Environmental impact assessment (EIA) screening and scoping of extraterrestrial exploration and development projects

ABSTRACT

Numerous space missions are planned by government agencies and private companies, with objectives including scientific research, prospecting for and mining resources, and establishing human settlements. These projects have potential to affect the extraterrestrial environment. Environmental impact assessment (EIA) is an important tool for assessing the potential impact of projects on Earth’s environment. However, the legal requirements to undertake EIA for extraterrestrial projects are limited and most EIAs that have been conducted have not considered impacts beyond Earth’s atmosphere. Technical barriers to extraterrestrial EIA also need to be overcome, including a lack of guidelines and methodologies. This paper addresses the latter issue by identifying the extraterrestrial impacts that may arise from space projects and relating them to the environmental topic areas in the European EIA Directive. An example is then provided of how EIA screening and scoping can be undertaken for the extraterrestrial elements of space projects, using six scenarios. Effective EIA screening and scoping is key to deciding whether EIA is required and if so which topic areas should be included.

KEYWORDS:

• Environmental impact assessment
• EIA
• screening
• scoping
• extraterrestrial environment
• outer space

Introduction

Since environmental impact assessment (EIA) was first established in the USA in 1970 as part of the project planning process it has become a globally used environmental protection tool (Therivel and Morris 2001). However, the use of EIA to assess the impact of projects on the extraterrestrial environment has been very limited, despite the accelerating pace of space exploration (Viikari 2004; Kramer 2014, 2017). The extraterrestrial environment is defined in this paper as the region beyond Earth and its atmosphere, including orbital environments, outer space and celestial bodies.

Examples of space projects underway or currently being planned include:

• SpaceX plans to send two tourists around the Moon in 2018 using the Falcon Heavy rocket and Crew Dragon capsule (Crane 2017).

• SpaceX also has an aspirational goal to send a cargo mission to Mars in 2022 (Musk 2017).

• NASA is sending a rover to Mars in 2020 that will conduct science and exploration technology investigations (NASA c2018).

• China’s Chang’e 4 mission is due to launch in December 2018 with the country’s second lunar lander and rover (Crane 2017) which will land on the unexplored lunar far side (Wang and Liu 2016).

• Moon Express is proposing missions to the Moon starting in 2018, with the initial aim of establishing a permanent robotic research outpost and completing the first commercial sample return mission by 2020 (Moon Express c2018).

• Planetary Resources intends to embark on a commercial deep space exploration program in 2020 to ultimately mine asteroids for water and structural and precious metals (Planetary Resources c2018).

The extent to which the existing legal framework applies to protection of the environment beyond Earth has been discussed by various authors including, inter alia, Manson (1991), Viikari (2008), Race (2011), Cinelli and Pogorzelska (2013) and Gupta (2016). The conclusion drawn is that although a number of existing laws apply, such as Article IX of the Outer Space Treaty, the level of legal protection is inadequate. The legal requirements for EIA have been reviewed by several authors including, inter alia, Manson (1991), Viikari (2004) and Kramer (2014) who concluded that they are limited. In some cases the legal system requires EIA to be undertaken for terrestrial activities such as space launches, but does not require assessment of impacts to the extraterrestrial environment. For example, NASA conducts detailed EIAs for its space programs and missions, but these exclude assessing impacts beyond Earth’s atmosphere. A letter from NASA contained in the Programmatic Environmental Impact Statement (PEIS) for the Constellation Program explicitly states this as follows: ‘NASA takes the position that potential environmental impacts in outer space, including the Moon, are beyond the scope of NEPA [National Environmental Policy Act] analysis’ (NASA 2008a). The legal frameworks of Belgium and France are exceptions as they require that EIA considers extraterrestrial impacts. Belgium’s Law on the Activities of Launching, Flight Operation or Guidance of Space Objects (Kingdom of Belgium 2013) requires that an EIA be submitted prior to the launch, assessing the effects of the action on both the Earth and any celestial body affected (Kramer 2014). The Technical Regulations linked to the French Space Operations Act require authorisation applications to include environmental impact studies and the measures to avoid, reduce or mitigate the adverse effects on the environment and on outer space (Lazare 2013).

The European Space Agency (ESA) undertakes Life Cycle Assessments (LCAs) rather than EIAs for its missions and ESA’s Clean Space Initiative has developed LCA guidelines to support this process (ESA 2016). However, the guidelines state that the ‘LCA methodology has been developed to quantify environmental impacts on the earth eco-sphere’ and therefore impacts to the extraterrestrial environment are presumably excluded from consideration. The LCA studies performed by ESA to date have focussed on spacecraft and launchers and have identified the environmental impact in terms of various environmental indicators such as global warming potential, ozone depletion potential, human toxicity potential and metal depletion potential, while upcoming studies will focus on ground segment buildings and equipment (ESA 2017).

