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solartim27

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Re: Satellite News
« Reply #50 on: October 15, 2020, 05:05:22 PM »
Sometime tonight there will be a close approach of a retired satellite and a rocket stage. I've seen closest approach estimates  range from 12 to 60 meters. The satellite has a 50 ft boom to add excitement.  TCA is 00:56 tomorrow UTC, or 7:56 pm today US EDT.

https://twitter.com/LeoLabs_Space/status/1316410780552699909?s=19

Edit: The rocket booster is 15 m long, this could be quite interesting. There is still debris being tracked from a 2009 Iridium collision.
https://en.m.wikipedia.org/wiki/2009_satellite_collision
« Last Edit: October 15, 2020, 07:32:41 PM by solartim27 »
FNORD

Tor Bejnar

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Re: Satellite News
« Reply #51 on: October 15, 2020, 06:00:42 PM »
It's not quite "satellite" news, only stratosphere news.
High-altitude airships company picks New Mexico for base


Quote
(AP) — A technology company aiming to send up high-altitude airships to monitor crops and bring broadband has chosen New Mexico for its U.S. production center, state Economic Development Secretary Alicia J. Keyes announced Tuesday.

The Switzerland-based Sceye picked the state as its U.S. base for stratospheric flights for earth observation and communication after spending more than $50 million in developing the stratospheric airship and building infrastructure, state officials said.

Officials said the company founded by global humanitarian Mikkel Vestergaard will locate its manufacturing operation in the state and will create 140 high-paying manufacturing and engineering jobs.

The move comes as Sceye works to develop a fleet of airships that could be parked for long periods of time about 65,000 feet (19,812 meters) in the air. Once in the sky, the blimp-like airships would monitor crop conditions, climate change, and human trafficking. The aircraft also may improve communication connections between drones, aircraft, satellites, and expand broadband.

The airships are controlled by pilots on the ground who move them as weather and the Earth’s atmosphere changes.
...
Arctic ice is healthy for children and other living things.

kassy

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Re: Satellite News
« Reply #52 on: October 23, 2020, 06:55:12 PM »
Norway funds satellite map of world's tropical forests

A unique satellite dataset on the world's tropical forests is now available for all to see and use.

It's a high-resolution image map covering 64 countries that will be updated monthly.

Anyone who wants to understand how trees are being managed will be able to download the necessary information for analysis - for free.

The Norwegian government is funding the project through its International Climate and Forests Initiative (NICFI).

....

"There are many parts of the world where high-resolution images simply aren't available, or where they are available - the NGOs, communities, and academia in those countries can't afford them because they're quite expensive.

"So, we've decided to foot the bill for the world, basically," he told BBC News.

The NICFI has awarded a $44m (£33m) contract to Earth-observation specialists Airbus, Planet and Kongsberg Satellite Services (KSAT) for access to their pictures and expertise.

European aerospace giant Airbus is opening up its Spot image archive going back to 2002.

US-based Planet operates the single biggest constellation of imaging satellites in orbit today. The San Francisco firm acquires a complete picture of the Earth's land surface daily (cloud permitting), and it will provide the bulk of the data for the monthly map going forward.

KSAT will tie the information together and provide the technical support for users.

see:

https://www.bbc.com/news/science-environment-54651453
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vox_mundi

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Re: Satellite News
« Reply #53 on: November 03, 2020, 11:22:19 AM »
NASA Objects to New Megaconstellation, Citing Risk of “Catastrophic Collison”
https://arstechnica.com/science/2020/11/nasa-objects-to-new-megaconstellation-citing-risk-of-catastrophic-collison/



NASA has formally commented (PDF) on a request by a US company to build a megaconstellation of satellites at an altitude of 720km above the Earth's surface, citing concerns about collisions. This appears to be the first time that NASA has publicly commented on such an application for market access, which is pending before the Federal Communications Commission.

https://licensing.fcc.gov/myibfs/download.do?attachment_key=2765834

"NASA submits this letter during the public comment period for the purpose of providing a better understanding of NASA's concerns with respect to its assets on-orbit, to further mitigate the risks of collisions for the mutual benefit of all involved," wrote Samantha Fonder, an engineer for the space agency.

At issue are plans put forth by AST & Science, which intends to build a constellation of more than 240 large satellites, essentially deploying "cell towers" in space to provide 4G and possibly 5G broadband connection directly to cell phones on Earth. The company, based in Midland, Texas, calls its constellation "SpaceMobile" and has raised an estimated $120 million.

