NASA - National Aeronautics and Space Administration

The Mars Science Laboratory rover, Curiosity, will assess whether Mars ever had an environment capable of supporting microbial life - habitability. Whether life has existed on Mars is an open question that this mission, by itself, is not designed to answer. Curiosity does not carry experiments to detect active processes that would signify present-day biological metabolism. Nor does it have the ability to image microorganisms or their fossil equivalents. However, if this mission finds that the field site in Gale Crater has had conditions favorable for habitability and for preserving evidence about life, those findings can shape future missions that would bring samples back to Earth for life-detection tests or for missions that carry advanced life-detection experiments to Mars. In this sense, the Mars Science Laboratory is the prospecting stage in a step-by-step program of exploration, reconnaissance, prospecting and mining evidence for a definitive answer about whether life has existed on Mars.

Mars Science Laboratory is part of a series of expeditions to the Red Planet that help meet the four main science goals of the Mars Exploration Program:

• Determine whether life ever arose on Mars
• Characterize the climate of Mars
• Characterize the geology of Mars
• Prepare for human exploration

To contribute to the four science goals and meet its specific goal of determining Mars' habitability, Mars Science Laboratory has the following science objectives.

Biological:

1. Determine the nature and inventory of organic carbon compounds
2. Inventory the chemical building blocks of life (carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur)
3. Identify features that may represent the effects of biological processes

Geological and Geochemical:

4. Investigate the chemical, isotopic, and mineralogical composition of the Martian surface and near-surface geological materials
5. Interpret the processes that have formed and modified rocks and soils

Planetary Process:

6. Assess long-timescale (i.e., 4-billion-year) atmospheric evolution processes
7. Determine present state, distribution, and cycling of water and carbon dioxide

Surface Radiation:

8. Characterize the broad spectrum of surface radiation, including galactic cosmic radiation, solar proton events, and secondary neutrons

It would be possible to grow plants on Mars only in technologically advanced, controlled environments that could keep the plants warm and give the plants enough atmosphere, light, and water to live. Scientists anticipate that humans would be able to use the Martian soil as a substrate for plant growth. Based upon results from the Phoenix Mars Lander mission, the soil pH and salt content are not detrimental to plants (scientists working on the mission found that the soil at the Phoenix landing site is very basic, with a pH of between eight and nine).

Human visitors would likely have to add a little fertilizer, but scientists still do not know enough about the chemistry of the Martian soil to determine what additional fertilizers plants may need. Studies of Martian soil characteristics will help future scientists develop ways to grow plants for human communities on Mars. You can read more about these results from the Phoenix Mars mission at: Phoenix Returns Treasure Trove for Science and NASA Phoenix Results Point to Martian Climate Cycles.

During the final few minutes of Curiosity's flight to the surface of Mars, the Mars Descent Imager, or MARDI, will record a full-color video of the ground below. This will provide the Mars Science Laboratory team with information about the landing site and its surroundings, to aid interpretation of the rover's ground-level views and planning of initial drives. Hundreds of the images taken by the camera will show features smaller than what can be discerned in images taken from orbit. The video will also give fans worldwide an unprecedented sense of what it might feel like to ride a spacecraft to a landing on Mars.

MARDI will record the video on its own 8 gigabyte flash memory, at about four frames per second and close to 1,600 by 1,200 pixels per frame. Thumbnails and a few samples of full-resolution frames will be transmitted to Earth in the first days after landing. The nested set of images from higher altitude to ground level will enable pinpointing of Curiosity's location. The pace of sending the rest of the frames for full-resolution video will depend on sharing priority with data from the rover's other investigations.

The full video — available first from the thumbnails in YouTube-like resolution and later in full detail — will begin with a glimpse of the heat shield falling away from beneath the rover. The first views of the ground will cover an area several kilometers (a few miles) across. Successive frames taken as the vehicle descends will close in and cover successively smaller areas. The video will likely nod up and down to fairly large angles owing to parachute-induced oscillations. Its roll clockwise and counterclockwise will be smaller, as thrusters on the descent stage control that motion. When the parachute is jettisoned, the video will show large angular motions as the descent vehicle maneuvers to avoid re-contacting the back shell and parachute. Rocket engine vibration may also be seen. A few seconds before landing, the rover will be lowered on tethers beneath the descent stage, and the video will show the relatively slow approach to the surface. The final frames, after landing, will cover a bath-towel-size patch of ground under the front-left corner of the rover.

In addition to meeting the main objective of providing geologic context for the observations and operations of the rover during the early part of mission on Mars, MARDI will also provide insight about Mars' atmosphere. Combining information from the descent images with information from the spacecraft's motion sensors will enable calculation of wind speeds affecting the spacecraft on its way down, an important atmospheric science measurement. The descent data will affect design and testing of future landing systems for Mars that could add more control for hazard avoidance.

