Europa Multiple-Flyby Mission
Concept artwork of the Europa Multiple-Flyby Mission spacecraft
|Names||Europa Clipper (2012-15)|
|Mission type||Europa reconnaissance|
|Mission duration||Cruise: 6.4 years (Atlas V), or
Cruise: 1.9 years (SLS Block I)
Science: 3.5 years
|Manufacturer||Jet Propulsion Laboratory|
|Power||600W from solar cells|
|Start of mission|
|Launch date||Between 2022 & 2025|
|Rocket||Atlas V 551 or SLS Block I|
The Europa Multiple-Flyby Mission (formerly known as the Europa Clipper) is an interplanetary space probe in development by NASA. Set for a launch in the 2020s, the spacecraft is being developed to study the Galilean moon Europa, through a series of flybys while in orbit around Jupiter.
The mission is a follow-up to studies made by the Galileo spacecraft during its eight years in Jupiter orbit, which indicated the existence of a subsurface ocean underneath Europa. Plans to send a spacecraft to Europa were initially conceived with projects such as Europa Orbiter and Jupiter Icy Moons Orbiter, in which a spacecraft would be injected into orbit around Europa. However, due to the strong impact of radiation from Jupiter's magnetosphere in Europan orbit, it was decided that it would be safer to inject a spacecraft into an orbit around Jupiter and make several close flybys of the moon instead. The mission was originally branded the Europa Clipper mission, and began as a joint investigation between the Jet Propulsion Laboratory and the Applied Physics Laboratory.
The Europa Mission spacecraft will be built and manufactured with a scientific payload of nine instruments, contributed by the JPL, APL, Southwest Research Institute, University of Texas, Arizona State University and University of Colorado Boulder. Two possibilities for transfer to Jupiter have been considered: one, using an Atlas V 551 to launch the spacecraft into a trajectory that will make use of multiple gravity assists from Earth and Venus, and the other using the Space Launch System to launch the spacecraft directly towards Jupiter.
Immediately following the Galileo spacecraft's discoveries, JPL conducted preliminary mission studies that envisioned a capable spacecraft such as the Jupiter Icy Moons Orbiter (a $16B mission concept ), the Jupiter Europa Orbiter (a $4.3B concept), an orbiter ($2B concept), and a multi-flyby spacecraft: Europa Clipper. The proposal and scope of the Europa Clipper mission are still in the conceptual stage, but the approximate cost is estimated at $2 billion. Meanwhile, the European Space Agency is already developing the Jupiter Icy Moon Explorer for a proposed launch in 2022.
In March 2013, $75 million USD were authorized to expand on the formulation of mission activities, mature the proposed science goals, and fund preliminary instrument development, as suggested in 2011 by the Planetary Science Decadal Survey. In May 2014, a House bill substantially increased Europa Clipper funding budget for the 2014 fiscal year from $15 million to $100 million. The funds would be applied to pre-formulation work.
The mission's science definition team is chaired by Louise Prockter from the Johns Hopkins University's the Applied Physics Laboratory (APL), and Barry Goldstein from the Jet Propulsion Laboratory (JPL), who presented an updated concept for Europa Clipper in July 2013.
Following the 2014 election cycle, bipartisan support was pledged to continue funding for the Europa Clipper project. The executive branch has also granted such a mission $30 million for preliminary studies, the most the White House has proposed for the mission.
In April 2015, NASA offered to the European Space Agency to submit concepts for an additional probe to fly together with the Europa Clipper spacecraft. It could be a simple probe, an impactor or a lander. An internal assessment at ESA is underway to see if there is interest and funds available.
In May 2015, NASA announced they had chosen the nine instruments that would fly onboard the orbiter. They will cost about $110 million over the next three years.
In June 2015, NASA announced its approval of the mission concept, allowing the orbiter to move to its formulation stage.
The goals of the proposed Europa Clipper space probe are to explore Europa, investigate its habitability and aid in the selection of future landing sites. Specifically, the objectives are to study:
- Ice shell and ocean: Confirm the existence, and characterize the nature, of water within or beneath the ice, and processes of surface-ice-ocean exchange.
- Composition: Distribution and chemistry of key compounds and the links to ocean composition.
- Geology: Characteristics and formation of surface features, including sites of recent or current activity.
The Europa Clipper would not orbit Europa, but instead orbit Jupiter and conduct 45 flybys of Europa at altitudes from 25 to 2700 km each during its mission. Each flyby would cover a different sector of Europa in order to achieve a medium-quality global topographic survey, including ice thickness. The Europa Clipper could conceivably flyby at low altitude through the plumes of water vapor erupting from the moon's icy crust, thus sampling its subsurface ocean without having to land on the surface and drill though the ice. Europa's surface needs to be scouted out first; thus, the Clipper concept has as a secondary goal: to characterize scientifically compelling sites for a future lander mission to Europa.