Despite the weak and inconsistent legal situation, two areas of space environmental protection have been taken more seriously by the international community, including measures to control levels of man-made space debris and ‘planetary protection’. These are covered internationally by the Inter-Agency Space Debris Coordination Committee’s (IADC’s) space debris mitigation guidelines (IADC 2007, 2014) and the Committee on Space Research’s (COSPAR’s) Planetary Protection Policy (COSPAR 2011). Space debris is defined by the IADC as ‘all man made objects including fragments and elements thereof, in Earth orbit or re-entering the atmosphere, that are non functional’ (IADC 2007). These pose a risk to spacecraft due to the high relative speed at which they may be travelling. Given the amount of debris already in orbit and the fact that when pieces collide they can fragment and multiply, there is concern that the number of objects could expand exponentially through ‘collisional cascading’ and thus limit future space activities in some orbits (NASA 2016a). Planetary protection relates to both the need to prevent microorganisms being carried by spacecraft to other planets (forward contamination), and to microorganisms being carried from other planets back to Earth (backward contamination). Conley and Rettberg (2010) state that:

Avoiding forward contamination is necessary to preserve planetary conditions for future biological and organic constituent exploration, and potentially for significant ethical reasons. Avoiding backward contamination is simple prudence – a necessary step to protect Earth and its biosphere from potential extraterrestrial sources of contamination.

However, other environmental issues have been given far less attention, including for example potential contamination by radioactive material which is often used within spacecraft and landers (Lyall 2010), atmospheric emissions (Horneck and Cockell 2010) and protection of environmental landscape features and historical/scientific or other resources of interest to humans (Ehrenfreund et al. 2013).

Context and aim

Given the weakness of the environmental governance framework for the extraterrestrial environment, a number of authors have recommended that treaties and laws should be strengthened (e.g. Kerrest 2011; von der Dunk 2012; Gupta 2016), and others have stressed the importance of developing standards and guidelines, international codes of conduct, protocols and other forms of ‘soft law’, by governmental, non-governmental and industry groups (e.g. Ehrenfreund et al. 2013; Kramer 2017). EIA is regarded as a supporting tool with strong potential (Viikari 2004, 2008; Kramer 2014, 2017) and Kramer (2017) believes that ‘environmental consulting firms, especially those with international reach, should consider this future potential’. A recent article in the professional press promoting extraterrestrial EIA, by the international consultancy firm WYG, demonstrates that the environmental profession is starting to take interest (Mustow 2017).

However, there are technical barriers to undertaking extraterrestrial EIA due to the lack of guidelines for impact assessment beyond Earth’s atmosphere. This paper contributes to addressing that issue by:

1. Identifying and describing the topic areas that are relevant to the extraterrestrial environment.

2. Considering the extraterrestrial impacts that could arise from space exploration and development projects that may take place in the next few years.

3. Providing an example of how to screen and scope EIAs to ensure that potentially significant effects on the extraterrestrial environment are identified and assessed. EIA screening is the process of determining whether EIA is required for a particular project (ERM 2001). EIA scoping involves deciding, from all of a project’s possible impacts and from all the realistic alternatives, which are the significant ones (Glasson et al. 2012). Glasson et al. (2012) advise that ‘an initial scoping of possible impacts may identify those impacts thought to be potentially significant, those thought to be not significant and those whose significance is unclear’.

Methodology

A literature review was undertaken to identify topic areas relevant to the space environment. This included a review of the scientific literature as well as relevant web sites and reports available online. Environmental Impact Statements (EISs) for space projects with significant extraterrestrial elements, that were readily available online, were also reviewed. These included EISs for the following programs and missions:

1. Apollo Program (NASA 1971)

2. Galileo Mission (NASA 1989)

3. Cassini Mission (NASA 1995, 1997)

4. International Space Station (NASA 1996)

5. Mars Surveyor 2001 Mission (NASA 1999)

6. Mars Exploration Rover-2003 Project (NASA 2002)

7. Horizontal Launch and Reentry of Reentry Vehicles Program (Federal Aviation Administration (FAA) 2005)

8. Mars Exploration Program (NASA 2005a)

9. New Horizons Mission (NASA 2005b)

10. Mars Science Laboratory Mission (NASA 2006)

11. Constellation Progam (NASA 2008a)

12. Launch of NASA Routine Payloads (NASA 2011)

13. Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) Mission (NASA 2013)

14. Mars 2020 Mission (NASA 2014)

The EISs were reviewed in relation to the environmental topics covered, in particular to determine whether these included consideration of the potential impacts to the extraterrestrial environment.

Relevant environmental topics identified from the literature review were grouped together and discussed under headings based on the factors listed within Article 3 of the European EIA Directive (European Council and Parliament 2014).

A number of realistic near-term space project scenarios were developed as ‘internally consistent projected series of events,’ which were based as closely as possible on actual (currently underway) and proposed (currently proposed or proposed in the recent past but never undertaken) programs and missions described in NASA EISs and other sources. These project scenarios were as follows with details provided in Table 1:

Table 1. Extraterrestrial Project Scenarios.

