PARKER PROBE

About MISSION:

NASA’s unique record-breaking spacecraft took off on the United Launch Alliance Delta IV Heavy rocket from Space Launch Complex 37 on Sunday, Aug. 12 at 3:31 a.m. EDT Cape Canaveral Air Force Station in Florida. The Parker Solar Probe, after a handful of gravity assists and preliminary orbits, will enter a stable orbit around the enormous nuclear fireball that gives us all life and sample its radiation from less than 4 million miles away. Believe me; you don’t want to get much closer than that.

Parker Solar Probe now begins its journey to the Sun’s atmosphere, also called the corona, to study an area previously only glimpsed through eclipses. The spacecraft will go closer to the Sun than any other spaceship in history. This means Parker Solar Probe will face exorbitant heat and radiation, absorbing temperatures as high as 1,400° C (2,500° F). Surprisingly the incredibly heat-resistant ship is pretty light, weighing only 1,400 pounds.

This is the first mission named after a living researcher, in this case, Eugene Parker who in the ’50s made a number of proposals and theories about the way that stars give off energy. He is the person, who gave us solar wind, and his research was hugely influential in the study of the sun and other stars — but it is only now that some of his hypotheses be tested directly.

Instruments:

“Directly” means going as close to the sun as technology allows — which leads us to the PSP’s first major innovation: its heat shield, or thermal protection system.

There is one good thing to be said for the heat near the sun: it’s a dry heat. Because there’s no water vapour or gases in space to heat up, find some shade and you’ll be quite comfortable. So the probe is essentially carrying the most heavy-duty parasol ever created.

It’s a sort of carbon sandwich, with superheated carbon composite on the outside and a carbon foam core. Altogether, it is less than a foot thick, but it reduces the temperature the probe’s instruments are subjected to from 2,500 degrees Fahrenheit to 85.

The car-sized Parker will orbit the sun and constantly rotate itself so the heat shield is facing inward and blocking the brunt of the solar radiation. The instruments mostly sit behind it in a big insulated bundle.

There are three major experiments or instrument sets on the probe.

WISPR (Wide-Field Imager for Parker Solar Probe) is a pair of wide-field telescopes that will watch and image the structure of the corona and solar wind. This is the kind of observation we’ve made before — but never from up close. We generally are seeing these phenomena from the neighbourhood of the Earth, nearly 100 million miles away. You can imagine that cutting out 90 million miles of cosmic dust, interfering radiation and other nuisances will produce an amazingly clear picture

SWEAP (Solar Wind Electrons Alphas and Protons investigation) looks out to the side of the craft to watch the flows of electrons as they are affected by solar wind and other factors. And on the front is the Solar Probe Cup, which is exposed to the full strength of the sun’s radiation; a tiny opening allows charged particles in, and by tracking how they pass through a series of charged windows, they can sort them by type and energy.

FIELDS is another that gets the full heat of the sun. Its antennas are the ones sticking out from the sides — they need to in order to directly sample the electric field surrounding the craft

They are all powered by solar panels, which seems obvious, but actually, it is a difficult proposition to keep the panels from overloading that close to the sun. They hide behind the shield and just peek out at an oblique angle, so only a fraction of the radiation hits them.

Even then, they will get so hot that the team needed to implement the first-ever active water cooling system on a spacecraft. The water is pumped through the cells and back behind the shield, where it is cooled by, well, space.

THE TRAJECTORY:

The sturdy craft starts its first trip aboard one of the world’s most powerful rockets, the Delta IV Heavy with an added third stage. Once in space, the craft only needs to drop 53,000 miles per hour (85295.232 Km/Hr.) of sideways motion to skim the sun’s atmosphere. Over its seven-year mission, Parker Solar Probe will need to undertake seven Venus gravity assists to draw its orbit closer to the Sun for a final record approach of 3.83 million miles (6163787.52 Km) from the star’s visible surface. Once there, the craft will use its incredible cutting-edge heat shield to protect itself as well as its autonomous cooling system.

