Io Volcano Observer
Encyclopedia
Io Volcano Observer is a proposed unmanned spacecraft
that, if approved and launched, would orbit
Jupiter and perform at least seven flybys
of Jupiter's moon Io
. IVO has been proposed to NASA
by the University of Arizona as both a science and engineering mission, originally as part of NASA's Discovery & Scout Mission Capability Expansion (DSMCE) concept-study program. Currently, the mission is a possible proposal to be submitted for NASA's Discovery program
. As such, IVO has not been funded and it is still in its conceptual phase; if selected, its intended launch window would be in January 2015.
IVO is a low-cost, outer-planet mission that would explore Io's active volcanism and the moon's impact on the Jupiter system as a whole by measuring its global heat flow, its induced magnetic field, the temperature of its lava, and the composition of its atmosphere, volcanic plumes, and lavas.
in March 1979. This significant amount of volcanism on Io
is the result of tidal heating, a process that has also resulted in increased internal heat within other outer planet satellites, such as Enceladus
and Europa
. On both of these latter moons, the tidal heating has allowed liquid water near the surface of these moons, dramatically effecting their geology and providing a possible habitat for life
. Since its discovery in 1979, the volcanic activity on Io was observed by ground-based astronomers as well as the Galileo, Cassini
, and New Horizons
. Galileo flew by Io seven times over the course of its nearly-eight-year mission at Jupiter. However, Galileo's low downlink bandwidth resulting from its broken high-gain antenna, camera and spectrometer problems, and safing events that occurred during several of the encounters limited the amount and quality of data that could be returned from these flybys. Both Cassini and New Horizons flew by the Jupiter system at distances greater than the orbit of Callisto
, the outermost of the Galilean satellites
, limiting the resolution and time span of their data.
Io Volcano Observer was a concept study for NASA's Discovery & Scout Mission Capability Expansion (DSMCE). The purpose of the program was to see what types of missions could be performed under a Discovery mission cost cap ($425 million) if a government-supplied Advanced Stirling Radioisotope Generator
(ASRG) was used as a power source. From the 40 proposals submitted to NASA's DSMCE Program, nine were selected for further study. This process was completed in February 2009 when the IVO team and the other groups submitted their final reports to NASA. Currently, NASA is soliciting for proposals for the next Discovery mission, of which IVO will likely be one such proposal.
(401) rocket during a launch window in January 2015. Following launch, the spacecraft would perform a VEEGA trajectory, using a gravity assist at Venus in January 2016 and two at Earth
in February 2017 and February 2019 to send the spacecraft on a Jupiter-bound trajectory. Following an Io flyby on its way in, the Io Volcano Observer in July 2021 would execute a Jupiter Orbital Insertion burn to go into an inclined orbit around Jupiter. Following an initial six-month orbit, IVO would encounter at 6-10 times during an 18-month primary mission. As IVO would be an inclined orbit (~49°), during each of these encounters would approach Io from over its south polar region, make its closest approach near the equator of Io at distances ranging from 100 to 1000 kilometers, and depart Io over its north polar region. To aid in change detection, the spacecraft would also encounter Io near the same point in Io's orbit, keeping similar lighting conditions over the course of the nominal mission. Following the primary mission, if the spacecraft and power source remains healthy, an extended mission could be approved. This extended mission could include pumping up the orbital period of IVO to one year in length as part of a test of the ASRGs life span, to monitor Io for changes over a longer time span, and to possibly encounter one of Jupiter's outer irregular satellites. Such an extended mission could last up to eight years, with the potential for up to eight additional encounters.
(ASRG), which is a prototype meant to provide availability of long-lived power supplies for planetary missions. The ASRG is a radioisotope power system using Stirling power conversion
technology and is expected to generate 140–160 W of electrical power; that is four times more efficient than RTG
s currently in use. Its mass is 20 kg and will have a nominal lifetime of 14 years.
Specifications:
Unmanned spacecraft
Unmanned spacecraft are spacecraft without people on board, and probably includes unmanned resupply spacecraft, space probes, and most space observatories. A difference between robotic spacecraft and unmanned spacecraft, is that unmanned spacecraft is inclusive to non-robotic unmanned spacecraft,...
that, if approved and launched, would orbit
Orbiter
An orbiter is a space probe that orbits a planet.-Asteroids:*NEAR Shoemaker...
