Matthew Golombek
Planetary geologist and Senior Research Scientist in the Mars Exploration Program of the Jet Propulsion Laboratory.
Dr. Golombek graduated from Rutgers College in 1976, and received a Ph.D. in Geology/Geophysics from the University of Massachusetts in 1981.
Dr. Golombek became a visiting scientist at the Lunar and Planetary Institute in Houston in 1981, and joined JPL in 1983 as a research scientist. He was chief scientist of the Mars Pathfinder, which landed on Mars in 1997, Science Operations Working Group Chair on the Mars Exploration Rover, and lead the group that selected the landing site. As well as continuing his Mars research, Dr. Golombek is currently on the landing-site selection team of the Mars Science Laboratory, which will go to Mars in 2011. He is co-writer of Mars: Uncovering the Secrets of the Red Planet, published by the National Geographic Society.
Planetary geologist and Senior Research Scientist in the Mars Exploration Program of the Jet Propulsion Laboratory.
Dr. Golombek graduated from Rutgers College in 1976, and received a Ph.D. in Geology/Geophysics from the University of Massachusetts in 1981.
Dr. Golombek became a visiting scientist at the Lunar and Planetary Institute in Houston in 1981, and joined JPL in 1983 as a research scientist. He was chief scientist of the Mars Pathfinder, which landed on Mars in 1997, Science Operations Working Group Chair on the Mars Exploration Rover, and lead the group that selected the landing site. As well as continuing his Mars research, Dr. Golombek is currently on the landing-site selection team of the Mars Science Laboratory, which will go to Mars in 2011. He is co-writer of Mars: Uncovering the Secrets of the Red Planet, published by the National Geographic Society.
Mars (Courtesy of NASA/JPL-Caltech)
Mars Pathfinder Rover exploring Mars (Courtesy of NASA/JPL-Caltech)
Twin Mars Exploration Rovers Spirit and Opportunity (Courtesy of NASA/JPL-Caltech)
Spacecraft, protected in an aeroshell, landing on Mars using a parachute (Courtesy of NASA/JPL-Caltech)
Phoenix Mars Lander (Courtesy of NASA/JPL-Caltech)
Q. What is the charm of exploration?
It's just finding out what's there that you didn't know before. That's really what exploration is about. It's the discovery of what no one knew before. And that's something that's in our psyches as people, to explore and to see what the boundaries are. I think ultimately, we as people like to see how we are different from everything else out there, how we fit in.
Q. Can you explain your current research on Mars?
I'm on the rover science team. My specific work is about relating the surface that the rover sees and traverses with what we see in the orbital images. So most of my research centers on understanding the surface from orbit, and then once we land, making sure that we got it right, that we understood it well. Currently I working to better understand how the climate on Mars has changed with time. My most recent work was trying to estimate how quickly the surface has eroded and changed over time, as a way to understand the climate: whether it's been super-dry like it is today, with very slow rates of change, versus the distant past, when it looked like terrain was eroding almost as fast as it did here on Earth, suggesting water, and maybe even rain. So, that's a relatively recent research project.
I also work on advance planning for the next mission, selecting the landing site for the Mars Science Laboratory, which is the large rover scheduled for launch in 2011. When you're selecting a landing site, you're using remote sensing data from orbit and trying to predict or infer that the surface is going to be safe. Some of that work has been understanding the rock distributions. Rocks that sit on the surface can be quite hazardous to landing spacecraft. The idea is to study the potential landing sites as much as you can prior to landing. The better you're able to do that – to infer the surface from orbit – the more successful you'll be with your selection of a landing site, and the better off you'll be if you ever want to select a landing site again in the future. I have helped select three landing sites – for Mars Pathfinder, Sprit and Opportunity – and they have been similar to what we expected from the remote sensing data. So I still have a job.
Q. What are the most important factors in selecting a landing site?
The most important factor is that it be safe for the lander and rover. You only get science if you land successfully, and understanding the surface is a big part of that. So the first question is, is the site safe to the best of your knowledge? And you study it, you study it, you study it. You do everything you can to be sure it's safe for the lander.
A big constraint is the elevation. Since all Mars landers use an aeroshell – which protects the lander from the high temperature when it rushes into Mars atmosphere – and a parachute, there are some altitudes you can't land on, such as the top of Olympus Mons. There, you're still on the aeroshell. There's no way to land at that altitude. You need to have enough atmosphere to slow the vehicle down, so it can get the parachute out, and enough time for it to sense the ground and measure the closing velocity. So the elevation is among the most important factors.