Number	Name of Mission/Program on which Scenario is Based	Type of Extraterrestrial Project Scenario	Description of Extraterrestrial Project Scenario	References
01	NASA’s Mars 2020 Mission	Mars exploration mission employing a robotic mobile science laboratory (rover)	Launch Mars 2020 spacecraft in 2020. Deliver a large, mobile science laboratory (rover) powered by a Multi-Mission Radioisotope Thermoelectric Generator and equipped with advanced instrumentation, to a scientifically interesting location on Mars early in 2021. Rover to conduct geological assessments of the landing site; determine the potential habitability of the environment; directly search for signs of ancient martian life; and select a collection of rock and soil samples to be stored for potential return to Earth by a future mission. Mission designated by NASA as Planetary Protection Category V: Restricted Earth Return and restricted from landing in, entering, or creating, a Special Region on Mars.	NASA 2014; Jet Propulsion Laboratory c2018
02	SpaceX’s Mars settlement program	Establishment of the first human settlement on Mars	In 2022 land at least two cargo ships on Mars. Confirm water resources and identify hazards. Place power, mining and life support infrastructure for future flights. In 2024 fly four ships to Mars, two cargo and two crew. On the first mission find the best source of water and on the second build the propellant plant. Construct the propellant depot which will consist of a large array of solar panels. Mine and refine water, draw CO2 out of the atmosphere and then create and store deep cryo CH4 and O2. The ships from these initial missions to also serve as the beginnings of SpaceX’s first Mars base.	Musk 2017
03	NASA’s New Frontiers Program, OSIRIS-REx Mission	Collection and return to Earth of surface samples from an asteroid	OSIRIS-REx spacecraft launched in 2016 to approach the Asteroid Bennu in October 2018. Spacecraft to undertake a detailed survey of Bennu lasting over a year, to include mapping potential sample sites. After the selection of the final site, the spacecraft to briefly touch the surface of Bennu to retrieve a sample. The sampling arm to make contact with the surface of Bennu for about five seconds to collect between 60 and 2000 g of material. Spacecraft to return to Earth with the sample, arriving in 2023.	NASA 2013; NASA c2017
04	Planetary Resources asteroid prospecting program	Prospecting of near Earth asteroids for water to identify where a mine will be established in space	In 2020 deploy multiple spacecraft via a single rocket launch. Rocket to carry the exploration spacecraft just beyond the influence of Earth’s gravity from where they will continue their journey using low-thrust ion propulsion systems. Each spacecraft to visit a pre-determined target near-Earth asteroid to collect data and test material samples obtained by firing four probes at areas of interest on the asteroid.	Planetary Resources c2018
05	NASA’s Constellation Program	Establishment of a permanently occupied human outpost on the Moon	Undertake initial short duration missions to the Moon culminating in a permanently occupied human outpost allowing missions of up to 180 days. Lunar lander to have a living module and to include a descent stage and an ascent stage. On return the descent stage to be left on the Moon’s surface. Ascent stage to be jettisoned and fall back to the Moon’s surface once the crew transfer back to the Orion spacecraft. Lunar surface systems to include resource extraction and utilisation equipment; habitation modules; and power generation, storage and surface mobility systems. Nuclear power sources to be used for surface electrical power generation.	NASA 2008a
06	Harvest Moon program, Moon Express	Prospecting on the Moon as a precursor to mining operations	Undertake three missions to the Moon starting in 2018 with the ‘Lunar Scout’ mission, followed by the ‘Lunar Outpost’ mission to the south pole of the Moon which has ‘peaks of eternal light’ where nearly continuous sunshine and direct communication with Earth are possible. Prospect for water and useful minerals, and employ a variety of research instruments. Then undertake the ‘Harvest Moon’ mission in 2020 to return ‘tens of kilograms’ of lunar material back to Earth.	Moon Express c2018; Bennett 2017

1. Uncrewed Mars exploration mission (based on NASA’s Mars 2020 Mission).

2. Establishment of the first human settlement on Mars (based on SpaceX’s Mars settlement program).

3. Collection and return to Earth of surface samples from an asteroid for scientific research (based on NASA’s OSIRIS-Rex Mission).

4. Commercial prospecting of near-Earth asteroids for water (based on Planetary Resources’ asteroid prospecting program).

5. Establishment of a permanently occupied human outpost on the Moon (based on NASA’s Constellation Program).

6. Commercial prospecting on the Moon and return to Earth of surface samples (based on Moon Express’s Harvest Moon program).

The elements of these project scenarios that could result in impacts to the extraterrestrial environment were identified, based on the findings of the literature review which are summarised in Table 2. An initial scoping exercise was conducted to determine whether the resulting effects could be significant, based on the nature and magnitude of impact and the sensitivity of the receptor. If a medium or high potential for significant effects was identified then these topic areas would need to be scoped into the EIA and assessed in more detail, with mitigation measures developed if necessary. A screening assessment was also undertaken to determine whether an EIA would be required.

Table 2. Extraterrestrial EIA topic areas.

