Exploration Mission to Uranus
Giant planets including Uranus and Neptune were thought to be static worlds. However, the study by Hofstadter (2) indicates that these worlds are dynamic. Ice giants such as Uranus have turbulent weather when viewed from ground-based convective features. Conversely, information from ground-based exploration is scanty and thus the need for a special exploratory mission to one of these Ice Giants. Exploration of ice giants remains one of the unexplored missions in space to date. Since the 1986 attempted voyage 2, there has never been another mission to ice giants. The study by Fletcher (2.15) indicates that ice giants have a unique environment that can be revealed only through a mission to one them.
Why Uranus Is Suitable Choice
A mission to ice giants takes into consideration some factors such as cost and uniqueness and the target planet, and thus Uranus becomes the easy target. Uranus is nearer and has a bizarre planetary tilt of 98 degrees based on the ecliptic plane. This tilt is the largest and challenges information on evolution and planetary information than any other planet (Hofstadter 5). Other physical properties of Uranus in comparison with other planets are shown in table 1.
Table 1: Physical properties of Uranus and other planets (Rencz 512)
The scientific model for the formation of the planet must be in agreement with available constraints for a generalized conclusion to be made. For Uranus, constraints such as planetary temperature, gravity, bulk composition, magnetic field and heat flux are not consistent with formation model. As a result, there exist an extensive list of scientific questions that ought to be answered. First, information about the internal fluid structure as well as the bulk composition of Uranus needs to be studied. This will enable scientists to provide answers to why ice giants differ from one point to another. Second, the Uranus’ atmosphere will be considered whereby information about its sluggish weather and climate will be laid bare. Third, the dynamics of the Uranium rings, which is a unique feature to this ice giant, will be analyzed.
Uranus has unusual magnetic configuration and thus its study is vital in understanding the Earth’s ancient magnetic field reversal concept. During solstice, the magnetosphere poles of Uranus points into the solar wind as opposed to other terrestrial magnetospheres that remains perpendicular to the solar wind. This provides a leeway for studies of magnetic reversal concepts.
Exploration mission to Uranus is possible because of the availability if appropriate technology. Following the launch of Voyager 2 in 1986, space technology has advanced leading to the creation of an orbiter (Hofstadter 4). This mission will thus involve Uranus Orbiter.
The orbiter will be launched using SLS space shuttle, also known as Space Launch System. SLS is an upgrade of the old Space Shuttle employed by NASA in its previous mission, and thus it will be suitable for launching Uranus Orbiter. NASA in conjunction with United Launch Alliance and Boeing is developing SLS (Nelson, Hutchison and Bolden 5). The payload capacity of SLS will be 130 tons with a total thrust of 32000KN. When completed, it will cost 500 million US dollars per every launch. Kennedy Space Center and LC-39B sites in the US are the most appropriate launch sites for the orbiter.
The Uranus Orbiter will be powered by MMRTGs, which are a type of generators that use thermoelectric power from radioisotopes. MMRTG was developed by NASA and was first used in 2003 meaning that the technology is feasible (Nelson, Hutchison and Bolden 2.17). At the start of the launch mission, MMRTGs that will be used are expected to produce 110W.
To accomplish its mandate successfully, the Uranus Orbiter will use similar hardware used on various missions by NASA in its interplanetary probe missions. The Orbiter’s payload will thus include a magnetometer, narrow-angle camera, radio science, plasma detector, IR imaging spectrometer, plasma and radio wave detector, and IR thermal bolometer.
Essential Instruments for the Mission
About eight primary instruments will be needed for this mission. They include a magnetometer for analyzing Uranus’ magnetic field, Narrow, and wide-angle cameras to image the Ice giant to the required level of details, and microwave radiometer. Doppler Spectro-Imager will also be used to take seismic measurements. Other instruments include VIS-NIR Image and Mass Spectrometers. The Ion and Neutral Mass Spectrometer needs to be complimented by Energetic Neutral Atomic Detector. In addition, a high-sensitivity accelerometer is required to be used during descent phase in the atmosphere.
The Uranus Orbiter mission can only be achieved through collaborative efforts with NASA and ESA since they have the technical capability. Since there is a need for testing and developing the orbiter, the most appropriate launch date is in 2022. Cruise time is expected to be 12 years meaning that it will reach orbit insertion in 2034. After that, the orbiter will take about 18 months to carry out its scientific mission.
The project is expected to take 1.3 billion US dollars. About 0.9 billion dollars will be spent on acquisition and launching of the orbiter while 0.4 billion will be dedicated to research. The project will involve a team of 115 engineers working in collaboration.
Fletcher, Leigh. “Future exploration of the outer solar system.” Astronomy & Geophysics Journal 54.2 (2013): 2.14-2.20.
Hofstadter, Mark. Ice Giant Science:The Case for a Uranus Orbiter. Decadal Survey Giant Planets Panel. Carlifonia: California Institute of Technology, 2009.
Nelson, Bill, Kay Hutchison and Charles Bolden. Future of NASA Space Program. Washington, D.C.: Cspan.org., 2011.
Rencz, Neil. Remote Sensing for the Earth Sciences: Manual of Remote Sensing. New York: John Wiley & Sons, 1999.