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NASA's Parker Solar Probe, powered and buttoned for takeoff on August 11 during the first flight mission through the sun's crown, arrived at its Launch pad at Cape Canaveral early Tuesday after a convoy trip from a nearby refueling and testing facility
On board a slow carrier, the spacecraft, its Star 48BV solid fuel star top and its protective aerodynamic fairing have left the Astrotech treatment facility. Titusville, Fla., Monday night for an overnight trip to the 37B launch base near Cape Canaveral Air Station
The convoy arrived at the launch pad before dawn Tuesday, and a Lifting crane hung at 63 feet – a 19-meter fairing to hoist it to the top of a Delta 4-Heavy rocket, a launcher's styling set in anticipation of a take-off before August 11.
The 45-minute launch window on August 11 opens at 3 pm: 48 pm EDT (07:48 GMT), kick ff a 43 minute flight across the Atlantic Ocean before the deployment of the Parker Solar Probe 1424-pound (646-kilogram) Star 48BV Upper Stage
"I am very pleased to say that Solar Probe is in the fairing and … is at the top of the Delta 4-Heavy Said Nicky Fox, a researcher at the Parker Solar Probe project at Johns Hopkins University's Applied Physics Laboratory, which developed the mission for NASA. "It was hoisted this morning … I think # It's fair to say that Parker Solar Probe is for the sun. "
Named for Eugene Parker, who correctly predicted the existence of the solar wind in 1958, Parker Solar Probe will head for Venus after its launch August 11, using the gravity of the planet to launch into orbit around the sun. will take place on August 11th, Parker Solar Probe will reach Venus on October 2nd, then make its first approach to the sun – or perihelion – on November 5th.
At its first solar encounter later this year, Parker Solar Probe will reach a distance of about 15 million miles (24.1 million kilometers) from the sun's surface, beating a record set by the mission US-German Helios 2, which rose to nearly 43 million kilometers from the sun April 1976.
Six more Venus flybys Spiral Parker Solar Probe ever closer to the sun, redirecting the trajectory of the craft to its closest encounter with the sun at a distance of 3.83 million miles (6.16 million kilometers) in 2024, about 4 percent of the distance of the sun from the Earth.
"Venus is very important to us," Fox said. "We are really using Venus to do gravity aids, not like the other missions you've heard of that are taking energy from the planet to accelerate, we are generously giving energy to Venus, and we let us use Venus to slow us down a bit, really to focus our orbit, almost like doing a small hand brake and spinning towards the sun.We will do 24 petal orbits, coming very close to the sun on one side, in going out around the orbit of Venus from the other. "
Parker Solar Probe will fly across the crown, an overheated plasma envelope surrounding the sun where temperatures rise to millions of degrees. The temperature on the sun's surface is hundreds of times colder, but it's still 10,000 degrees Fahrenheit (6,000 degrees Celsius).
The corona is also considered by scientists as the origin of the solar wind, a supersonic current of charged particles flowing from the sun in all directions, influencing the entire solar system and driving the time of the sun. # 39; space.
"How does the solar wind accelerate very rapidly up to millions of km / h in the solar corona? The work that Dr. Parker has presented is the fundamental work to understand this process, and that Is one of the main goals of the Parker solar probe, "said Alex Young, deputy director of science of the heliophysical division of NASA's Goddard Space Flight Center in Maryland.
" Why does it all matter? We live in the atmosphere of this dynamic sun. We live in the solar wind flowing over the Earth, dripping on other planets, "said Young." We see beautiful results with the dawn, but it also creates an incredibly dynamic environment that affects our planet. technology, makes the environment hostile to astronauts and, in the most extreme cases, may even have an impact on the technology and power systems on Earth. 19659003] The arrival of Parker Solar Probe at the railroad ramp launch is a milestone in the mission's $ 1.5 billion launch campaign.In the coming days, the ground crews will ensure that the spacecraft is properly attached to the Delta 4-Heavy rocket. According to Andrew Driesman, Parker Solar Probe's project director at Johns Hopkins University's Applied Physics Laboratory, launching rehearsals are also expected over the next week and a half.
"Imagi nose this 63-foot-tall fairing vehicle traveling through Cape Town and part of Titusville, "said Driesman in an interview. "They arrive at the platform, hang on to the crane, and lift that structure up to 70 feet up to the top of the rocket, move it onto the top of the rocket, and then they lock it . "
"Once we get there, once the mechanical operations are over, one of the first things we will do is feed the spaceship and do what we call a vitality test. Said Driesman. "It's to make sure everything has been safely transported, and there is no problem with the spacecraft or the instruments."
