Swati Mohan has Mars on her mind

Real life sometimes writes scripts that are far more other-worldly than fiction – or, as in Swati Mohan's case, science fiction. Growing up in the Northern Virginia/Washington D.C. metro area in the U.S., she got hooked on space as a schoolgirl after watching Star Trek: The Next Generation. Her home was proximate to a NASA centre, and when it opened up for internships, she applied, while still in high school. That three-week internship – at the Goddard Space Flight Center – propelled Swati into a higher orbit of 'space nerddom' and an academic flight path that took her to Cornell University and the Massachusetts Institute of Technology, and eventually landed her a dream job at NASA's Jet Propulsion Laboratory (JPL). "It was about being at the right place at the right time," she says. At NASA, she has worked on the Cassini mission to Saturn, and the Gravity Recovery And Interior Laboratory (GRAIL) mission to study the Moon's gravitational field. Swati has been closely involved in NASA's Mars project, and as the Guidance, Navigation, and Controls Operations Lead for the Perseverance mission to Mars, she played a critical role in the rover's landing on the Red Planet. In an interview to Shaastra, Swati, who is currently the Mars Launch System Chief Engineer, speaks on the wonder of space missions and the importance of international collaborations to advance the frontiers of knowledge. Excerpts:

What lessons did the GRAIL mission offer?
GRAIL was constantly orbiting the Moon, using a one-dimensional radar between two spacecraft to measure the separation between the two. Depending on where they were flying over, the separation would give you (a measure of) the gravity. Because gravity would pull one of the spacecraft first, the separation would decrease or increase, and by monitoring that, you could tell what the gravity was right underneath it. Other missions have mapped out the topography of the Moon, but when you get gravity plus topography, you can actually tell the composition and the structure. It is one step towards verifying theories about how the Moon originated from the Earth.

What has been the greatest challenge in your career?
The Mars 2020 mission was the most challenging from a technical point of view. I had to build the hardware, the test beds, the code... very hands on. I was writing the appointments, analysing data, determining performance. It was the first time I was doing this for a mission from beginning to end.

Next, I worked on the Psyche mission, launched in October (2023), to study an asteroid. It was originally to have launched in 2022, but fell behind. That mission was a leadership challenge: I had to convince the project (team) they were so far behind that they couldn't launch with a satisfactory probability of success. As the reward for telling them that, I was put in charge of fixing it! I had to formulate a strategy for how we were going to get the group to work towards a critical, schedule-driven goal.

What is in store for the Mars expedition?
The Perseverance rover collected samples on Mars. Now we have to bring them back, which is even more challenging. This mission stacks all the tasks we have done, in serial. It has to launch, arrive at Mars, land there, collect the samples – and then it has to launch itself from Mars, which has never been done before. When it is in orbit, it has to have another launch in order to (enter) the Martian orbit, and then that system has to leave the Martian orbit and return to Earth. The launch will happen in the 2030s.

Where do you see space exploration taking us over the next two decades?
I don't claim to be a fortune-teller, but there are two aspects that I'd like to see. One is the near-Earth: I refer to the Earth-Moon, and even the Earth-Sun systems. I think the commercial and private sector can start to contribute more.

Over the longer term – over 50 years, rather than 20 – I'd like to see, beyond our planetary neighbours, missions like the Voyager... If we can actually design missions that would go beyond the solar system and figure out how it interacts with the rest of our galaxy, that would be really cool... Larger telescopes can help us find habitable worlds that are farther away.
 
After the Mars mission, have there been any engineering solutions that will be used again in future missions?
The auto navigation system that was necessary for the Perseverance rover landing will definitely be used for the next one, the Mars Sample Return mission. They are going back to the same location and getting the samples. That same technology will be adapted for other planetary bodies such as (Jupiter's moon) Europa and (Saturn's moon) Enceladus.

The role of private players in the space industry has been increasing. How do you see this evolving in the future?
I think we are still learning how to balance the private sector with the government sector. In general, the government sector has been much more about first-of-a-kind (programmes) or large complex structures where there isn't a financial call, but it is done for co-operation or science or some such thing. If there is a repetitive side to it, that can be streamlined; it can be better done by private players. But the first-of-a-kind (projects), or the more complicated (ones), need the government because it can invest the larger portion, it can harness a lot more technical capability, because it has the opportunity to leverage not just the government side but also the commercial side through key contracts.

We need the private industry because only then will things get done cheaper; the government sector can't do that. Once prices come down, you can get more efficient and you can do more, build more infrastructure.

How important are international co-operation and partnerships in the space industry?
The bigger and more daring the missions we are trying to do, the more necessary will international co-operation be. We've reached the limit of what we can do as a single agency.

The missions we are doing now, like going beyond the solar system and so on, we need more international co-operation to get these ideas off the ground. Even the Mars Sample Return mission is an example of how there are so many different pieces...  The co-operation is between NASA and the ESA (European Space Agency).

The NASA-ISRO mission is a good trial. (The NASA-ISRO Synthetic Aperture Radar, or NISAR, mission is a joint project to co-develop and launch a dual-frequency synthetic aperture radar on an Earth observation satellite.) It is a very equitable partnership between NASA and ISRO. If we can get that one to work, we can do more.

You're fond of science fiction. Which sci-fi work has impressed you in recent times?
The most recent one I've read is The Martian by Andy Weir. Another one that I read recently was Project Hail Mary, also by Weir. I liked the premise: a bacterium in the Sun, which originated in Alpha Centauri, is slowly destroying it. The world has to come together to build a vessel that can go to the star and find a cure for our Sun. In going to the nearest star neighbour, humans discover an alien, and have to work together to save both the star systems. It underlines the idea that there is only one Earth, and if something happens to the Sun, all of us have to get together.

How important are science communication skills for scientists?
When I was young, my mother told me: "It doesn't matter how much you know; if you can't communicate it to people, it's almost as if you don't know it."

There are several aspects to it: the first, being able to communicate what you do for your own career prospects so that your peers and others within your own scientific community know of it. Second, support for the space exploration industry is built from the public – not just from the scientific community. That support goes through to government agencies who will decide whether to fund it or not. Third, being able to communicate to the public in a way that gets them excited, in a way they can feel part of it, in a way that they can advocate for it and relate to it is critical in building that base.

Which is your favourite picture of space?
I don't have a single (favourite) picture. I like the Hubble Deep Field view. It captures one microradian portion of the sky: it's just filled with galaxies. It just shows how our galaxy is not even one in a million, it's more like one in a hundred million. It tells us how small we are in a cosmic perspective. I love the picture of Earth from the Moon. Space is a neutral, peaceful territory, and we are all working together there.