Because Europa lies well within the harsh radiation fields surrounding Jupiter, even a radiation-hardened spacecraft in near orbit would be functional for just a few months. Another key limiting factor on science for a Europa orbiter is not the time the instruments can make observations. Rather, it is the time available to return data to Earth. Most instruments can gather data far faster than the communications system can transmit it to Earth, but there are a limited number of antennas available to receive the scientific data.
Studies by scientists from the Jet Propulsion Laboratory show that by performing several flybys with many months to return data, the Europa Clipper concept would enable a $2B mission to conduct the most crucial measurements of the cancelled $4.3B Jupiter Europa Orbiter concept. Between each of the flybys, the spacecraft would have seven to ten days to transmit data stored during each brief encounter. That would let the spacecraft have up to a year of time to transmit its data compared to just 30 days for an orbiter. The result would be almost three times as much data returned to Earth, while reducing exposure to radiation.
Europa Clipper would inherit tested technology of the Galileo and Juno Jupiter orbiters with regards to radiation protection. Shielding will be provided by 150 kilograms of material. To maximize its effectiveness, the electronics will be nested in the core of the spacecraft for additional radiation protection.
Design and construction
Both radioisotope thermoelectric generator and photovoltaic power sources were analyzed as possible power for the mission. In September 2013 it was decided that solar panels are the least expensive option to power the spacecraft. Early analysis suggest that each panel will have a surface area of 18m2 and produce 150 watts continuously when pointed towards the Sun while at Jupiter. While in Europa's shadow, batteries will enable the spacecraft to continue gathering data. However, ionizing radiation can damage solar cells. The Europa Clipper's orbit causes the spacecraft pass through Jupiter's intense magnetosphere, which is expected to gradually degrade the solar cells as the mission progresses.
The alternative to solar panels considered is Multi-Mission Radioisotope Thermoelectric Generators, fueled with plutonium-238. The power source has already been demonstrated in the Mars Science Laboratory mission. Five units are currently available, with one reserved for the Mars 2020 rover mission and another as backup. If funding becomes available, providing a restart of plutonium production and the replacement of the equipment needed to press it into pellets, it would be feasible to use MMRTGs on Europa Clipper.
On 3 October 2014, it was announced that solar panels have been chosen to power Europa Clipper. The mission's designers have determined that, despite the fact that solar power is only 4% as intense at Jupiter as it is in Earth's orbit, solar was both cheaper than plutonium and practical to use on the spacecraft. Despite the increased weight of solar panels compared to plutonium-powered generators, the vehicle's mass had been projected to still be within acceptable launch limits.
The spacecraft and trajectory are subject to change as the design matures. The nine science instruments, announced in May 2015, have an estimated total mass of 82 kg (181 lb) and are listed below:
- The Plasma Instrument for Magnetic Sounding (PIMS) works in conjunction with a magnetometer and is key to determining Europa's ice shell thickness, ocean depth, and salinity by correcting the magnetic induction signal for plasma currents around Europa.
- Principal investigator: Joseph Westlake, Applied Physics Laboratory
- The Interior Characterization of Europa using Magnetometry (ICEMAG) is a magnetometer that will measure the magnetic field near Europa and – in conjunction with the PIMS instrument – will probe the location, depth, thickness and salinity of Europa's subsurface ocean using multi-frequency electromagnetic sounding.
- Principal investigator: Carol Raymond, Jet Propulsion Laboratory
- The Mapping Imaging Spectrometer for Europa (MISE) instrument will probe the surface composition of Europa, identifying and mapping the distributions of organics, salts, acid hydrates, water ice phases, and other materials to determine the habitability of Europa's ocean. From these measurements, scientists expect to be able to relate the moon's surface composition to the habitability of its ocean. MISE is built in collaboration with the Johns Hopkins University Applied Physics Laboratory (APL).
- Principal investigator: Diana Blaney, Jet Propulsion Laboratory
- The Europa Imaging System (EIS) is a wide and narrow angle camera instrument that will map most of Europa at 50 m (160 ft) resolution, and will provide images of selected surface areas at up to 100 times higher resolution.
- Principal investigator: Elizabeth Turtle, Applied Physics Laboratory
- The Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) is a dual-frequency ice penetrating radar instrument that is designed to characterize and sound Europa's ice crust from the near-surface to the ocean, revealing the hidden structure of Europa's ice shell and potential water pockets within. This instrument will be built by JPL and the University of Iowa.
- Principal investigator: Donald Blankenship, University of Texas
- The Europa Thermal Emission Imaging System (E-THEMIS) is a "heat imager", which will provide high spatial resolution, multi-spectral thermal imaging of Europa to help detect active sites, such as potential vents erupting plumes of water into space. This instrument is derived from the Thermal Emission Imaging System (THEMIS) on 2001 Mars Odyssey orbiter, also developed by Philip Christensen.
