Space probe transmits stunning new views of Pluto
Fists hit the air. Tiny American flags fluttered overhead. This was July 14. In a Laurel, Md., conference room, a large crowd cheered. It was all for the New Horizons spacecraft's closest approach to Pluto. At 7:50 a.m. ET, the spacecraft swept past Pluto's surface. It flew past at a distance of about 7,706 miles. That was closer to the tiny world than most GPS satellites get to Earth.
After an afternoon of nervous anticipation, the jubilation hit a high at 8:52 p.m. ET. Then Alice Bowman made an announcement. The spacecraft had made its long-awaited "phone home" signal.
The signal was confirmation that the flyby was successful. And that the spacecraft was healthy and ready to transmit some of its first data from the encounter.
Bowman is the mission operations manager. She works at the Johns Hopkins University Applied Physics Laboratory.
"There's a little bit of drama, because this is true exploration. New Horizons is flying into the unknown," mission manager Alan Stern of the Southwest Research Institute said. He spoke during a briefing just after the flyby.
"This is just the beginning," John Grunsfeld, told the crowd. He is NASA's associate administrator for science missions. "As a team, we all have made history. This can never be repeated. This is in the history books."
As part of its last safety check before the flyby, New Horizons beamed back one high-resolution color picture of Pluto. It showed the varied terrain on this alien world. With a resolution of about 2.5 miles per pixel, the image was stunning. It hinted at a dynamic planet. Pluto has possible tectonic activity and strong atmospheric cycles, Stern said. Tectonic activity is about movement of Pluto's crust, perhaps similar to earthquakes.
"This image is oriented with north at the top. The dark regions are near Pluto's equator," he says. "We can see a history of impacts, a history of surface activity. Pluto has a lot more to teach us with the data coming down."
There was a reason for the long delay between the flyby and the signal home. It was because of the journey New Horizons was designed to endure, Bowman said.
To ensure its health during the voyage, the team wanted the spacecraft to have as few moving parts as possible. So the antenna that transmitted data was a fixed instrument. The spacecraft must take aim to Earth whenever it wants to communicate. Its not always the best position for collected data.
"This is the closest approach. And this is when it gets the best science," Bowman told reporters. "We don't want it to turn to Earth and talk to us. We want it to do science."
Even though the spacecraft was out of touch during this scientifically important time, the mission team remained confident. Everything appeared to be happening as planned.
"We always talk about the spacecraft being like a child, like a teenager," Bowman said at the time. "Right now there's nothing the operations team can do. We just have to trust that we have prepared it well and send it off on its journey."
Stern was confident. He noted that the team had done hours of modeling. Much data had been collected on any safety hazards. Those included debris around Pluto. It could have damaged the fast-moving spacecraft. The odds of something going wrong, he said, were extremely low.
"The probability of loss has an upper limit at around 2 parts in 10,000. You could fly hundreds of New Horizons through the Pluto system and expect them to survive," he said.
On the chance that something did break, New Horizons had been taking fail-safe data. It collected and transmitted key snippets for the main mission objectives each time it sent back a health status report. That included the newly arrived image. And shots of the large moon Charon. The data included mapping, spectroscopy, thermal data and information about the dust and plasma environments around Pluto and its moons. The July 14 signal, while a sign of success, did not include any additional teasers.
"The signal we got tonight was entirely engineering data no science data came home tonight," Stern said during the evening briefing. "We wanted that report to be as brief as possible because as soon as it was over, New Horizons went back to work to collect that data."
Once mission managers knew the craft was safe and loaded with data, the team eagerly awaited a fresh round of scientific wonders.
"It is truly amazing. The recovery was flawless. We were up to the challenge. We met it," Bowman added. "And on a personal note, I can't express how I'm feeling to have achieved a childhood dream of space exploration. I'm pretty overwhelmed at this moment.
"Please tell your children and anybody out there: Do what you're passionate about. Give yourself that challenge and you will not be sorry for it."