Design a site like this with WordPress.com
Get started
Featured

Appeal by Astronomers

Safeguarding the Astronomical Sky (IT)

paper_I_arXivpaper_II_(arXiv) -> the FULL paper <- press EN_PDFpress IT_PDF

THIS APPEAL HAS BEEN SIGNED BY

2050+ ASTRONOMERS

VIEW SIGNATURES

(the refresh rate of the counter may slow down).

To sign/subscribe follow this link.

This is an international appeal by professional astronomers open for subscription to ask for an intervention from institutions and governments.

Astronomical observations from the ground can be greatly harmed by the ongoing deployment of large satellite fleets in preparation for the next generation of telecommunications.

For centuries the astronomical observations from the ground have led to exceptional progress in our scientific understanding of the Laws of Nature. Currently, the capability of astronomical instrumentation from the ground is endangered by the deployment of satellites fleets.

Through this international appeal and following the same concerns expressed by the International Astronomical Union, IAU [1] and other institutions, we raise a formal request for greater effective protection and safeguard for professional astronomical observations from the ground, guaranteeing the right to observe a sky free from unnecessary artificial polluting sources.

In particular, all the signers, astronomers and collaborators wish to manifest humanly and personally their worry and contrariety to the sky coverage produced by artificial satellites, which represent a dramatic degradation of the scientific content for a huge set of astronomical observations.

The sky degradation is not only due to light pollution in the sky near cities and the most populated areas, but it is also due to artificial satellite fleets crossing and scarring observations with bright parallel streaks/trails at all latitudes.

Astronomers are extremely concerned by the possibility that Earth may be blanketed by tens of thousands of satellites, which will greatly outnumber the approximately 9,000 stars that are visible to the unaided human eye. This is not some distant threat. It’s already happening. The american private company SpaceX has already put 180 of these small satellites, collectively called Starlink, in the sky and plans to constellate the whole sky with about 42,000 satellites (placed at three different quota: 340km, 550km and 1150km). Thus, together with other telecommunication space projects in the near future (i.e. the English OneWeb, the Canadian Telesat, the American Amazon, Lynk and Facebook, the Russian Roscosmos and the Chinese Aerospace Science and Industry corp), there could be over 50,000 small satellites encircling the Earth (at different altitudes) for various telecommunication purposes but mainly delivering internet.

These new satellites are small, mass-produced, and orbit very close to the Earth with the intent to provide speedy internet connection with low-latency signals. But that closeness (~340Km) also makes them more visible, and brighter in the night sky especially when lighted by the Sun (satellites launched by SpaceX, 180 at the present day, are brighter than 99 percent of the population of objects visible by the Earth orbit ).

The current total number of cataloged objects in Earth orbit is less than 20,000 among spacecrafts, rocket bodies, fragmented mission and other related debrids, so with only the nominal Starlink fleet the total number of orbiting objects will triple (see pictures).(*)

In the mid and long term, this will severely diminish our view of the Universe, create more space debris, and, deprive humanity of an unblemished view of the night sky. It has been computed that most of these satellites will be visible to the naked eye (with a brightness between the 3rd and 7th magnitude particularly in the time after sunset and before sunrise, reaching the brightness of the stars in the Ursa Minor constellation (e.g. there are only 172 stars in the whole sky exceeding the expected brightness of Starlink satellites). Thus with 50k satellites the “normality” will be a sky crowded with artificial objects (every one square degree of the sky will have a satellite crawling in it along the whole observing night).

Not only observations with wide-field survey telescopes will be damaged (e.g. LSST [2] capable to scan and perform a survey of the entire sky in three nights or VST [3] with its 268MegaPixels camera and a FOV of 1 square degree or Pan-STARRS [4] with its FOV of 7 square degrees and 1.4 Giga pixels camera, …), but also deep/long exposures with small-field facilities will be unavoidably impaired, see picture and [7].