Topic Area*	Aspects Relevant to the Extraterrestrial Environment
Population and human health	The only permanent human habitation in space is currently the International Space Station. In coming years it is possible that there will be human populations on other spacecraft as well as on the Moon and Mars. Human health needs to be considered in relation to the potential impact of a project on populations external to the project and on the health of those involved in the project itself. The latter is important given the risks posed to health by living in space and on other celestial bodies, for example due to Solar Particle Events (Hu 2017).
Biodiversity	Conditions suitable for life are believed to be present within the subsurface oceans of Europa, Titan, and possibly Enceladus, and the subsurface, possibly near-surface, aquifers of Mars (Nicholson et al. 2009; Conley and Rettberg 2010). The Committee on Space Research (COSPAR) maintains the international policy on planetary protection and has designated five categories for target body/mission type combinations and their respective suggested ranges of requirements (COSPAR 2011). Category 1 has no planetary protection requirements and includes ‘any mission to a target body which is not of direct interest for understanding the process of chemical evolution or the origin of life’. The greatest planetary protection requirements are required for Categories 4 and 5 which may ‘comprise certain types of missions (mostly probe and lander) to a target body of chemical evolution and/or origin of life interest and for which scientific opinion provides a significant chance of contamination which could compromise future investigations’. Category 5 also includes Earth return of samples and so has additional requirements to avoid back contamination of the Earth and the Moon. COSPAR has also designated ‘Special Regions’ on Mars which require strict protocols to be followed by any mission that enters them to avoid forward contamination (COSPAR 2011). A Special Region is defined as a ‘region within which terrestrial organisms are likely to replicate’ and/or ‘any region which is interpreted to have a high potential for the existence of extant martian life forms’ (COSPAR 2011).
Land	As developments start to take place on celestial bodies such as the Moon and Mars issues around land take could arise, given that only limited areas may be suitable for development. For example the lunar poles have been identified as prime locations to develop infrastructure because they have so-called ‘peaks of eternal light’ although these are extremely limited in extent (Milligan 2016). These are areas of quasi-permanent sunlight on the rims of craters that are relatively thermally benign and where using photovoltaics to generate power may be feasible (Spudis 2010). They may also contain water ice (Milligan 2016). Another location of concern is the lunar farside, which is the only place in space relatively close to Earth, where radio transmissions from the Earth do not reach as they are blocked by the Moon (Maccone Forthcoming). The establishment of safeguards has been recommended to ensure the preservation of appropriate sites on the lunar farside for high sensitivity radio astronomy (Horneck and Cockell 2010). Mars has the same land area as Earth and although some areas may be more suitable for settlement than others (e.g. those with supplies of water and building materials and canyons or lava tubes which provide radiation shielding) the availability of land is unlikely to be a significant issue (Lavars 2016). However, as the areas most suitable for human colonisation may be those most suitable for extraterrestrial life, planetary protection protocols could introduce some restrictions. Planetary geology also requires consideration, given the great scientific value of geological research of the solar system. Certain types of space projects may impact geological features thus limiting or destroying their value to science. To protect planetary geology Martínez-Frías et al. (2011) have argued that the scope of the definition of ‘geoethics’ should be extended beyond the Earth.
Soil	Lunar soils are sensitive because their study could lead to important scientific findings about the origin of the solar system and Earth (Ehrenfreund et al. 2013). Martian soils may be sensitive for similar scientific reasons and also because they have the nutrients required to grow terrestrial plants in controlled environments on Mars (Jordan 2015).
Water	Water will be a key resource in space exploration and development. Jupiter’s moon Europa and Saturn’s moon Enceladus appear to have large, subsurface water oceans (Ehrenfreund et al. 2013). Both the Moon and Mars have water ice which will be crucial for human survival, both for drinking, washing, agricultural and industrial uses and potentially also as a raw material for manufacturing both rocket fuel and oxygen (Kramer 2017). On the Moon there may be water ice present in the permanent shadows of deep, cold craters, safe from vaporizing sunlight (Horneck and Cockell 2010). On Mars there are potentially deposits of water trapped within the ice caps at the north and south, as well as subsurface frozen water, frozen water in the bottom of craters, frozen water in permafrost and possibly liquid water flowing from some steep, relatively warm slopes on the surface (Redd 2017). Numerous proposals have been announced by commercial ventures to exploit water and minerals from asteroids (Ehrenfreund et al. 2013). Water is also a sensitive resource in relation to its link to potential extraterrestrial life as outlined under ‘Biodiversity’.
Atmosphere and climate**	The atmospheres of celestial bodies such as the Moon and Mars are sensitive due to the risk of pollution by substances from Earth which could disrupt scientific study of their nature and origins (e.g. Debus 2005, CSCEM 2007). As a result of its low mass, the lunar atmosphere is incredibly fragile and it contains substances that have great scientific and potentially practical value (CSCEM 2007). Natural lunar exospheric components such as gas and dust may be detectable now, but may become difficult to detect in the presence of intense exploration (Horneck and Cockell 2010). CSCEM notes that ‘a human outpost [on the Moon] might see sufficient traffic and outgassing from landings, lift-offs, and extravehicular activities (EVAs), for example, to completely transform the nature of this pristine environment’ (CSCEM 2007). The climate of Mars derives from a variety of factors, including its ice caps, water vapour and dust storms, which at times can blanket the entire planet and last for months (Sharp 2017). The atmosphere of Mars is about 100 times thinner than Earth’s, and it is 95 percent carbon dioxide (Sharp 2017). The Mars atmosphere has already been contaminated by terrestrial compounds and dormant microorganisms as a result of previous exploration missions (Debus 2005). This will also be the case with the Moon. Given the high prevalence of dust on Mars and the Moon the potential for this to be released into the atmosphere through exploration and development activities may also require consideration in future, as it could adversely affect infrastructure such as photovoltaic arrays.
Material assets	Assessment of impacts on material assets may be required, for example due to the potential for: orbital debris to be produced which may damage satellites and other spacecraft. the availability of orbital niches for satellites to be reduced as these are a limited resource (Milligan 2016). space mining operations to reduce stocks of rare minerals and other resources. sterilising stocks of commercial minerals, for example by developing the surface above them. wasting important materials for example by including non-reusable spacecraft components. Entry, Descent and Landing System (EDLS) hardware from landing spacecraft to be jettisoned. These have been observed by orbiting spacecraft strewn over the martian surface and present a risk of disruption to future missions landing nearby (Paton 2017). the huge number of electromagnetic transmissions associated with space commerce to clog electrocommunications channels and cause interference (Manson 1991).
Cultural heritage	Orbital objects and objects left on other celestial bodies, such as from the Apollo Moon landings, are the cultural heritage of the ‘Space Age’ started by the launch of Sputnik I in 1957 (Gorman 2005). The potential for a project to affect these objects therefore requires consideration. For example, NASA has developed guidelines to preserve the integrity of lunar heritage sites and adjacent areas during international robotic missions by Google Lunar X Prize competitors (Ehrenfreund et al. 2013).
Landscape	The sensitivity of extraterrestrial landscapes will depend on the types of celestial bodies on which they occur. For example, Almár (2010) states that: Human interactions may be important for the future of a small celestial body (e.g. the nucleus of a comet as the target of an impacting rocket may fall into pieces), but on fast changing surfaces there is generally less danger that human interaction would destroy something which otherwise would stay unaltered for billions of years. In contrast, very old, non-variable surfaces such as the Moon, Mercury, and several satellites and asteroids, are absolutely vulnerable and their scientific value would be irrevocably damaged if a large-scale intervention occurs. Gorman (2005) considers that Earth’s orbital landscape requires consideration stating that ‘both the materials in it and their location in this landscape, or spacescape, may have significance in social, historical, scientific and aesthetic terms’. In the future should human populations be present beyond Earth’s orbit, visual impacts of projects will also need to be considered. For example, views of landscape features such as Olympus Mons on Mars, the largest volcano in the Solar System, and of the lunar Alps, could be sensitive. Horneck and Cockell (2010) have suggested that ‘planetary parks’ should be established on celestial bodies similar to national parks on Earth. As well as enforcing the COSPAR planetary protection policy these would be designed to preserve regions for historic value, natural beauty, scientific interest/use and for future generations.

