![]() Mosaic of images of Uranus and its 5 major moons from Voyager 2 | |
Mission type | Uranus orbiter |
---|---|
Operator | NASA |
Mission duration | Cruise: 13.4 years Science phase: 4.5 years [1] |
Spacecraft properties | |
Launch mass | 7,235 kg (15,950 lb) [1] |
Dry mass | 2,756 kg (6,076 lb) [1] |
Payload mass | 60.5 kg (133 lb) plus 19.7 kg (43 lb) atmospheric probe [1] |
Dimensions | Height: 7.1 m (23 ft) Diameter: less than 5 m (16 ft) [1] |
Power | 735 W (0.986 hp) from 3 Mod1 Next-Generation Radioisotope thermoelectric generators [1] |
Start of mission | |
Launch date | not earlier than 2031 [1] [2] |
Rocket | Falcon Heavy Expendable (proposed) [1] |
Launch site | Kennedy Space Center Launch Complex 39A (proposed) [1] |
Flyby of Earth (gravity assist) | |
Closest approach | not earlier than 2033 |
Distance | 450 km (280 mi) |
Flyby of Jupiter (gravity assist) | |
Closest approach | not earlier than 2035 |
Distance | 370,000 km (230,000 mi) |
Uranus orbiter | |
Orbital insertion | not earlier than 2044 |
Uranus atmospheric probe | |
Atmospheric entry | not earlier than 2045 |
Large Strategic Science Missions Planetary Science Division |
The Uranus Orbiter and Probe is an orbiter mission concept to study Uranus and its moons. [1] The orbiter would also deploy an atmospheric probe to characterize Uranus's atmosphere. The concept is being developed as a potential large strategic science mission for NASA. The science phase would last 4.5 years and include multiple flybys of each of the major moons.
The mission concept was selected as the highest priority Flagship-class mission by the 2023–2032 Planetary Science Decadal Survey,ahead of the Enceladus Orbilander. [3] [4] A Neptune orbiter mission concept,Neptune Odyssey,that would address many of the same scientific goals regarding ice giants was also considered,but for logistical and cost reasons a mission to Uranus was favored.
The original proposal targeted a launch in 2031 using a Falcon Heavy expendable launch vehicle with a gravity assist at Jupiter,allowing arrival at Uranus in 2044. In 2023,however,NASA announced that due to a shortfall in plutonium production a mid to late 2030s launch would be more likely. [2]
Voyager 2 is the only space probe to have visited the Uranus system, completing a flyby on January 24, 1986. The 2011-2022 Planetary Science Decadal Survey recommended a Flagship-class orbiter mission to an ice giant with priority behind what would become the Mars 2020 rover and the Europa Clipper. [5] [6] [7] Ice giants are now appreciated as a common type of exoplanet, precipitating the need for further study of ice giants in the Solar System. [8] The ice giants Uranus and Neptune were seen as unique yet equally compelling scientific targets, but a Uranus orbiter and atmospheric probe was given preference for logistical and cost reasons. [5] [7] A Uranus orbiter would logically follow Flagship-class orbiter missions undertaken at Jupiter and Saturn ( Galileo and Cassini , respectively).