Considering that large area astronomical observations and sky survey are commonly used in NEO and asteroids monitoring and research related projects to guard the Earth planet from potential impact events, such satellite constellations could negatively impact on the ability to prevent and warn the whole humankind.(*)

Few starlink satellites visible in a mosaic of an astronomical image (NSF’s National Optical-Infrared Astronomy Research Laboratory/NSF/AURA/CTIO/DELVE)

This light pollution is extremely damaging for astronomical observations at all wavelengths. The recent attempt to use non-reflecting paint on the body (i.e. not the solar panels which represents 75% of the reflecting surface) of one of the Starlink satellite (n.1130 DARKSAT), see [8], even if their brightness would reduce to zero (which is impossible since the solar panels, which represent 3/4 of the reflective surface, would remain uncovered), the degradation for scientific observations will remain high for two reasons: 1) the stars and other objects in the universe will be eclipsed, therefore harming time-dependent (variability) studies, and,  2) the reflectivity of surface depends on the observational wavelength, so what becomes dark in one part of the spectrum (e.g. visible) remains bright or shines in other parts of the spectrum  (e.g. infrared or radio).(**)

It should also be noted that during nominal service operations SpaceX expects to dismiss and replace from 2,000 to 8,000 Starlink satellites every year, disintegrating them in the lower atmosphere, with all related issues.(*)

What is not widely acknowledged is that the development of the latest generation telecommunication networks (both from space and from Earth) already has a profound impact on radio-astronomical observations (at all sub-bands): with LEO satellite fleets it is feared that the situation will become unbearable.

In particular, low Earth orbit satellite’s spectral windows identified to communicate with earth stations in the Ku (12-18GHz), Ka (27-40GHz) and V (40-75GHz) bands will overlap with the nominal radio-astronomy bands and so will interfere with ground radio telescopes and radio interferometers, making the radio detectors enter in a non-linear regime in the K band (18.26.5GHz) and in Q band (33-50GHz). This fact will irreparably compromise the whole chain of analysis in those bands with repercussions on our understanding of the Universe, or even, making the astrophysics community blind to these spectral windows.

To aggravate the matter, with the current technological development, the planned density of radio frequency transmitters is impossible to envisage. In addition to millions of new commercial wireless hot spot base stations on Earth directly connected to the ~50,000 new satellites in space, will produce at least 200 billion of new transmitting objects, according to estimates, as part of the Internet of Things (IoT) by 2020-2022, and one trillion of objects a few years later. Such a large number of radio-emitting objects could make radio astronomy from ground stations impossible without a real protection made by countries’ safe zones where radio astronomy facility are placed. We wish to avoid that technological development without serious control would turn radio astronomy practice into an ancient extinct science.

FOR ALL THESE REASONS

We, astronomers subscribing to this appeal state THERE IS NO MORE TIME TO DISCUSS, IT IS TIME TO ACT!

ASK GOVERNMENTS, INSTITUTIONS AND AGENCIES ALL AROUND THE WORLD

  1. to be committed to provide legal protection to ground astronomical facilities in all of the available observation electromagnetic windows.
  2. to put on hold further Starlink launches (and other projects) and carry out an accurate moratorium on all technologies that can negatively impact astronomical observations from space and from the ground, or impact on the scientific, technological and economic investments that each State engages in astrophysical projects.
  3. to put in place a clear evaluation of risks and predictive impacts on astronomical observatories (i.e. loss of scientific and economic value), giving stringent guidelines to private individuals, societies and industries to plan satellite investments without clearly understanding all of the negative effects on outstanding astronomical facilities.
  4. that the US Federal Communications Commission (FCC) and any other national agency be wary of granting permission to ship non-geostationary low-orbit  satellites into orbit or alternatively to limit the authorization of only satellites  being above the airspace of the “home country”.
  5. to demand a worldwide orchestration, where national and international astronomical agencies can impose the right of veto on all those projects that negatively interfere with astronomical outstanding facilities.
  6. to limit and regulate the number of telecommunication satellite fleets to the “strictly necessary number” and to put them in orbit only when old-outdated technology satellites are deorbited, according to the Outer Space Treaty (1967) – the Art IX [5], and the United Nations Guidelines for the Long-term Sustainability of Outer Space Activities (2018) – guideline 2.2(c) [6], requiring the use of outer space be conducted “so as to avoid [its] harmful contamination and also adverse changes in the environment of the Earth” and […omissis…] risks to people, property, public health and the environment associated with the launch, in-orbit operation and re-entry of space objects”.