Throughout Curiosity's mission on Mars, MARDI will offer the capability to obtain images of ground beneath the rover at resolutions down to 0.06 inch (1.5 millimeters) per pixel, for precise tracking of its movements or for geologic mapping - the science team will decide whether or not to use that capability. Each day of operations on Mars will require choices about how to budget power, data and time.

Although sound could be recorded on Mars, Curiosity does not carry a recording device. There are three NASA sites that might help you explore the relevant concepts further:

› Mars Polar Lander: What Sounds Will the Mars Microphone Record?
› Mars Microrover Telecommunications FAQ: Does the Lander or the Rover have a microphone for recording sounds?
› Speed of Sound: Mathematical Models

While the Mars Exploration Rovers, Spirit and Opportunity, also did not carry a microphone, the audio excerpts at http://marsrover.nasa.gov/spotlight/20100222a.html represent the journeys the Mars rovers made while driving across the plains, mountains and craters of Mars during their first six years on the red planet. You can also listen to a podcast about these audio files.

Additionally, the Phoenix Mars Lander (2007-2008 mission) web page answers the question, "Does Phoenix have a microphone to 'hear' the sounds of Mars?" Answer: "Phoenix, like the 1999 Polar Lander, originally had a microphone to hear the sounds of the descent to Mars. It was part of the MARDI system which was turned off to due to the small risk that it could trip a critical landing system. So far, no spacecraft has successfully captured the sounds of Mars. However, the European Space Agency's orbiter Mars Express captured the sounds of Phoenix's descent.

The oxygen content of the Martian atmosphere is only 0.13 percent, compared with 21 percent in Earth's atmosphere. Carbon dioxide makes up 95.3 percent of the gas in the atmosphere of Mars. It also contains nitrogen and argon and very small amounts of water and methane.

Although the Mars Science Laboratory rover, Curiosity, does not have a tool specifically for digging, as on the earlier rovers, the mobility system can be used to dig beneath the surface by rotating one corner wheel while keeping the other five wheels immobile. However, whether life has existed on Mars is an open question that this mission, by itself, is not designed to answer. Curiosity does not carry experiments to detect active processes that would signify present-day biological metabolism, nor does it have the ability to image microorganisms or their fossil equivalents.

However, if this mission finds that the field site in Gale Crater has had conditions favorable for habitability and for preserving evidence about life, those findings can shape future missions that would bring samples back to Earth for life-detection tests or for missions that carry advanced life-detection experiments to Mars. In this sense, the Mars Science Laboratory is the prospecting stage in a step-by-step program of exploration, reconnaissance, prospecting and mining evidence for a definitive answer about whether life has existed on Mars. NASA's Astrobiology Program has aided in development of the Mars Science Laboratory science payload and in studies of extreme habitats on Earth that can help in understanding possible habitats on Mars.

Curiosity carries the Dynamic Albedo of Neutrons (DAN) instrument, which can detect water bound into shallow underground minerals along Curiosity's path. The DAN instrument shoots neutrons into the ground and measures how they are scattered, giving it a high sensitivity for finding any hydrogen to a depth of about 20 inches (50 centimeters) directly beneath the rover. The instrument can be used to help identify places for examination by Curiosity's other tools. Also, rock formations that Curiosity's cameras view at the surface may be traced underground by DAN, extending scientists' understanding of Mars' geology.

Thanks to the SHARAD (Shallow Radar) instrument onboard the Mars Reconnaissance Orbiter, we do know more about what lies beneath the surface of Mars. SHARAD looks for liquid or frozen water in the first few hundreds of feet (up to 1 kilometer) of Mars' crust. SHARAD probes the subsurface using radar waves within a 15- to 25-megahertz frequency band to get the desired, high-depth resolution. The radar wave return, which is captured by the SHARAD antenna, is sensitive to changes in the electrical reflection characteristics of rock, sand, and any water that may be present in the surface and subsurface. Water, like high-density rock, is highly conducting, and has a very strong radar return. Changes in the reflection characteristics of the subsurface, caused by layers deposited by geological processes in the ancient history of Mars, are also visible.

In 2008, SHARAD revealed vast Martian glaciers of water ice under protective blankets of rocky debris at much lower latitudes than any ice previously identified on the Red Planet. In 2010 it revealed subsurface geology allowing scientists to reconstruct the formation of a large chasm and a series of spiral troughs on the northern ice cap of Mars.

