OrbitalHub

Credits: NASA/JPL

The Mars Reconnaissance Orbiter (MRO) has completed the first phase of its science mission. During this phase, the orbiter returned seventy-three terabits of science data to Earth, which is more than all earlier Mars missions combined. The next phase of the MRO mission will take two years.

The list of scientific discoveries and observations made by MRO is stunning. We know now that Mars has a long history of climate change and that water was present in liquid form on its surface for hundreds of millions of years.

Signatures of a variety of watery environments have been observed, so future missions will be aware of locations that might reveal evidence of past life on Mars, if it ever existed.

MRO has imaged nearly forty percent of the Martian surface at such a high resolution that house-sized objects can be seen in detail. MRO has also conducted a mineral survey of the planet, covering sixty percent of its surface. Global weather maps were assembled using the data returned by MRO, and profiles of the subsurface and the polar caps have been put together using the radar mounted on MRO.

Credits: NASA/KSC

“These observations are now at the level of detail necessary to test hypotheses about when and where water has changed Mars and where future missions will be most productive as they search for habitable regions on Mars,” said Richard Zurek, Mars Reconnaissance Orbiter project scientist.

The images returned by MRO have been used by the Phoenix team to change the spacecraft’s landing site, and will help the NASA scientists select landing sites for future missions, like the Mars Science Laboratory (MSL).

Another role played by MRO was to relay commands to and to return data from the Phoenix lander during the five months the lander was operational on the Martian surface. MRO shared this task with the Mars Odyssey Orbiter.

MRO lifted off on August 12, 2005, from launch Complex 41 at Cape Canaveral Air Force Station. The cruise phase of the mission lasted seven months, the spacecraft reaching Mars orbit on March 10, 2006, after traveling on an outbound arc intercept trajectory.

MRO entered the final low orbit suited for science-data collection on November 2006, after slowing down in the Martian atmosphere by using aerobraking for five months. The first phase of the mission consisted in gathering information about Mars, and the remaining time left of its operational life will be dedicated mainly to using the spacecraft as a communication relay.

Credits: NASA/KSC

The declared goals of the MRO mission are: to determine whether life ever arose on Mars, to characterize the climate of Mars, to characterize the geology of Mars, and to prepare for human exploration.

The launcher of choice for the MRO mission was the Atlas V-401 launch vehicle, the smallest of the Atlas V family. This was the first launch of an Atlas V on an interplanetary mission.

The Atlas V-401 is a two-stage launch vehicle that does not use solid rocket boosters. The Atlas V-401 is fifty-seven meters tall and has a total mass at liftoff of 333,000 kg. Out of this, about 305,000 kg is fuel. In order to reach Mars orbit, MRO was accelerated to 11 km per second.

The first stage of the Atlas V, the Common Core Booster, is powered by liquid oxygen and RP-1. For the MRO mission, the first stage used a RD-180 engine. The RD-180 engine has an interesting story. It is a Russian-developed rocket engine, derived from the RD-170 used for the Zenit rockets.

Credits: NASA/JPL/KSC/Lockheed Martin Space Systems

Rights to use the RD-180 engine were acquired by General Dynamics Space Systems Division (later purchased by Lockheed Martin) in the early 1990s. The engine is co-produced by Pratt & Whitney and all production to date has been in Russia. According to Pratt & Whitney, RD-180 delivers a ten percent performance increase over current operational U.S. booster engines.

The stage weighs approximately 305,000 kg at launch and it provides about four million Newton of thrust for four minutes.

The upper stage of the Atlas V is the Centaur Upper Stage Booster. The Centaur is powered by liquid oxygen and liquid hydrogen. In the case of the MRO mission, it provided the remaining energy necessary to send the spacecraft to Mars.

The payload fairing used for the MRO mission was four meters in diameter. The role of the payload fairing was to protect the spacecraft from the weather on the ground as well as from the dynamic pressure during the atmospheric phase of the launch.

Lockheed Martin Commercial Launch Services developed the Atlas V as part of the US Air Force Evolved Expendable Launch Vehicle (EELV) program.

There are six science instruments, three engineering instruments, and two science-facility experiments carried by the MRO. The low orbit on which MRO is operating allowed the observation of the surface, atmosphere, and subsurface of Mars in unprecedented detail.

The science instruments are the HiRISE camera (High Resolution Imaging Science Experiment), the CTX camera (Context Camera), the MARCI camera (Mars Color Imager), the CRISM spectrometer (Compact Reconnaissance Imaging Spectrometer for Mars), the MCS radiometer (Mars Climate Sounder), and the SHARAD radar (SHAllow RADar).

Credits: HiRISE/MRO/LPL/NASA

The HiRISE camera provided the highest-resolution images from orbit to date, while the SHARAD can probe the subsurface using radar waves in the 15-25 MHz frequency band (these waves can penetrate the Martian crust up to one kilometer).

