قالب وردپرس درنا توس
Home / Science / SpaceX closes the year with the successful launch of GPS satellites – Spaceflight Now

SpaceX closes the year with the successful launch of GPS satellites – Spaceflight Now



SpaceX's Falcon 9 rocket takes off from Cape Canaveral on Sunday. Credit: SpaceX

A new era in GPS navigation began on Sunday when a SpaceX Falcon 9 rocket with a satellite built by Lockheed Martin climbed into orbit for higher positioning, navigation, and time signals has been designed around the world to provide military and military signals to civilian users with more accurate data that are more resistant to growing noise.

The satellite was successfully launched on Sunday – known as GPS 3 SV01 and named after the Italian explorer Amerigo Vespucci nicknamed "Vespucci" – is the first of a new generation of GPS navigation stations, with improved services and longer life designed to ensure that the US military network is available to troops, pilots, sailors and the public for decades to come.

The 229-meter-tall Falcon 9-starter was lifted off the Cape Canaveral's Complex 40 launch ramp at 8:51 pm EST (1351 GMT) Sunday after several delays over the last five days, including countdowns held by SpaceX The first stage of the rocket and in bad weather at the Florida Spaceport.

However, Sunday's countdown seemed to follow the book, and the SpaceX startup team agreed to load super cooled kerosene and liquid oxygen propellants into the two-stage rocket at 35 minutes before takeoff. In the final minutes of the countdown, the GPS satellite in the Falcon 9 was switched to the internal battery voltage, and the rocket's automatic countdown sequencer computer thermally cooled the booster's main engines, performed a final pre-flight steering, and pressurized the fuel tanks liftoff. With a command from the Falcon 9's on-board computer at T-minus 3 seconds, nine Merlin 1D engines at the rocket base were brought to life and propelled the Falcon 9 for a thundering holiday in a clear morning sky departure this weekend Launch of Cape Canaveral in a calendar year since 1995.

"Merry Christmas, GPS," announced a member of the SpaceX launch team at the start.

The Falcon 9 flew from Florida's Space Coast to the northeast. powered by 1.7 million pounds of boost in the first stage combustion, which lasted nearly three minutes. The kerosene powered booster was shut down and crashed to fall into the Atlantic as the second stage Merlin engine burned for the first of two burns to inject its target orbit for the latest GPS navigation satellite.

Unlike spaceX's recent missions, the first leg did not attempt to land a flight on Sunday, as the GPS payload required the full capacity of the rocket, so the booster would have no fuel reserves to keep up with Return to the ground. The Air Force decided to add extra fuel to give the spacecraft additional "durability" and possibly longer life, and the military demands that rockets carry national security satellites to bring their consumed upper levels into circulation.

These requirements summed up The Falcon 9 must use more of its fuel for the main mission with the GPS satellite. Read our previous story for details on why SpaceX did not recover the first leg on Sunday.

Air Force officials told reporters earlier this month that Falcon 9 could later be launched with GPS satellites, but could involve a first landing, but managers would not commit to deciding on the rocket's performance for that decision Mission on Sunday.

The SpaceX cameras delivered live views of the camera from the upper stage as it climbed away from Earth, showing the curvature of the planet's horizon in front of the blackness of space in front of the GPS 3 SV01 satellite. Less than two hours after that Take off at a height of more than 8,700 kilometers separated.

"The launch is always a monumental event, especially as it is the first GPS satellite of its generation to be launched on SpaceX's first national security space," said Lieutenant General John Thompson, commanding Space and Missile Air Force Systems Center and Air Force Program Officer for Space. "As more GPS-3 satellites join the constellation, it will result in a technology that is now fully interwoven into the fabric of every modern civilization.

"GPS holds the gold standard for positioning, navigation, and timing information that provides secure access when and where it matters – this event was a highlight, but it does not mean we're done Perform a series of checkout and testing procedures to ensure that all Vespucci features work as designed, "Thompson said in a statement.

Concept of an artist of a GPS 3 satellite in space. Picture credits: Lockheed Martin

US. Military data shows that the Falcon 9 has placed the new GPS satellites in an orbit between 1140 km and 20,198 km altitude, with the orbit tilted 55 degrees to the equatorial plane.

These numbers kicked off SpaceX kicked off the first company with a major US security burden, marking a milestone in the company's years of efforts to enter the military launch market.

