Solar Probe Plus will use seven Venus flybys over nearly seven years, using the gravity of Earth's sister planet to gradually shrink its oval-shaped orbit around the Sun. The spacecraft will will eventually come about 3.7 million miles (5.9 million kilometers) from the Sun, well within the orbit of Mercury and about eight times closer than any spacecraft has come before.
- Launch: July 30-August 18, 2018 (20-day window)
- Gravity assists: seven Venus flybys
- Final solar orbit
- Closest point (known as perihelion): about 3.7 million miles
- Farthest point (known as aphelion) : about 67.9 million miles
- Inclination: 3.4 degrees from the ecliptic plane, or the "line" on which most planets orbit the Sun
- Orbit period: 88 days
- Launch to first perihelion: approximately 3 months
- Launch to minimum perihelion: 6 years, 142 days
- Mission duration (which includes three passes within 4.32 million miles): 6 years, 321 days
- Estimated launch mass: about 1,350 pounds (610 kilograms)
- Fuel available for velocity adjustments (known as the "delta-V" budget): about 121 pounds (55 kilograms) of propellant, which allows for 170 meters per second worth of adjustments.
Artist's concept of the Solar Probe Plus spacecraft, fully deployed in cruise configuration, getting one of seven gravity assists from Venus.
The baseline Solar Probe Plus trajectory uses Venus flybys and no deep space maneuvers to reach a minimum perihelion of 8.5 solar radii (above the Sunís surface) in 6.4 years.