Additionally, landed missions such as the Mars Exploration Rovers and the Phoenix Mars Mission have enhanced our understanding of what lies just beneath the surface. The Phoenix Mars Mission did this with its specially-designed robotic arm with scoop and the Mars Exploration Rovers did so by locking five of their six wheels and using the free wheel to dig into the sand and soil in an activity the mission team called "trenching" (for example: Opportunity Digs, Spirit Advances). Curiosity's mobility system can be used in a similar way.

In the continuing pursuit of water on Mars, the polar regions are a good place to probe, as water ice is found there. NASA has already sent two lander missions to the poles of Mars. The first, Mars Polar Lander (1999) - an ambitious mission to set a spacecraft down on the frigid terrain near the edge of Mars' south polar cap and dig for water ice with a robotic arm - was lost upon arrival. The 2007-2008 Phoenix Mars Mission to the north pole of Mars, on the other hand, was a great success. Phoenix landed farther north than any previous mission, at a latitude equivalent to that of northern Alaska on Earth, and used a robotic arm to dig through the protective top soil layer to the water ice below, bringing both soil and water ice to the lander platform for sophisticated scientific analysis. Read more about the results of this exciting polar mission at the Phoenix Mars Mission website.

There are a number of informative videos about the challenges of landing on Mars available in the Mars Exploration Program video archive. You can read specifically about the landing of the Phoenix Mars Mission at Phoenix Mars Mission: Entry, Descent and Landing.

It sounds like your class might be a great match for NASA's Mars Student Imaging Project (MSIP), because the heart of MSIP is students coming up with their own research questions about Mars. MSIP is a NASA opportunity, for anyone from grade 5 through college, to participate in NASA research opportunities free of charge. This program offers teams or classes of students the opportunity to work (either in person or via distance-learning technologies) with scientists, mission planners and educators on the team (at Arizona State University's Mars Space Flight Facility) that manages the THEMIS visible wavelength camera onboard the Mars Odyssey spacecraft currently orbiting Mars.

In MSIP, participants engage in a curricular unit that scaffolds their creation of an observation plan, from determining the question to analyzing the data. With the help of spacecraft controllers, the students send the commands to the spacecraft in orbit around Mars. When the spacecraft has completed the requested observations, it sends the image back to Earth to be processed and analyzed by participating students. This project is not intended to add to the regular science curriculum. Instead, as a National Science Education Standards-aligned series of activities, it can be used to teach standards-based material in a new and exciting way. And because students are working with real data, real discoveries are possible. In fact, a middle school team in California discovered a cave skylight on Mars.

The atmosphere of Mars is thin, cold, and dry and contains much less oxygen than the atmosphere of Earth. The oxygen content of the Martian atmosphere is only 0.13 percent, compared with 21 percent in Earth's atmosphere. Carbon dioxide makes up 95.3 percent of the gas in the atmosphere of Mars. It also contains nitrogen and argon and very small amounts of water and methane. Additionally, the atmospheric pressure on Mars is only about 1/100 that of Earth's!

Scientists are studying why Mars' atmosphere is so thin. It may be because there's not as much sunlight arriving at Mars as there is on Earth, since Mars is 1 1/2 times farther away from the sun than the Earth is. It may be that Mars had a lot of atmosphere in the early part of the planet's history, but once its magnetic field disappeared, this lack of a protective barrier allowed sunlight to strip away the upper atmosphere, making the atmosphere thinner. (The upper atmosphere of a planet is constantly bombarded by the solar wind, a fast stream of very light particles emanating from the sun. This wind itself is fairly benign, but it also carries a magnetic field. This field picks up ions from the upper atmosphere, accelerates them, and then smashes them back into other ions at several hundred kilometers per second, knocking ions out to space. If the planet itself has a magnetic field, it can shield the upper atmosphere from the solar wind. However, because it is a small planet, Mars cooled rapidly so that its inner dynamo disappeared and it lost its original magnetic field quickly.)

Many people have considered how humans might keep time on Mars. You can read more at:
› Martian Timekeeping
› Planetary Society:Mars Calendar
› Mars Seasons
› Download a Mars rover calendar from 2009-2010 (PDF)

As with other Mars missions, you can access data from Curiosity. Visit http://mars.jpl.nasa.gov/msl. Additionally, a new way of following the day-to-day discoveries on Mars is available through an online virtual experience called Curiosity's Journey.

Learn more about the way communications are handled between Earth and Mars at MSL: Communication With Earth. For a more detailed look at how this will work during Curiosity's surface operations, see the Mars Science Laboratory Landing Press Kit available for download at the MSL Newsroom.

Whether life has existed on Mars is an open question that this mission, by itself, is not designed to answer. Curiosity does not carry experiments to detect active processes that would signify present-day biological metabolism, nor does it have the ability to image microorganisms or their fossil equivalents. However, if this mission finds that the field site in Gale Crater has had conditions favorable for habitability and for preserving evidence about life, those findings can shape future missions that would bring samples back to Earth for life-detection tests or for missions that carry advanced life-detection experiments to Mars.

