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As a 2023 Diverse Dozen member, Pablo Carlos Budassi delivered a message advocating for space sustainability during his talk at the Ascend Space event in Las Vegas on October 24, 2023. On this page, we will present our analysis of the situation, including a comprehensive master diagram depicting sustainability issues under consideration during the 2020s decade:

In the grand cosmic expanse, humanity has embarked on a journey that transcends our earthly confines. Space exploration and utilization have brought us quite an interconnected everyday life at many levels, but the feeling that Earth’s orbital space and the universe are a part of us is not quite there yet. Space isn’t just a part of us; it’s also home to us, and you don’t throw dangerous trash inside your home.




Similar to early historical maps, small objects in low Earth orbit (LEO) and medium-sized objects in geosynchronous Earth orbit (GEO) remain as blank uncharted areas. Naturally, there is ample space and comparatively few objects in GEO but providing life extension services could serve as a sustainable means to keep it this way. Most urgently, LEO, a precious and limited resource, is becoming increasingly congested and needs our full attention and urgent action.




Megaconstellations are suddenly altering the night sky and impacting scientific research, cultural heritage, and more importantly: climate and ecology. De-orbiting satellites bring pollutants like aluminum into the atmosphere, affecting Earth’s circulation in ways we cannot quite predict. Rocket launches introduce greenhouse gasses and pollutants into the upper atmosphere, potentially influencing the ozone layer and other climate patterns. 
Mapping Our Cosmic Priorities



Some argue that our current environmental challenges on Earth should take precedence over space sustainability efforts. They suggest that focusing on issues like climate change and biodiversity loss should be our primary concern. This is true, but we should not underestimate the interconnectedness of these fragile shells. Space sustainability isn’t just about protecting outer space; it is about recognizing how our actions in space can exacerbate problems on Earth. Addressing these problems can lead to innovative solutions that benefit both our planet and our cosmic endeavors. 



The blueprint for space sustainability is not a static diagram. As we incorporate more data and integrate machine learning into our situational awareness, and as space exploration continues to advance, new issues will undoubtedly emerge. Ideally, we should be prepared to address them. Setting a goal to make this map reasonably navigable within the next decade would be a worthwhile objective. Achieving relatively clean and organized LEO orbits may only be possible if we start taking deliberate action today.
Celestial Guardianship Through Every Step of the Course


As we venture beyond Earth’s orbit and set our sights on celestial neighbors, responsible exploration becomes the only acceptable modus operandi. Lunar exploration must be conducted in a collaborative and respectful manner to prevent the creation of another landscape spoiled by orbital congestion and debris.

While sustainable space mining may be theoretically achievable, we should refrain from altering the trajectories of asteroids for any purpose to ensure the safety of Earth and other celestial bodies from unintended anthropogenic-caused impacts. Exploring other worlds that we believe could potentially harbor extraterrestrial life also necessitates the utmost caution on our part.

A Shared Responsibility as One with the Universe



Shared human existence can be conceived as a cosmic symphony. We must not lose sight of our interconnectedness with the universe. Our actions resonate far beyond our planet. While for the moment all decisions are being made from Earth’s surface, our ethical footprint is boundless.

Yes, we will strive to address pressing environmental and social issues on Earth in the next decade, as well as environmental and social issues in the heavens. Yes, it is challenging to agree and work together in a competition-driven model of a world. We should begin by acknowledging that our choices today have ripple effects across time and space, impacting many generations yet to come.



Overview of key space sustainability issues under consideration in 2023. 
A graphic and Op-Ed by Pablo Carlos Budassi for ASCEND’s Diverse Dozen Program
Solar System objects images credit: NASA/ESA/UAESA. Space debris orbits scheme data: Moriba Jah/Privateer. Space debris density in LEO diagram data: 2021 NASA Space Debris Presentation to STSC
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Description of the graphic:

Overview of the key space sustainability issues being considered in the 2020s decade. In the upper left corner, an axonometric view displays various Earth orbits, illustrating space debris and active satellites. The diagram includes a separate sheet for each orbit type, detailing the height, typical speed of objects, the number of active satellites, and essential sustainable practices for damage prevention and mitigation. To the right, a diagram displays Low Earth Orbit’s debris density, and notable active satellites by height. At the bottom, the graphic enumerates crucial points for the sustainable utilization of space across diverse celestial bodies, such as Earth, the Moon, Mars, the asteroid belt, and other sensitive celestial bodies within our solar system.

Text transcript from the graphic:

GEO Graveyard Orbit:
. 36,100km 11,000km/h  

. far future problem

Geostationary Orbit (GEO):
. 35,786km 11,050km/h – 600sats +15/year 
. fairly regulated and organized
. 0-2.5 km/s collision speeds

. service for extending life is needed

Geosynchronous Orbit (GSO):
. 35,000-36,000km – 800sats +20/year
. mostly big trackable inactive sats 
. will stay in orbit indefinitely   
. one 50 m close approach per year  
. should be moved to “graveyard” orbit   

. not an urgent priority

Superspreader Debris Ring:

. large rocket body

Highly Elliptical Orbit (HEO):
. 2,000-40,000km – 60 sats +2/year
. very few satellites and debris

. almost null risk of collision

GPS, GLONASS, BeiDou, Galileo:
. 19,000-23,000km – 110sats

. very few satellites and debris

Medium Earth Orbit (MEO):
. 2,000-32,000km – 160sats +12/year
. sats should be de-orbited as would naturally decay in +1000 years
. not an urgent priority since there is still no congestion
. speeds range from 5-7 km/s

