Uranus Orbiter and Probe

{{Short description|Proposed NASA space mission to Uranus}}

{{Infobox spaceflight

| name = Uranus Orbiter and Probe

| names_list =

| image = Uranus Montage.jpg

| image_caption = Mosaic of images of Uranus and its 5 major moons from Voyager 2

| mission_type = Uranus orbiter

| operator = NASA

| COSPAR_ID =

| SATCAT =

| website =

| mission_duration = Cruise:
13.4 years
Science phase:
4.5 years{{cite journal |last1=Simon |first1=Amy |last2=Nimmo |first2=Francis |last3=Anderson |first3=Richard C. |title=Journey to an Ice Giant System: Uranus Orbiter and Probe |journal=Planetary Mission Concept for the 2023–2032 Planetary Science Decadal Survey |date=7 June 2021 |url=https://drive.google.com/drive/folders/1Qlun6EF0v472eOMXXokHxa6B2tBLNkdv |access-date=1 May 2022 |publisher=NASA}}

| manufacturer =

| launch_mass = {{cvt|7235|kg|lb}}

| dry_mass = {{cvt|2756|kg|lb}}

| payload_mass = Orbiter:
{{cvt|60.5|kg|lb}}
Atmospheric Probe:
{{cvt|19.7|kg|lb}}

| dimensions = {{cvt|7.1|xx|5.0|xx|5.0|m|ft}}

| power = {{cvt|735|W}} from 3 Mod1 Next-Generation Radioisotope thermoelectric generators

| launch_date = Not earlier than 2031{{r|Concept|Faust}}

| launch_rocket = Proposed:
Falcon Heavy (expendable)

| launch_site = Kennedy LC-39A

| launch_contractor =

| interplanetary = {{Infobox spaceflight/IP

|type = flyby

|object = Earth

|note = gravity assist

|distance = {{cvt|450|km|mi}}

|arrival_date = Not earlier than 2033

}}

{{Infobox spaceflight/IP

|type = flyby

|object = Jupiter

|note = gravity assist

|distance = {{cvt|370000|km|mi}}

|arrival_date = Not earlier than 2035

}}

{{Infobox spaceflight/IP

| type = orbiter

| object = Uranus

| orbits =

| arrival_date = Not earlier than 2044

}}

{{Infobox spaceflight/IP

| type = atmospheric

| object = Uranus

| arrival_date = Not earlier than 2045

}}

| insignia =

| insignia_caption =

| insignia_size =

| programme = Large Strategic Science Missions
Planetary Science Division

| previous_mission = Mars Sample Return

| next_mission = Enceladus Orbilander

| programme2 = Solar System Exploration program

| previous_mission2 = Europa Clipper

| next_mission2 = Enceladus Orbilander

}}

The Uranus Orbiter and Probe is an orbiter mission concept to study Uranus and its moons. 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.{{cite book |title=Origins, Worlds, and Life: A Decadal Strategy for Planetary Science and Astrobiology 2023-2032 |year=2022 |publisher=National Academies Press |isbn=978-0-309-47578-5 |pages=800 |doi=10.17226/26522 |s2cid=248283239 |edition=Prepublication |url=https://nap.nationalacademies.org/catalog/26522/origins-worlds-and-life-a-decadal-strategy-for-planetary-science |access-date=30 April 2022}}{{cite news|last=Foust|first=Jeff|url=https://spacenews.com/planetary-science-decadal-endorses-mars-sample-return-outer-planets-missions/|title=Planetary science decadal endorses Mars sample return, outer planets missions|publisher=SpaceNews|date=19 April 2022|access-date=19 April 2022}}

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.{{Cite web |last=Foust |first=Jeff |date=2023-05-03 |title=Plutonium availability constrains plans for future planetary missions |url=https://spacenews.com/plutonium-availability-constrains-plans-for-future-planetary-missions/ |access-date=2023-05-03 |website=SpaceNews |language=en-US}}

