass the Moon's orbit in about nine hours and is destined to reach Jupiter early next year.

If all goes well, New Horizons should turn its seven instruments toward Pluto in July 2015.

UPDATE: 2:42 p.m. EST

After two successful burns, the Centaur upper stage for NASA's New Horizons spacecraft has shut down.

The stage successfully separated from New Horizons' Star 48B third stage, which then fired its own engine to propel the spacecraft toward Pluto.

New Horizons is slated to separate from the Star 48B stage at about 2:47 p.m. EST (1947 GMT), according to its flight plan.

UPDATE: 2:32 p.m. EST

The Centaur upper stage attached to NASA's New Horizons spacecraft has successfully restarted its engine for the second of two planned burns.

UPDATE: 2:15 p.m. EST

NASA's New Horizons spacecraft has completed the first of two planned burns with its Centaur upper stage and is in a coast phase for the next 16 minutes.

Currently in a parking orbit, New Horizons will fire its Centaur stage engine once more at about 2:32 p.m. EST (1932 GMT).

UPDATE: 2:06 p.m. EST

NASA's New Horizons spacecraft has reached space and begun the first of two planned burns with its Centaur upper stage. This burn will last just over five minutes.

UPDATE: 2:00 p.m. EST

Launch! NASA's New Horizons spacecraft and its Atlas 5 rocket have launched from Cape Canaveral Air Force Station on the first mission to Pluto.

Liftoff took place at 2:00 p.m. EST (1900 GMT).

About one minute and 33 seconds after liftoff, the booster's five strap-on rockets are expected to separate, followed by jettison of the protective fairing shrouding New Horizons about three minutes and 23 seconds into the flight. It should take the Atlas 5-New Horizons combo about four minutes to reach space and separate from its first stage.

The first of two planned burns of the Centaur upper stage is planned for four minutes and 43 seconds after launch.

UPDATE: 1:56 p.m. EST

The countdown is ticking away once more at T-4 minutes and counting for a 2:00 p.m. EST (1900 GMT) launch of NASA's New Horizons probe bound for the planet Pluto.

UPDATE: 1:47 p.m. EST

The launch of NASA's New Horizons spacecraft is now set for 2:00 p.m. EST (1900 GMT), delayed almost one hour from the opening of its flight window earlier today.

Thick cloud cover over the probe's Cape Canaveral Air Force Station launch site has continuously thwarted the launch of New Horizons and its Atlas 5 booster.

UPDATE: 1:45 p.m. EST

Flight controllers have added an extra five minutes to the current countdown hold as low cloud cover continues to delay the planned launch of NASA's Pluto-bound New Horizons spacecraft.

The earliest the probe can launch atop its Atlas 5 booster is 1:55 p.m. EST (1855) GMT, though the target is not set in stone, NASA officials said.

Today's launch window for New Horizons runs just about two hours, closing at 3:07 p.m. EST (2007 GMT).

UPDATE: 1:32 p.m. EST

Cloud cover over the launch site for NASA's New Horizons Pluto probe appears to again be a problem for today's planned space shot.

An Atlas 5 rocket was set to launch New Horizons spaceward at 1:40 p.m. EST (1840 GMT) in a space shot to be staged from Complex 41 at Cape Canaveral Air Force Station in Cape Canaveral, Florida. A new launch time is expected shortly.

"Just when we thought the weather had cleared we are now in the a 'No-Go status," NASA spokesperson Bruce Buckingham said.

Today's launch window for New Horizons runs through 3:07 p.m. EST (2007 GMT).

UPDATE: 1:25 p.m. EST

Low clouds continue to dog flight controllers for today's New Horizons launch. The clouds could obscure launch camera views of the planned liftoff, NASA officials said.

A new launch time has been set for 1:40 p.m. EST (1840 GMT). Today's launch window stretches through 3:07 p.m. EST (2007 GMT).

UPDATE: 1:13 p.m. EST

Flight controllers have set a new launch target of 1:30 p.m. EST (1830 GMT).

UPDATE: 1:05 p.m. EST

Launch range officials reported that they were 'No-Go' for today's on-time launch due to the cloud ceiling above the New Horizons launch site.

The launch is now set for 1:25 p.m. EST (1825 GMT), about 17 minutes later than initially planned. Today's launch window runs until 3:07 p.m. EST (2007 GMT).

"We have a cloud ceiling that is borderline," NASA spokesperson Bruce Buckingham said. "The broken cloud deck is in violation [of launch rules]."

UPDATE: 12:53 p.m. EST

Broken cloud cover over the launch pad for NASA's New Horizons spacecraft is the only issue facing flight controllers for today's planned space shot, weather officials said.

New Horizons can launch in scattered clouds, though not heavier broken clouds, NASA spokesperson Bruce Buckingham said.

