Interview/ Dr Nicola Fox, associate administrator, NASA Science Mission Directorate-NASA headquarters
When Apollo 11, the American spaceflight, first landed humans on the moon, nine-month-old Nicky stirred in her crib at her family home in Hitchin, Hertfordshire, in England. Her father then “propped her up” in front of the TV and gave a running commentary of the momentous occasion. Nicky grew up to become Dr Nicola Fox—only the second woman after astronaut Mary Cleave to be head of science at National Aeronautics and Space Administration (NASA). And, it comes as no surprise that she credits her father for her passion in space science.
Fox, who was appointed associate administrator for NASA’s Science Mission Directorate (SMD)-NASA headquarters last February, was on her first visit to India this March. She was in Bengaluru to celebrate the partnership between NASA and the Indian Space Research Organisation on the soon-to-be launched NISAR (NASA-ISRO Synthetic Aperture Radar), an advanced radar imaging system that will provide an unprecedented and detailed view of earth. A day prior to her visit to ISRO’s U.R. Rao Satellite Centre, Fox, who studied in an all-girls school, visited Maharani Lakshmi Ammanni College for Women along with NASA’s Earth Science director Dr Karen M. St Germain. The two women spoke their minds during ‘Space Talk with NASA Women Scientists’, organised by the US Consulate General, Chennai.
During the interaction, Fox took the audience through the functions and pursuits of the six divisions at NASA’s SMD—planetary science, joint agency satellite, astrophysics, biological and physical sciences, earth science and heliophysics—that have an annual funding of $8 billion. Exhorting students to pursue careers in space science without any self-doubt, Fox said the key to being a scientist is to love asking questions. If you are fascinated about how and why things work, you are already a scientist, she said.
In her nearly three-decade-long career at NASA, Fox has been part of several missions, including the Parker Solar Probe—first spacecraft to touch the sun—and the Van Allen Probes to study the Van Allen radiation belts that surround the earth. She is currently working on the Interstellar Mapping and Acceleration Probe.
On the sidelines of the student interaction, Fox spoke to THE WEEK about matters close to her heart but far away in space—from the Parker Solar Probe to NISAR to Aditya-L1 and the much-awaited total solar eclipse in April. Excerpts from an exclusive interview:
Q/How would you explain heliophysics to a layman?
A/ Heliophysics is the study of the sun and literally everything the sun touches. We think of the sun as a bright light in the sky, but it is much more than that. The outer atmosphere of the sun—the corona that you see during a total solar eclipse—actually sort of moves away. It gets accelerated and moves away from the sun and it calves out to [create a] protective bubble for our whole solar system as we are orbiting in the Milky Way. So the sun’s atmosphere kind of protects us from interstellar space. The solar wind, what we call the atmosphere, interacts with all of the planets, including our earth, and can cause big effects. We call that space weather, which can impact power grids to orbiting spacecraft. For me, what’s really cool about heliophysics is that the sun is a star and it is our star, and even though it is hard for us to send missions to the sun, it is a lot easier to send them to the sun than to another star. By learning about the sun, we can learn how other stars work and that, of course, will help search for life in the universe.
Q/The Parker Solar Probe was launched on August 12, 2018, decades after Dr Eugene Parker predicted the existence of solar wind. Why did it take so long for NASA to launch a probe?
A/ It took 60 years for the probe after a paper that was published in 1958 had predicted that the sun’s atmosphere would indeed form a solar wind and expand away from the sun. A lot of people did not believe the paper then. So, the only way to prove whether or not that was correct was to actually send a spacecraft into the solar wind. A few years later, they did discover there is an atmosphere and the space is not empty. Going to the sun is hard. It took us a long time to get to the technology needed for it. In 1958, the type of electronics available to communicate was a rotary telephone that was on the wall. And now, we all have iPhones that we use for probably everything, except for making a phone call! Think about how much technology you hold in your hand when you hold a mobile phone. Getting everything miniaturised, light weighted and then also finding materials that could withstand the incredible heat when we go to the sun… yes, it took us 60 years to get a mission that could actually live and survive in the sun’s corona.
Q/When the solar probe completes its seven-year mission in 2025, what would it have accomplished?
A/ The solar probe is doing these sort of orbits, like the petals of a flower, and it is going very close to the sun and then it comes out around the orbit of the planet Venus. We fly by Venus, and we use that to kind of make the orbit smaller and smaller. So as we are going through the sun’s atmosphere, we are closer and closer to the sun. Actually, it is around the end of December 2024 that we will do our closest approach and get within four million miles of the sun surface. If it does not sound particularly close, [imagine] the sun and the earth are put one metre apart, the Parker Solar probe will be 4cm from the sun. So, it kind of makes you realise how close to the sun it is. Formally, the seven-year mission finishes in 2025. But as long as the spacecraft is healthy, it will continue to do these paddle orbits around the sun and give us more and more data about what is going on in the corona.