FINALLY

All of these requests come from the heartfelt concern of scientists arising from threatens to be barred from accessing the full knowledge of the Cosmos and the loss of an intangible asset of immeasurable value for humanity. In this context, all co-signers of this appeal consider ABSOLUTELY NECESSARY to put in place all possible measures to protect the night sky right also on the legal side. It would be desirable to adopt contingent and limiting resolutions to be ratified with shared international rules, which must be adopted by all space agencies to ensure protection for astronomical bands observable from the ground. All of this to continue to admire and study our Universe, for as long as possible.

References:

[1]  https://www.iau.org/https://www.iau.org/news/announcements/detail/ann19035/?lang

[2]  https://www.lsst.orghttps://en.wikipedia.org/wiki/Vera_C._Rubin_Observatory

[3]  https://www.eso.org/public/https://en.wikipedia.org/wiki/VLT_Survey_Telescope

[4]  https://panstarrs.stsci.edu/

[5]  https://www.unoosa.org/oosa/en/ourwork/spacelaw/treaties/introouterspacetreaty.html

[6]  https://www.unoosa.org/res/oosadoc/data/documents/2018/aac_1052018crp/aac_1052018crp_20_0_html/AC105_2018_CRP20E.pdf

[7] Simulated prediction of “only” 12k Starlink satellites in the sky: https://youtu.be/LGBuk2BTvJE and https://www.youtube.com/watch?v=z9hQfKd9kfA

[8] Visualization tool to find, plot and search satellite orbits: https://celestrak.com/cesium/orbit-viz.php?tle=/satcat/tle.php?INTDES=2020%2D001&satcat=/pub/satcat.txt&orbits=20&pixelSize=3&samplesPerPeriod=90

This appeal/petition can be signed by professional Astrophysicists & Astronomers, Technologists/Engineers , Collaborators & PHD Students involved in professional astronomical observations.

Note that (*) Such a sentence was added the 13/01/2020.

Note that (**) Such a sentence was added the 16/01/2020.

To sign/subscribe this appeal/petition you can follow this link.

Advertisement

New Statements of IAU, let’s go on with statements rather than likely ACTIONS!

AST Space Mobile plans to send into orbit six BlueWalker 3 satellites each month! For a total of more than 100 satellites at an altitude between 500 and 600Km above sea level and emitting radiation in the L and V band (from 400MHz and 800MHz to 40-50GHz).

These satellites will be directly connected to the Starlink constellation in order to provide mobile connection directly to final users without passing through radio stations on the Earth surface. The STARLINK CEO Elon Musk already admit that there is a statement of understanding with Apple in order to modify apple phones to directly connect to satellites signal… a portable, mobile microwave owen in your pocket!

In the meantime IAU found the BlueWalker program (only 6 months after us) and released a new statement against these constellations! Well done… Now AST Space Mobile, SpaceX Apple and all other stuff will be extremely scared!

Here is the link: https://www.iau.org/news/pressreleases/detail/iau2211

In the meatime 2nd generation of starlink satellites will be 2 times bigger with a luminosity 4 times greater… bye bye ground based RADIO ASTRONOMY!

Rubin Observatory LSST@Europe4 NO-WAY to talk of Satellite Constellations!

Here we are!

The LSST-Vera Rubin Observatory at sunset

Here we have one of the best astronomical ground based observatory, which is called Vera Rubin (LSST) Observatory: it is a very large area FOV telescope located in Cerro Pachon (north of Chile) at an altitude of 2600m. and for this reason it is considered the most damaged telescope by the trails of telecommunications satellites.

We knew that a dedicate conference it will take place in Rome in October: the LSST europe-4 group has organized a conference to talk about the project, but the conference will be crippled by the political impossibility of talking about what will surely compromise the scientific content of this telescope observations.

The reason is that to focus a conference slot or create a round-table on treats generated by the satellite constellations (not only by Starlink@SpaceX constellation) could have created frictions between colleagues, especially those Americans who do not see any problems in this regard!

Considering that Starlink is currently used as military asset in US “peace-keeping” military campaigns it is clear that US astronomers are unable (or warned) from taking a position, regardless of their professional ethics: they should say “with LSST we will do science even if we have to invent astronomical images from scratch!”

from this monitoring video of LSST of 16August 2020, the number of orbiting starlink satellites has increased by a factor of 6 since then (currently there are ~2500 orbiting satellites) and 420 were in the 2nd week of august 2020. In order not to alarm public and private investors, they immediately stopped making these kind of videos!