Current projections call for broken clouds over Launch Complex 41, where New Horizons and its Atlas 5 booster stand poised for launch, at the opening of today's launch window at 1:08 p.m. EST (1808 GMT). Conditions should ease to scattered clouds during the one-hour and 59-minute launch window, with only a 20 percent chance of violating launch rules, weather officials said.

"There is a definite trend for the better, which could let us launch on-time at the opening of the window," Buckingham said.

Today's launch window closes at 3:07 p.m. EST (2007 GMT).

The countdown is paused at T-4 minutes for a planned 10-minute hold.

UPDATE: 12:45 p.m. EST

Launch preparations are on schedule for NASA's Pluto-bound New Horizons probe.

With less than 15 minutes remaining in the countdown, all systems appear go for today's launch at 1:08 p.m. EST (1808 GMT). A final weather briefing is expected at about 12:50 p.m. EST (1750 GMT), as well as a planned 10-minute hold in the countdown at T-minus 4 minutes, NASA officials said.

Unlike Tuesday's launch attempt, high wind speeds have not been a problem so far in today's lauch attempt.

UPDATE: 12:30 p.m. EST

Fueling operations for NASA's New Horizons mission to Pluto are now complete with less than 30 minutes remaining in the countdown for launch.

Weather conditions continue to be optimal for today's planned 1:08 p.m. EST (1808 GMT) launch.

"It looks like we will have an on-time launch," NASA spokesperson Bruce Buckingham said.

An Atlas 5 rocket is set to launch New Horizons, a seven-instrument probe about the size of a grand piano, spaceward at about 36,000 miles per hour, fast enough to pass the Moon's orbit in nine hours, NASA officials said, adding that the flight is the fastest ever to fly for the space agency.

Today's countdown is the third launch attempt in as many days for New Horizons. High winds and a power outage at the mission's Maryland-based control center prevented earlier attempts.

UPDATE: 12:15 p.m. EST

Less than one hour remains in the countdown for NASA's New Horizons spacecraft, which sits poised atop a Lockheed Martin-built Atlas 5 booster at Launch Complex 41 of Cape Canaveral Air Force Station in Florida.

Weather conditions continue to look good for today's planned space shot, which is slated for 1:08 p.m. EST (1808 GMT). Fueling of the Atlas 5 rocket nears completion as flight officials prepare for the spaceflight.

New Horizons is NASA's first spacecraft bound to explore the planet Pluto, its moons and the distant Kuiper Belt objects beyond. The spacecraft's lauch window extends through 3:07 p.m. EST (2007 GMT) today.

UPDATE: 12:00 p.m. EST

Fueling is underway of the Atlas 5 rocket set to launch NASA's New Horizons Pluto probe from Cape Canaveral Air Force Station later today.

The Centaur upper stage of New Horizon's 200-foot tall rocket has been filled with liquid oxygen needed for launch and its first stage booster is currently being fueled with the supercold materal, NASA officials said. Liquid hydrogen is also being pumped into the Centaur stage, they added.

The rocket is on track for today's planned launch at 1:08 p.m. EST (1808 GMT).

UPDATE: 10:45 a.m. EST

All systems appear go for today's launch of NASA's New Horizons spacecraft from Cape Canaveral Air Force Station in Cape Canaveral, Florida.

The countdown clock is at T-2 hours and holding as flight controllers and engineers prepare the Pluto-bound spacecraft for launch. Liftoff of the probe and its Lockheed Martin-built Atlas 5 rocket is currently scheduled for 1:08 p.m. EST (1808 GMT), though the space shot has a launch window that extends until 3:06 p.m. EST (2006).

Today is the third consecutive launch attempt for NASA's New Horizons spacecraft. High winds at the probe's Complex 41 launch site prevented a Tuesday launch attempt. A Wednesday launch attempt was foiled by a power outage in Maryland, where sever stormed knocked out electricity at the New Horizons mission control center at Johns Hopkins University's Applied Physics Laboratory.

Weather officials predict and 80 percent chance of favorable launch conditions today, NASA officials said. The potential for low-lying clouds are the only weather concern, they added.

Currently, all systems and conditions are green for launch, with no technical issues under study, NASA spokesperson Bruce Buckingham said.

Launch officials expected to begin fueling New Horizons' at about 11:00 a.m. EST (1600 GMT).

NASA's New Horizons spacecraft is about the size of a grand piano and carries seven primary instruments to study Pluto, its moon system and Kuiper Belt object. It is expected to arrive at Pluto in 2015, marking the first probe to the distant planet.

UPDATE: 8:23 a.m. EST

NASA officials are hoping that the third time is a charm as they prepare to launch the Pluto-bound New Horizons probe from Cape Canaveral, Florida.

The spacecraft's launch has been delayed twice in two consecutive days this week, once due to high winds and again due to a power outage at the probe's mission operations center.

New Horizons is now set to launch on Jan. 19 at 1:08 p.m. EST (1808 GMT), though it has a launch window that extends for one-hour and 59 minutes.