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Wednesday, September 10, 2014

MAVEN spacecraft makes final preparations for Mars

On Sept. 21, 2014, the Mars Atmosphere and Volatile Evolution spacecraft will complete roughly 10 months of travel and enter orbit around the Red Planet.

The orbit-insertion maneuver will be carried out as the spacecraft approaches Mars, wrapping up an interplanetary journey of 442 million miles (711 million kilometers). Six thruster engines will fire briefly for a “settling” burn that damps out deviations in pointing. Then the six main engines will ignite two by two in quick succession and will burn for 33 minutes to slow the craft, allowing it to be captured in an elliptical orbit.

This milestone will mark the culmination of 11 years of concept and development for MAVEN, setting the stage for the mission’s science phase, which will investigate Mars as no other mission has.

“We’re the first mission devoted to observing the upper atmosphere of Mars and how it interacts with the sun and the solar wind,” said Bruce Jakosky, principal investigator for MAVEN at the University of Colorado in Boulder.

These observations will help scientists determine how much gas from Mars’ atmosphere has been lost to space throughout the planet’s history and which processes have driven that loss.



En route
Procedures to line up MAVEN for proper orbit insertion began shortly after MAVEN launched in November 2013. These included two trajectory-correction maneuvers, performed in December 2013 and February 2014.

Calibration of the mission’s three suites of science instruments—the Particles and Fields Package, the Remote Sensing Package and the Neutral Gas and Ion Mass Spectrometer—was completed during the cruise phase to Mars.

“Every day at Mars is gold,” said David Mitchell, MAVEN’s project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The early checks of instrument and spacecraft systems during cruise phase enable us to move into the science collection phase shortly after MAVEN arrives at Mars.”

The voyage also gave the team an opportunity to take data on the interplanetary solar wind using the Fields and Particles Package.

Meanwhile, teams in California, Colorado, and Maryland carried out rehearsals of the entire orbit insertion twice. The science team also performed a weeklong simulation of the planning and implementation required to obtain science data. Two months prior to arrival at Mars, all instruments were turned off, in preparation for orbit insertion.

Into orbit
During orbit insertion, MAVEN will be controlled by its on-board computers. By that time, the team will have uploaded the most up-to-date information about the spacecraft’s location, velocity and orientation. The insertion instructions will have been updated, and the fuel valves will be open, to warm the fuel to an operating temperature of about 77 to 79 degrees Fahrenheit (25 to 26 degrees Celsius).

If all goes well, the spacecraft will need no further commands from the ground. The important exception is that final trajectory corrections could be made, if needed, 24 hours or 6 hours prior to insertion. That would only happen, however, if the navigation team concluded that the spacecraft was coming in at too low of an altitude.

Otherwise, during the last 24 hours, the spacecraft will carry out preprogrammed procedures to make all systems as “quiet” as possible, which is the safest condition for orbit insertion. These steps include automatically executing a new version of the fault protection, which will tell the craft how to react to an on-board component anomaly leading up to or during orbit insertion.

In addition, the spacecraft will have to reorient itself so that the thrusters are pointed in the correct direction for the burn. In this final orientation, MAVEN’s high-gain antenna, which is used for most communication with the spacecraft, will point away from Earth. During that period, MAVEN’s low-gain antenna will be used for limited communication capacity at a reduced data rate.

At last, the insertion will begin. For the next 33 minutes, the craft will burn more than half the fuel onboard as it enters an orbit 236 miles (380 kilometers) above the northern pole.

Three minutes after the engines turn off, the MAVEN computers will reinstate the normal safeguards, reorient the spacecraft to point the high-gain antenna toward Earth, and reestablish normal communications. At that point, MAVEN will transmit the data obtained during the insertion back to Earth, along with information on the state of the spacecraft, and the MAVEN team will learn if everything worked properly.

“Then, there will be a sigh of relief,” said Carlos Gomez-Rosa, MAVEN mission and science operations manager at Goddard.

Later, the team will upload new instructions for the science portion of the mission, as well as turn on and check out the science instruments.

New view of Mars
The team will perform six maneuvers to move the spacecraft from its insertion orbit into the four-and-a-half-hour orbit that will be used to gather science data.

This science orbit will be elliptical, with the spacecraft flying about 90 miles (approximately 150 kilometers) above the surface at periapsis, or closest point, in the orbit to “sniff” the upper atmosphere. At apoapsis, the farthest point from the surface, MAVEN will pull back 3,900 miles (roughly 6,300 kilometers) to observe the entire atmosphere.

With each pass, MAVEN will make measurements of the composition, structure and escape of atmospheric gases.

“MAVEN’s orbit through the tenuous top of the atmosphere will be unique among Mars missions,” said Jakosky. “We’ll get a new perspective on the planet and the history of the Martian climate, liquid water and planetary habitability by microbes.”