- Principal investigator: Philip Christensen, Arizona State University
- The MAss SPectrometer for Planetary EXploration/Europa (MASPEX) is a spectrometer that will determine the composition of the surface and subsurface ocean by measuring Europa's extremely tenuous atmosphere and any surface material ejected into space. Jack Waite, who developed MASPEX, was selected as the Science Team Lead of the Ion and Neutral Mass Spectrometer (INMS) on Cassini spacecraft. The INMS was developed as a facility instrument at NASA Goddard Space Flight Center under the direction of Dr. Hasso Niemann.
- Principal investigator: Jack Waite, Southwest Research Institute
- The Ultraviolet Spectrograph/Europa (UVS) instrument will be able to detect small plumes and will provide valuable data about the composition and dynamics of the moon's exosphere. He discovered plumes erupting from Europa while using the Hubble Space Telescope in the UV spectrum.
- Principal investigator: Kurt Retherford, Southwest Research Institute
- The SUrface Dust Mass Analyzer (SUDA) instrument will measure the composition of small solid particles ejected from Europa, providing the opportunity to directly sample the surface and potential plumes on low-altitude flybys. The instrument is capable of reliably identifying traces of organic and inorganic materials in the ice matrix of ejecta.
- Principal investigator: Sascha Kempf, University of Colorado Boulder
The scientists proposing this mission are also considering deploying from the spacecraft several miniaturized satellites of the CubeSat format, possibly driven by ion thrusters, to sample and analyse Europa's plumes. Europa Clipper would relay signals from the satellites with its high-gain antenna back to Earth. With propulsion, some nanosatellites could be capable of entering orbit around Europa. However, including additional mass would only be possible if the Europa Clipper is launched with the powerful Space Launch System (SLS) heavy lift launch vehicle.
A baseline profile for the mission would involve launch aboard an Atlas V 551. By using a Venus-Earth-Earth gravity assist trajectory the transit time to Jupiter would be about 6 years. Alternately, if the mission was launched by NASA's Space Launch System, it could arrive at Jupiter on a direct trajectory in less than 3 years.
- Europa Jupiter System Mission – Laplace
- Europa Lander by Russia
- Europa Orbiter
- Exploration of Jupiter
- Jupiter Icy Moon Explorer
- Leone, Dan (22 July 2013). "NASA's Europa Mission Concept Progresses on the Back Burner". Space News.
- Phillips, Cynthia B.; Pappalardo, Robert T. (20 May 2014). "Europa Clipper Mission Concept:". Eos, Transactions American Geophysical Union 95 (20): 165–167. doi:10.1002/2014EO200002. Retrieved 2014-10-01.
- Goldstein, Barry; Pappalardo, Robert (19 February 2015). "Europa Clipper Update" (PDF). Outer Planets Assessment Group.
- Wall, Mike (5 March 2014). "NASA hopes to launch ambitious mission to icy Jupiter moon". Space.com. Retrieved 2014-04-15.
- Clark, Stephen (14 March 2014). "Economics, water plumes to drive Europa mission study". Spaceflight Now. Retrieved 2014-04-15.
- Dreier, Casey (12 December 2013). "Europa: No Longer a "Should," But a "Must"". The Planetary Society.
- All Systems Go for NASA's Mission to Jupiter Moon Europa. NASA News, 17 June 2015
- "Europa Multiple Flyby Mission". Solar System Exploration. National Aeronautics and Space Administration. Retrieved 9 July 2015.
- Schulze-Makuch, Dirk; Irwin, Louis N. (2001). "Alternative Energy Sources Could Support Life on Europa" (PDF). Departments of Geological and Biological Sciences. University of Texas at El Paso. Archived from the original (PDF) on 2006-07-03.
- Zabarenko, Deborah (7 March 2011). "Lean U.S. missions to Mars, Jupiter moon recommended". Reuters.
- "Project Prometheus final report - page 178" (PDF). 2005. Retrieved 20 January 2015.
- Kane, Van (26 August 2014). "Europa: How Less Can Be More". Planetary Society. Retrieved 2014-08-29.
- "ESA—Selection of the L1 mission" (PDF). April 17, 2012.
- "Destination: Europa". Europa SETI. 29 March 2013.
- Zezima, Katie (8 May 2014). "House gives NASA more money to explore planets". Washington Post. Retrieved 2014-05-09.
- Morin, Monte (8 May 2014). "$17.9-billion funding plan for NASA would boost planetary science". Los Angeles Times. Retrieved 2014-05-09.