The space agency felt compelled to comment on AST's proposal for several reasons. Most notably, the proposed altitude for the SpaceMobile constellation lies near the "A-Train," a group of 10 Earth-science monitoring satellites operated by NASA and the US Geological Survey, as well as partners in France and Japan. "Historical experience with the A-Train constellation has shown that this particular region of space tends to produce a large number of conjunctions between space objects," the NASA letter states.

The satellites are also very large. In order to provide service, AST plans to build spacecraft with large phased array antennae—900 square meters. According to NASA, in planning for potential conjunctions with other satellites and debris in this orbit, this would require proscribing a "hard-body radius" of 30 meters, or as much as 10 times larger than other satellites.

Maneuvering around the proposed SpaceMobile constellation would be extraordinarily taxing, NASA said. "For the completed constellation of 243 satellites, one can expect 1,500 mitigation actions per year and perhaps 15,000 planning activities," the space agency stated. "This would equate to four maneuvers and 40 active planning activities on any given day."

Finally, the space agency is concerned because AST has never built a satellite remotely close in size to the 1-ton or larger vehicles that will populate its constellation. Given this lack of experience, it is expected that 10 percent or more of the satellites may fail, making them unable to maneuver to avoid collisions. NASA found the risk of a catastrophic collision to be "unacceptably high."

... When it comes to megaconstellations—including SpaceX's Starlink, OneWeb, and others—the FCC has been considering the debris issue when it comes to putting hundreds, if not thousands, of new satellites into low Earth orbit. Therefore, it will be interesting to see in which direction the FCC goes on this issue because the federal agency has two competing interests.

In the big picture, Weeden said, this dustup between NASA and AST is more evidence that the US government—and other spacefaring nations around the world—need to do a better job ensuring that low Earth orbit remains as debris-free as possible. There is no governmental agency specifically charged with ensuring low Earth orbit remains safe, and the existing models are failing to fully capture the threat from new and old satellites, spent rocket second stages, and known debris. So in some sense, with all the megaconstellations flying into space today, regulators are flying blind, he said.

"We should have done a lot of this work over the last 10 years," he said. "From a government policy oversight perspective, we're behind the power curve."
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gerontocrat

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Re: Satellite News
« Reply #54 on: November 15, 2020, 10:49:00 PM »
EU announces big programme of new Copernicus satellites. UK is out of the frame unless a post-Brexit deal is made next year.

https://www.bbc.co.uk/news/science-environment-54926152
New Sentinel satellites to check the pulse of Earth
Quote
Yet more Sentinel satellites are to be built for the EU's Copernicus Earth observation network.

Contracts have been announced with industry to procure spacecraft that can provide information on a range of parameters - from the extent of Arctic sea-ice to the condition of soils in drought-hit regions of the world.

The new satellites are expected to launch towards the decade's end. This depends, however, on sufficient further funding being identified.

Copernicus, with its Sentinel spacecraft, represents arguably the most ambitious EO programme in the world right now.

While a number of commercial concerns are launching larger numbers of satellites to map the Earth, none is investing in so wide a range of high-fidelity sensor types. What's more, all the data from the Sentinels is free and open, including to users outside Europe.

The contracts announced by the European Space Agency (Esa) on Friday begin the development of three systems that, for the moment, carry only codenames:

- CHIME (Copernicus Hyperspectral Imaging Mission for the Environment): A hyperspectral imager to return detailed information on the health of crops and other plants. The prime contractor is Thales Alenia Space (TAS) France. Total value of the programme is €455m, which would procure two satellite models.
- LSTM (Land Surface Temperature Monitoring): A thermal infrared sensor to measure land-surface temperature. Again, useful in agriculture and to predict drought. The prime contractor is Airbus Spain. The total value of this programme is €380m; and, again, it would secure two satellite models.
- CIMR (Copernicus Imaging Microwave Radiometer): A microwave radiometer to measure sea-surface temperature and salinity, and sea-ice concentration. The prime contractor is Thales Alenia Space Italy. Total value is €495m and, likewise, would secure two spacecraft.

Once Esa and the European Commission are satisfied the financing and the technical wherewithal is in place to fully implement these missions, they will be given a Sentinel designation - just as the six existing programmes have: Sentinel-1, -2, -3, -4, -5 and -6.

n July this year, a contract was awarded to OHB-System of Germany to provide Sentinels (Codename: CO2M) to map carbon dioxide concentrations in the atmosphere; and in September, Airbus Germany was asked to get working on a Sentinel that could measure the shape and thickness of polar ice (Codename: Cristal).

There is also one other mission that is planned but has yet to reach the contract stage. That's for an L-band radar that can also observe ice but many other targets as well, including forests and soils. Thales Alenia Space Italy will be the prime for the mission, codenamed Rose-L. The contract specifics should be tied up by December at the latest.


