Spacecraft
The VERITAS spacecraft is a solar-powered Venus orbiter based on the design of the MAVEN spacecraft, which NASA has successfully operated at Mars since 2014. The MAVEN design was adapted to accommodate the VERITAS science instruments, as well as the space environment at Venus, which is much closer to the Sun.
Solar power
VERITAS will have two solar array wings with three solar panels on each wing. The arrays will deploy shortly after launch and have a total area of just over 300 square feet (28 m2). They will produce about 3,400 watts of power at the distance of Earth's orbit, and about 5,900 watts at Venus. One side of the outermost solar array panel on each wing is used as a drag flap during aerobraking.
Mission Phases
Launch, Cruise, and Arrival
VERITAS is currently planned to launch no earlier than 2031. The spacecraft will arrive at Venus after a six-month cruise, and enter a polar orbit (orbiting over the poles, rather than the equator). VERITAS will perform an orbit insertion maneuver using its six main engines.
The spacecraft's initial orbit at Venus will be highly elliptical, lasting 120 hours. A second burn of the engines, called a period reduction maneuver, will shrink the size of the orbit and reduce the period to just 10 hours.
After that, VERITAS will use two phases of aerobraking – dipping repeatedly into the upper atmosphere of Venus and using drag on the solar arrays to reduce the spacecraft's speed and further lower its orbit. Each aerobraking phase lasts about five months. Once aerobraking is completed, VERITAS will be in its final science orbit.
Aerobraking
VERITAS will enter its first aerobraking phase about a month after arrival. The two aerobraking phases, together, reduce the spacecraft's orbital altitude at its farthest point from Venus (known as apoapsis) from nearly 20,000 miles to 250 miles (32,000 kilometers to 400 kilometers). Aerobraking reduces the spacecraft's orbit period (the time it takes to orbit Venus) from 10 hours to 1.6 hours.
During a pause in aerobraking lasting about four-and-a-half months, the mission will conduct its first science phase, with only the Venus Emissivity Mapper (VEM) collecting data. After the second aerobraking phase, the second science phase begins, and will last more than 2.5 Earth years, or only four Venus days. One day on Venus, a complete rotation, is about 247 Earth days long.
Science Operations
The VERITAS science mission consists of two phases. Science phase I occurs while aerobraking is paused, about six months after arrival at the planet. Science phase II starts after further aerobraking places VERITAS into a circular, low-altitude orbit over the poles that allows global observations. Nominally, during each day of operations in science phase II, VEM and VISAR will collect data for 16 hours, then the spacecraft will point its high-gain antenna at Earth and lock up with the DSN for an eight-hour session, during which the mission acquires gravity science data.
Over the four Venus days of the nominal science mission, VERITAS is estimated to return about 28 terabits (3.5 terabytes) of science data.