The Rosetta spacecraft rendezvoused with comet 67P/Churyumov-Gerasimenko in 2014–2016 and observed its surface morphology and mass loss process. The large obliquity (52°) of the comet nucleus introduces many novel physical effects not known before. These include the ballistic transport of dust grains from the southern hemisphere to the northern hemisphere during the perihelion passage, thus shaping the dichotomy of two sides, with the northern hemisphere largely covered by dust layers from the recycled dusty materials (back fall) and the southern hemisphere consisting mostly of consolidated terrains. A significant amount of surface material up to 4–10 m in depth could be transferred across the nucleus surface in each orbit. New theories of the physical mechanisms driving the outgassing and dust ejection effects are being developed. There is a possible connection between the cometary dust grains and the fluffy aggregates and pebbles in the solar nebula in the framework of the streaming-instability scenario. The Rosetta mission thus succeeded in fulfilling one of its original scientific goals concerning the origin of comets and their relation to the formation of the solar system.
The study of active asteroids is a relatively new field of study in Solar System science, focusing on objects with asteroid-like orbits but that exhibit comet-like activity. This field, which crosses traditionally drawn lines between research focused on inactive asteroids and active comets, has motivated reevaluations of classical assumptions about small Solar System objects and presents exciting new opportunities for learning more about the origin and evolution of the Solar System. Active asteroids whose activity appears to be driven by the sublimation of volatile ices could have significant implications for determining the origin of the Earth’s water—and therefore its ability to support life—and also challenge traditional assumptions about the survivability of ice in the warm inner Solar System. Meanwhile, active asteroids whose activity appears to be caused by disruptive processes such as impacts or rotational destabilization provide exciting opportunities to gain insights into fundamental processes operating in the asteroid belt and assessing their effects on the asteroid population seen in the 21st century.
Christopher J. Newman
Space activity within the United Kingdom (U.K.) has undergone a significant period of change with successive governments viewing space as a significant source of economic growth. This has seen increasing attention being paid to both space policy and regulation. As a signatory to the Outer Space Treaty 1967, the U.K. is internationally responsible for the space activity of both its governmental and commercial entities. These obligations were initially discharged through the Outer Space Act 1986 and the licensing framework that emerged from that. The decision of the government to develop the capability to launch small satellites from within the U.K., coupled with the promise of high-altitude activities and horizontal launch, meant that action was needed to update the law and regulation of space activity within the U.K. The need for investment to fuel the ambition of the U.K. is set out in the National Space Strategy.
The Austrian Outer Space Act, which entered into force in December 2011, and the Austrian Outer Space Regulation, which has been in force since February 2015, form the legal framework for Austrian national space activities. The elaboration of this national space legislation became necessary when the first two Austrian satellites were developed, to ensure compliance with Austria’s obligations as State Party to the five United Nations space treaties. The legislation comprehensively regulates legal aspects related to space activities, including the authorization, supervision, and termination of space activities; the registration of space objects; insurance requirements; and possibilities for recourse of the government against the operator. One of the main purposes of the law is to ensure the authorization of national space activities. The Outer Space Act sets forth the conditions for authorization, which, inter alia, refer to the expertise of the operator, requirements for orbital positions and frequency assignments, space debris mitigation, insurance requirements, and the safeguard of public order, public health, and national security, as well as of Austrian foreign policy interests and international law obligations. The Austrian Outer Space Regulation complements these provisions by specifying the documents the operator must submit as evidence of the fulfillment of the authorization conditions, which include the results of safety tests, emergency plans, and information on the collection and use of Earth observation data. Particular importance is attached to the mitigation of space debris. Operators are required to take measures in accordance with international space debris mitigation guidelines for the avoidance of operational debris, the prevention of on-orbit breakups and collisions, and the removal of space objects from Earth orbit after the end of the mission. Another specificity of the Austrian space legislation is the possibility of an exemption from the insurance requirement or a reduction of the insurance sum if the space activity is in the public interest. This allows the support of space activities that serve science, research, and education. Moreover, the law also provides for the establishment of a national registry for objects launched into outer space by the competent Austrian ministry.
Elina Morozova and Alena Laurenava
Space activities are technically sophisticated and challenging endeavors involving high risk. Notwithstanding precautionary measures that are taken by commercial operators, damage may be caused during space objects’ launching, passing through air space, in-orbit maneuvering and operating, and de-orbiting. The rules and procedures aimed at ensuring the prompt payment of a full and equitable compensation for such damage constitute the international liability regime, which is of crucial importance in space law. The first reference to international liability for damage caused by space objects and their component parts on Earth, in air space, or in outer space can be traced back to the very beginning of the space era. In 1963, just a few years after the first ever artificial satellite was launched, international liability was declared by the United Nations General Assembly as one of the legal principles governing the activities of states in the exploration and use of outer space. It was later made legally binding by inclusion in the 1967 Outer Space Treaty and received further development in the 1972 Liability Convention. The latter is generally referred to as lex specialis when the interrelation between the two international treaties is described and introduces several provisions that treat liability for damage caused in specific circumstances somewhat differently. International space law imputes liability on states that launch or procure launchings of space objects and states from whose territory or facility space objects are launched. This does not, however, exclude liability for damage caused by space objects that are operated by private entities. Still, international liability for accidents involving commercial operators stays with the so-called launching states, as this term is defined by the Liability Convention for the same states that are listed in the Outer Space Treaty as internationally liable. Insurance is well known to address damages and liability issues, including those arising from commercial launches; however, it is not always mandatory. Frequently, space-related accidents involve nonfunctional space objects and their component parts, which are usually referred to as “space debris.” This may include spent rocket stages and defunct satellites, as well as fragments from their disintegration. Since the nonfunctional state of a space object does not change its legal status, the relevant provisions of international space law that are applicable to space objects continue to apply to what is called space debris. This means, in particular, that launching states are internationally liable for damage caused by space debris, including cases where such debris was generated by private spacecraft. The probability of liability becomes even higher when it comes to active space debris removal. Such space activities, which are extensively developed by private companies, are inextricably linked to potential damage. Yet, practical problems arise with identification of space debris and, consequently, an efficient implementation of the liability regime.