Finally, breaking yet another record, Parker Solar Probe will reach 430,000 miles per hour (692017.92 Km/hr.) on its final orbits, bolstered by the Sun’s extreme gravity to become the fastest-ever human-made object.

The research mission will return key information about the Sun including data on its corona, solar winds, and magnetic fields. Humans have been examining the solar wind for over 50 years, but the wind is processed by the time it reaches Earth. Through studying it much closer to the Sun, the Parker Probe will be able to tell us such things as what part of the Sun is providing the energy source for the wind’s particles and how they can accelerate to such incredibly high speeds.

The Parker Solar Probe mission’s to touch the Sun will inevitably revolutionize our understanding of the giant, dynamic star. NASA has revealed that the spacecraft will do 24 orbits around the Sun’s corona or atmosphere, which entails a number of hot and cold cycles. The $1.5 billion Parker Solar Probe needed enormous speed to escape Earth’s orbit, hence the three rocket stages that fired during the launch. That will carry it to the neighbourhood of Venus in just six weeks, arriving by late September.

THE PLAN:

On Sept. 28, the spacecraft will need to pull off a careful manoeuvre designed to gently slow it down and begin its activity around the sun. That manoeuvre called a gravity assist, will pass a little of the spacecraft’s acceleration to the planet and edge the probe a little closer to the sun. The Parker Solar Probe will then begin its first of 24 orbits around the sun, with its first close approach, or perihelion, coming on November 1.

Each orbit will be petal-shaped, skimming over the sun closely and then flying out farther into space to close out the orbit. The bulk of the probe’s science work will come when it is within a quarter of the distance between Earth and the sun — although NASA is hoping that the instruments can be turned on for as much of the mission as possible. The early orbits, while remaining farther away from the sun, will be special because the spacecraft will spend its time close to the sun is essentially the equivalent of geosynchronous orbit, hovering over the same region. During these periods, which scientists call fast radial scans, the spacecraft will swoop in at a speed that closely matches the sun’s speed of rotation, and then swoop out again.

While the spacecraft keeps pace with the sun’s rotation, it will be able to watch how the same region of the sun behaves over a period of about 10 days. That means there is plenty of science to look forward to years before the spacecraft completes its closest approach to the sun near the end of the mission. As the mission continues, PSP will move closer and closer to the sun, eventually coming to less than 4 million miles (6 million kilometres) above the visible layer of the sun that we think of as the surface. On each orbit, the spacecraft will take the same measurements at different depths in the sun’s atmosphere, which is called the corona. That layer, which is invisible from Earth except during a total solar eclipse, reaches temperatures of millions of degrees (Fahrenheit or Celsius). The mission is scheduled to end in June 2025. The first data download from the Parker Solar Probe expected in early December after the probe reaches its first close approach of the sun in November.

TECHNICAL FACTS:

· It will be travelling at a speed of around 200km/s, making it the fastest human-made object ever.

· Solar Orbiter’s heat shield must deal with a continuous 600°C. There is no ducking out into deep space for a month or two to cool down. Should the spacecraft lose control or accidentally turn the heat shield away from the sun, the unshielded areas will quickly melt if control is not immediately re-established.

· The Parker probe is expected to make 24 loops of the Sun over seven years. The spacecraft will fly by Venus at speeds of 430,000 mph, the equivalent of flying from New York to Tokyo in one minute.

· The specially shielded Parker Solar Probe will have to endure temperatures up to 2,500 degrees Fahrenheit (1,370 degrees Celsius) and solar radiation intensities 475 times higher than we are used to here on Earth. The cooling system is designed to maintain 30°C for the internal systems of the PSP despite the flaming temperatures of the outside.

WHAT IS THE MISSION ALL ABOUT?

§ To trace the flow of energy that heats the corona and accelerates the solar wind.

§ To determine the structure and dynamics of the magnetic fields at the sources of solar wind.

§ To determine what mechanisms accelerate and transport energetic particles.