Tuesday, December 3, 2013

MAVEN Spacecraft Successfully Launches to Mars

At 1:28 p.m. EST, the MAVEN spacecraft began its 10-month journey to Mars orbit, launching aboard a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station in Florida. The Atlas V and the spacecraft have performed flawlessly in the early hours after launch. MAVEN’s “gull wing” solar arrays have deployed, sending power to the instruments onboard, and mission ground support personnel have confirmed the receipt of telemetry, indicating that communications with the spacecraft are proceeding as expected.
As of Nov. 25th, MAVEN operations are going smoothly with all spacecraft systems healthy. MAVEN uses 24-hour Deep Space Network communications coverage and all communication events have been nominal. The mission is now in its early cruise mission phase and the spacecraft is approximately 1.39 million miles (2.24 million kilometers) from Earth. MAVEN’s current Sun-centered speed is 73,497 mph. The next big milestone for the team is a planned trajectory correction maneuver (TCM) on Dec. 3, followed by the power up of the eight science instruments between Dec. 4 and Dec. 10.

“Thus far the MAVEN spacecraft has flown and operated as we had all hoped and planned,” said David F. Mitchell, MAVEN project manager. “There are some big events coming up in the days ahead but I couldn’t be more pleased with how the journey has started.”

Friday, June 21, 2013

Environmental Testing

Guy Beutelschies

Guy Beutelschies is the Chief Systems Engineer at Lockheed Martin Space Systems Company and MAVEN Flight Systems Manager

How do you make sure a spacecraft can survive in space?  Facing the sun, surfaces can get hotter than any desert.  In the shade, it is colder than any winter in Antarctica.  The vacuum of space can wreak havoc if you don’t use the right materials.  Launch is even tougher.  If you‘ve ever been lucky enough to see a launch in person, you can feel the vibration rumbling in your chest from over a mile away.  Now imagine what the spacecraft is experiencing as it sits on top of that “controlled explosion.”

The answer is testing, lots of testing.  We arrange the tests in roughly the same order as the spacecraft will experience in its mission.  That means we do launch first.  It may not be readily obvious, but the sound during launch is so intense that it can actually break things.  To simulate this, we put the spacecraft in a special test chamber with enormous speakers and crank up the sound to deafening levels.  Although it is tempting to play some Led Zeppelin, we use a noise spectrum that simulates the Atlas V rocket firing.

The next one is a vibration test.  We put the spacecraft on a large device called a shaker table that moves a plate back and forth to provide the vibration that the vehicle will get on the rocket.  After shaking it in the horizontal axes, we rotate the piston-like device on the shaker table so that it moves the spacecraft up and down.  It wasn’t easy for me to see the spacecraft we’ve spent so much time carefully building being shaken like that, but it was important to do.

Soon after launch, we will then deploy the solar arrays.  This is a tricky test on Earth because of the gravity down here.  We need to make sure gravity is not “helping” the arrays deploy during our ground testing.  To mitigate this, we turn the spacecraft and deploy the arrays to the side so that the hinges are perpendicular to the ground.  We also used special stands to support the weight of each array while allowing them to move freely across the floor as they deploy.   We follow the same process for deployment tests on the Articulated Payload Platform boom and the Solar Wind Electron Analyzer boom.

The third major environmental test involves radio waves.  Most of our regular tests use cables between the ground equipment and the spacecraft to send commands and receive telemetry.  During the mission, our only link to the spacecraft is through radio signals.  For this test, we set up a special acoustics chamber to block out all outside radio signals that might interfere, and then use special ground antennas to talk to the spacecraft antennas as if MAVEN were out in space.  The tests also make sure that the various portions of the spacecraft do not interfere with each other and that the radio waves from the ground do not interfere with equipment on the spacecraft.

The Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft is lowered into a thermal vacuum (TVAC) chamber at Lockheed Martin, near Denver, Colorado. TVAC testing ensures that the spacecraft is able to withstand the temperature extremes it will  encounter during its mission to study the upper atmosphere of Mars. (Courtesy Lockheed Martin)
The Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft is lowered into a thermal vacuum (TVAC) chamber at Lockheed Martin, near Denver, Colorado. TVAC testing ensures that the spacecraft is able to withstand the temperature extremes it will encounter during its mission to study the upper atmosphere of Mars. (Courtesy Lockheed Martin)
The final environmental test is our biggest one.  The MAVEN spacecraft is put in a thermal vacuum chamber; think giant thermos bottle.  Once inside, we pump out the air and flood the hollow walls with liquid nitrogen which brings the temperature down to -290 degrees Fahrenheit.   Giant lamps in the ceiling simulate the direct heat from the sun. This test makes the spacecraft “feel” as if it’s in space. We spend several weeks in vacuum simulating the entire mission from the heat of the sun you get being near Earth, to the cold it will experience in the shadow of Mars.  It is almost as tough on the team as it is on the spacecraft because the test consoles need to be monitored around the clock for the entire test.  That is a lot of evenings, weekends, and graveyards shifts. 