The LSST project cost is more than $ 350 million and so an inert astronomical community in the face of such scientific damage will eventually have to account for all this wasted public money without doing anything!

These considerations should be extended to any astronomical ground based facility, especially those built up with public investments from all around the World.

STARLINK with NO-VISOR & Increased Dimensions: an unprecedented failure of astronomical politics!

NASA’s APOD: Image Credit & Copyright: Joshua Rozells

During a panel discussion held at the 240th meeting of the American Astronomical Society, scientists discussed the scientific impact of the Starlink satellite constellations, demonstrating concern that the last 53 satellites launched are brighter than the previous ones and that the second ones. generation will be significantly larger and potentially brighter.

While from NASA’s Kennedy Space Center launch pad 39A on Friday, June 17, SpaceX put another 53 Starlink satellites into orbit – bringing the total number of Starlink satellites in orbit to over 2450 – on the other side of the United States of America. , in Pasadena, astronomers had devoted a round table of the 240th meeting of the American Astronomical Society just a few days earlier to discuss the scientific impact of these constellations of satellites.

Scientists fear that Elon Musk’s company decides to pull the oars in the boat in an effort to reduce the brightness of its satellites. The fear is dictated by the fact that they found that the last 53 satellites are different from the previous ones. In fact, this is version 1.5, in which the visors present in the satellites launched in 2020 have not been installed to prevent sunlight from reaching reflective surfaces and therefore reduce their brightness from the ground. The decision to remove the visors was dictated by the fact that they were not compatible with the laser inter-satellite links installed on version 1.5.

An increase of more than 1 visual magnitude because of the remove of the “visor” in the visorsat configuration.

Our comment:

We could only reiterate that Starlink has always given a damn about astronomers and has only done what was convenient for him to avoid hitches, revocation of authorizations, etc. Today with the war we have understood (we hope so) that that fleet of satellites is certainly not used for commercial purposes. And … Consequently, the problem will not be solved by the IAU or the AAS or RAS… , but Russia will solve it by triggering a chain reaction by destroying those that are in effect spy satellites.

It is a total fail of the Astronomical world wide institutions and it could be represent the end of astronomical ground based observation…

But only mad people (and children) could believe to lobbysts!

Other References:

https://gizmodo.com/starlink-spacex-satellites-astronomy-1849076758

https://www.cnn.com/videos/world/2022/06/11/satellite-pollution-threatens-night-sky-fisher-pkg-ndwkd-vpx.cnn

UPDATE ON SATELLITES: OneWeb will launch their satellites by SpaceX facilities

The irradiation of Heaven and Earth continues to accelerate, as SpaceX marches ever more quickly toward a constellation of 42,000 satellites. It launched 53 satellites on May 13; 53 more on May 14; and 53 more on May 18. And it has reached agreement with UK-based OneWeb, which plans its own fleet of 7,088 satellites, on how to share the skies. OneWeb will sell its services to telecommunications providers, governments, airlines, and ships, while SpaceX will sell to individuals.

OneWeb, which was launching its satellites from the Russian-operated Baikonur Cosmodrome in Kazakhstan, has been forced to temporarily halt its launches because of the war in Ukraine. But it is expected to resume launching satellites shortly. As part of its agreement with SpaceX, OneWeb’s satellites will be launched from the United States on SpaceX’s Falcon 9 rockets going forward.

Honey bees, birds, whales and trees the world round, their future in peril, are depending on the human race to wind down, and get rid of, their satellites, their antennas, and the devices that are creating the demand: their mobile phones. And people from many countries are beginning to organize together to spread that message widely. Stay tuned.

References: https://oneweb.net/resources/oneweb-resume-satellite-launches-through-agreement-spacex

…few steps to Kessler’s horizon!

Why one should obtain authorization to saturate the Low Earth Orbit with satellites? To obtain monopoly and/or to subcontract orbital shells in a second time to private investors. In the first case clearly there is not Rwanda behind this request, in the second case maybe.Anyway we are destined to crash, the only hope is to rapidly enter in the Kessler’s Syndrome… let’s create a Faraday Cage with satellites debris to prevent future sats communications! Come on it is our only chance to survive!