Member states to Esa gave the agency's Copernicus activities more than was requested when they convened at a special council meeting last year - some €1.8bn. But on Tuesday this week, discussions around the EU's next seven-year budget began to solidify - and it wasn't good news for Copernicus.

The proposed €4.8bn envelope would leave a significant shortfall in funding of about €2bn.

There is hope that the UK, which left the EU in January, can soon re-associate, which would bring with it a potential subscription worth several hundred millions euros over the seven years.

But this association is at the mercy of the wider post-Brexit trade deal between the EU-27 and Britain. If the current talks fail - and the mood music has soured again in recent days - then Copernicus membership for the UK will almost certainly come off the table as well, in the short term at least.

On a brighter note, the first Sentinel-6 satellite is due to be launched on 21 November.

This is a radar altimeter that will measure very precisely the height of the world's oceans. It's data that is critical for understanding sea-level rise but also for weather forecasting and a host of maritime applications, such as efficient routing for ships.

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kassy

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Re: Satellite News
« Reply #55 on: November 19, 2020, 01:51:11 PM »
Sentinel-6 satellite: Watching the sea level rise

New offspring for the Copernicus family! The Earth observation satellite Sentinel-6 is scheduled to be launched on November 21. Its superpower: Sentinel-6 can monitor the ocean with millimeter precision.

...

The Earth observation satellite is intended to measure our oceans and chart the sea level. And this is likely to be a rather depressing sight from space. After all, it is no secret that the sea level is tending to rise  with growing rapidity. While it increased by only 2 centimeters (0.79 inches) in the entire 18th century, it already went up by 6 centimeters in the 19th century and a whole 19 centimeters in the 20th. Industrialization and human-made global warming certainly have had something to do with this.

...

Sentinel-6 is the first of two identical satellites that are to be launched into space. Sentinel-6B, the twin satellite, is scheduled for launch in 2025. The two satellites are meant to collect data for at least five years.

...

It will scan 95% of the global sea surface within 10 days — from an altitude of more than 1,300 kilometers (800 miles) and to an accuracy of less than 1 millimeter.

In addition, it is also to collect precise data on atmospheric temperature and humidity, which can help improve weather forecasts and climate models.

The satellite sends out radar impulses that are reflected from the sea surface and then received again by the spacecraft. "Nobody can do anything with this data at first. It has to be converted into a high-precision distance measurement," says Manfred Lugert, head of Copernicus Mission Development and Jason-CS/ Sentinel 6 program manager at EUMETSAT. He said wave heights and atmospheric influences would also have to be taken into account when measuring distances.

Two independent navigation systems are also on board for determining the location. The satellite's orbit is regularly measured with a laser.

By working together with other satellites, Sentinel-6 will also help to make inferences about the density and thickness of ice. This is important, says Josef Aschbacher, ESA's director for Earth observation programs. The Greenland ice sheet is currently melting  at three times the rate in the 1990s, he says. "We will now get a global measurement every 10 days — in other words, a picture of what the momentary situation is like," says Aschbacher. "The satellite will provide data that has not been available in this detail before."

What's so special about Sentinel-6?
Earth observation satellites as such have been around for decades — for example, TIROS-1, the first experimental weather satellite, was launched on April 1, 1960.

The Copernicus Earth Observation Program launched the Sentinel-1A satellite on April 3, 2014, followed by 1B on April 25, 2016. Since then, other types of Sentinel satellites have been added.

...

The Sentinel-1 satellites provide detailed radar images of the planet's surface in all types of weather, day and night. Sentinel-2's  specialty is to detect changes in vegetation and do things like provide crop forecasts, chart forests and monitor the growth of wild and agricultural plants. Sentinel-3 provides temperature measurements of land and ocean.

Sentinel-4, whose launch is planned for 2022, will collect data on the concentration of pollutants in the air. Sentinel-5 is a mission to measure atmospheric gases worldwide. Sentinel-5P  analyzes the composition of the atmosphere.

But Aschbacher says there is still a lot to be done and still parameters that need to be measured more accurately. For example, he says, the greenhouse gas carbon dioxide is still not being measured precisely and comprehensively enough.

...

https://www.dw.com/en/sentinel-6-satellite-watching-the-sea-level-rise/a-55659812
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gerontocrat

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Re: Satellite News
« Reply #56 on: November 28, 2020, 03:46:37 PM »
So new satellites go up (see above), but old satellites fall down with perhaps no or very late replacements to mantain the continuous record.