Next, you want a surface that's load-bearing. We think there are locations on Mars where the spacecraft would sink into low-cohesion dust deposits that could be very thick. Landing in dust deposits is also bad for the solar arrays, which could be covered in dust, reducing their power generation. And then you don't want too many rocks – rocks that are poking up, so if you landed on one you'd get hurt. You don't want steep scarps, because you could confuse the radar and miss-time the touchdown. So I talk to the engineers who designed the spacecraft and try to understand the requirements, and then we look at Mars and try to find a place that meets them.
Now, if it's a solar-powered spacecraft, and if you want it to last a long time, you want to be where solar power is greatest. So you probably want to be near the equator, where you get the most sun. If you go towards the pole, like with the Phoenix lander, the sun goes down and then your spacecraft is gone, it's dead from lack of solar power. So, latitude is very important.
The other half is the science. What is the mission trying to accomplish? What are the instruments on board the spacecraft? And will there be materials at the landing site that allow them to do their job? If you want to learn about ancient environments, you want to go to a place where there are ancient rocks exposed at the surface. If it's just a broken up mishmash of soil, you won't be able to do this. Each lander or rover is going to have different instruments and different science objective. So those are the two main factors: the science and the safety.
It's just finding out what's there that you didn't know before. That's really what exploration is about. It's the discovery of what no one knew before. And that's something that's in our psyches as people, to explore and to see what the boundaries are. I think ultimately, we as people like to see how we are different from everything else out there, how we fit in.
Q. Can you explain your current research on Mars?
I'm on the rover science team. My specific work is about relating the surface that the rover sees and traverses with what we see in the orbital images. So most of my research centers on understanding the surface from orbit, and then once we land, making sure that we got it right, that we understood it well. Currently I working to better understand how the climate on Mars has changed with time. My most recent work was trying to estimate how quickly the surface has eroded and changed over time, as a way to understand the climate: whether it's been super-dry like it is today, with very slow rates of change, versus the distant past, when it looked like terrain was eroding almost as fast as it did here on Earth, suggesting water, and maybe even rain. So, that's a relatively recent research project.
I also work on advance planning for the next mission, selecting the landing site for the Mars Science Laboratory, which is the large rover scheduled for launch in 2011. When you're selecting a landing site, you're using remote sensing data from orbit and trying to predict or infer that the surface is going to be safe. Some of that work has been understanding the rock distributions. Rocks that sit on the surface can be quite hazardous to landing spacecraft. The idea is to study the potential landing sites as much as you can prior to landing. The better you're able to do that – to infer the surface from orbit – the more successful you'll be with your selection of a landing site, and the better off you'll be if you ever want to select a landing site again in the future. I have helped select three landing sites – for Mars Pathfinder, Sprit and Opportunity – and they have been similar to what we expected from the remote sensing data. So I still have a job.
Q. What are the most important factors in selecting a landing site?
The most important factor is that it be safe for the lander and rover. You only get science if you land successfully, and understanding the surface is a big part of that. So the first question is, is the site safe to the best of your knowledge? And you study it, you study it, you study it. You do everything you can to be sure it's safe for the lander.
A big constraint is the elevation. Since all Mars landers use an aeroshell – which protects the lander from the high temperature when it rushes into Mars atmosphere – and a parachute, there are some altitudes you can't land on, such as the top of Olympus Mons. There, you're still on the aeroshell. There's no way to land at that altitude. You need to have enough atmosphere to slow the vehicle down, so it can get the parachute out, and enough time for it to sense the ground and measure the closing velocity. So the elevation is among the most important factors.
Next, you want a surface that's load-bearing. We think there are locations on Mars where the spacecraft would sink into low-cohesion dust deposits that could be very thick. Landing in dust deposits is also bad for the solar arrays, which could be covered in dust, reducing their power generation. And then you don't want too many rocks – rocks that are poking up, so if you landed on one you'd get hurt. You don't want steep scarps, because you could confuse the radar and miss-time the touchdown. So I talk to the engineers who designed the spacecraft and try to understand the requirements, and then we look at Mars and try to find a place that meets them.
Now, if it's a solar-powered spacecraft, and if you want it to last a long time, you want to be where solar power is greatest. So you probably want to be near the equator, where you get the most sun. If you go towards the pole, like with the Phoenix lander, the sun goes down and then your spacecraft is gone, it's dead from lack of solar power. So, latitude is very important.
The other half is the science. What is the mission trying to accomplish? What are the instruments on board the spacecraft? And will there be materials at the landing site that allow them to do their job? If you want to learn about ancient environments, you want to go to a place where there are ancient rocks exposed at the surface. If it's just a broken up mishmash of soil, you won't be able to do this. Each lander or rover is going to have different instruments and different science objective. So those are the two main factors: the science and the safety.