Link: https://www.spaceintelreport.com/rwanda-submits-itu-filing-for-constellation-of-327320-satellites-27-orbital-shells-at-550-640-km/

On 21st September, the Rwandan Government submitted an International Telecommunications Union (ITU) filing for two satellite constellations named CINNAMON-217 and CINNAMON-937 at Non-geostationary orbital positions. CINNAMON-217 will have 217 planes, and CINNAMON-937 will have 937 planes. 

According to the filing to the ITU, the API filing of CINNAMON-217 is a subset of the CINNAMON-937. It has the same beams and assignments as CINNAMON-937, but the orbital characteristics are different; it has only seven orbital shells. Each orbital shell, except the equatorial shell made of one single plane, has 8,640 satellites. The seven orbital shells comprise 52,080 satellites. In addition, an orbital shell is here defined as the set of orbits with the same inclination. There are 27 of such orbital shells. Each orbital shell, except the equatorial shell made of one single plane, has 12,960 satellites. The 27 orbital shells comprise 327,320 satellites.

This filing follows up on an earlier filing of ANTON-1N0 on 20th August 2021, which was done under the name ‘MARVEL SPACE COMMUNICATIONS CO’ with 181 planes. The filing of ANTON-1N0 was unsuccessful.

“Filings with the ITU are essential to register satellite frequencies and orbital slots and to secure the possibility of future satellite launches. This process is consistent with the ambition of the Government of Rwanda to make space a new frontier for our national development. With the technology now available to make full use of these slots, Rwanda plans to develop projects that will provide various essential services and open up the country as a hub for the African space industry”. – Francis Ngabo, Chief Executive officer of the Rwandan space agency.

Rwanda launched its first satellite, RwaSat-1, in 2019 with the help of Japan, and in March 2021, Rwanda’s Chamber of Deputies voted on the law establishing the Rwanda Space Agency (RSA). “The establishment of Rwanda Space Agency aims at having coordination of Rwanda’s space sector activities geared towards securing communication, Intelligence, Surveillance and Reconnaissance (ISR) as well as purchasing and playing a custodian role of national spatial data and imagery”, said the Chamber of Deputies earlier in March.

Before RwaSat-1, it was involved in the Icyerekezo satellite launched as part of OneWeb’s constellation, aimed at providing internet to remote schools in the country. Regarding this filing, it is not clear what the plan of the Rwandan government is. The East African country may be planning a constellation of communications satellites through the government agency or a new private establishment, or it may be related to its investment in OneWeb. 

What is the Kessler’s Horizon (or Syndrome?), you can read here -> http://www.spacesafetymagazine.com/space-debris/kessler-syndrome/

Uscire a riveder le stelle… Get out to see the stars again…

Please share and sign this petition (in Italian) to reach the larger possible number of subscriptions before the Space Agency G20 of 21st of September.

https://www.change.org/p/autorit%C3%A0-preposte-uscire-a-riveder-le-stelle?signed=true