The launch was originally scheduled for July 31, but software reviews and problems encountered during the encapsulation of the vessel spacecraft inside the payload fairing of the Delta 4-Heavy have caused a delay
The launch period of the mission in August is governed by the positions of the Earth and Venus in their orbits around of the Sun. The interplanetary launch period of Parker Solar Probe was supposed to end on August 19th, but trajectory analyzes suggest that the mission could leave Earth until August 23rd and meet with Venus in early October, offering managers four additional launch opportunities. . 11 days of the interplanetary launch period
If further delays hold Parker Solar Probe on Earth after August 23, the next chance to launch the mission will come in May 2019.
But Driesman tells Spaceflight Now he is confident The mission will begin in August
"Operations are moving to what I would call a normal pace," he said. "There is always time for not doing things right, and at this point we are on the right track for the launch date of August 11."
The Parker Solar Probe launch campaign was in full swing In April, with the arrival of the spacecraft at the Johns Hopkins launch base On April 3, the probe's heat shield arrived a few weeks later and ULA crews transferred the Delta rocket 4-Heavy on the firing point on April 16, then the next day by lifting the vertical launcher
.In the interior of the Astrotech clean room, technicians installed the solar panels and the shield The solar panels have a custom design to withstand the heat and sunlight that electric generators will see near the sun, using a unique water-cooling system to stay in place. temperature tolerances.
of a piece of carbon composite of a thickness of 11.4 centimeters that extends about 8 feet (nearly 2.5 meters) wide. The thermal shield, or thermal protection system, will absorb heat during close encounters of the probe with the sun, keeping most of the spacecraft – with the exception of solar panels and some scientific sensors – a little above the ambient temperature.
The spacecraft has autonomous control software to ensure that temperature-sensitive components do not become too hot, using the inputs of the temperature sensors to measure where the probe needs to be pointed. Some engineers have added a redundant set to the spacecraft, according to Fox.
The Parker Solar Probe team of Astrotech charged about 80 kilograms of hydrazine into the propellant propulsion system of the craft on July 7th. The probe will use fuel and 12 tiny rocket boosters to alter its trajectory during its mission of more than seven years and help unload the pulse of four rotating reaction wheels located inside the main body of the spaceship.
Once powered, Parker Solar Probe has been raised on its Star 48BV rocket engine, which will serve as the third stage of the launch. Equipped with a guiding nozzle, the solid kick floor was built by Northrop Grumman Innovation Systems, formerly known as ATK Orbital
The Star 48BV engine will fire approximately 89 seconds after the second-stage separation of the Delta 4-Heavy , giving Parker Solar Probe an extra boost of velocity. The Delta 4-Heavy's first three-core stage, powered by three RS-68A main engines producing 2.1 million pounds of thrust, will give the mission its first push, followed by two shots of an RL10 engine before that Star 48BV does not burn.
"Since we are so close to the sun, we need to lose a lot of energy, a lot of angular motion, associated with Earth's orbit," said Jim Kinnison, Parker Solar Probe Mission System Engineer , in an interview with Spaceflight Now. "To do this, we need a very large rocket that can provide us with a high level (escape speed) .The Delta 4-Heavy was the best we could get, but even that was n & # 39; It was not enough.We still needed a third step to provide even more of a boost for us.The third step will do it, but we are also aiming at Venus for the gravity helps to lose. even more. "
During his closest approaches in 2024 and 2025, Parker Solar Probe will experience 478 times the sun on Earth, which orbits about 150 km from the sun. The ship's speed will increase to around 430,000 km / h or nearly 700,000 km / h during its last perihelion rounds, setting a new mark for the fastest human object in history.
SpaceX's Falcon Heavy rocket can carry heavier than the Delta 4-Heavy, but NASA would not commit to launching a high-priority scientific probe on an unproven booster. When the NASA Delta 4-Heavy rocket was selected for the Parker Solar Probe mission in early 2015, the Falcon Heavy was still three years from its first test flight
With the spacecraft now on its Delta 4-Heavy launcher, the ULA and Parker Solar Probe teams plan to perform an integrated systems test, a check to verify electrical connections between the rocket and the payload. Engineers also plan to pack the Parker Solar Probe battery to maximize its life, according to Driesman.
"We (will) go through a check of all software and flight settings," said Driesman. "We are going to throw the whole bit of the spacecraft and compare it to what it should be, and make sure we have a good load not only of the flight software, but the parameters themselves. . "
There are also training sessions are planned for the planned launch team. The ULA controllers have already performed two countdown repetitions in early July, during which they filled the Delta 4-Heavy with liquid hydrogen and liquid oxygen and then evacuated cryogenic rocket propellants
"We do other launch rehearsals to make sure the team is as ready as the spacecraft," Driesman said. "And then we'll go into the fairing, there are just a few red covers on board that cover some sensitive instruments, we're going to crawl into the fairing and remove the blankets from the red tags, and then we're ready, at this point, to throw.
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