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SpaceX plans Falcon 9 launch Thursday from Kennedy Space Center – Spaceflight Now

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A SpaceX Falcon 9 rocket rolls out of the hangar at pad 39A in this file photo. Credit: SpaceX

Forecasters predict a 60 percent chance of favorable weather for launch of a SpaceX Falcon 9 rocket Thursday from NASA’s Kennedy Space Center in Florida to carry more Starlink broadband satellites into orbit.

The launch — set for 2:19 p.m. EDT (1819 GMT) Thursday — will add 60 more Starlink satellites to SpaceX’s ever-growing broadband network. SpaceX has launched more than 700 Starlink satellites to date, making the company the owner of the largest fleet of spacecraft in orbit.

Like the previous Starlink launches, a 229-foot-tall (70-meter) Falcon 9 rocket head northeast from Florida’s Space Coast with 1.7 million pounds of thrust from nine Merlin main engines, then shed its first stage booster about two-and-a-half minutes into the flight.

A single Merlin engine on the Falcon 9’s second stage is expected to fire two times before release of the stack of Starlink satellites in a near-circular orbit between 172 miles (278 kilometers) and 162 miles (261 kilometers), with an inclination of 53 degrees, according to pre-launch estimates.

Separation of the 60 Starlink satellites from the rocket is scheduled about 61 minutes after launch.

SpaceX plans to recover the Falcon 9’s first stage aboard the drone ship “Just Read the Instructions” positioned northeast of Cape Canaveral in the Atlantic Ocean, roughly due east of Charleston, South Carolina. The propulsive landing of the first stage is expected around eight minutes after liftoff.

The first stage on Thursday’s launch has flown two previous times, including the launch May 30 of two NASA astronauts on SpaceX’s Crew Dragon capsule, and the July 20 launch of South Korea’s Anasis 2 military communications satellite. One half of the clamshell-like payload shroud on Thursday’s mission is also a veteran of two previous Falcon 9/Starlink launches, according SpaceX.

SpaceX also plans to retrieve the payload fairing after Thursday’s launch. The two halves of the shroud are designed to descend under parachutes.

The mission Thursday will mark the 13th launch of Starlink satellites since SpaceX kicked off deployment of the network in May 2019. SpaceX’s most recent launch Sept. 3 carried up the previous 60 Starlink satellites.

The official launch weather forecast issued Wednesday by the 45th Weather Squadron at Cape Canaveral calls for a 60 percent chance of good conditions for liftoff of the Falcon 9 Thursday. The primary weather concerns Thursday will be with cumulus and anvil clouds associated with afternoon thunderstorms.

If the launch is delayed to Friday, there’s a 40 percent chance of acceptable weather conditions in the forecast.

SpaceX eventually plans to launch thousands of Starlink satellites, but the first tranche of Starlinks will number 1,440 spacecraft, according to Jonathan Hofeller, SpaceX’s vice president of Starlink and commercial sales.

“The total global constellation we’re targeting is 1,440 satellites, of which a good number of those are already on orbit,” Hofeller said.

Some of the satellites, including those on the first Starlink launch last May, are being moved to lower altitudes and deorbited.

Each flat-panel Starlink satellite weighs about a quarter-ton, and they are built at a SpaceX facility in Redmond, Washington, near Seattle. Extending on SpaceX’s penchant for building hardware in-house, the aerospace company is manufacturing its own Starlink satellites, user terminals and ground stations.

SpaceX’s Starlink megaconstellation is already the largest fleet of satellites in the world, but hundreds more will be launched in the coming months.

Hofeller said last month that SpaceX is building six Starlink spacecraft per day, and plans to launch Starlink missions at intervals of every two to three weeks until completing the initial Starlink network of around 1,440 satellites.

A stack of 60 Starlink satellites before a previous mission. Credit: SpaceX

SpaceX has regulatory approval from the Federal Communications Commission to eventually operate nearly 12,000 Starlink satellites to blanket the planet with high-speed, low-latency Internet signals. SpaceX also also signaled plans to launch up to 30,000 additional Starlink satellites — beyond the 12,000 already approved — in filings with the International Telecommunication Union.

The Starlink network is one of two major development projects SpaceX is pursuing, alongside the company’s next-generation Starship super-heavy-lift rocket.

In a discussion at the ASCEND Space Science and Technology Summit last month, Hofeller said that the private beta testing is being rolled out in the Pacific Northwest. With roughly 700 satellites, the Starlink network has enough coverage to provide connectivity to users at high latitudes, but more launches are required to expand coverage to other regions.

SpaceX has asked people interested in participating in the public beta test phase to sign up on the Starlink website.

With the beta testing program now underway, SpaceX is collecting latency statistics and performing speed tests. The company says it’s pleased with the initial results.

