The Europa Orbiter [1] was a planned NASA mission to Jupiter's Moon Europa, that was cancelled in 2002. [2] Its main objectives included determining the presence or absence of a subsurface ocean and identifying candidate sites for future lander missions. [3] Europa Orbiter received pre-project funding in 1998, and resulted from NASA's Fire and Ice project. [3]
Europa Orbiter was a design for a mission to the Jovian moon Europa, based on a 900 kg (2,000 lb) orbiter, of which 500 kg (1,100 lb) was fuel for maneuvers. [4] It would have been powered by Radioisotope thermoelectric generator (RTG) power and launched from the Space Shuttle in 2003. [4] This would have meant an arrival at Jupiter in 2007, at which time it would commence in a three-part science tour focused on Europa. [4] The spacecraft would be radiation hardened to survive a predicted 4 megarads of radiation. [4]
The science payload would include a radar to determine the thickness of ice at Europa, and determine what was below it. [5] Other instruments would be an altimeter and imaging systems, among other devices. [6]
In 1999, NASA issued an announcement of opportunity that solicited experiments for Europa Orbiter, Pluto Kuiper Express, and Parker Solar Probe. [4]
The results of the studies on the Europa Orbiter have been conducive to the Jupiter Europa Orbiter (JEO), NASA's contribution to the planned international Europa Jupiter System Mission (EJSM) that was slated for launch in 2020. EJSM was cancelled in 2011.
The Europa Orbiter-concept should not be confused with the Jovian Europa Orbiter, a feasibility study conducted by the European Space Agency (ESA) which was finally superseded by the EJSM, too.
Another Europa mission in this era was the Europa Ice Clipper, a Stardust mission-like sample return mission. [5]
The next NASA mission to Jupiter was Juno , which was selected in 2005 as the next New Frontiers mission after New Horizons . [7] It was launched in 2011 and arrived at Jupiter in the summer of 2016.
A 2002 paper noted the following challenges for this mission: "substantial energy required for a direct trajectory, the long duration of the mission, the high total-radiation dose, and the need for radioisotope thermoelectric generators". [8] One mission plan involved first entering Jovian orbit, then use multiple gravity assists from the Moons of Jupiter to help it to enter the orbit of Europa with less rocket fuel. [9]
Later in the 21st century, it was suggested the goal of the Europa Orbiter should have been to find places where the freshest sub-surface material had been brought to the surface. [10] This location would then be the target of a lander which could study what would hopefully be subsurface material, without having to drill down through the ice layer. [11]
Another aspect that has been noted was that this concept was studied about three years leading up to its cancellation in 2002. [11] After Europa Orbiter, NASA turned its attention to a nuclear fission powered orbiter for Europa for Project Prometheus. [11]
Comparison of notional NASA missions targeting Jupiter's moon Europa.
Name | Time Period | Power | Launcher |
---|---|---|---|
Europa Orbiter | 1999–2002 | RTG | Space Shuttle |
Jupiter Icy Moons Orbiter | 2004–2005 | Fission | Delta IV Heavy |
Jupiter Europa Orbiter (EJSM ) | 2008–2011 | RTG | Delta IV Heavy, Atlas V, etc. |
Europa Clipper | 2015– | Solar | Falcon Heavy |
Galileo was an American robotic space program that studied the planet Jupiter and its moons, as well as several other Solar System bodies. Named after the Italian astronomer Galileo Galilei, the Galileo spacecraft consisted of an orbiter and an entry probe. It was delivered into Earth orbit on October 18, 1989 by Space ShuttleAtlantis on the STS-34 mission, and arrived at Jupiter on December 7, 1995, after gravitational assist flybys of Venus and Earth, and became the first spacecraft to orbit Jupiter. It launched the first probe into Jupiter, directly measuring its atmosphere. Despite suffering major antenna problems, Galileo achieved the first asteroid flyby, of 951 Gaspra, and discovered the first asteroid moon, Dactyl, around 243 Ida. In 1994, Galileo observed Comet Shoemaker–Levy 9's collision with Jupiter.