Here is the Appeal in English: Get out to see the stars again…

Italians have the privilege of speaking the same language as Dante Alighieri, but are in danger of not being able to share his own experiences. The three Canticles of the Comedy end with the word “stars” and in particular the first with “… so we went out to see the stars”. ‘Seeing the stars’ is becoming an idiomatic turn of phrase, unattached to any real experience. This is due to the light pollution that has obliterated the natural night and darkness. SAIt, the Italian Astronomical Society, intends to express its deep concern for the new dangers that lie ahead and invites scholars and enthusiasts to share it near the autumn equinox, a date on which, taking into account the reform of the Gregorian calendar, corresponds to the death of Dante 700 years ago. Light pollution is, first of all, a form of environmental pollution, as underlined by the IUCN, the International Union for the Conservation of Nature. This pollution could be limited given more incisive measures, such as applying the specific laws that have been approved by almost all Italian regions. In this context, we ask that CONSIP, the central purchasing office for public goods in Italy, stipulate conventions for public lighting that highlight a strong reduction of artificial night light and compliance with the best laws against light pollution. It is a source of concern that the Italian National Recovery and Resilience Plan, which will lead to new industrial and social development activities, does not propose parallel initiatives to reduce artificial light, despite the European Parliament asking for a strong limitation to this pollutant in the Biodiversity Strategy 2030. There is therefore a real risk of a consequential overwhelming increase in light pollution. Even the diffusion of the internet, now indispensable for our civil life (i.e. access to public services), is leading to the proliferation of constellations of satellites that risk interfering negatively with the ability to observe the sky at both visible and radio wavelengths. These are issues that seem to evolve faster than the public administration’s ability to react. For this reason it is important that the problem be brought to the attention of everyone and, in particular, of the heads of the G20 Space Agencies who will meet in Rome at the Italian Space Agency headquarters on September 20 and 21, and of the leaders of the G20 countries, in occasion of the Italian Presidency. Since the Divine Comedy is closely connected to the starry sky, it seems to us that it is up to us who love astronomy and the night sky to commemorate Dante this year by expressing our concern of an increasing and uncontrolled pollution of the sky.

deorbiting 100thousand satellites will surely hit someone?

The FCC says hundreds of fragments from the Starlink constellation could reach the Earth’s surface every day

References in this link https://spectrum.ieee.org/tech-talk/aerospace/satellites/the-odds-that-one-of-spacexs-internet-satellites-will-hit-someone

When SpaceX plugged the numbers into NASA’s Debris Assessment Software, the package calculated that there was, at most, a 1 in 18,200 chance that an individual satellite in its LEO orbital shells would hurt or kill someone. VLEO satellites were generally slightly riskier, with up to a 1 in 17,400 chance. All figures are handily less than the 1 in 10,000 figure that NASA has adopted as a standard, and that U.S. and European space agencies require for space missions.

However, the FCC didn’t stop there. In March and June 2017, the FCC calculated the aggregate risk to humans from the entire constellation. Assuming the 11,927 satellites are launched on a regular basis, they will fail in the same way. Starting around six years from the first launch, an average of five satellites a day will reenter the Earth’s atmosphere, each with a tiny chance of failing to completely burn up, resulting in a part that could hit someone. 

But with more than a thousand satellites falling a year, those tiny risks add up. The FCC figured out that, over their lifetime, satellites in the LEO shells posed a 1 in 5 risk of hurting or killing someone, and the VLEO satellites carried a 1 in 4 risk. IEEE Spectrum’s calculations using SpaceX’s most up-to-date information suggests that the overall risk of debris from the constellation causing an injury or death will be 45 percent.

This means that NASA’s software says that it is nearly as likely than not, that one of the Starlink satellites will injure or kill someone, about every six years.

On the contrary SpaceX noted that between 62 and 242 meteorites larger than 10 grams make it to ground level on an average day: SpaceX responded by saying its satellites would create, at most, 10 fragments each over its lifetime, only a fraction of which would pose a risk to people. That works out to around 120,000 objects overall or 54 daily—comparable to a quiet day of natural meteorites, but hardly insignificant.

In September 2017, space Internet rival OneWeb pointed out that some components from SpaceX’s satellites would survive reentry with an energy of more than 960 joules—equivalent to a baseball travelling at more than 400 kph. It asked the FCC to “require SpaceX to address the aggregate risk posed by its very large LEO and VLEO constellations and adopt adequate measures to mitigate that risk.”

Under FCC rules, SpaceX must have half of its 11,927 Starlink satellites in orbit and operating no later than November 2024 (and other 30thousands later).

The list of more than 500 constellation projects can be found here: https://www.newspace.im/

Thank to megaconstellation a new O3 hole?

The Cygnus re-supply vehicle, which delivers cargo to the International Space Station, burning up in the atmosphere during its reentry. (Image credit: ESA/Alexander Gerst)

Here is the reference for this news: https://www.space.com/amp/starlink-satellite-reentry-ozone-depletion-atmosphere

Chemicals released as defunct satellites burn in the atmosphere could damage Earth’s protective ozone layer if plans to build megaconstellations of tens of thousands of satellites, such as SpaceX’s Starlink, go ahead as foreseen, scientists warn. 