The launch of Sunday was a milestone for SpaceX and the Air Force

SpaceX has launched a handful of missions for US security customers, including a classified payload for the National Reconnaissance Office and an Air Force X-37B (2017) spacecraft spacecraft were booked separately from the Air Force's Evolved Expendable Launch Vehicle or EELV program. The SpaceX Falcon rocket family and the Atlas and Delta rocket fleets operated by United Launch Alliance competitors are currently certified by the Air Force to participate in EELV-class missions, including the military's most expensive and highest-priority military.

The Air Force The Falcon 9 rocket was certified in 2015 after extensive testing of the design, reliability and performance of the vehicle for the National Safety Zone. This is a multi-year process, which was partly triggered by legal disputes of SpaceX founder Elon Musk under the Sole Source Treaty of the Air Force agreement with ULA.

Following the certification of the Falcon 9 national security launch missile in 2015, SpaceX won its first GPS 3 launch contract in 2016, an agreement estimated at US $ 82.7 million, according to the Air Force. The Air Force has awarded SpaceX contracts for four more satellite launches of the GPS-3 series in direct competitions with ULA, which was the only company approved for a decade of the EELV class.

SpaceX Falcon Heavy The rocket was certified by the Air Force earlier this year when the heavy truck's first test flight took place in February. The Air Force has already given the Falcon Heavy a national security startup deal since it was approved for such missions, while ULA has won three new launch orders in the new era of military launch procurement for the military.

The ULA Delta-4 rocket is on the schedule To launch the second GPS-3 spacecraft nicknamed "Magellan," an Air Force spokesman told Spaceflight Now last summer last week. This is a few months later than the launch date scheduled for April. The industry is of the opinion that the Air Force preferred to test GPS 3 SV01 in space before launching the second GPS 3 model.

With the launch of the satellite GPS 3 SV02 next year, the last "single stick" configuration of the Delta 4 will be completed. ULA is retiring the smaller variants of the Delta 4 – but keeping the Delta 4-Heavy three-body in action – and is focusing on the cheaper Atlas 5 rocket over the next few years, as he re-equips the next-generation Vulcan launcher with reusable components Blue Origin develops BE-4 engines, which could eventually be retrieved and overhauled.

The third GPS-3 spacecraft, called "Columbus," is said to fly on a Falcon 9 rocket from Cape Canaveral, the Air Force, in December 2019. Subsequent GPS launches are scheduled at intervals of up to four and a half months, but officials will set a starting schedule based on the needs and health of the entire GPS network, according to an Air Force spokesman.

The GPS 3 SV01 navigation satellite separates from the Falcon 9's upper stage. Credit: SpaceX

Overall, SpaceX has been commissioned to launch five of the first six GPS-3 satellites on Falcon 9 rockets , Lockheed Martin is commissioned to build up to 32 GPS-3 satellites, starting with a block of 10 spacecraft planned for launch in the early 2020s, followed by a stack of up to 22 planned GPS-3Fs -Satellite Begin of launch in 2026.

According to the Air Force, some of the GPS satellites could be launched on Falcon 9 rockets with previously flown boosters that have given commercial satellite owners and NASA bargains over launch costs. Flying with previously used rockets also relieves SpaceX's production line and supply chain.

"We intend to certify previously launched launchers," said Col. Robert Bongiovi, Director of Launch Enterprise Systems at the Air Force Space and Missile Systems Center. "We work with SpaceX to go through and understand what's different and what's better and what to look out for when working with already flown hardware. You have the total return, the cash register and all that stuff. SpaceX has a lot of experience with it. We've learned a lot with them and try to make a plan that will help us learn that too, but it's a process. We will do this in a very deliberate manner to ensure that the satellite orbits on each of the carrier vehicles we procure. "

SpaceX has fired 18 times recycled rockets for orbital missions includes a pair of previously flown boosters for the opening ceremony of the Falcon Heavy rocket in February.

New GPS satellite will replace 21-year-old navigation boats

Lockheed Martin said after the launch of Sunday that ground controller in the company's launch and cash register system Denver had contacted the satellite GPS 3 SV01 to test the aircraft in orbit, which could take more than a year.

The GPS 3 The space probe SV01 is to reach a circular orbit in the height of the GPS fleet about ten days after the start, said Whitney. Seven shots of the liquid-filled main engine of the satellite are to circularize the orbit of the aircraft at a height of 12,550 miles, followed by the use of the solar arrays and antennas of the satellite.