Callisto, or Jupiter IV, is the second-largest moon of Jupiter, after Ganymede. In the Solar System it is the third-largest moon after Ganymede and Saturn's largest moon Titan, and as large as the smallest planet Mercury, though only about a third as massive. Callisto is, with a diameter of 4821 km, roughly a third larger than the Moon and orbits Jupiter on average at a distance of 1883000 km, which is about six times further out than the Moon orbiting Earth. It is the outermost of the four large Galilean moons of Jupiter, which were discovered in 1610 with one of the first telescopes, being visible from Earth with common binoculars.
Europa, or Jupiter II, is the smallest of the four Galilean moons orbiting Jupiter, and the sixth-closest to the planet of all the 95 known moons of Jupiter. It is also the sixth-largest moon in the Solar System. Europa was discovered independently by Simon Marius and Galileo Galilei and was named after Europa, the Phoenician mother of King Minos of Crete and lover of Zeus.
Ganymede, or Jupiter III, is the largest and most massive natural satellite of Jupiter as well as in the Solar System, being a planetary-mass moon. It is the largest Solar System object without an atmosphere, despite being the only moon in the Solar System with a substantial magnetic field. Like Titan, it is larger than the planet Mercury, but has somewhat less surface gravity than Mercury, Io or the Moon.
The Jupiter Icy Moons Orbiter (JIMO) was a proposed NASA spacecraft designed to explore the icy moons of Jupiter. The main target was Europa, where an ocean of liquid water may harbor alien life. Ganymede and Callisto, which are now thought to also have liquid, salty oceans beneath their icy surfaces, were also targets of interest for the probe.
Io, or Jupiter I, is the innermost and third-largest of the four Galilean moons of the planet Jupiter. Slightly larger than Earth's moon, Io is the fourth-largest moon in the Solar System, has the highest density of any moon, the strongest surface gravity of any moon, and the lowest amount of water of any known astronomical object in the Solar System. It was discovered in 1610 by Galileo Galilei and was named after the mythological character Io, a priestess of Hera who became one of Zeus's lovers.
Juno is a NASA space probe orbiting the planet Jupiter. It was built by Lockheed Martin and is operated by NASA's Jet Propulsion Laboratory. The spacecraft was launched from Cape Canaveral Air Force Station on August 5, 2011 UTC, as part of the New Frontiers program. Juno entered a polar orbit of Jupiter on July 5, 2016, UTC, to begin a scientific investigation of the planet. After completing its mission, Juno will be intentionally deorbited into Jupiter's atmosphere.
The exploration of Jupiter has been conducted via close observations by automated spacecraft. It began with the arrival of Pioneer 10 into the Jovian system in 1973, and, as of 2023, has continued with eight further spacecraft missions in the vicinity of Jupiter. All of these missions were undertaken by the National Aeronautics and Space Administration (NASA), and all but two were flybys taking detailed observations without landing or entering orbit. These probes make Jupiter the most visited of the Solar System's outer planets as all missions to the outer Solar System have used Jupiter flybys. On 5 July 2016, spacecraft Juno arrived and entered the planet's orbit—the second craft ever to do so. Sending a craft to Jupiter is difficult, mostly due to large fuel requirements and the effects of the planet's harsh radiation environment.
The advanced Stirling radioisotope generator (ASRG) is a radioisotope power system first developed at NASA's Glenn Research Center. It uses a Stirling power conversion technology to convert radioactive-decay heat into electricity for use on spacecraft. The energy conversion process used by an ASRG is significantly more efficient than previous radioisotope systems, using one quarter of the plutonium-238 to produce the same amount of power.
The Europa Jupiter System Mission – Laplace (EJSM-Laplace) was a proposed joint NASA/ESA uncrewed space mission slated to launch around 2020 for the in-depth exploration of Jupiter's moons with a focus on Europa, Ganymede and Jupiter's magnetosphere. The mission would have comprised at least two independent elements, NASA's Jupiter Europa Orbiter (JEO) and ESA's Jupiter Ganymede Orbiter (JGO), to perform coordinated studies of the Jovian system.