This regimen of environmental testing may sound like a lot of work, but after spending years designing and building it, we want to make sure everything work correctly. If something needs to be fixed, we want to learn about it while it here on the ground. Once we launch, there is no bringing it back to the shop for repairs. These tests give us a lot of confidence that MAVEN will be ready for its launch on November 18th.

With the recent completion of thermal vacuum testing, the MAVEN spacecraft has now successfully completed and passed all of its environmental test procedures. The team will now focus on the remaining Launch Operations Readiness Tests (ORTs), a final Planetary Protection review, and a spacecraft pre-ship review in preparation for shipping MAVEN to Cape Canaveral, Florida, in early August.



Tuesday, April 23, 2013

A conversation about Education and Public Outreach

Stephanie Renfrow, MAVEN Education & Public Outreach lead & Laura Peticolas, EPO co-lead







Stephanie Renfrow (left) and Laura Peticolas lead education and public outreach efforts on behalf of MAVEN. In this joint post, the two leads discuss the program and what it means to them. (Courtesy MAVEN) 



Let’s start by asking a question: how is it that you know about Mars and current space exploration? For example, how did you come to find this blog posting?

The MAVEN Education and Outreach program is MAVEN’s way of reaching out to the public, students, and educational audiences to share the excitement and learning-power that surrounds a mission of this size. We do this through social media, classroom programming, teacher professional development, public lectures, museum programs, and every other way we can think of to spread the word. Do you ever wonder, who are the people who bring that information to you online, to the staff at the museums you visit, or to the teachers who spend time with your children?

In a nutshell, the answer is: that’s us! The EPO team for MAVEN works to find ways to bring the mission to you through every possible avenue (except via traditional journalists, which is the purview of Public Affairs). We are in many ways translators and educators. We translate the mission, engineering, and science in ways that teachers, afterschool providers, museum/science center staff, and others can use.

So, for MAVEN, we first did some research to uncover what audiences would most benefit from learning about Mars’ atmosphere. This research, together with our team’s expertise, gave us a starting point in selecting partners and projects to develop a full education and public outreach plan. With the plan reviewed, tweaked, and approved, we’ve been able to use it as our blueprint in developing and implementing the program you see.
We also work hard to understand perspectives from many different people and learn in what ways other NASA Mars missions have been successful in engaging people, perhaps people like you. We even tap into our non-science circles from time-to-time. Both of us talked extensively with family and friends about the Mars Curiosity rover and how it connects to what we do. While our personal networks “rediscovered” our professional lives as they asked us questions, we learned what Curiosity educational activities really caught their attention and made them want to learn more. We now can apply what we learned from these conversations and many others with people from around the country into our own MAVEN educational programs.

In addition to enjoying the opportunity to answer everyone’s questions, the Curiosity landing served as an incredible reminder for just how exciting exploration of Mars is to millions of people. In our view, we have the best job on the whole mission: we get to share how your tax payer dollars take us to new scientific and technical heights, while finding meaningful ways to connect with your sense of wonder and facilitate making personal ties to science and the learning process. It is thrilling to explore Mars. It is thrilling to share the new discoveries to kindle real people’s excitement for science and exploration!

Over the coming months, we’ll be highlighting some of our EPO programming here on the blog—stay tuned to learn more, and in the mean time, visit “Education & Outreach” at http://lasp.colorado.edu/maven!

Friday, December 28, 2012

Did Solar Storms Blow Away the Atmosphere of Mars?

Janet Luhmann, MAVEN Science team
Dr. Janet Luhmann is a Senior Fellow at the Space Sciences Laboratory of the University of California Berkeley and the Principal Investigator of the IMPACT suite of instruments on the twin spacecraft STEREO mission. Currently, in addition to STEREO and the Cassini mission, she is studying Venus Express observations and helping prepare MAVEN for its upcoming investigation of the Martian upper atmosphere as one of the mission science leads. (Courtesy Janet Luhmann)

Humans tend to think that what is happening now represents the way things have always been. However, we know from our own experience and from investigations of the Earth’s past that there have been, and may still be, episodes of extremes, such as ice ages, major volcanic eruptions and earthquakes, catastrophic tsunamis and floods—some of which can happen several times in a short human lifetime. Cosmically, there have been asteroid impacts that changed Earth’s landscape and climate, and comet impacts that altered landscapes and brought materials to Earth while blasting others away. These episodes can individually and collectively alter the course of life on Earth or change the planet itself.

