LAUREL, Md. — Signals from a spacecraft 3 billion miles away swept over Earth on Tuesday, confirming that NASA's New Horizons probe survived its history-making Pluto flyby.
The radio signals were received by a Deep Space Network antenna in Spain four and a half hours after they were sent out from the spacecraft at the speed of light, and a full 13 hours after the probe made its close pass. But they electrified hundreds of VIPs, journalists and Pluto fans here at Johns Hopkins University Applied Physics Laboratory as if the main event had just happened.
The audience stood up, applauded and waved American flags as, one by one, mission controllers reported "nominal" status for the hardware that was their responsibility.
"We have a healthy spacecraft, we've recorded data of the Pluto system, and we're outbound from Pluto," mission operations manager Alice Bowman declared just before 9 p.m. ET, setting off the last and biggest round of applause. She said the procedure went "just like we planned it, just like we practiced."
The transmission not only assured the team that the piano-sized spacecraft was in good health, nine and a half years after its launch, but it also suggested that groundbreaking images and observations of Pluto and its moons would be streaming in from New Horizons for months to come.
The flyby actually took place at 7:49 a.m. ET Tuesday, with New Horizons traveling at more than 30,000 mph (50,000 kilometers per hour) and coming within 7,750 miles (12,500 kilometers) of the dwarf planet's mottled surface. But the spacecraft was so busy making observations that it couldn't turn its antenna back toward Earth to send the all-clear signal until hours later.
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To mark the occasion, NASA released a colorized view of the dwarf planet that was sent back to Earth before New Horizons went out of contact on Monday night. The picture featured the dwarf planet's bright heart-shaped region as well as the head of a dark "whale" feature. It was part of a "fail-safe" series of observations that were made just in case the spacecraft suffered a catastrophic failure during the flyby.
After the image was released, mission scientists went into high gear, pointing to features in the photo such as a bright bull's-eye crater nicknamed the "whale's blowhole," a point that may be a frost-capped peak, linear streaks that may (or may not) hint at tectonic activity — and mounds of icy material on the surface.
The mission's principal investigator, Alan Stern of the Southwest Research Institute, was asked whether it was now fair to say that it snows on Pluto. "It sure looks that way," he replied.
"It's a moment of celebration, because we've just done the 'anchor leg,'" Stern said on NASA TV, using a track-and-field metaphor. "We have completed the initial reconnaissance of the solar system."
No new images were transmitted on Tuesday — just the telemetry reporting the spacecraft's health. The first images and data from the close flyby are due to be received and unveiled on Wednesday, and they'll continue coming down for the next 16 months.
John Grunsfeld, NASA's associate administrator for science, said the heart of New Horizons' appeal is its status as the first mission to the last frontier — that is, the icy worlds that lie beyond the orbit of Neptune, in a region known as the Kuiper Belt. "Pluto is kind of a capstone of our solar system exploration, and also opening up this new realm," he said.
Among those on hand for Tuesday night's "Phone Home" celebration were the children of late astronomer Clyde Tombaugh, who discovered Pluto in 1930; the daughter of the late astronomer Gerard Kuiper, after whom the Kuiper Belt is named; Jim Christy, the discoverer of Charon, Pluto's largest moon; and a group of 9-year-old children who were born on the day of New Horizons' launch.
The next round of images from NASA's New Horizons mission to Pluto and its moons will be unveiled during a news briefing at 3 p.m. ET Wednesday. The briefing will air on NASA TV.
Alan Boyle is the science editor for NBC News Digital. He joined MSNBC.com at its inception in July 1996, and took on the science role in July 1997 with the landing of NASA's Mars Pathfinder probe. Boyle is responsible for coverage of science and space for NBCNews.com.
Boyle joined NBCNews.com from the Seattle Post-Intelligencer, where he was the foreign desk editor from 1987 to 1996. Boyle has won awards for science journalism from numerous organizations, including the National Academies, the American Association for the Advancement of Science and the National Association of Science Writers. Boyle is the author of "The Case for Pluto: How a Little Planet Made a Big Difference." He lives in Bellevue, Wash.