*Based on the factors listed within Article 3 of the European EIA Directive.

**Adapted from the factor ‘air and climate’.

Results

Review of the EISs referenced above revealed that the majority of those produced by NASA included comprehensive coverage of topics related to Earth’s environment. However, they did not cover potential impacts to the extraterrestrial environment, including to Earth’s orbital environment. In contrast the EIS produced by the FAA for the Horizontal Launch and Reentry of Reentry Vehicles Program did cover the potential impacts of orbital debris on the orbital environment (FAA 2005).

The wider literature review revealed the potential for impacts to arise to the extraterrestrial environment as a result of space exploration and development projects over a range of topic areas, as described in Table 2. Potential for impacts to occur was identified within all the topic areas (or factors) covered by the European EIA Directive. No potential extraterrestrial environmental impacts were identified that could not be categorised within the topic areas covered by the European EIA Directive. It was therefore concluded that these topic areas were appropriate to use in the screening and scoping exercise. The only required modification was to change the name of the ‘air and climate’ topic to ‘atmosphere and climate’ because although some celestial bodies have atmospheres, they do not consist of air.

The results of the screening and initial scoping exercise are shown in Table 3, with the key outcomes being:

1. For the two projects that involved surveying asteroids the potential for significant extraterrestrial environmental effects was low for all topic areas. Based on the extraterrestrial elements of these projects they could therefore be screened out of requiring EIA, although a separate screening exercise would still be required covering the terrestrial elements.

2. For the two projects involving uncrewed missions to the Moon and Mars, in two out of the nine topic areas a medium potential for significant effects was identified, but in the other topic areas the potential was low. These projects would therefore be screened as requiring EIA, although only a small number of extraterrestrial topic areas would be scoped in (atmosphere/climate and biodiversity for Mars and atmosphere/climate and cultural heritage for the Moon).