The engineering instruments assist the spacecraft navigation and communication. The Electra UHF Communications and Navigation Package is used as a communication relay between the Earth and landed crafts on Mars. The Optical Navigation Camera serves as a high-precision camera to guide incoming spacecrafts as they approach Mars. The Ka-band Telecommunications Experiment Package demonstrated the use of the Ka-band for power effective communications.

The science facility experiments are the Gravity Field Investigation Package, used for mapping the gravity field of Mars, and the Atmospheric Structure Investigation Accelerometers, which helped scientists understand the structure of the Martian atmosphere.

For more details on the MRO scientific payload, you can check out the dedicated page on the MRO mission web site.

The MRO was built by Lockheed Martin for NASA’s Jet Propulsion Laboratory in California. Fully loaded, the spacecraft had a mass of almost two tons. The spacecraft carried 1,149 kg of propellant for trajectory correction maneuvers and for the burns needed for the Mars capture.

Credits: NASA/JPL

The main bus of the spacecraft presents two massive solar arrays that can generate 2,000 W of power. On top, the high-gain antenna is the main means of communication with both Earth and other spacecrafts. The SHARAD antenna is the long pole behind the bus.

Other visible features are the HiRISE camera, the Electra telecommunications package, and the Context Imager (CTX).

You can visit the home page of the MRO mission on the NASA web site.

Credits: NASA

Last week we presented GOSAT a.k.a. Ibuki, a mission that has as its objective the mapping of carbon dioxide and methane in the Earth’s atmosphere. A similar mission is getting ready to launch on the other side of the Pacific: the Orbiting Carbon Observatory (OCO). OCO is a NASA Earth System Science Pathfinder (ESSP) Program mission.

The mission team includes the Orbital Sciences Corporation, the Jet Propulsion Laboratory, and Hamilton Sundstrand Sensor Systems.

The atmospheric carbon dioxide (CO₂) is an important greenhouse gas. CO₂ absorbs and traps infrared radiation emitted by the Earth’s surface, preventing it from escaping to space. OCO will provide global CO₂ measurements from space. The data collected during the mission will help scientists understand the global carbon cycle. This understanding is essential to improve the predictions of future atmospheric CO₂ increases and its impact on the climate.

The OCO has a mass of 407 kg. The two GaAs solar arrays will provide 324 W orbit average for the scientific payload onboard. The satellite will use hydrazine thrusters for stabilization while on orbit. The estimated life span for the mission is 24 months.

The scientific payload includes three spectrometers. The spectrometers can detect what gases are in the Earth’s atmosphere and determine their amounts. The measurements will translate into monthly estimates of atmospheric CO₂ over 621-square-mile regions of the Earth’s surface. From its sun-synchronous orbit, OCO will map the globe once every sixteen days. These maps will help locate CO₂ sources and sinks.

Credits: NASA / Orbital

OCO will be placed on orbit by a Taurus XL launch vehicle. Taurus XL is a solid fuel launch vehicle built by the Orbital Sciences Corporation. According to the Taurus fact sheet, it provides launch capability for satellites weighing up to 1,590 kg. The range of launch missions supported by Taurus include low inclination low Earth orbit (LEO), polar LEO, sun-synchronous LEO, geo-transfer orbit, and interplanetary trajectory.

Depending on the configuration, Taurus can have a mass from 69,000 to 77,000 kg and can have a length from 27 to 32 m.

The mission launch is scheduled for early 2009. The Taurus XL launch vehicle will lift off from Vandenberg Air Force Base, California.

Credits: NASA

In 2002, an instrument on the Mars Odyssey spacecraft detected hydrogen under the Martian surface. This was regarded as clear evidence that there is subsurface water ice on Mars.

In 2003, NASA decided to revive a mission that was cancelled in 2001 due to the fact that a previous mission, the Mars Polar Lander, was lost in 1999. The revived mission was named Phoenix.

A Lander that could reach out and touch the ice was needed. The half-built spacecraft for the previously cancelled mission already had in place a 7.7-foot robotic arm that could do the trick.

A JPL team reviewed the data from the failed mission in 1999 and corrected the mistakes made. Every system used in the previous design was taken apart, tested, and examined. The suspected culprits were the retrorockets used during landing. More than a dozen issues that could have caused a failure of the new planned mission were found and fixed.

Credits: NASA / JPL

The Phoenix mission inherited a capable spacecraft partially built for the Mars Surveyor Program 2001. As we mentioned, the lessons learned from the Mars Polar Lander helped improve the existing systems. As for any other space mission, the conditions in which the spacecraft operates dictate the design.

