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Home / Science / Iridium messaging network gets another boost from SpaceX – Spaceflight Now

Iridium messaging network gets another boost from SpaceX – Spaceflight Now



A Falcon 9 rocket climbs off Friday from the Space Launch Complex 4-East at Vandenberg Air Force Base in California. Credit: SpaceX

Ten other satellites for the Iridium commercial communications network flew into orbit on Friday with a Falcon 9 rocket from Vandenberg Air Force Base in California, bringing the total number of upgraded Iridium spacecraft to 50 and the number of Iridium spacecraft SpaceX supply ship left route from Cape Canaveral to the International Space Station Monday

The 70 meter Falcon 9 rocket took off at 7:13:51 PDT (10:13:51 EDT; 1413): 51 GMT ) Friday after a smooth countdown. Nine Merlin 1D engines on the Falcon 9's re-used first-stage engine slowed to full power, delivering 1.7 million pounds of thrust as the rocket turned southward from the military spaceport on California's Central Coast northwest of Los Angeles.

After exceeding the speed The first phase of the Falcon 9 was switched off and dropped off two and a half minutes later. The booster broke away to perform experimental descent maneuvers, but SpaceX did not try to find the rocket again on Friday.

SpaceX disposes of its reused missiles of the older generation – as launched on Friday – as an uprated Falcon 9 version "Block 5" will debut next month. The first stage of the Block 5 configuration is designed for multiple reuses.

The Falcon 9s single Merlin upper stage engine ignited twice during Friday's flight, placing the 10 Iridium satellites in a circular orbit with a target range of 625 kilometers.

In a secondary target, SpaceX salvage teams attempted to retrieve part of the Falcon 9's payload fairing with a fast moving ship in the Pacific Ocean, but according to Elon Musk, founder and CEO of the billionaire, the experiment ran into trouble

The boat-making boat, named Mr. Steven, is equipped with a net – or "catcher's glove" – ​​to catch the shroud as it descends slowly under a controllable parafoil guided by GPS navigation signals. On Friday, SpaceX wanted to get back half of the disguise, a bulbous nose cones fired in two segments three and a half minutes after launch.

The aerodynamic fairing covers the sensitive satellites during the final launch from Preps and the first phase of the flight.

But Musk wrote on Twitter that the parafoil of the panel was twisted, and it hit the Pacific Ocean at high speed.

SpaceX finally wants to regain and reuse payload panels as it does first-stage boosters.

The company's engineers developed a method to capture the fairing after it "falls away from space at about eight times the speed of sound," Musk wrote on Instagram before attempting a similar retrieval after launching in February. "It has on board engines and a guidance system to keep it intact through the atmosphere, then a parafoil and our ship, named Mr. Steven, with basically a huge catcher's glove welded on, trying to catch it."

On the last attempt to catch it, the shroud appeared a few hundred meters from Mr. Steven. But engineers want to catch the disguise before hitting the sea to minimize the pollution from seawater pollution.

Mr. Steven is currently based in the Port of Los Angeles, so SpaceX's disguise experiments are limited to California launches for the time being.

SpaceX ended its live webcast unusually early due to what the company's starting commentator said were images from the upper tier of the Falcon 9. On most SpaceX missions, on-board cameras broadcast live views of engine fires and incident events.

The NOAA is responsible for the control of remote sensing cameras that observe the Earth from space, such as high-resolution commercial reconnaissance satellites, military movements, the detection of cars and ships, and the detection of other activities.

But "rocketcams," as used on SpaceX, United Launch Alliance, and other missions, are not as sharp-sighted.

SpaceX recently told NOAA second-stage cameras, which are used for technical purposes, are considered a "remote sensing system" and are positioning the cameras within the government's regulatory reach. A preliminary license obtained by SpaceX for launch prohibited the company from sending second-tier views once in orbit

SpaceX does not expect this restriction to remain in force once the company receives a full license. It is not expected that such image limits will be expected during the next Falcon 9 flight scheduled for Monday from Cape Canaveral.

According to the NOAA's guidelines, small handheld cameras are not to be considered remote sensing space systems and should free the regulations.

A NOAA spokesman did not answer questions in this matter.

On-board cameras made a splash last month during the maiden flight of SpaceX's Falcon Heavy Rocket. The SpaceX cameras delivered spectacular, widespread imagery of a space-suit-wearing Dummies Musk nicknamed "Starman," which started on the Falcon Heavy in the driver's seat of Musk's Tesla sports car.

The video crash had no impact on the mission, and the Falcon 9's top-stage machine successfully put the 10 Iridium payloads into orbit and deployed the satellites one hour after launch.

Iridium officials said all 10 satellites – each with sophisticated L-band and Ka-band radios and antennas as well as aircraft and vessel tracking equipment were healthy after starting on Friday.

The spacecraft will replace 10 aging satellites on the Iridium network, which has recently surpassed one million subscribers.