Shot to remember: Dr Nicola Fox (right) takes a selfie with colleague Dr Karen M. St Germain and students at Maharani Lakshmi Ammanni College for Women in Bengaluru | Bhanu Prakash Chandra
Q/Till now, what kind of data has the probe sent back?
A/ We wanted to study three main mysteries from the data. One was sort of like a head-scratcher over why the atmosphere of the star is 300 times hotter than the surface of the star. That does not make sense—if you walk away from a campfire, it gets colder; it does not get hotter. But if you moved away from the sun, it gets much, much hotter, and there was no sort of physical or scientific phenomena that could explain it. So the only way to study it was to go right up into it and take the data there. The other mystery was basically why, once superheated, can this atmosphere break away from the pull of a giant star and accelerate out into the solar system. The third mystery was basically why the sun has these flares and why does it have these sort of explosive releases of energy.
We will use data from other solar spacecraft to be able to put together the whole picture. But Parker Solar Probe has actually flown into the region where this magic happens, where suddenly the corona is superheated and where the acceleration starts and we have actually gone on the other side of that boundary. The sun has a magnetic field just like the earth does. Everything rotates like one rigid body when it is close to the sun. But as you get across this boundary, the atmosphere starts to accelerate and moves away. So going beneath it to look at what physical processes are happening helps. There are a couple of physical processes that are going on. One is called ‘magnetic reconnection’—essentially where magnetic field lines break, attach and break again and that actually puts out a ton of energy into the system. This can cause a lot of heat. We also saw magnetic field lines were twisted on themselves, and like a garden hose, which springs back straight again when you put in a kink, the magnetic fields break and go straight, releasing a lot of energy and heat into the atmosphere.
Q/When you say solar atmosphere protects the earth and the rest of the solar system, what is it protecting us from?
A/ Solar atmosphere protects us from a lot of cosmic rays and processes that happen outside our solar system. Cosmic rays coming from outside our solar system can actually cause a lot of damage. The shield that the sun’s atmosphere forms keeps out about 70-75 per cent of cosmic rays. So it protects us from all the stuff that is going on in interstellar space. In future, we will send a mission that will go straight out and tell us what is in interstellar space and then we will better understand what we are being protected against.
Q/After the Parker Solar Probe launch (NASA) in 2018 and the Solar Orbiter launch (NASA-European Space Agency) in 2020, ISRO launched Aditya-L1 in 2023. Is there a progression in what we are trying to see in terms of data and technology upgrade? Where do these three probes meet in terms of the knowledge gathered and the technology?
A/ The location of Aditya being at the L1 point means it is sitting exactly at the same point (staying put) between the sun and the earth. It is like a warning system to tell us what is coming towards the earth and it tells us roughly an hour before the solar wind actually impacts the earth. The solar wind travels at about a million miles an hour. It is a million miles away and tells us what to expect here at the planet. It also has a coronagraph that flies with it and blocks out the light of the sun, so essentially it creates a solar eclipse. So you can really study the corona and look at the big events that will be coming towards us. The Parker Solar Probe is taking the measurements really close to the sun. The Solar Orbiter is able to look at the sun in different wavelengths. The orbiter will actually move out of the ecliptic plane so that the earth’s sun line will move up and it will be able to look down on the poles of the sun, which is going to be a unique viewpoint for us…. So, the three of them together make a great team to study the sun; they complement each other.
Q/Could you please elaborate on the NISAR project?
A/ In Earth Sciences, we have our first joint mission with India— NISAR—to provide an unprecedented, detailed view of earth using advanced radar imaging. NISAR is the big thing I am so, so excited about now. It is groundbreaking science. Also, the applications are really important to India, as it helps look at agriculture, how agriculture is changing, how the coastal regions are changing, the soil moisture, the changes to the Himalayan glaciers affecting climate. So it is a really great partnership of not just doing amazing science together, but also producing results that really impact our daily lives and our ability to protect our planet.
Q/Why is the total solar eclipse in April important for NASA?
A/ We have 18 missions focusing on and taking data of the sun during that eclipse and we are really excited. Aditya-L1 will be doing the same and we will pool all of that data to study the event through different experiments. The eclipse creates an artificial nighttime and the protective layer—ionosphere—changes, too. It is very different from the sun setting in the regular cycle. It is an instant nightfall and you can see animals going quiet, the nocturnal animals coming out. We will have sounding rockets and balloons that will look at how the planet changes because of an eclipse. Obviously, it is a great time to look really close at the sun and since it is an actual moon, we are able to look at and study the photosphere. The data will be public, and as part of our citizen science initiative, we will have volunteers all over the world joining us to make scientific discoveries with our data. We really encourage anyone to look up our NASA Citizen Science programme (science.nasa.gov). But I am very excited about PACE (plankton, aerosol, cloud, ocean ecosystem), launched last month, bringing those first light images of our planet. If you think the planet is beautiful, wait till you see the PACE images.