Jupiter and perform at least seven flybys
Flybys
Flybys is the second full-length album by California Pop music band The Curtains, released in 2003 on the independent, Los Angeles-based Thin Wrist label...
of Jupiter's moon Io
Io (moon)
Io ) is the innermost of the four Galilean moons of the planet Jupiter and, with a diameter of , the fourth-largest moon in the Solar System. It was named after the mythological character of Io, a priestess of Hera who became one of the lovers of Zeus....
. IVO has been proposed to NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
by the University of Arizona as both a science and engineering mission, originally as part of NASA's Discovery & Scout Mission Capability Expansion (DSMCE) concept-study program. Currently, the mission is a possible proposal to be submitted for NASA's Discovery program
Discovery Program
NASA's Discovery Program is a series of lower-cost, highly-focused American scientific space missions that are exploring the Solar System. It was founded in 1992 to implement then-NASA Administrator Daniel S. Goldin's vision of "faster, better, cheaper" planetary missions...
. As such, IVO has not been funded and it is still in its conceptual phase; if selected, its intended launch window would be in January 2015.
IVO is a low-cost, outer-planet mission that would explore Io's active volcanism and the moon's impact on the Jupiter system as a whole by measuring its global heat flow, its induced magnetic field, the temperature of its lava, and the composition of its atmosphere, volcanic plumes, and lavas.
Background
Active volcanism was discovered on Jupiter's moon Io by Voyager 1Voyager 1
The Voyager 1 spacecraft is a 722-kilogram space probe launched by NASA in 1977, to study the outer Solar System and eventually interstellar space. Operating for as of today , the spacecraft receives routine commands and transmits data back to the Deep Space Network. At a distance of as of...
in March 1979. This significant amount of volcanism on Io
Volcanism on Io
Volcanism on Io, a moon of Jupiter, produces lava flows, volcanic pits, and plumes of sulfur and sulfur dioxide hundreds of kilometres high. This volcanic activity was discovered in 1979 by Voyager 1 imaging scientists...
is the result of tidal heating, a process that has also resulted in increased internal heat within other outer planet satellites, such as Enceladus
Enceladus (moon)
Enceladus is the sixth-largest of the moons of Saturn. It was discovered in 1789 by William Herschel. Until the two Voyager spacecraft passed near it in the early 1980s very little was known about this small moon besides the identification of water ice on its surface...
and Europa
Europa (moon)
Europa Slightly smaller than Earth's Moon, Europa is primarily made of silicate rock and probably has an iron core. It has a tenuous atmosphere composed primarily of oxygen. Its surface is composed of ice and is one of the smoothest in the Solar System. This surface is striated by cracks and...
. On both of these latter moons, the tidal heating has allowed liquid water near the surface of these moons, dramatically effecting their geology and providing a possible habitat for life
Astrobiology
Astrobiology is the study of the origin, evolution, distribution, and future of life in the universe. This interdisciplinary field encompasses the search for habitable environments in our Solar System and habitable planets outside our Solar System, the search for evidence of prebiotic chemistry,...
. Since its discovery in 1979, the volcanic activity on Io was observed by ground-based astronomers as well as the Galileo, Cassini
Cassini-Huygens
Cassini–Huygens is a joint NASA/ESA/ASI spacecraft mission studying the planet Saturn and its many natural satellites since 2004. Launched in 1997 after nearly two decades of gestation, it includes a Saturn orbiter and an atmospheric probe/lander for the moon Titan, although it has also returned...
, and New Horizons
New Horizons
New Horizons is a NASA robotic spacecraft mission currently en route to the dwarf planet Pluto. It is expected to be the first spacecraft to fly by and study Pluto and its moons, Charon, Nix, Hydra and S/2011 P 1. Its estimated arrival date at the Pluto-Charon system is July 14th, 2015...
. Galileo flew by Io seven times over the course of its nearly-eight-year mission at Jupiter. However, Galileo's low downlink bandwidth resulting from its broken high-gain antenna, camera and spectrometer problems, and safing events that occurred during several of the encounters limited the amount and quality of data that could be returned from these flybys. Both Cassini and New Horizons flew by the Jupiter system at distances greater than the orbit of Callisto
Callisto (moon)
Callisto named after the Greek mythological figure of Callisto) is a moon of the planet Jupiter. It was discovered in 1610 by Galileo Galilei. It is the third-largest moon in the Solar System and the second largest in the Jovian system, after Ganymede. Callisto has about 99% the diameter of the...
, the outermost of the Galilean satellites
Galilean moons
The Galilean moons are the four moons of Jupiter discovered by Galileo Galilei in January 1610. They are the largest of the many moons of Jupiter and derive their names from the lovers of Zeus: Io, Europa, Ganymede and Callisto. Ganymede, Europa and Io participate in a 1:2:4 orbital resonance...