In 2017, prior to the 2023–2032 survey, a committee narrowed twenty mission concepts to three scenarios for Uranus and a fourth for Neptune. [8] [9] [10] [11] A mission to Neptune is viewed by some to be of greater scientific merit [12] because Triton, likely a captured Kuiper belt object and ocean world, is a more compelling astrobiology target than the moons of Uranus (though Ariel and Miranda in particular are possible ocean worlds). [13] There was also a study that considered a New Frontiers-level Uranus orbiter mission concept if a Flagship-class mission to Neptune were favored. [14] Nevertheless, again due to cost and logistical considerations including launch vehicle availability and available launch windows, the 2023–2032 Planetary Science Decadal Survey recommended the Uranus Orbiter and Probe instead of an analogous proposal for Neptune, Neptune Odyssey. [3] [4]
The orbiter paired with an atmospheric probe will address a variety of scientific questions across all aspects of the Uranus system: [3]
The atmospheric probe element of this mission would study the vertical distribution of cloud-forming molecules, thermal stratification, and wind speed as a function of depth. The 2010 mission design envisioned a probe of 127 kg (280 lb), less than half that of the Galileo atmospheric probe. [7] A later design study suggested results could be significantly enhanced by adding a second probe which could be as small as 30 kg (66 lb) in mass and about 0.5 m (20 in) in diameter. [15]
The orbiter is proposed to carry the following instruments in the baseline concept, with additional instruments possible should they prove to be within mass, power, and cost limitations: [1]
Instrument | Heritage Instrument | Heritage Mission |
---|---|---|
Magnetometer | MESSENGER Magnetometer | MESSENGER |
Narrow-Angle Camera | Long Range Reconnaissance Imager (LORRI) | New Horizons |
Thermal Infrared Camera | Diviner | Lunar Reconnaissance Orbiter |
Langmuir Probe and Waves | MAVEN Langmuir Probe and Waves (LPW) | MAVEN |
Search coil magnetometer | TRACERS search coil magnetometer (MSC) | TRACERS |
Fast imaging plasma spectrometer | MESSENGER energetic particle and plasma spectrometer (EPPS) | MESSENGER |
Electrostatic analyzers | Solar Wind Electrons Alphas and Protons (SWEAP) | Parker Solar Probe |
Energetic Charged Particle Detector | EPI-Lo | Parker Solar Probe |
Visible-Near Infrared Imaging Spectrometer & Wide-angle camera | L'Ralph | Lucy |
Radio Science Experiment | UltraStable Oscillator | none (part of spacecraft communications system) |
The atmospheric probe is proposed to carry 4 scientific instruments as part of the baseline concept. [1]
Instrument | Heritage Instrument | Heritage Mission |
---|---|---|
Double focus mass spectrometer | Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) | Rosetta |
Atmospheric Structure Instrument | Huygens Atmospheric Structure Instrument (HASI) | Huygens |
Ortho-Para H2 Detector | (in development) [8] | none |
Radio Science Experiment | UltraStable Oscillator | none (part of probe communications system) |
Voyager 2 is a space probe launched by NASA on August 20, 1977, as a part of the Voyager program. It was launched on a trajectory towards the gas giants Jupiter and Saturn and enabled further encounters with the ice giants Uranus and Neptune. It remains the only spacecraft to have visited either of the ice giant planets, and was the third of five spacecraft to achieve Solar escape velocity, which will allow it to leave the Solar System. It has been sending scientific data to Earth for 46 years, 11 months, 8 days, making it the oldest active space probe. Launched 16 days before its twin Voyager 1, the primary mission of the spacecraft was to study the outer planets and its extended mission is to study interstellar space beyond the Sun's heliosphere.
Uranus is the seventh planet from the Sun. It is a gaseous cyan-coloured ice giant. Most of the planet is made of water, ammonia, and methane in a supercritical phase of matter, which astronomy calls "ice" or volatiles. The planet's atmosphere has a complex layered cloud structure and has the lowest minimum temperature of all the Solar System's planets. It has a marked axial tilt of 82.23° with a retrograde rotation period of 17 hours and 14 minutes. This means that in an 84-Earth-year orbital period around the Sun, its poles get around 42 years of continuous sunlight, followed by 42 years of continuous darkness.
Titania, also designated Uranus III, is the largest of the moons of Uranus. At a diameter of 1,578 kilometres (981 mi) it is the eighth largest moon in the Solar System, with a surface area comparable to that of Australia. Discovered by William Herschel in 1787, it is named after the queen of the fairies in Shakespeare's A Midsummer Night's Dream. Its orbit lies inside Uranus's magnetosphere.
An ice giant is a giant planet composed mainly of elements heavier than hydrogen and helium, such as oxygen, carbon, nitrogen, and sulfur. There are two ice giants in the Solar System: Uranus and Neptune.
The New Frontiers program is a series of space exploration missions being conducted by NASA with the purpose of furthering the understanding of the Solar System. The program selects medium-class missions which can provide high science returns.
The exploration of Uranus has, to date, been through telescopes and a lone probe by NASA's Voyager 2 spacecraft, which made its closest approach to Uranus on January 24, 1986. Voyager 2 discovered 10 moons, studied the planet's cold atmosphere, and examined its ring system, discovering two new rings. It also imaged Uranus' five large moons, revealing that their surfaces are covered with impact craters and canyons.
The exploration of Saturn has been solely performed by crewless probes. Three missions were flybys, which formed an extended foundation of knowledge about the system. The Cassini–Huygens spacecraft, launched in 1997, was in orbit from 2004 to 2017.