3. For the two projects involving crewed missions to the Moon and Mars a medium or high likelihood of significant effects was predicted for six (Mars) and seven (Moon) of the topic areas, including between both projects all topic areas other than land. These projects would therefore be screened as requiring EIA and a large number of extraterrestrial topic areas would be scoped in.

Table 3. Potential for significant effects to arise from space project scenarios.

	Potential for significant extraterrestrial effects to arise*
Topic Area	1. NASA Mars 2020 Mission	2. SpaceX’s Mars settlement program	3. NASA’s OSIRIS-REx asteroid mission	4. Planetary Resources 2020 asteroid prospecting mission	5. NASA’s Constellation Program, Moon	6. Moon Express, Harvest Moon program
Population and human health	Low – no humans present.	High – human health a key issue e.g. due to crew radiation exposure levels.	Low – no humans present.	Low – no humans present.	High – as per SpaceX program.	Low – no humans present.
Biodiversity	Medium – uncrewed mission outside Special Regions, but soil will be penetrated to collect samples increasing forward contamination risk.	High – presence of humans and mining of water present a high risk of forward contamination even if outside of Special Regions.	Low – asteroids fall into Category I or II of the COSPAR Planetary Protection Protocol which have no or very limited planetary protection requirements.	Low – as per OSIRIS-REx mission.	Low – missions of this type to the Moon would fall into Category II of the COSPAR Planetary Protection Protocol and would thus have very limited planetary protection requirements.	Low – as per Constellation Program.
Land	Low – no land take and negligible impact on geology.	Low – negligible land take and slight impact on geology.	Low – no land take and negligible impact on geology.	Low – as per OSIRIS-REx mission.	Low – negligible land take and negligible impact on geology**.	Low – as per Constellation Program.
Soil	Low – negligible impact.	Medium – as per Constellation Program and could deplete availability of growing medium.	Low – soil not present.	Low – soil not present.	Medium – activities such as spacecraft landing, spillages from equipment/storage containers and waste disposal could degrade soil locally, confounding future scientific studies.	Low – slight impact.
Water	Low – negligible impact.	Medium – quality and quantity of local water resources could be depleted.	Low – negligible impact.	Low – negligible impact.	Medium – as per SpaceX program.	Low – negligible impact.
Atmosphere and climate	Medium – an accident leading to release of radioactive material and/or other substances on entry to the martian atmosphere or on landing could confound future scientific studies.	High – release of substances from infrastructure placement, resource extraction and other activities could confound future scientific studies. Mission activities would also disperse dust. Release of radioactive substances (if used) and/or other materials could also occur through accidents e.g. on landing.	Low – atmosphere not present.	Low – atmosphere not present.	High – as per SpaceX program.	Medium – some potential for emissions from landing and take-off (and accidents if they occur) to impact the lunar atmosphere and for dust to be dispersed.
Material assets***	Low – slight impact from risk of jettisoned EDLS hardware affecting future missions landing nearby.	Low – as per Mars 2020 Mission	Low – negligible impact.	Low – negligible impact.	Medium – depletion of local water and other resources could be an issue given the limited areas on the Moon that are suited for development.	Low – negligible impact.
Cultural heritage	Low – assumed that mission unlikely to impact previous artefacts on Mars surface or in Mars orbit if appropriately planned.	Low – as per Mars 2020 Mission.	Low – no previous missions to the asteroid.	Low – as per OSIRIS-REx mission.	Medium – given the relatively high number of previous Moon missions it would need to be checked that previous artefacts would not be disturbed on the lunar surface or in lunar orbit.	Medium – as per Constellation Program.
Landscape	Low – negligible impact.	Medium – moderate impact on landscape features and human presence introduces visual receptors.	Low – negligible impact.	Low – negligible impact.	Medium – as per SpaceX program.	Low – negligible impact.
Number of topic areas with medium or high potential for significant effects	2	6	0	0	7	2

*For the purposes of this screening and initial scoping exercise it is considered that a significant effect will arise if an impact of moderate or substantial magnitude arises to a receptor (topic area) of medium or high sensitivity. The potential for a significant effect to arise is categorised as low, medium or high. If medium or high potential is identified for one or more topic areas then the project should be screened as requiring EIA. Topic areas with medium or high potential should be scoped into the EIA, and those with low potential should be scoped out. If the potential is unclear the topic area should be scoped into the EIA for further assessment.

**Subsequent projects may need to assess cumulative impacts on land given the limited areas on the Moon suited to development. These scenarios have assumed that the missions would not be to the lunar farside.

*** It is assumed that measures would be taken to prevent debris remaining in Earth orbit as a result of the launch, e.g. by following NASA’s Procedural Requirements for Limiting Orbital Debris (NASA 2008b), and therefore that there would be low potential for a significant effect from this.

Discussion

In relation to the original projects forming the basis of the four project scenarios screened as requiring EIA:

• The EISs for NASA’s Constellation Program and Mars 2020 Mission did not consider extraterrestrial effects (NASA 2008a, 2014). The former was cancelled but the latter is still due to launch in 2020.

• EIAs do not appear to have been undertaken for Moon Express’s Harvest Moon program or SpaceX’s Mars settlement program.