. multi-orbit constellations will start using it with no regulation

Inner Van Allen Radiation Belt:
. 1,500-10,000km 

. few active satellites here due to charged particles risk

Sun-Synchronous Orbit (SSO):
. 600-1000km – 800 sats +150/year
. mostly Earth observation sats
. danger crossing zones near the poles
. conjunctions are steadily increasing

. also used as a graveyard orbit

Low Earth Orbit (LEO):
. 200-2,000km – 10,000 sats +2400/year
. rapidly getting crowded
. 9-14 km/s collision speeds

. needs urgent protection

Notable debris clouds and spacecraft in LEO:
2,000km: debris naturally decaying in 50,000 years
2,000km: Samsung Korea constellation (4,700 planned satellites)
1,500-1,800km: Few satellites due to inner Van Allen belt risk to spacecraft
1,500km: Gonets Russian communications satellites (12 active)
1,400km: unknown debris cloud
1,400km: Astrome Tech India constellation (600 planned satellites)
1,340km: Jason-3 Meteorological Satellites (EUMETSAT-NASA)
1,300km: Sentinel-6 Michael Freilich ocean topography measurement sat (S6MF)
1,200km: OneWeb constellation of 542 active satellites (648 planned)
500-1154km: GuoWang China constellation (12,992 planned satellites)
1,050km: Hisaki ultraviolet astronomy satellite
1,000km: debris naturally decaying in 1,000 years
865km: 2007 Chinese anti-satellite missile test
850km: debris naturally decaying in 200 years
817km: MetOp Meteorological Operational satellite (3 sats)
790km: 2009 Iridium-Kosmos collission (~2000 trackable objects)
710km: Terra Earth Observing System
670km: 1996 Cerise French satellite collision with debris from Ariane
600km: debris naturally decaying in 20 years
590-630km: Project Kuiper mecgaonstellation (3,236 planned satellites)
590km: Hubble Space Telescope
340-615km: Starlink constellation of 3,905 active sats (30,000 planned)
530km: Fermi Gamma-ray Space Telescope
510km: Lynk constellation (5,000 planned satellites)
490km: WISE Wide-field Infrared Survey Explorer
480km: 2021 Russia anti-satellite missile test (~1500 trackable objects)
340-450km: Tiangong space station
330-430km: International Space Station
390km: former Mir Space Station
350km: Sat Revolution Poland constellation (1,024 planned satellites)
250km: debris below naturally decaying in weeks
215km: Sputnik 1 perigee (first satellite in orbit 1957-1958)
150km: debris below naturally decaying in hours
95km: solar arrays break-off on reentry
80km: average spacecraft break up
27-52km: high altitude balloons
15-40km: ozone layer

10km: aircraft

Space Sustainability challenges on Earth:
. Bright satellite megaconstellations disrupt the natural night sky affecting astronomy, astrophotography, and cultural significance.
. De-orbiting satellites add pollutants like aluminum to the atmosphere impacting climate and circulation.
. The launch of rockets releases greenhouse gases and other pollutants into the upper atmosphere, which can contribute to climate change.
. Rocket emissions can also alter the composition of the stratosphere, potentially affecting the ozone layer and regional climate patterns.
. Radio frequencies and electromagnetic radiation for communication can potentially interfere with sensitive ecological systems and wildlife 
navigation and migration.
. Space asset development relies on Earth mining for rare minerals, which can result in habitat destruction, soil erosion, pollution, and water source contamination.

. The unequal distribution of benefits from space activities can exacerbate social and economic inequalities among different populations and nations.

Space Sustainability challenges in other celestial bodies:

. Because of limited useful Lunar orbits compared to Earth’s orbits, exploration could soon lead to satellite congestion and space debris around the Moon.
. Anticipated to increase in the upcoming decade, there are already over 200 tons of defunct spacecraft and mission-associated items on the Moon.
. Moon’s shadowed regions need protection to preserve potential organic molecules.
. Both biological and non-biological contamination, including waste from humans and machines on limited ice deposits, have been considered

. New regulation for responsible practices on Lunar exploration is needed.


. Both the orbit and surface of Mars should remain as free as possible from debris and litter to preserve its pristine environment for scientific exploration and potential future habitation.
. Spacecraft and habitats should be designed with minimal emissions of gases that could contribute to the pollution of Mars’ thin atmosphere.
. Before we rule out the life-containing status of Mars, spacecraft, rovers, and equipment should be sterilized to avoid introducing Earth’s microorganisms to Mars and vice versa.


. Asteroid mining, if done sustainably, offers potential benefits, such as access to rare minerals and reducing the environmental impact of traditional mining on Earth.

. Altering the trajectory of an asteroid, even for scientific research, could potentially lead to unintended consequences including a new path that intersects with Earth or other celestial bodies.

Solar System:
. Large populations of living organisms may already be thriving on ocean worlds like Europa, Enceladus, Ganymede, Callisto or Titan.
.Forward contamination should be prevented by sterilizing space probes sent to sensitive areas of the Solar System.
.The Committee on Space Research (COSPAR) presents recommendations for avoiding interplanetary contamination depending on the type of space mission and the celestial body explored.

.For both landers and orbiters, spacecraft trajectories should be designed so that if communications are lost, they will miss the target to prevent unintended impacts.



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