Neptune has been directly explored by one space probe, Voyager 2, in 1989. As of 2024, there are no confirmed future missions to visit the Neptunian system, although a tentative Chinese mission has been planned for launch in 2024. NASA, ESA, and independent academic groups have proposed future scientific missions to visit Neptune. Some mission plans are still active, while others have been abandoned or put on hold.
Neptune is the eighth and farthest known planet from the Sun. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times the mass of Earth and slightly more massive, but denser and smaller, than fellow ice giant Uranus. Being composed primarily of gases and liquids, it has no well-defined solid surface, and orbits the Sun once every 164.8 years at an orbital distance of 30.1 astronomical units. It is named after the Roman god of the sea and has the astronomical symbol , representing Neptune's trident.
The Planetary Science Decadal Survey is a serial publication of the United States National Research Council produced for NASA and other United States Government Agencies such as the National Science Foundation. The documents identify key questions facing planetary science and outlines recommendations for space and ground-based exploration ten years into the future. Missions to gather data to answer these big questions are described and prioritized, where appropriate. Similar decadal surveys cover astronomy and astrophysics, earth science, and heliophysics.
Uranus Pathfinder was a mission concept for the Uranian system evaluated in the 2010s by the European Space Agency. In 2011, scientists from the Mullard Space Science Laboratory in the United Kingdom proposed the joint NASA–ESA Uranus Pathfinder mission to Uranus. It would have been a medium-class (M-class) mission to be launched in 2022, and was submitted to the ESA in December 2010 with the signatures of 120 scientists from around the globe. ESA caps the cost of M-class missions at €470 million. Uranus Pathfinder was proposed in support of ESA's Cosmic Vision 2015–2025. The mission study including several possible combinations of launch dates, trajectories, and flybys, including flybys of Earth, Venus, and of the planet Saturn. Indeed, the study noted the velocity change requirements are only marginally higher than for typical missions to Saturn of this period.
ODINUS is a space mission concept proposed to the European Space Agency's Cosmic Vision programme. The ODINUS mission concept proposes to expand the Uranus orbiter and probe mission to two twin orbiters— dubbed Freyr and Freyja, the twin gods of the Norse pantheon. Their primary mission would be to study Neptune and Uranus with one orbiter each. If selected, ODINUS would launch in 2034.
MUSE is a European proposal for a dedicated mission to the planet Uranus to study its atmosphere, interior, moons, rings, and magnetosphere. It is proposed to be launched with an Ariane 6 in 2026, travel for 16.5 years to reach Uranus in 2044, and would operate until 2050.
The Europa Lander is a proposed astrobiology mission concept by NASA to send a lander to Europa, an icy moon of Jupiter. If funded and developed as a large strategic science mission, it would be launched in 2027 to complement the studies by the Europa Clipper orbiter mission and perform analyses on site.
The Ocean Worlds Exploration Program (OWEP) is a NASA program to explore ocean worlds in the outer Solar System that could possess subsurface oceans to assess their habitability and to seek biosignatures of simple extraterrestrial life.
OCEANUS is a mission concept conceived in 2016 and presented in 2017 as a potential future contestant as a New Frontiers program mission to the planet Uranus. The concept was developed by the Astronautical engineering students of Purdue University during the 2017 NASA/JPL Planetary Science Summer School. OCEANUS is an orbiter, which would enable a detailed study of the structure of the planet's magnetosphere and interior structure that would not be possible with a flyby mission.
Neptune Odyssey is an orbiter mission concept to study Neptune and its moons, particularly Triton. The orbiter would enter into a retrograde orbit of Neptune to facilitate simultaneous study of Triton and would launch an atmospheric probe to characterize Neptune's atmosphere. The concept is being developed as a potential large strategic science mission for NASA by a team led by the Applied Physics Laboratory at Johns Hopkins University. The current proposal targets a launch in 2033 using the Space Launch System with arrival at Neptune in 2049, although trajectories using gravity assists at Jupiter have also been considered with launch dates in 2031.
The Enceladus Orbilander is a proposed NASA Flagship mission to Saturn's moon Enceladus. The Enceladus Orbilander would spend a year and a half orbiting Enceladus and sampling its water plumes, which stretch into space, before landing on the surface for a two-year mission to study materials for evidence of life. The mission, with an estimated cost of $4.9 billion, could launch in the late 2030s on a Space Launch System or Falcon Heavy with a landing in the early 2050s. It was proposed in the 2023–2032 Planetary Science Decadal Survey as the third highest priority Flagship mission, after the Uranus Orbiter and Probe and the Mars Sample Return program.