Artist concept of several Iridium Next satellites, with Iridium's Block 1 satellite fleet in the background. Credit: Thales Alenia Space

"It is a unique coincidence that we exceeded the one million subscriber mark at the time of this launch and it is particularly exciting because we exceeded this milestone earlier than expected," said Matt Desch , CEO of Iridium, in a statement. "The new satellites and services we launch and continued strong subscriber growth consolidate our position as an industry leader and key global communications platform, underscoring the significant transformation we've seen as a company over the last decade."

With the mission of Friday, the Iridium launched the second half of its eight launch campaign with SpaceX. Four previous missions – in January, June, October and December 2017 – delivered 10 Iridium Next satellites each.

Iridium ordered 81 new satellites from a Thales Alenia Space / Orbital ATK industrial team to refresh the company's communications fleet of news, data and voice communications worldwide. Iridium's old satellites started in the late 1990s and early 2000s and now work well beyond their planned seven-year missions.

The upgraded satellites – the heart of a $ 3 billion upgrade investment – will ensure that Iridium subscribers have uninterrupted telephone service. also outside the mobile sector, and they also enable higher speed applications, such as broadband video and data communications.

SpaceX is under contract to launch 75 satellites. Sixty-six will be needed for Iridium's entire network, and another nine will serve as spare parts. The six remaining satellites will remain on the ground for the time being, to replenish the constellation in the future.

"Two thirds of our satellites are now in orbit and performance exceeds expectations," said Denis Allard, vice president of constellations for Thales Alenia Space.

Iridium expects the 10 satellites that will be launched on Friday to ascend to higher orbit by 484 miles (780 kilometers) in the coming weeks. They will occupy positions near the old satellites so that ground controllers can switch the network one-to-one into the upgraded spacecraft over the next 30 days, Iridium said.

Desch said in an interview before starting on Friday that he was pleased with the pace of satellite deployments since the campaign began in January 2017.

"It meets our needs," said Desch. "We're really focusing on completing our Iridium Next setup this year, and I'd like to finish it in the third quarter, if possible." What I'm really excited about is SpaceX's progress this year. [19659003] "Unlike last year, where we may have been waiting for SpaceX, I'm trying to ensure this year that my suppliers deliver fast enough to fly as fast as possible," he said.

Iridium says more than that Half of its 66 satellite network is now equipped with Iridium Next satellites.

"When you look at the service, every customer gets a new satellite about 60 percent of the time, so it's been more than half the time, that they will be served by the new satellites, just by the way the beams settle, "Desch said.

A new broadband service powered by Iridium Next satellites, known as Iridium Cer tus, will begin commercial operation in mid-2018, Desch said. The L-band broadband service will reach users on land, at sea and in the air, and ground station testing is in full swing.

Each Iridium Next satellite also hosts one from Harris Corp. The surveillance project, led by an Iridium subsidiary called Aireon, will be commissioned at least 66 times after the spacecraft Iridium Next is in space.

"They are conducting many trials and demonstrations with all their customers, but they really can not provide air navigation services if they do not have 100 percent coverage, so they need all 66 satellites in operation," said Desch. "It is expected that they will start their service later this year when the network goes live … and they will begin to cover air traffic controllers in fractions of a second." [10809003] The 10 satellites launched on Friday also carry ship tracking antennas for executeEarth, a Canadian company.

Engineers disable Iridium's returning satellites built by Lockheed Martin as the new relay stations arrive in orbit. Most of the old satellites are maneuvered out of orbit to fall back into the earth's atmosphere, and the others are subjected to a process known as "passivation" in which their batteries and fuel tanks are drained, making them sluggish and likely Explosion in the future.

Iridium Flares, a popular phenomenon for sky watchers in the last 20 years, will end when the last of the old satellites retires. The Iridium satellites, built by Lockheed Martin, have silver-coated Teflon antennas that behave like mirrors, reflecting sunlight to Earth shortly before sunrise and just after sunset.

The torches are predictable – the second – and the satellite briefly becomes one of the brightest objects in the night sky. Sky-watching apps and websites can deliver the days of upcoming Iridium torches around the world.

The Iridium Next satellites designed by Thales Alenia Space have a different antenna shape that does not produce flares

"Unfortunately, the era is coming to an end someday," said Desch.

"The most important thing when watching flares is that the vehicle is upright and predictable – its flywheels are spinning and it's up and running," said Desch. "In other words, it does not stumble because it has been relieved and / or passivated . "

The last predictable iridium flare is likely to occur in late 2018 or early 2019.

" It's a bit different for me because it's the way out of the network, but I found it almost an emotional experience, when I first saw it, "he said," It was almost like a signal to me. "

" People love to see the International Space Station for the same reason because they know there are people, "he said he is. "It's hundreds of miles away , and yet you can still shine it. I really encourage people to go out (and see a flare up). I think it's really cool – a great party trick for friends and a great way to win a drink at the right time in a bar.

Three more Iridium satellite launches are scheduled by SpaceX, the next in May 19659003] SpaceX's next launch of Falcon 9 is scheduled for 16:30 EDT (2030 GMT) Monday from Pad 40 at Cape Canaveral Air Force Station A Dragon cargo ship, loaded with tons of supplies and experiments for the International Space Station, will launch the Falcon 9 into orbit.

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Episode Stephen Clark on Twitter: @ StephenClark1 .


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