SpaceX said earlier this month that the tests so far show the network has “super low latency” with download speeds greater than 100 megabits per second. That’s fast enough to stream multiple HD movies at once, and still have bandwidth to spare, according to SpaceX.

SpaceX has also begun testing spacecraft with inter-satellite laser links, which could eventually allow data traffic to flow through the network without going through ground relay stations. The first batch of Starlink satellites did not carry inter-satellite links

Hofeller hinted at upgraded Starlink satellites in his virtual presentation at ASCEND Space Science and Technology Summit last month

“With 1,440 satellites, that’s when we get 24/7 global coverage, and the plan is to not stop there,” Hofeller said. “We’ll continue to launch, and with each launch, we can provide more and more capacity. There’s never enough capacity. You can’t limit what your kids want to watch, and what your family wants to consume. So we’ll continue to densify the network.”

SpaceX will deorbit older Starlink satellites as upgraded spacecraft come online, according to Hofeller.

After the launch Thursday, SpaceX’s next mission is set to take off from pad 40 at Cape Canaveral Air Force Station on Sept. 30, when a Falcon 9 rocket will deploy the U.S. Space Force’s next GPS navigation satellite.

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Follow Stephen Clark on Twitter: @StephenClark1.

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Salty ponds found on Mars suggest stronger prospect of life on red planet, scientists say – CBC.ca

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A network of salty ponds may be gurgling beneath the South Pole on Mars, alongside a large underground lake, raising the prospect of tiny, swimming Martian life.

Italian scientists reported their findings Monday, two years after identifying what they believed to be a large buried lake. They widened their coverage area by a couple hundred miles, using even more data from a radar sounder on the European Space Agency’s Mars Express orbiter.

In the latest study appearing in the journal Nature Astronomy, the scientists provide further evidence of this salty underground lake, estimated to be 20 to 30 kilometres across and buried 1.5 kilometres beneath the icy surface.

Even more tantalizing, they’ve also identified three smaller bodies of water surrounding the lake. These ponds appear to be of various sizes and are separate from the main lake.

Roughly four billion years ago, Mars was warm and wet, like Earth. But the red planet eventually morphed into the barren, dry world it is today.

The research team led by Roma Tre University’s Sebastian Emanuel Lauro used a method similar to those used on Earth to detect buried lakes in the Antarctic and Canadian Arctic. They based their findings on more than 100 radar observations by Mars Express from 2010 to 2019; the spacecraft was launched in 2003.

All this potential water raises the possibility of microbial life on — or inside — Mars. High concentrations of salt are likely keeping the water from freezing at this frigid location, the scientists noted. The surface temperature at the South Pole is an estimated -113 degrees C and gets gradually warmer with depth.

These bodies of water are potentially interesting biologically and the researchers wrote that “future missions to Mars should target this region.” 

Earlier this year, a new computer model by NASA scientists lent further support to the theory that the ocean beneath the thick, icy crust of Jupiter’s moon Europa could be habitable.

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Salty lake, ponds may be gurgling beneath South Pole on Mars – CP24 Toronto's Breaking News

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Marcia Dunn, The Associated Press


Published Monday, September 28, 2020 7:46PM EDT

CAPE CANAVERAL, Fla. – A network of salty ponds may be gurgling beneath Mars’ South Pole alongside a large underground lake, raising the prospect of tiny, swimming Martian life.

Italian scientists reported their findings Monday, two years after identifying what they believed to be a large buried lake. They widened their coverage area by a couple hundred miles, using even more data from a radar sounder on the European Space Agency’s Mars Express orbiter.

In the latest study appearing in the journal Nature Astronomy, the scientists provide further evidence of this salty underground lake, estimated to be 12 miles to 18 miles (20 kilometres to 30 kilometres) across and buried 1 mile (1.5 kilometres) beneath the icy surface.

Even more tantalizing, they’ve also identified three smaller bodies of water surrounding the lake. These ponds appear to be of various sizes and are separate from the main lake.

Roughly 4 billion years ago, Mars was warm and wet, like Earth. But the red planet eventually morphed into the barren, dry world it remains today.

The research team led by Roma Tre University’s Sebastian Emanuel Lauro used a method similar to what’s been used on Earth to detect buried lakes in the Antarctic and Canadian Arctic. They based their findings on more than 100 radar observations by Mars Express from 2010 to 2019; the spacecraft was launched in 2003.

All this potential water raises the possibility of microbial life on – or inside – Mars. High concentrations of salt are likely keeping the water from freezing at this frigid location, the scientists noted. The surface temperature at the South Pole is an estimated minus 172 degrees Fahrenheit (minus 113 degrees Celsius), and gets gradually warmer with depth.

