Planetary Spacecraft Missions

Geologists on Earth take their tools and are able to examine formations on the surface first-hand. They are able to obtain rock samples, and to analyze them in the laboratory. Earth geologists may also use remote sensing, or images and data from special satellites in space.

What if you want to study one of the other planets? Or a moon? The other planets are so far away that we are limited in what we can learn on Earth using telescopes to observe. So far, people have only visited the Earth's moon in person. No one has travelled to Mars or any of the other planets. So how do we learn about them?

Scientists and engineers design and build spacecraft to travel to other planets. Some fly past the planet and are called flybys; Voyagers 1 and 2 were flyby spacecraft that visited Jupiter, Saturn, Uranus and Neptune. Spacecraft that go into orbit around a planet are called orbiters, and typically have missions of more than four years. Landers touch down on the surface of another planet. Rovers study the surface of another planet and are able to move about.

Scientific Instruments

Once a spacecraft reaches another planet, how does it gather information for scientists to study? All spacecraft have specially created scientific instruments of different types on board to gather information, or data and images, about the planet and its moons. These instruments study many wavelengths of the electromagnetic spectrum and include:

• Visible-wavelength cameras: These instruments take high-resolution images (pictures) of a planet's surface. Examples include the Cassini orbiter's Imaging Science Subsystem (ISS) camera, and the main cameras on the Mars Exploration Rovers.
• Spectrometers: These instruments analyze light and help determine what elements or compounds are present on a planet's surface or in its atmosphere. In other words, it figures out what a planet's rocks or atmosphere are made of. An example is the VIMS instrument on Cassini.
• Special-Wavelength Cameras: Some cameras view a planet in the infrared, ultraviolet, or other range of light.
• Radar Instruments: On Earth, meteorologists use radar information to study storm systems. On other planets, radar instruments can be used to map the surface through thick cloud cover, such as on Venus or Titan, Saturn's moon.
• Magnetometers: Like the Earth, some many other planets have large magnetic fields, called magnetosphers. By studying the magnetospheres of planets, we can learn alot about their interiors.
• And many other instruments!

My Work

To study the surfaces of other planets and their moons, I use a lot of images from visible-wavelength cameras on spacecraft. The two missions I am most involved with right now are New Horizons and the Mars Exporation Rovers.

New Horizons

For the New Horizons mission to Pluto, I am responsible for planning what regions will be targetted for images. Long before the spacecraft reaches this icy world and its large moon, Charon, we have to decide on the best ways to study them. Then the engineers and computer programmers at NASA will carefully write computer programs full of instructions for the spacecraft and its instruments.

Mars Exploration Rovers

Currently I am doing research on Mars using images and data from the Mars Exploration Rovers, which have been successfully operating on the surface of the Red Planet since January, 2004. These two robotic explorers are able to move about on Mars, take images on the surface, and drill into rocks to study them. They are also equipped with spectrometers to determine what the martian rocks and geologic formations are made of.