, limiting the resolution and time span of their data.
Io Volcano Observer was a concept study for NASA's Discovery & Scout Mission Capability Expansion (DSMCE). The purpose of the program was to see what types of missions could be performed under a Discovery mission cost cap ($425 million) if a government-supplied Advanced Stirling Radioisotope Generator
Advanced Stirling Radioisotope Generator
The Advanced Stirling Radioisotope Generator is a radioisotope power system using Stirling power conversion technology currently being developed under joint sponsorship by the United States Department of Energy and NASA for potential future space missions...
(ASRG) was used as a power source. From the 40 proposals submitted to NASA's DSMCE Program, nine were selected for further study. This process was completed in February 2009 when the IVO team and the other groups submitted their final reports to NASA. Currently, NASA is soliciting for proposals for the next Discovery mission, of which IVO will likely be one such proposal.
Mission Profile
IVO's launch would be with an Atlas VAtlas V
Atlas V is an active expendable launch system in the Atlas rocket family. Atlas V was formerly operated by Lockheed Martin, and is now operated by the Lockheed Martin-Boeing joint venture United Launch Alliance...
(401) rocket during a launch window in January 2015. Following launch, the spacecraft would perform a VEEGA trajectory, using a gravity assist at Venus in January 2016 and two at Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
in February 2017 and February 2019 to send the spacecraft on a Jupiter-bound trajectory. Following an Io flyby on its way in, the Io Volcano Observer in July 2021 would execute a Jupiter Orbital Insertion burn to go into an inclined orbit around Jupiter. Following an initial six-month orbit, IVO would encounter at 6-10 times during an 18-month primary mission. As IVO would be an inclined orbit (~49°), during each of these encounters would approach Io from over its south polar region, make its closest approach near the equator of Io at distances ranging from 100 to 1000 kilometers, and depart Io over its north polar region. To aid in change detection, the spacecraft would also encounter Io near the same point in Io's orbit, keeping similar lighting conditions over the course of the nominal mission. Following the primary mission, if the spacecraft and power source remains healthy, an extended mission could be approved. This extended mission could include pumping up the orbital period of IVO to one year in length as part of a test of the ASRGs life span, to monitor Io for changes over a longer time span, and to possibly encounter one of Jupiter's outer irregular satellites. Such an extended mission could last up to eight years, with the potential for up to eight additional encounters.
Science objectives
The science objectives of this proposed mission are:- Understand Io’s currently active volcanism and implications for volcanic processes on other planetary bodies throughout geologic time.
- Understand Io’s interior structure and tidal heating mechanisms and implications for the coupled orbital-thermal evolution of satellites and extrasolar planets.
- Understand the processes that form mountains and paterae on Io and the implications for tectonics under high heat-flow conditions that may have existed early in the history of other planetary bodies.
- Understand how Io affects the Jovian system, and implications for the study of otherplanetary systems.
- Seek evidence for activity in Io's deep interior and understand the generation of internal magnetic fields.
Power source
The high-data rate during Io flybys by IVO rules out the use of solar panels like the ones that have kept the Mars orbiters functioning for years. If selected by NASA, the Io Volcano Observer would be the test flight of two of the new Advanced Stirling Radioisotope GeneratorAdvanced Stirling Radioisotope Generator
The Advanced Stirling Radioisotope Generator is a radioisotope power system using Stirling power conversion technology currently being developed under joint sponsorship by the United States Department of Energy and NASA for potential future space missions...
(ASRG), which is a prototype meant to provide availability of long-lived power supplies for planetary missions. The ASRG is a radioisotope power system using Stirling power conversion
Stirling engine
A Stirling engine is a heat engine operating by cyclic compression and expansion of air or other gas, the working fluid, at different temperature levels such that there is a net conversion of heat energy to mechanical work....
technology and is expected to generate 140–160 W of electrical power; that is four times more efficient than RTG
Radioisotope thermoelectric generator
A radioisotope thermoelectric generator is an electrical generator that obtains its power from radioactive decay. In such a device, the heat released by the decay of a suitable radioactive material is converted into electricity by the Seebeck effect using an array of thermocouples.RTGs can be...
s currently in use. Its mass is 20 kg and will have a nominal lifetime of 14 years.
Specifications:
- ≥14 year lifetime
- Nominal power : 140 W
- Mass ~ 20 kg
- System efficiency: ~ 30 %
- 2 GPHS modules
- Uses 0.8 kg plutonium-238Plutonium-238-External links:**...