Researchers also caution that the poorly understood atmospheric processes triggered by those chemicals could lead to an uncontrolled geoengineering experiment, the consequences of which are unknown.

For years, the space community was content with the fact that the amount of material that burns in the atmosphere as a result of Earth’s encounters with meteoroids far exceeds the mass of defunct satellites meeting the same fate. Even the rise of megaconstellations won’t change that. The problem, however, is in the different chemical composition of natural meteoroids compared to artificial satellites, according to Aaron Boley, an associate professor of astronomy and astrophysics at the University of British Columbia, Canada. 

“We have 54 tonnes (60 tons) of meteoroid material coming in every day,” Boley, one of the authors of a paper published May 20 in the journal Scientific Reports, told Space.com. “With the first generation of Starlink, we can expect about 2 tonnes (2.2 tons) of dead satellites reentering Earth’s atmosphere daily. But meteoroids are mostly rock, which is made of oxygen, magnesium and silicon. These satellites are mostly aluminum, which the meteoroids contain only in a very small amount, about 1%.”

The scientists realised that megaconstellations have a significant potential to change the chemistry of the upper atmosphere compared to its natural state. But not only that. The burning of aluminum is known to produce aluminum oxide, also known as alumina, which can trigger further unexplored side effects. 

“Alumina reflects light at certain wavelengths and if you dump enough alumina into the atmosphere, you are going to create scattering and eventually change the albedo of the planet,” Boley said. 

Albedo is the measure of the amount of light that is reflected by a material. In fact, increasing Earth’s albedo by pumping certain types of chemicals into the higher layers of the atmosphere has been proposed as a possible geoengineering solution that could slow down global warming. However, Boley said, the scientific community has rejected such experiments because not enough is known about their possible side effects. 

“Now it looks like we are going to run this experiment without any oversight or regulation,” Boley said. “We don’t know what the thresholds are, and how that will change the upper atmosphere.”

The atmospheric reentry process generates extreme heat and mechanical loads, which lead to the satellite’s disintegration at the altitude of about 45 miles.

The aluminum from re-entering satellites also has a potential to damage the ozone layer, a problem well known to humanity, which has been successfully solved by widespread bans on the use of chlorofluorocarbons, chemicals used in the past in aerosol sprays and refrigerators. 

In their paper, Boley and his colleague Michael Byers cite research by their counterparts from the Aerospace Corporation, a U.S. non-profit research organization, which identified local damage to the planet’s ozone layer triggered by the passage of polluting rockets through the atmosphere.

“We know that alumina does deplete ozone just from rocket launches themselves because a lot of solid-fuel rockets use, or have, alumina as a byproduct,” Boley said. “That creates these little temporary holes in the stratospheric ozone layer. That’s one of the biggest concerns about compositional changes to the atmosphere that spaceflight can cause.”

The ozone layer protects life on Earth from harmful UV radiation. The depletion of ozone in the stratosphere, the second lowest layer of the atmosphere extending between altitudes of approximately 7 to 40 miles (10 to 60 kilometers), led to an increased risk of cancer and eye damage for humans on Earth. 

Gerhard Drolshagen, of the University of Oldenburg, Germany, who has published papers about the effects of meteoroid material on Earth, told Space.com that reentering satellites usually evaporate at altitudes between 55 and 30 miles (90 and 50 km), just above the ozone-rich stratosphere. However, he added, the particles created as a result of the satellites’ burning will eventually sink to the lower layers. 

Boley said that as the alumina sinks into the stratosphere, it will cause chemical reactions, which, based on existing knowledge, will likely trigger ozone destruction.

Drolshagen, who wasn’t involved in the recent study, agreed that because “satellites are mostly made of aluminum, the amount of aluminum deposited in the atmosphere will certainly increase.”

Concerns about the effects of aluminium oxides on the atmosphere have been cited by U.S. telecommunications operator Viasat in its request to the US Federal Communications Commision to suspend launches of SpaceX’s Starlink megaconstellation until a proper environmental review of its possible impacts is conducted. 

Megaconstellations cause serious worries to the space community as they increase the risks of orbital collisions in the already cluttered orbital environment. 

