MUSE (Mission to Uranus for Science and Exploration) is a European proposal for a dedicated mission to the planet

Uranus Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus ( Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars), grandfather of Zeus (Jupiter) and father of ...

to study its atmosphere, interior,

moons A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body (or sometimes another natural satellite). Natural satellites are often colloquially referred to as ''moons'' ...

rings Ring may refer to: * Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry * To make a sound with a bell, and the sound made by a bell :(hence) to initiate a telephone connection Arts, entertainment and media Film and ...

, and magnetosphere. It is proposed to be launched with an

Ariane 6 Ariane 6 is a European expendable launch system currently under development since the early 2010s by ArianeGroup on behalf of the European Space Agency (ESA). It is intended to replace the Ariane 5, as part of the Ariane launch vehicle famil ...

in 2026, travel for 16.5 years to reach Uranus in 2044, and would operate until 2050. The

European Space Operations Centre The European Space Operations Centre (ESOC) serves as the main mission control centre for the European Space Agency (ESA) and is located in Darmstadt, Germany. ESOC's primary function is the operation of unmanned spacecraft on behalf of ESA and ...

would monitor and control the mission, as well as generate and provide the raw data sets. In 2012, the cost was estimated at €1.8 billion. The mission addresses the themes of the ESA Cosmic Vision 2015–2025. This was designed as an L-Class flagship level mission; however, it is constrained by the need for RTGs. MUSE was also analyzed in the US as an Enhanced New Frontiers class mission in 2014.

Orbiter

The orbiter science phase would consist on the Uranus Science Orbit (USO) phase of approximately 2 years in a highly elliptic polar orbit to provide best gravimetry data, during which 36 Uranus orbits are performed. Subsequently, the orbiter will continue to the Moon Tour (MT) phase, which would last three years. During this phase, the periapsis would be raised, facilitating nine flybys of ''each'' of Uranus' five major moons: Miranda,

Ariel Ariel may refer to: Film and television *Ariel Award, a Mexican Academy of Film award * ''Ariel'' (film), a 1988 Finnish film by Aki Kaurismäki * ''ARIEL Visual'' and ''ARIEL Deluxe'', 1989 and 1991 anime video series based on the novel series ...

, Umbriel, Titania, and

Oberon Oberon () is a king of the fairies in medieval and Renaissance literature. He is best known as a character in William Shakespeare's play ''A Midsummer Night's Dream'', in which he is King of the Fairies and spouse of Titania, Queen of the Fairi ...

. Because of the long distance from the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

(20 AU on average), the orbiter would not be able to use solar panels, requiring instead four Advanced Stirling Radioisotope Generators (ASRGs) to be developed by ESA. The propulsion system for the Earth-Uranus transfer would be chemical: Monomethylhydrazine and Mixed Oxides of Nitrogen (MMH/MON) propellant combination is used.

Atmospheric probe

Understanding why Uranus emits such a small amount of heat can only be done in the context of thermodynamic modeling of the atmosphere (density, pressure, and temperature). Therefore, the atmosphere needs to be characterized from both a composition and a thermodynamic point of view. The chemical information to retrieve is the

elemental An elemental is a mythic being that is described in occult and alchemical works from around the time of the European Renaissance, and particularly elaborated in the 16th century works of Paracelsus. According to Paracelsus and his subsequent fo ...

concentrations, especially of disequilibrium species, isotopic ratios and

noble gas The noble gases (historically also the inert gases; sometimes referred to as aerogens) make up a class of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low ch ...

es, in combination with information regarding the distribution of aerosol particles with depth. Twenty days before entry, the atmospheric probe would separate from the spacecraft and enter the outer atmosphere of Uranus at an altitude of 700 km at 21.8 km/s. It would descend by free fall and perform atmospheric measurements for about 90 minutes down to a maximum of pressure.

Proposed instruments

The total mass budget for scientific instruments is ; if all of proposed instruments are selected, they would sum a total payload mass of . In the table below, a green background denotes instruments to go on the entry probe; the rest are for the orbiter.

MUSE as new New Frontiers mission

In 2014, a paper was released considering MUSE under the constraints of an enhanced New Frontiers mission. This included a cost cap of US$1.5 billion, and one of the big differences was the use of an Atlas V 551 rocket.

References

{{Future spaceflights Missions to Uranus Orbiters (space probe) Proposed space probes European Space Agency space probes 2026 in spaceflight

Orbiter

Atmospheric probe

Proposed instruments

MUSE as new New Frontiers mission

See also

References