These bodies of water are potentially interesting biologically and “future missions to Mars should target this region,” the researchers wrote.

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Another look at possible under-ice lakes on Mars: They’re still there – Ars Technica

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In recent decades, we’ve become aware of lots of water on Earth that’s deep under ice. In some cases, we’ve watched this water nervously, as it’s deep underneath ice sheets, where it could lubricate the sheets’ slide into the sea. But we’ve also discovered lakes that have been trapped under ice near the poles, possibly for millions of years, raising the prospect that they could harbor ancient ecosystems.

Now, researchers are applying some of the same techniques that we’ve used to find those under-ice lakes to data from Mars. And the results support an earlier claim that there are bodies of water trapped under the polar ice of the red planet.

Spotting liquids from orbit

Mars clearly has extensive water locked away in the forum of ice, and some of it cycles through the atmosphere as orbital cycles make one pole or the other a bit warmer. But there’s not going to be pure liquid water on Mars—the temperatures just aren’t high enough for very long, and the atmospheric pressures are far too low to keep any liquid water from boiling off into the atmosphere.

Calculations suggest, however, that liquid water is possible on Mars—just not on the surface. With enough dissolved salts, a water-rich brine could remain liquid at the temperatures prevalent on Mars—even in the polar areas. And if it’s trapped under the Martian surface, there might be enough pressure to keep it liquid despite the thin atmosphere. That surface could be Martian soil, and people are thinking about that possibility. But the surface could also be one of the ice sheets we’ve spotted on Mars.

That possibility helped motivate the design of the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) on the Mars Express orbiter. MARSIS is a radar device that uses wavelengths that water ice is transparent to. As a result, most of the photons that come back to the instrument are reflected by the interface between ice and something else: the atmosphere, the underlying bedrock, and potentially any interface between the ice and a liquid brine underneath it.

And that’s what the original results, published in 2018, seemed to indicate. In an area called Ultimi Scopuli near Mars’ south pole. The researchers saw a bright reflection, distinct from the one caused by the underlying bedrock, at some specific locations under the ice. And they interpreted this as indicating a boundary between ice and some liquid brines.

Now with more data

Two things have changed since those earlier results were done. One is that Mars Express has continued to pass over Mars’ polar regions, generating even more data for analysis. The second is that studies of ice-covered lakes on Earth have also advanced, with new ones identified from orbit using similar data. So some of the team behind the original work decided it was time to revisit the ice sheets at Ultimi Scopuli.

The analysis involves looking at details of the photons reflected back to the MARSIS instrument from a 250 x 300 square kilometer area. One aspect of that is the basic reflectivity of the different layers that can be discerned from the data. Other aspects of the signal can tell us about how smooth the surface of the reflective boundaries are and whether the nature of the boundary changes suddenly.

For example, the transition from an ice-bedrock boundary to an ice-brine one would cause a sudden shift from a relatively weak, uneven signal to a brighter and smoother one.

The researchers generated separate maps of the intensity and the smoothness of the signal and found that the maps largely overlapped, giving them confidence that they were identifying real transitions in the surfaces. A separate measure of the material (called permittivity) showed that it was high in the same location.

Overall, the researchers found that the largest area that’s likely to have water under the ice as about 20 by 30 kilometers. And it’s separated by bedrock features from a number of similar but smaller bodies. Calling these bodies “lakes” is speculative, given that we have no idea how deep they are. But the data certainly is consistent with some sort of under-ice feature—even if we use the standards of detection that have been used for under-ice lakes on Earth.

How did that get there?

The obvious question following the assumption that these bodies are filled with a watery brine is how that much liquid ended up there. We know that these salty solutions can stay liquid at temperatures far below the freezing point. But the conditions on Mars are such that most of minimum temperatures for water to remain liquid are right at the edge of the possible conditions at the site of the polar ice sheets. So some people have suggested geological activity as a possible source of heat to keep things liquid.

That’s not necessarily as unlikely as it may sound. Some groups have proposed that some features indicate that there was magma on the surface of Mars as recently as recently as 2 million years ago. But the researchers here argue that if things are on the edge of working under current climate conditions, there’s no need to resort to anything exceptional.

Instead, they suggest that the sorts of salts we already know are present on Mars can absorb water vapor out of the thin Martian atmosphere. Once formed, these can remain liquid down to 150 Kelvin, when the local temperatures at Ultimi Scopuli are likely to be in the area of 160 Kelvin and increase with depth.

And if that’s true, there could be liquid in many more locations at Mars’ poles. Not all of them are as amenable to orbital imaging as Ultimi Scopuli, but it’s a safe bet that this team will try to find additional ones.

Nature Astronomy, 2020. DOI: 10.1038/s41550-020-1200-6 (About DOIs).

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