The Jupiter Magnetospheric Orbiter is a cancelled space probe proposed by the Japanese Aerospace Exploration Agency (JAXA), to undertake detailed in situ studies of the magnetosphere of Jupiter as a template for an astrophysical magnetised disk.
As a part of the defunct Europa Jupiter System Mission – Laplace (EJSM-Laplace), the Jupiter Europa Orbiter (JEO) was a proposed orbiter probe slated for lift-off in 2020 and planned for detailed studies of Jupiter's moons Europa and Io as well as the Jovian magnetosphere. Its main goal would have been to look for evidence of a possible subsurface ocean.
The exploration of Io, Jupiter's innermost Galilean and third-largest moon, began with its discovery in 1610 and continues today with Earth-based observations and visits by spacecraft to the Jupiter system. Italian astronomer Galileo Galilei was the first to record an observation of Io on January 8, 1610, though Simon Marius may have also observed Io at around the same time. During the 17th century, observations of Io and the other Galilean satellites helped with the measurement of longitude by map makers and surveyors, with validation of Kepler's Third Law of planetary motion, and with measurement of the speed of light. Based on ephemerides produced by astronomer Giovanni Cassini and others, Pierre-Simon Laplace created a mathematical theory to explain the resonant orbits of three of Jupiter's moons, Io, Europa, and Ganymede. This resonance was later found to have a profound effect on the geologies of these moons. Improved telescope technology in the late 19th and 20th centuries allowed astronomers to resolve large-scale surface features on Io as well as to estimate its diameter and mass.
JunoCam is the visible-light camera/telescope onboard NASA's Juno spacecraft currently orbiting Jupiter. The camera is operated by the JunoCam Digital Electronics Assembly (JDEA). Both the camera and JDEA were built by Malin Space Science Systems. JunoCam takes a swath of imaging as the spacecraft rotates; the camera is fixed to the spacecraft, so as it rotates, it gets one sweep of observation. It has a field of view of 58 degrees with four filters.
Laplace-P was a proposed orbiter and lander by the Russian Federal Space Agency designed to study the Jovian moon system and explore Ganymede with a lander.
The Jupiter Icy Moons Explorer is an interplanetary spacecraft that was launched on 14 April 2023 from Guiana Space Centre in the French Guiana by the European Space Agency (ESA) with Airbus Defence and Space as the main contractor. The mission is planned to study Ganymede, Callisto, and Europa, three of Jupiter's Galilean moons. They are thought to have significant bodies of liquid water beneath their icy surfaces which would make them potentially habitable environments.
Europa Clipper is an interplanetary mission in development by NASA comprising an orbiter. Planned for launch in October 2024, the spacecraft is being developed to study the Galilean moon Europa through a series of flybys while in orbit around Jupiter.
Juno Radiation Vault is a compartment inside the Juno spacecraft that houses much of the probe's electronics and computers, and is intended to offer increased protection of radiation to the contents as the spacecraft endures the radiation environment at planet Jupiter. The Juno Radiation Vault is roughly a cube, with walls made of 1 cm thick titanium metal, and each side having an area of about a square meter. The vault weighs about 200 kg (500 lbs). Inside the vault are the main command and data handling and power control boxes, along with 20 other electronic boxes. The vault should reduce the radiation exposure by about 800 times, as the spacecraft is exposed to an anticipated 20 million rads of radiation It does not stop all radiation, but significantly reduces it in order to limit damage to the spacecraft's electronics.
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 Interior Characterization of Europa using Magnetometry (ICEMAG) is a multi-frequency magnetometer that was proposed to be flown on board the Europa Clipper mission to Jupiter's moon Europa, but its inclusion was cancelled in March 2019. Magnetic induction is a powerful tool for probing the subsurface and determine Europa's ocean depth, salinity, and ice shell thickness, as well as detecting erupting plume activity.
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