The project scenarios that showed the greatest potential for significant effects to arise were the crewed missions to Mars and the Moon. This is not surprising, as crewed missions require a greater level of support infrastructure, require resources such as water to be extracted from the local environment and, in the case of Mars, significantly increase the risk of forward contamination. The latter is because:

● Humans carry a high microbiological load and spacesuits and other equipment provide an incomplete barrier (Groemer 2010).

● Human settlements may be preferentially established in areas potentially suitable for life, as they will require access to water resources and shielding from radiation, possibly underground.

●Also, crewed missions introduce a human population to the extraterrestrial environment which requires consideration of population and human health effects, which may be significant due to exposure to high natural radiation levels and other health risks. The introduced population may also be a receptor for noise, vibration, visual and other impacts.

Significant effects were predicted to arise in few topic areas in the scenarios involving uncrewed missions to Mars and the Moon, reflecting that they were relatively small in scale and would not include humans. However, should the operations of Moon Express expand beyond those currently proposed, involving extensive mining operations, then there would be a greater chance of significant effects arising, particularly in relation to land, soil, water, atmosphere & climate, material assets and landscape.

Assessment of the two robotic missions to asteroids indicated a low potential for significant environmental effects in all topic areas. That was primarily because humans would not be present on the missions, the asteroids would be unlikely to have detectable atmospheres; conditions would be unsuitable for life; and there would only be a very limited impact on the surface of the asteroid. If subsequent missions were to mine the resources of the asteroid, as is proposed by Planetary Resources and other companies, then there would be a greater chance of significant effects on water and material assets. However, this would need to be considered in the context of more than 15,000 near-Earth asteroids having already been discovered (NASA 2016b), suggesting that they are abundant.

All of the project scenarios were predicted to have a low potential for significant effects on land. That is primarily because the projects have relatively small footprints and thus minimal land take and also because they would have negligible (or at most slight) impact on geology. However, as development in space intensifies land-related effects are likely to become more significant, particularly in relation to activities such as mining which may deplete resources and to development on the Moon, where the most suitable areas may be limited. It is therefore considered appropriate to retain ‘land’ as a topic area to be considered in the EIA screening and scoping methodology proposed in this paper, although rigorous scoping of all topic areas should always be undertaken to avoid unnecessary work and expenditure. The topic areas that were predicted to have high potential for significant effects to arise under at least one project scenario were population & human health, biodiversity and atmosphere & climate. The first of these was linked to the health risks to human crews associated with the extraterrestrial environment, the second to the potential for microbial life to be introduced to Mars and the third to the lack of data on the lunar and martian atmospheres.

The lack of baseline data on extraterrestrial environments increases the chances of effects being classified as significant, following the precautionary principle. Also, the alteration of a feature by human intervention before it has been comprehensively studied could result in invaluable scientific information being lost. Key examples are the risk of forward contamination of the martian environment by life forms from Earth and contamination of the lunar atmosphere with terrestrial substances, which could impact studies of the origin of life (Conley and Rettberg 2010) and the history of the solar system (CSCEM 2007).

The methodology proposed in this paper is necessarily based on expert opinion, given the limited baseline data and the lack of established techniques to assess the sensitivity of the various extraterrestrial environmental features and the magnitude of potential impacts. Further work will be required to fill these gaps and to ensure that assessment methods are specific to the extraterrestrial environment and are not unduly influenced by terrestrial experience. However, terrestrial EIA screening and scoping is also a relatively subjective process. Provided that the precautionary principle is adopted when assessing the potential for significant effects to arise, the proposed methodology is considered to be sufficiently robust. It is certainly an improvement on the current situation in which there is apparently no guidance available for EIA of extraterrestrial projects.

Conclusions

This study has shown that EIA of space projects has not been undertaken when it should have been, for ethical if not legal reasons, or when it has been undertaken that it has almost always failed to consider extraterrestrial impacts. This reflects similar observations by others (Viikari 2004, 2008; Kramer 2014, 2017). The reasons for this include a lack of legal requirements to undertake EIA covering the extraterrestrial environment (Manson 1991; Viikari 2004; Kramer 2014), an assumption in some quarters that the space environment does not warrant the same protection as Earth’s environment (Viikari 2004) and a need to enhance the ‘soft law’ regime, for example by generating standards and guidelines (Kramer 2017).

The most recent publication which extensively examined EIA governance was produced by Arts et al. (2012), who compared the situation in the UK and the Netherlands. They concluded that the mandatory status of EIA, as well as transparency and positive attitudes, contributed to explaining EIA effectiveness in both countries. They noted that differences between the two countries could be explained mainly in terms of governance mechanisms such as scoping, quality control and the development of alternatives. This supports the points in the current paper regarding the need to strengthen the legal requirements for EIA of extraterrestrial projects and to develop bespoke guidance on scoping.

