NASA is a step closer to its first mission to “touch” the sun as the space agency’s Solar Probe Plus passed a critical development milestone on July 7. The spacecraft is entering the system assembly, integration, test and launch stage of the project, on track towards its scheduled launch in 2018.

The spacecraft, currently being constructed by the Johns Hopkins Applied Physics Laboratory (APL), passed the NASA management review.  It will move on to Phase D, a stage where the Solar Probe Plus will undergo simulated launch and space conditions.

“Reaching this stage means a lot to the team and our stakeholders,” adds Andy Driesman, Solar Probe Plus project manager at the Johns Hopkins Applied Physics Laboratory (APL), which manages the mission for NASA and is building the spacecraft. “It shows we’ve designed a spacecraft, instruments and a mission that can address the engineering challenges associated with the harsh solar environment, and send back the data that scientists have sought for decades. It’s humbling to see designs and ideas start to become a spacecraft.”

Solar Probe Plus

Artist’s impression of the Solar Probe Plus spacecraft. Credit: NASA/JHUAPL.

Solar Probe Plus will fly as close as 3.9 million miles or more than 6.2 million kilometers from the sun’s surface, about seven times closer than any spacecraft before it. Overall, scientists estimate that Solar Probe Plus will experience 500 times more solar intensity than any instruments face while orbiting our planet.

The spacecraft is expected to launch on July 31, 2018. It will carry four instruments that will gather new information about solar activity and add more data crucial to forecasting space weather events that can affect everything on Earth. The instruments will be protected by a carbon composite shield as thick as 4.5 inches, enough to withstand almost 2,500 degrees Fahrenheit or more than 1,300 degrees Celsius.

Solar Probe Plus will analyze the flow of energy of the sun and the exact heating mechanism of the star’s corona. It will also how solar wind arises and the material it spreads into the solar system.