Background

{{further|Exploration of Uranus}}

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.{{cite web |title=Visions and Voyages for Planetary Science in the Decade 2013–2022 |url=https://solarsystem.nasa.gov/resources/598/vision-and-voyages-for-planetary-science-in-the-decade-2013-2022/ |access-date=20 April 2021}}{{cite web |url=http://www.nasaspaceflight.com/2013/11/new-sls-options-new-large-upper-stage |title=New SLS mission options explored via new Large Upper Stage |author=Chris Gebhardt |publisher=NASASpaceFlight |date=20 November 2013}}{{cite web |last1=Hubbard, William B. |title=SDO-12345: Ice Giants Decadal Study |url=https://www.nap.edu/resource/13117/App%20G%2023_Uranus_Orbiter_and_Probe.pdf |website=National Academies Press |publisher=National Academy of Sciences |access-date=22 June 2020 |archive-url=https://web.archive.org/web/20210506092409/https://www.nap.edu/resource/13117/App%20G%2023_Uranus_Orbiter_and_Probe.pdf |archive-date=6 May 2021 |date=3 June 2010 |url-status=live}} Ice giants are now appreciated as a common type of exoplanet, precipitating the need for further study of ice giants in the Solar System.{{cite web |title=Ice Giants Pre-Decadal Survey Mission Study Report (June 2017) |url=https://www.lpi.usra.edu/NASA-academies-resources/full-report-ice-giants.pdf |access-date=13 Feb 2024}} 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. 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.[https://www.theverge.com/2017/6/16/15810926/nasa-uranus-neptune-mission-voyager-2-spacecraft It’s time to explore Uranus and Neptune again — and here's how NASA could do it]. Loren Grush, The Verge. 16 June 2017.[http://www.planetary.org/blogs/jason-davis/2017/20170621-revisiting-ice-giants.html Revisiting the ice giants: NASA study considers Uranus and Neptune missions]. Jason Davis. The Planetary Society. 21 June 2017.[https://www.nasa.gov/feature/nasa-completes-study-of-future-ice-giant-mission-concepts NASA Completes Study of Future ‘Ice Giant’ Mission Concepts] {{Webarchive|url=https://web.archive.org/web/20200806062812/https://www.nasa.gov/feature/nasa-completes-study-of-future-ice-giant-mission-concepts/ |date=2020-08-06 }}. NASA TV. 20 June 2017. A mission to Neptune is viewed by some to be of greater scientific merit{{cite journal |title=Exploration Strategy for the Outer Planets 2023–2032: Goals and Priorities |year=2021 |doi=10.3847/25c2cfeb.1f297498 |url=https://baas.aas.org/pub/2021n4i371/release/1 |access-date=20 April 2021|last1=Moore |first1=Jeff |last2=Spilker |first2=Linda |last3=Bowman |first3=Jeff |last4=Cable |first4=Morgan |last5=Edgington |first5=Scott |last6=Hendrix |first6=Amanda |last7=Hofstadter |first7=Mark |last8=Hurford |first8=Terry |last9=Mandt |first9=Kathleen |last10=McEwen |first10=Alfred |last11=Paty |first11=Carol |last12=Quick |first12=Lynnae |last13=Rymer |first13=Abigail |last14=Sayanagi |first14=Kunio |last15=Schmidt |first15=Britney |last16=Spilker |first16=Thomas |journal=Bulletin of the AAS |volume=53 |issue=4 |page=371 |bibcode=2021BAAS...53d.371M |s2cid=214641023 |arxiv=2003.11182 |doi-access=free }} 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).{{cite journal |title=NASA Roadmap to Ocean Worlds |year=2019 |doi=10.1089/ast.2018.1955 |last1=Hendrix |first1=Amanda R. |last2=Hurford |first2=Terry A. |last3=Barge |first3=Laura M. |last4=Bland |first4=Michael T. |last5=Bowman |first5=Jeff S. |last6=Brinckerhoff |first6=William |last7=Buratti |first7=Bonnie J. |last8=Cable |first8=Morgan L. |last9=Castillo-Rogez |first9=Julie |last10=Collins |first10=Geoffrey C. |last11=Diniega |first11=Serina |last12=German |first12=Christopher R. |last13=Hayes |first13=Alexander G. |last14=Hoehler |first14=Tori |last15=Hosseini |first15=Sona |last16=Howett |first16=Carly J.A. |last17=McEwen |first17=Alfred S. |last18=Neish |first18=Catherine D. |last19=Neveu |first19=Marc |last20=Nordheim |first20=Tom A. |last21=Patterson |first21=G. Wesley |last22=Patthoff |first22=D. Alex |last23=Phillips |first23=Cynthia |last24=Rhoden |first24=Alyssa |last25=Schmidt |first25=Britney E. |last26=Singer |first26=Kelsi N. |last27=Soderblom |first27=Jason M. |last28=Vance |first28=Steven D. |journal=Astrobiology |volume=19 |issue=1 |pages=1–27 |pmid=30346215 |pmc=6338575 |bibcode=2019AsBio..19....1H |s2cid=53043052 |doi-access=free }} There was also a study that considered a New Frontiers-level Uranus orbiter mission concept if a Flagship-class mission to Neptune were favored.[http://www.lpi.usra.edu/decadal/opag/UranusOrbiter_v7.pdf THE CASE FOR A URANUS ORBITER], Mark Hofstadter et al. 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.

Key science questions

The orbiter paired with an atmospheric probe will address a variety of scientific questions across all aspects of the Uranus system:

=Origin, interior, and atmosphere=

=Magnetosphere=

=Satellites and rings=

  • What are the internal structures and rock-to-ice ratios of the large Uranian moons and which moons possess substantial internal heat sources or possible oceans?
  • How do the compositions and properties of the Uranian moons constrain their formation and evolution?
  • What geological history and processes do the surfaces record and how can they inform outer solar system impactor populations? What evidence of exogenic interactions do the surfaces display?
  • What are the compositions, origins and history of the Uranian rings and inner small moons, and what processes sculpted them into their current configuration?

Mission details

[[File:2021 Uranus Orbiter and Probe schematic.jpg | thumb | 220x124px | right | alt= Explanation of the components of a 7200-kg probe for Uranus |

Schematic of the 2021 concept study design for the Orbiter and Probe]]

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 {{cvt|127|kg}}, less than half that of the Galileo atmospheric probe. A later design study suggested results could be significantly enhanced by adding a second probe which could be as small as {{cvt|30|kg}} in mass and about {{cvt|0.5|m|inch}} in diameter.K. M. Sayanagi, R. A. Dillman, A. A. Simon, et al. " [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170006873.pdf Small Next-generation Atmospheric Probe (SNAP) Concept]", LPI 2083 (2018): 2262. Long version of paper: Space Sci Rev, 216, 72 (June 10, 2020) [https://link.springer.com/article/10.1007/s11214-020-00686-7 Small Next-Generation Atmospheric Probe (SNAP) Concept to Enable Future Multi-Probe Missions: A Case Study for Uranus]. Retrieved June 22, 2020.

=Orbiter instruments=

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:

class="wikitable"
InstrumentHeritage InstrumentHeritage 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)

=Atmospheric probe instruments=

The atmospheric probe is proposed to carry 4 scientific instruments as part of the baseline concept.

class="wikitable"
InstrumentHeritage InstrumentHeritage 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)

| none

Radio Science Experiment

| UltraStable Oscillator

| none (part of probe communications system)

See also

;Uranus mission proposals

References