- Pappalardo, Robert; Cooke, Brian; Goldstein, Barry; Prockter, Louise; Senske, Dave; Magner, Tom (July 2013). "The Europa Clipper" (PDF). OPAG Update (PDF). Lunar and Planetary Institute.
- Nola Taylor Redd (5 November 2014). "To Europa! Mission to Jupiter's Moon Gains Support in Congress". Retrieved November 2014.
- Dreier, Casey (3 February 2015). "It's Official: We're On the Way to Europa". Retrieved 8 February 2015.
- Kane, Van (3 February 2015). "2016 Budget: Great Policy Document and A Much Better Budget". Retrieved 8 February 2015.
- Clark, Stephen (March 10, 2015). "Europa Clipper concept team aims for launch in 2022". Space Flight Now. Retrieved 2015-04-09.
- Clark, Stephen (10 April 2015). "NASA invites ESA to build Europa piggyback probe". Space Flight Now. Retrieved 2015-04-17.
- Klotz, Irene (26 May 2015). "NASA's Europa Mission Will Look for Life's Ingredients". Discovery News. Retrieved 2015-05-26.
- Howell, Elizabeth (20 June 2015). "NASA's Europa Mission Approved for Next Development Stage". Space.com. Retrieved 2015-06-21.
- Kane, Van (26 May 2013). "Europa Clipper Update". Future Planetary Exploration.
- Pappalardo, Robert T.; Vance, S.; Bagenal, F.; Bills, B.G.; Blaney, D.L.; Blankenship, D.D.; Brinckerhoff, W.B.; Connerney, J.E.P.; Hand, K.P.; Hoehler, T.M.; Leisner, J.S.; Kurth, W.S.; McGrath, M.A.; Mellon, M.T.; Moore, J.M.; Patterson, G.W.; Prockter, L.M.; Senske, D.A.; Schmidt, B.E.; Shock, E.L.; Smith, D.E.; Soderlund, K.M. (2013). "Science Potential from a Europa Lander". Astrobiology 13 (8): 740–73. doi:10.1089/ast.2013.1003. PMID 23924246. Retrieved 2013-12-14.
- Senske, D. (2 October 2012). "Europa Mission Concept Study Update" (PDF). Presentation to Planetary Science Subcommittee (PDF).
- "Europa Clipper". NASA - JPL. 2015. Retrieved 2015-02-08.
- A. Eremenko et al., “Europa Clipper spacecraft configuration evolution,” 2014 IEEE Aerospace Conference, pp. 1-13, Big Sky, MT, March 1-8, 2014
- Dreier, Casey (5 September 2013). "NASA's Europa Mission Concept Rejects ASRGs -- May Use Solar Panels at Jupiter Instead". The Planetary Society.
- Leone, Dan (28 July 2014). "Europa Clipper Would Wash Out Other Nuclear-powered Missions". Space News. Retrieved 2014-08-29.
- Foust, Jeff (8 October 2014). "Europa Clipper Opts for Solar Power over Nuclear". Retrieved 8 February 2015.
- "NASA's Europa Mission Begins with Selection of Science Instruments". Jet Propulsion Laboratory (NASA News). 26 May 2015. Retrieved 2015-05-27.
- Westlake, Joseph (2014). "Workshop on the Habitability of Icy Worlds (2014)" (PDF). Retrieved 2015-05-27.
- "Europa Mission to Probe Magnetic Field and Chemistry". Jet Propulsion Laboratory. 27 May 2015. Retrieved 2015-05-29.
- Blaney, Diana L. (2010). "Europa Composition Using Visible to Short Wavelength Infrared Spectroscopy". JPL (American Astronomical Society, DPS meeting #42, #26.04; Bulletin of the American Astronomical Society, Vol. 42, p.1025).
- "Radar Techniques Used in Antarctica Will Scour Europa for Life-Supporting Environments". University of Texas Austin. 1 June 2015. Retrieved 2015-06-04.
- Grima, Cyril; Schroeder, Dustin; Blakenship, Donald D.; Young, Duncan A. (15 November 2014). "Planetary landing-zone reconnaissance using ice-penetrating radar data: Concept validation in Antarctica". Planetary and Space Science 103: 191–204. doi:10.1016/j.pss.2014.07.018.
- Roth, Lorenz (2014). "Transient Water Vapor at Europa’s South Pole". Science 343 (171). doi:10.1126/science.1247051. ISSN 1095-9203.
- Kempf, Sascha; et al. (May 2012). "Linear high resolution dust mass spectrometer for a mission to the Galilean satellites". Planetary and Space Science 65 (1): 10–20. doi:10.1016/j.pss.2011.12.019. Retrieved 2015-05-27.
- "JPL Selects Europa CubeSat Proposals for Study". Jet Propulsion Laboratory (NASA). 8 October 2014. Retrieved 2015-04-17.