In this sense, the Mars Science Laboratory is the prospecting stage in a step-by-step program of exploration, reconnaissance, prospecting and mining evidence for a definitive answer about whether life has existed on Mars. NASA's Astrobiology Program has aided in development of the Mars Science Laboratory science payload and in studies of extreme habitats on Earth that can help in understanding possible habitats on Mars.

You could go to Mars! Astronauts have a variety of science, technology, engineering and mathematics backgrounds, and an even broader group of people on Earth will support Mars exploration missions! NASA will need people to help us learn how to prepare for the journey, grow food during the trip, handle recycling needs and build systems to take us to Mars and support systems here on Earth. We also will need experts in software development and communications systems.

There are many possible landing sites of scientific interest. Current robotic missions on Mars are helping NASA scientists learn about the Martian surface and its environment. This information will help us select the actual site. That site will depend on many factors, including terrain, soil and surface properties; areas of science priority; and access to and quality of local resources.

Absolutely. We want our crews to return with valuable scientific insights. Also, their unique learning experiences will greatly benefit future missions to the Red Planet.

NASA currently is working to build the systems to take astronauts beyond low Earth orbit. NASA is working to meet the President's goal to send humans to Mars in the 2030s. We are developing the technology we will need and designing safety measures to protect our astronauts from the harsh environment beyond low Earth orbit.

It depends on how you go, what kind of rocket is used and what technologies are available. With current technology, our robotic missions usually take about 8 months to travel to Mars. We are exploring options that will minimize the duration of a human trip to Mars.

Earth's and Mars' orbit around the sun allow for an opportunity to embark to Mars about every 26 months. There are two scenarios for going to Mars and returning to Earth. The first requires astronauts to remain on Mars for only a few weeks before returning. The second scenario will see astronauts spending over a year on the Red Planet. The overall mission duration ranges from about a year to close to three years.

Any mission that takes humans beyond the safety of Earth includes hazards. Entry through Mars' atmosphere and landing on the planet is a challenge in itself. NASA still is learning about the environment on Mars, including radiation levels and dust. In fact, the Mars Science Laboratory spacecraft will take important measurements during the course of entry and descent through the atmosphere, and the Curiosity rover will measure the radiation environment on the surface. Curiosity also carries instruments to measure the characteristics of Martian soil.

Spacesuits used in low Earth orbit are designed for microgravity. The gravity on Mars is about one-third of the gravity on Earth. Spacesuits for Mars also will be designed for walking on the surface and performing science and other activities.

It won't be just one spacecraft. We are going to need to take enough parts that allow us to travel safely over long times and distances. These different parts include a habitat for the crew to live and work in as well as the spacecraft for the crew to launch from Earth and also be able to land when we return.

NASA is busy building the next generation of spacecraft that will take humans further into the solar system than ever before. Although the lessons learned from our trips to the moon will greatly enhance our understanding of exploring planets other than our own, our current focus is to travel to a near-Earth asteroid by 2025 and then on to Mars after that.

Yes. The robotic missions that NASA has flown to Mars already have provided us with valuable information that will help in planning for the first human mission to Mars.

NASA does have the rocket technology to get humans to Mars. However, current technology is not advanced enough to get us there efficiently. We are continuing to develop technologies to improve that efficiency. Another challenge we are actively working to overcome is the heat shield that will be needed to protect the returning capsule as it passes through Earth's atmosphere.

NASA has conducted several studies on the feasibility of establishing a permanent settlement on Mars. At this time, we are not looking to implement such a plan. We will be in a better position to evaluate such a plan after we have perfected the ability to go to Mars and return safely, as well as ensuring that we have the technology to create the necessary resources while on the Red Planet to survive.

NASA is evaluating several different kinds of fuel for trips to Mars. Options include nuclear thermal, nuclear electric, solar electric and various chemical propellants.

NASA is looking at a variety of options to sustain human exploration on Mars. Although it is possible to carry all the necessary resources with us for a trip to and from Mars, it is not feasible. The weight of all of those resources would preclude an efficient launch. As such, NASA is looking at ways to extract resources such as oxygen and water from the Martian atmosphere and soil. We also are looking at ways to create other necessities like fuel and food from the natural resources found on the Red Planet.

In-space propulsion is a key technology hurdle to shorten a trip to Mars. NASA's In-Space Propulsion Systems Roadmap (PDF) included a good discussion on this topic.

NASA is working on laser communications technology that will improve data rates in space. Current data transmission capabilities do not allow for live video feed from deep space. Read more about this new technology at the Deep Space Optical Communications Project website.