As soon as it joins the rest of the GPS constellation, the new The satellite will be inspected for six to nine months to check the condition of key spacecraft systems and the functionality of Harris Corp. tested navigation instruments. Another test phase to check the compatibility of the new GPS satellite with the rest of the navigation network According to Col. Steve Whitney, director of the Global Positioning Systems Directorate of the Space and Missile Systems Center of the Air Force, it will take another six to nine months.

If GPS 3 SV01 is ready, it will do so Replace SVN 43 in level F, position 6 of the GPS fleet. The Air Force currently operates 31 GPS satellites, including six-orbit replacement parts, to ensure the network provides uninterrupted global positioning, navigation and timing services to military and civilian users.

SVN 43 survived its twenty-seven years. The lifespan of half a year since its launch as a GPS 2R-2 satellite aboard a Delta 2 rocket in July 1997. The GPS-3 SV01 satellite is referred to as SVN 74 to GPS users when in use, Whitney said.

These GPS-3 satellites will introduce streamlined features and signals that are three times more accurate and up to eight times stronger than previous generations, "Whitney said. "They also emit a signal that is compatible with other global satellite navigation systems, allowing users around the world to receive and use signals from multiple constellations, maximizing the availability and accuracy of navigation signals worldwide."

The GPS network currently provides a network of users with position estimates with an accuracy of about 50 centimeters or about 20 inches, Whitney said, assuming receivers would not compete with terrain, trees, or buildings.

The last spacecraft of the previous series of GPS spacecraft manufactured by Boeing Whitney said in 2016 that the GPS fleet of 31 active satellites is "healthy, stable and robust".

The first launch of GPS 3 is four years behind schedule

The Air Force hoped to become the first GPS satellite of the GPS-3 series in 2014 As the Pentagon 2008 approved the full development of the multi-billion dollar program, a government account Office Office report.

Officials reported technical problems with the satellite navigation payloads for much of the four-year delay. According to Harris Corp. The navigation payload consists of extremely precise rubidium atomic clocks, radiation-hardened processors and powerful L-band transmitters.

The first improved US Air Force GPS navigation satellite undergoes electromagnetic testing at the Lockheed Martin plant in Denver. Photo credits: Lockheed Martin

New features in the 3 Series GPS satellites include a fourth civilian L-band (L1C) signal that is interoperable with other global navigation satellite fleets. A similar signal is provided by Europe's Galileo, China's Beidou and Japan's QZSS navigation satellite networks. Users can combine navigation fixes with satellites of different fleets to get a more accurate position estimate.

Just as more satellites allow users to make more accurate position estimates, stacking signals at different frequencies allows receivers to sort out distortions that occur as the radio waves pass through the upper atmosphere, further refining the accuracy of GPS navigation.

Contributing GPS-3 delays included issues with failed and damaged capacitors and components According to a GAO report from last year, the satellite's navigation payloads store and release electrical charges.

"According to program officials, each satellite has over 500 capacitors of the same type that failed," the GAO wrote in a May 2017 report to Congress.

Officials found that the subcontractor had delivered the cap The components were not qualified for use in the GPS satellites. The engineers invalidated the parts reliability test results before the capacitors were finally declared fit for the GPS satellites.

However, the GPS 3 SV01 is still equipped with suspicious capacitors, says the GAO.

"The Air Force" I've decided to take the risk of a capacitor failure and continue with the first satellite, which is mainly made up of questionable lots of capacitors, "the GAO wrote last year. "The program replaced the suspect capacitors in the second and third satellites, the only other satellites that had the suspect parts."

GPS 3 Upgrades Global Navigation Fleet [19659003] GPS-3 satellites are built to last for at least 15 years, and their higher-powered transmitters make their navigation signals less vulnerable Traffic jams.

"The big things we're going to see here with GPS 3 are we you will see an increase in power," Whitney said. "We have been calling for stronger signals to try to combat some of the disruptions we see, especially in our military signals. We have also made the demand for higher accuracy. The user will eventually see that when it goes online. We added a few extra civil signals. "

Like the previous line of GPS 2F satellites, the GPS-3 spacecraft also sends a special L5 signal that supports air navigation. The GPS-3 satellites continue to emit an encrypted military navigation signal called the M code.

"GPS-3 satellites will also provide the full capability of using M code and increase the resistance to congestion in support of our warfighters and allies," said Whitney.