The article below is about the European CryoSat-2 and American IceSat-2 spacecraft. But the satellites that produce the NSIDC and JAXA data are even more extremely long in the tooth. At any day they could go kaput. Quite why there is so little news about that is a bit of a mystery, though there is this letter dated April 2019 - https://iopscience.iop.org/article/10.1088/1748-9326/ab09b3 Essential gaps and uncertainties in the understanding of the roles and functions of Arctic sea ice  (The newer satellites produce more detailed datasets but they are not compatible with the JAXA and NSIDC datasets).

Ah well, I need a holiday.

https://www.bbc.co.uk/news/science-environment-55109092
Polar scientists wary of impending satellite gap

There is going to be a gap of several years in our ability to measure the thickness of ice at the top and bottom of the world, scientists are warning.

Quote
The only two satellites dedicated to observing the poles are almost certain to die before replacements are flown. This could leave us blind to some important changes in the Arctic and the Antarctic as the climate warms.

The researchers have raised their concerns with the European Commission and the European Space Agency. A letter detailing the problem - and possible solutions - was sent to leading EC and Esa officials this week; and although the US space agency (Nasa) has not formally been addressed, it has been made aware of the correspondence.

At issue is the longevity of the European CryoSat-2 and American IceSat-2 missions. These spacecraft carry instruments called altimeters that gauge the shape and elevation of ice surfaces.

They've been critical in recording the loss of sea-ice volume and the declining mass of glaciers.

CryoSat-2 and IceSat-2
IMAGE COPYRIGHTESA/NASA
image captionArtwork: CryoSat-2 (top) and IceSat-2 (bottom) will hopefully last until mid-decade

What's unique about the satellites is their orbits around the Earth. They fly to 88 degrees North and South from the equator, which means they see the entire Arctic and Antarctic regions, bar a small circle about 430km in diameter at the poles themselves.

In contrast, most other satellites don't usually go above 83 degrees. As a consequence, they miss, for example, a great swathe of the central Arctic Ocean and its frozen floes.

The worry is that CryoSat-2 and IceSat-2 will have been decommissioned long before any follow-ups get launched.

CryoSat-2 is already way beyond its design life. It was put in space in 2010 with the expectation it would work for at least 3.5 years. Engineers think they can keep it operating until perhaps 2024, but battery degradation and a fuel leak suggest not for much longer.

IceSat-2 was launched in 2018 with a design life of three years and fuel until 2025. Its altimeter also uses lasers which are a complex technology to maintain in space.

"Without successful mitigation, there will be a gap of between two and five years in our polar satellite altimetry capability," the scientists' letter states. "This gap will introduce a decisive break in the long-term records of ice sheet and sea-ice thickness change and polar oceanography and this, in turn, will degrade our capacity to assess and improve climate model projections."

The only satellite replacement currently in prospect is the EC/Esa mission codenamed Cristal. It will be like Cryosat, although with much greater capability thanks to a dual-frequency radar altimeter. Industry has started work on the spacecraft but it won't launch until 2027/28, maybe even later because full funding to make this date a reality is not yet in place.

Dr Josef Aschbacher, the director of Earth observation at Esa, said his agency was working as fast as it could to plug the gap. "This is a concern; we recognise it," he told the BBC. "We've put plans in motion to build Cristal as quick as we can. Despite Covid, despite heavy workloads and video conferences by everyone - we have gone through the evaluation... and Cristal was kicked off in early September."

Just over 10% of the near-600 signatories to the letter are American scientists.

Dr Thomas Zurbuchen, the head of science at Nasa, is not being sent the letter because it is primarily aimed at European funders - and most of the signatories are European. Nonetheless, Dr Zurbuchen is aware of the letter and its contents. He said he was hopeful any polar gap could be plugged or minimised.

"I think there are multiple options at this moment in time that we can deploy to that end, in partnership or otherwise," he commented.

One of those solutions in Europe would be to run a version of Nasa's IceBridge project.
This was an airborne platform that the US agency operated in the eight years between the end of the very first IceSat mission in 2010 and the launch of IceSat-2 in 2018.

An aeroplane flew a laser altimeter over the Arctic and the Antarctic to gather some limited data-sets that could eventually be used to tie the two IceSat missions together.

There are many who think a European "CryoBridge" is the most affordable and near-term option to mitigate the empty years between CryoSat-2 and Cristal. The cost of manufacture of the airborne radar altimeter could be accomplished for perhaps €5m (£4.5m), scientists believe, but its design and fabrication would likely take two years. Such a project would therefore have to get under way relatively soon. It would, of course, also need an operational budget.

The signatories to the letter sent to the EC and Esa include leading scientists using CryoSat and IceSat data, the president of the International Glaciology Society, and lead authors on the United Nations' Intergovernmental Panel on Climate Change, which prepares the authoritative state-of-the-climate reports for world governments.
« Last Edit: November 28, 2020, 04:03:27 PM by gerontocrat »
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