So far, Voyager 2 has been the only spacecraft to visit the planets Uranus and Neptune, but that may change soon.
NASA has revealed that they are considering sending an orbital mission to Neptune or Uranus. The mission, which is expected to cost no more than $2 billion, will be launched between 2024 and 2037.
Four Options For Neptune And Uranus
NASA has proposed four potential options for the possible mission to Uranus and Neptune. One would be a mission to Neptune with an atmospheric probe, and the other would be an orbiter with a probe to Uranus. The third option is an orbital Uranus mission without the atmospheric probe. The fourth option would be a flyby mission to Uranus, which would carry a probe and capture images of the planet's moons.
Each mission has its own benefits and downsides. The probe missions would only carry three instruments: a narrow-angle camera, a Doppler imager, and a magnetometer These missions would have the benefit of letting NASA examine the planets' inner atmospheres. The non-probe option would carry 15 instruments and would give NASA a lot more information about the planet but would not let it gather data on the inner atmosphere.
Why The Ice Giants
While neither Neptune or Uranus are capable of supporting life, information on Neptune and Uranus would go a long way toward helping us understand the origin of planets and the universe. Beyond that, ice giants are among the most common planets in our galaxy accounting for the majority of exoplanets that NASA has discovered so far.
"Exploration of at least one ice giant system is critical to advance our understanding of the Solar System, exoplanetary systems, and to advance our understanding of planetary formation and evolution," said the report's executive summary.
Given how far these planets are from Earth, the missions are expected to last at least 11 years. To reduce the amount of fuel used as well as the cost of the mission, the spacecraft would make use of Jupiter's gravity to help push it toward the target planets. This would also affect the launch date of the missions. If NASA chooses to send the spacecraft to Jupiter, then the ideal launch windows for Uranus would be between 2030 and 2034. Neptune has a tighter launch window with the craft needing to be launched between 2029 and 2030. After that, there will not be another launch window until 2041.