The M code is designed to give the US and its allies an advantage on the battlefield by allowing GPS satellites to transmit higher-power, spurious-resistant signals to specific regions. It could also give the military the ability to disrupt or block civil signals in a particular region without affecting the M code signals, giving the friendly forces an advantage.

"A long time ago there was a capacity for what we do then called selective availability where we could mine a civil signal or not spend so accurately," he said. "This ability no longer exists in the system, but we have chosen this new M-code signal for our military users, which has the same frequency but is slightly separated spectrally. That allows us to do special things for them. "

Even with the launch of the first GPS 3 satellite, all upgrades of the new generation of navigation satellites will not be available to military and civilian users until the developers work on one system. Modernized ground control system to take advantage of the improvements.

Raytheon is commissioned to develop the Next Generation Operational Control segment. Known as the OCX, the command and control system is expected to exceed $ 6 billion or more than $ 2 billion in costs and is at least five years behind schedule. The full version of OCX, known as Block 1, is unlikely to be ready before 2021 or 2022, and only then will the full potential of the GPS-3 satellites be realized, Whitney told reporters on December 14th.

The GAO found that "bad detection decisions and slow detection of development problems" caused the delays in the new ground GPS command and control system, which is backwards compatible with older GPS satellites, and for the processing of the M code Military signal and the new interoperable is needed L1C civil signal. The Air Force has a first version of the OCX Control and Control System – Block 0 – ready to handle the launch and verification of the GPS-3 satellites in orbit, and Whitney said the Air Force is working on a preliminary upgrade of the existing GPS system Control system to test the M code signal with military units in 2020, 15 years after the launch of the first M code satellite.

Legislators and GAO have also expressed concerns about the willingness of user receivers to process the M code signal, and every new GPS feature has global coverage only when used on 24 satellites.

"Full M-code capability – both the ability to send a signal via satellites, as well as a ground system and user equipment to receive the signal – takes at least a decade when the services are MGUE receivers (military GPS) User equipment), "the GAO wrote last year in a review of the GPS 3 program.

Despite delays and technical hurdles, more users than ever rely on GPS satellites, and the reach of the network spans the globe, infiltrating many facets of society and billions of people. The applications range from banks to online dating.

"For the civilian, GPS has become a palette to create and innovate," said Johnathon Caldwell, Lockheed Martin's vice president of navigation systems. "I do not think people thought you had your apps to ride with you five years ago, or you could grab a scooter and move around the big cities. They would not see productivity in the heart of America without the innovations in agriculture.

"The world is changing fast," said Caldwell. "We talk about autonomous cars. How can we work more economically with airplanes and cars? How can we better manage our environment? GPS and these new advanced features give people the opportunity to do creative things and innovate.

SpaceX launched 21 missiles this year

With the GPS launch Sunday SpaceX, 2018 ended with its 21st successful flight of the year, breaking a record for the highest launch rate of the company set at 18 last year.

This year's launches included six missions from Vandenberg Air Force Base in California and fifteen from Florida's Space Coast – 12 from Pad 40 at Cape Canaveral Air Force Station and three from nearby Pad 39A at NASA's Kennedy Space Center.

A highlight of the year for SpaceX was the first test flight of the Falcon Heavy rocket The combination of three rocket boosters from Falcon 9 generates more than 5 million pounds of thrust. The Falcon Heavys debut on February 6th sent a Tesla Roadster out of Musk's Collection on a trajectory farther from the Sun than the orbit of Mars, into the solar system.

SpaceX launched into orbit with eight missions at the International Space Station ISS Iridium communications satellites and eight flights with geostationary communications payloads. Further missions in 2018 launched NASA's Transiting Exoplanet Survey Satellite – an observatory built to discover planets around other stars – and Earth observation satellites for Spain and Argentina.

SpaceX plans about 18 launches next year, according to Vice President Hans Koenigsmann Construction and Air Safety. Biggest starts next year include the first two test flights of CrewX's crew-owned Crew Dragon capsule. Astronauts will travel to the International Space Station ISS in mid-2019 with the spaceship. [20110314] The company's 2019 startup schedule is January 7 with the launch of a Falcon 9 rocket and a stack of ten next generation Iridium voice and data communications satellites from Vandenberg Air Force Base, California,

E-mail to the author.

Follow Stephen Clark on Twitter: @ StephenClark1 .


Source link