In the case of the Phoenix mission, the following phases were considered: the launch, the cruise, the atmospheric entry, the touchdown, and the surface operations phase. The launch induces tremendous load forces and vibrations. The 10-month cruise to Mars exposes the spacecraft to the vacuum of space, solar radiation, and possible impacts with micrometeorites. During the atmospheric entry, the spacecraft is heated to thousands of degrees due to aero braking, and has to withstand tremendous deceleration during the parachute deployment. The extremely cold temperatures of the Martian arctic and the dust storms must be considered during the surface operations phase.

Credits: NASA / JPL

Several instruments are mounted on the Lander: the robotic arm (RA), the robotic arm camera (RAC), the thermal and evolved gas analyzer (TEGA), the Mars descent imager (MARDI), the meteorological station (MET), the surface stereo imager (SSI), and the microscopy, electrochemistry, and conductivity analyzer (MECA).

The RA was built by the Jet Propulsion Laboratory and was designed to perform the scouting operations on Mars, such as digging trenches and scooping the soil and water ice samples. RA delivered the samples to the TEGA and the MECA. RA is 2.35 meters long, it has an elbow joint in the middle, and it is capable of digging trenches 0.5 meters deep in the Martian soil.

The University of Arizona and the Max Planck Institute in Germany built the RAC. The camera is attached to the RA, just above the scoop placed at the end of the arm. RAC provided close-up, full-color images.

Credits: NASA / JPL

TEGA was developed by the University of Arizona and University of Texas, Dallas. TEGA used eight tiny ovens to analyze eight unique ice and soil samples. By employing a process called scanning calorimetry, and by using a mass spectrometer to analyze the gas obtained in the furnaces as the temperature raised to 1000 degrees Celsius, TEGA determined the ratio of various isotopes of hydrogen, oxygen, carbon, and nitrogen.

MARDI was built by Malin Space Science Systems. From what I could gather, the MARDI was not used by the Lander due to some integration issues.

The Canadian Space Agency (YAY Canada!) was responsible for the overall development of the meteorological station (MET). Two companies from Ontario, MD Robotics and Optech Inc., provided the instruments for the station.

The SSI served as the eyes of the Phoenix mission. SSI provided high-resolution, stereo, panoramic images of the Martian arctic. An extended mast holds the SSI, so the images were recorded from two meters above the ground.

Credits: NASA / JPL

MECA was built by the Jet Propulsion Laboratory. The instrument was used to characterize the soil by dissolving small amounts of soil in water. MECA determined the pH, the mineral composition, as well as the concentration of dissolved oxygen and carbon dioxide in the soil samples that were collected.

We would like to highlight some of the important moments during the mission:

August 4, 2007 – Delta II rocket launch from Cape Canaveral. The three-stage Delta II rocket with nine solid rocket boosters lifted off from Cape Canaveral, carrying the Phoenix spacecraft on the first leg of its journey to Mars.

Credits: NASA / JPL -Caltech / University of Arizona

May 25, 2008 – Phoenix Mars Lander touchdown. The Phoenix entered the Martian atmosphere at 13,000 mph. It took 7 minutes for the Lander to slow down with the aid of a parachute and to land using its retrorockets. The mission team did not have to wait long before discovering ice because the blasts from the retrorockets had blown away the topsoil during landing and revealed ice patches under the lander.

November 2, 2008 – Last signal received from the Lander. On this date, communication was established for the last time with Phoenix. Due to the latitude of the landing site, not enough sunlight is available and the solar arrays are unable to collect the power necessary to charge the batteries that operate the instruments mounted on the Lander. At the landing site, the weather conditions are worsening.

November 10, 2008 – Mission declared completed. NASA declares that the Mars Phoenix Lander has completed a successful mission on the Red Planet. Phoenix Mars Lander has ceased communications after being operational for more than five months (the designed operational life of the mission was 90 days).

November 13, 2008 – Mission Honored. NASA’s Phoenix Mars Lander was awarded Best of What’s New Grand Award in the aviation and space category by Popular Science magazine.

Credits: NASA / JPL

The Mars Phoenix Lander made significant contributions to the study of the Red Planet. Phoenix verified the presence of water ice under the Martian surface, and it returned thousands of pictures from Mars. Phoenix also found small concentrations of salts that could be nutrients for life, it discovered perchlorate salt, and calcium carbonate, which is a marker of effects of liquid water.

Phoenix provided a mission long weather record, with data on temperature, pressure, humidity, and wind, as well as observations on snow, haze, clouds, frost, and whirlwinds.

Principal Investigator Peter H. Smith of the University of Arizona led the Phoenix mission. The project management was done at NASA’s Jet Propulsion Laboratory and the development at Lockheed Martin Space Systems in Denver. Other contributors were the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen (Denmark), the Max Planck Institute (Germany), and the Finnish Meteorological Institute.

For more information about the Phoenix mission, check out the NASA Phoenix Mars Lander Page.