The current study provides a method for screening and initial scoping of extraterrestrial EIA but further work will be needed to develop wider EIA procedures and capabilities. Areas requiring particular attention include:

• (1) To improve accuracy and reliability considerably more baseline data are required on extraterrestrial environments. For example, Kramer (2014) notes that baseline data ‘would be especially critical from remote surface areas, microclimates and unique subsurface environments such as lava tubes, ice layers or pockets of liquid water.’

• (2) More information is needed on the mechanisms and pathways by which extraterrestrial projects may impact the receiving environment. For example the Committee on the Scientific Context for Exploration of the Moon (CSCEM 2007) has stated that:

  Before extensive human and robotic activity alters the tenuous lunar atmosphere, it is important to understand its composition, transport mechanisms, and escape processes. At the same time, the lunar dust environment must be well characterized so that effective human exploration and astronomical observations can be planned.

• (3) Specific procedures for detailed assessments of extraterrestrial topics need to be developed such as are available for terrestrial EIA (e.g. Landscape Institute & IEMA 2013).

• (4) Reliable mitigation measures specific to the extraterrestrial environment need to be developed such as are available for many of the impacts from terrestrial projects.

• (5) Consultation and approval methods need to be developed, which may be a complex task as outer space is considered to be ‘the province of all mankind’ (Pop 2016). Therefore establishing boundaries for public consultation while remaining sufficiently inclusive will be difficult. Consultation with regulatory authorities will also be complicated as there are no environmental agencies with clear regulatory powers for the extraterrestrial environment, although bodies such as COSPAR have an important role. The situation is similar to that on Earth with projects in international waters and the Antarctic (Kerrest 2011; Race 2011; Ehrenfreund et al. 2013; Kramer 2017), and it may be possible to draw lessons on consultation from these.

Recommendations

The following recommendations are made to enhance protection of the extraterrestrial environment through the use of EIA:

• (1) The International Association for Impact Assessment (IAIA), the Institute of Environmental Management and Assessment (IEMA) and other leading international technical and professional bodies that promote EIA should include the extraterrestrial environment within their remit. They should establish groups of specialists and include EIA of the extraterrestrial environment within their recommended procedures for professional practice. They should promote the use of extraterrestrial EIA even when it is not currently required by the legal framework. These bodies should also work with organisations undertaking space projects and developing legal frameworks to persuade them of the advantages of EIA. These advantages include protecting the extraterrestrial environment, improving the public acceptability and long term sustainability of the space sector and achieving cost savings through appropriate design and mitigation.

• (2) EIA legislation should be updated to include coverage of space projects, specifically including an obligation to assess extraterrestrial impacts. France and Belgium already have this legislative requirement which should be rolled out at a wider European level when the EIA Directive is next amended. It is also important that similar changes are made to NEPA in the USA and to equivalent legislative frameworks in Russia, China and other spacefaring nations.

• (3) EIA screening and scoping should be undertaken for space projects to ensure that EIA is carried out when required and that the appropriate topics are covered, while resources are not wasted assessing topics where significant effects are unlikely to arise. This paper provides a method for screening and scoping in extraterrestrial EIA which can be developed and refined as required. For example, EIA practitioners working in jurisdictions outside the European Union could amend the topic areas to correspond to those used in their own regional procedures (e.g. NEPA in the USA).

• (4) Further work is required to increase the efficiency and effectiveness of extraterrestrial EIA, including for example research to better establish baseline conditions and how developments may impact them; the development of detailed procedures for assessing impacts in each topic area; procedures for undertaking consultation; and the design and testing of mitigation measures. This work will be the responsibility of various organisations involved in space research and development and it should ideally be co-ordinated by an appropriate international body such as COSPAR.

• (5) Complementarities between EIA and other environmental assessment methods such as LCA, Strategic Environmental Assessment (SEA) and Sustainability Impact Assessment (SIA) (the latter two recommended by Viikari (2004)) should be recognised and promoted. LCA assesses the potential environmental impacts associated with products, processes or services, SEA does the same for plans and programs, while SIA additionally encompasses social and economic aspects. The screening and scoping method proposed in this paper would also be relevant to SEA. As extraterrestrial projects often involve a number of separate missions, and could therefore be considered to represent a ‘program’, judgment will be required as to whether SEA is required prior to EIA. LCA is a valuable tool, for example, for developing new space hardware that minimises the creation of space debris. However, it is less relevant to assessing the impacts of a proposed extraterrestrial development. SIA could be complementary to EIA by including consideration of wider social and economic issues, such as the impact to the economy of developing significant new supplies of rare minerals from asteroids.

• (6) The extraterrestrial EIA process should be open and transparent with documentation made widely available online to encourage broad public participation and understanding (NASA has set a good example in this regard). The use of digital EIA techniques, where documents are web enabled, would help promote this further.

Acknowledgments

The author is grateful to Jessica Delaval, ESA’s Clean Space Coordinator, for providing information on ESA’s approach to LCA for space activities and to Margaret S. Race, Petra Rettberg, Rajeswari Rajagopalan and Jinyuan Su for providing copies of articles. The author is also grateful to the two anonymous referees who made valuable comments on the submitted manuscript.

Disclosure statement

No potential conflict of interest was reported by the author.