SpaceX’s Starlink in particular came under fire also due to the effects the visible trains of their satellites have on astronomical observations. SpaceX pledged to cooperate with the astronomical community and modify the design of their satellites to mitigate the problem. However, earlier this year, the International Astronomical Union asked a specialised United Nations’ committee to protect the pristine night sky against light pollution from megaconstellations. 

Last week, the chief of European launch provider ArianeSpace, Stephane Israel, accused SpaceX mastermind Elon Musk of monopolizing space and squeezing out competitors. 

In addition to SpaceX, Musk also gained recognition with his sustainability-focused ventures Tesla and Solar City, the goal of which was to help wean the world off fossil fuels. Earlier this year, Musk launched the $100 million Carbon Removal X Prize, the richest incentive prize in history. The prize’s goal is to develop technologies that can help stave off the worst effects of human-caused climate change.

SpaceX didn’t respond to Space.com’s request for comment.

In their study, Boley and his colleagues looked only at the effects of the first generation of the Starlink megaconstellation, which is expected to consist of 12,000 satellites. More than 1,700 of these have already been launched. As a result of SpaceX’s activities (and to a lesser extent those of other constellation operators), the number of active and defunct satellites in low Earth orbit, the region of space below the altitude of 620 miles (1,000 km), has increased by 50% over the past two years, according to the paper. 

“The problem is that there are now plans to launch about 55,000 satellites,” Boley said. “Starlink second generation could consist of up to 30,000 satellites, then you have Starnet, which is China’s response to Starlink, Amazon’s Kuiper, OneWeb. That could lead to unprecedented changes to the Earth’s upper atmosphere.”

Megaconstellation operators, inspired by the consumer technology model, expect fast development of new satellites and frequent replacement, thus the high amount of satellites expected to be burning in the atmosphere on a daily basis. 

“Humans are exceptionally good at underestimating our ability to change the environment,” said Boley. “There is this perception that there is no way that we can dump enough plastic into the ocean to make a difference. There is no way we can dump enough carbon into the atmosphere to make a difference. But here we are. We have a plastic pollution problem with the ocean, we have climate change ongoing as a result of our actions and our changing of the composition of the atmosphere and we are poised to make the same type of mistake by our use of space.”

Losing the Sky – Public debate at RAS

This is a very fruitful and complete DEBATE on the ASTRONOMICAL and ENVIRONMENTAL issues related to Satellites Constellations following the prof. Andy Lawrence “Losing the Sky” book settings hosted by the Royal Astronomical Society of Edinburgh.

We recommend the viewing.


LOSING THE SKY PUBLIC DEBATE!

Here il the link where it is talked on the SAS Foundation:

https://youtu.be/ESoM3Noz5zk?t=6861

Just few comments:

============

Just to point out, being unable to reply (for the short time) to the Niklas Hedman considerations on Stefano Gallozzi:

the SAS Foundation intention was not to have a new international regulation (it is desirable, but not our goal).

Our intention was to avoid threats and so to stop the launches. Legal action is therefore more than appropriate to stop everything and “take time”. At that point the regulation comes by itself (nations and governments will agree, otherwise they would not be able to send anything more in LEO, because any new constellation authorization could be blocked in the same way).

So what’s the point in saying you have to go and ask to your governments? If my government agrees to ship 1 million satellites regardless of astronomy and the environment, should I ask my government to stop launching? Not at all.

SAS Foundation is an action made by citizens, certainly not by politics and in some cases legal path could be successful and this kind of push is not always wrong.

Satellites’ Constellations at G7 obliterated!

At this link it is possible to find arguments and concerns related to the crowding of objects and satellites in the Earth’s orbit in the last G7 meeting regarding the sustainable use of Space activities.

https://www.gov.uk/government/news/g7-nations-commit-to-the-safe-and-sustainable-use-of-space

They concentrated on space debris an how to avoid them. Unfortunately no member/speaker has identified the satellites’ constellations as the main danger in the future use of the Earth’s orbit in particular regarding the pacific use of the Low Earth Orbit as UN-COPUOS should safeguard and watch over. In particular it is important to note the military use of a large fraction of SpaceX satellites constellation ( https://spacenews.com/u-s-army-signs-deal-with-spacex-to-assess-starlink-broadband/ ) for US Army and AIR Force.

When politics fails and represents only a mirror for ladols!