Mars is exposed to many of the same types of events, and like those on Earth, the details of their historical impacts are speculative and debatable. It is hard to be a history “detective” when the evidence is often hidden or destroyed over time. As a result, questions related to Mars’ current frigid climate and related thin atmosphere are the focus of space missions and theoretical thinking and modeling. We do know that Mars lacks a planetary magnetic field like Earth’s, and, as a result, has been exposed to additional natural assaults.

All of the planets in the solar system are submerged in a nearly continuous outflow of ionized hydrogen gas from the Sun. This “solar wind” is essentially the Sun’s outermost atmosphere. It flows outward because it is heated at its base and because the surrounding space is a relative vacuum. It is ionized because it is so hot—over a million degrees Kelvin—that the nuclei of the hydrogen atoms (protons) and their electrons cannot stay bound together. The resulting ionized gas, or plasma, also carries the solar magnetic field with it as it expands outward. We thus literally live in the solar atmosphere, but because Earth has a fairly strong magnetic field of its own, it is usually shielded from direct impact within a magnetic bubble called the magnetosphere. The magnetosphere deflects most of the solar wind around the Earth well above its atmosphere. Mars, however, is another story. 

The 2001 Mars Global Surveyor mission proved what earlier Russian missions hinted at—that the Martian magnetic field was too weak to prevent solar wind from penetrating its upper atmosphere. These Russian missions also found evidence that ionized elements from the Martian atmosphere were being carried away into the more distant reaches of the Solar System by solar wind. This “erosion” of atmosphere is currently being measured on the European Space Agency Mars Express spacecraft.

While it is apparent that atmosphere escape is occurring at Mars, the historical importance of that process is not as clear. In particular, if the rates of atmosphere escape measured by Mars Express occurred throughout Mars’ four billion year history, they would not have been enough to wipe away the early substantial Martian atmosphere.

For decades, other space missions have studied how solar activity related to sunspots and geomagnetic storms at Earth affect conditions in interplanetary space. Today we know much more about how variable the solar wind can be, especially around the maximum of the Sun’s activity cycle. For example, we know that coronal mass ejections (CMEs), or large eruptions of material from the Sun’s corona, can enter the solar wind. There, CMEs can produce disturbances that cause extreme solar wind behavior by increasing its velocity, density, and magnetic field. (While normal solar wind flows outward from the Sun at about 350 km/s, the disturbed solar wind may flow out at more than one thousand km/s.)

MAVEN will investigate what these extreme conditions do to Mars’ atmosphere erosion rates. The Mars Express measurements hint at increased rates, but energetic particle impacts on the spacecraft systems during storm events can compromise the measurements. The experiments on MAVEN have been specifically designed to definitively answer whether nature’s space weather storms increase atmosphere escape rates to historically important levels.

Of course, MAVEN will need major solar activity in order to do its job. MAVEN should arrive at Mars at a time in the solar cycle that is traditionally rich in major events. Our MAVEN team will keep watching both the Sun and Mars, making use of the great resources for space weather observations currently at our disposal. We are also particularly lucky that the STEREO mission is now observing conditions on the far side of the Sun, giving us the unique opportunity to effectively monitor space weather far from Earth—where Mars usually is and where MAVEN will be.

SOHO real time solar activity
SOHO, the Solar & Heliospheric Observatory, is a project of international collaboration between ESA and NASA to study the Sun from its deep core to the outer corona and the solar wind. The latest 48 hours worth of data are available as animated GIF movies (click image for current animation). The movies are updated every hour that scientists are in real-time contact with the satellite. (Courtesy LASCO/NRL/SOHO)

Thursday, October 25, 2012

Preparing for Science Data

Dave Brain, MAVEN Science Team Co-Investigator 

Teamwork.

The success of MAVEN hinges almost entirely on teamwork. As a scientist that uses data returned by spacecraft, it is sometimes easy for me to forget the number of people involved in making it possible for those squiggly lines of data to dance across my computer screen. After all, I simply need to load the data into my analysis software, make a plot, and learn something new about the planet I am studying (Ha! I laughed out loud as I wrote this because it is never this simple). I love doing this—a few times a year, as I look at my screen, I realize that I am the only person on the face of the Earth that has some new tidbit of information. The ‘A-ha!’ moment is an incredible rush, as is the period where I get to share the result with others.

Being involved in MAVEN has reminded me that science efforts are never independent. Thousands of people are working to make MAVEN successful. The instrument teams are testing and tweaking their instruments in preparation for delivery over the next few months to Lockheed Martin, where they will be incorporated onto the spacecraft. The spacecraft team has been working hard to get the many necessary components (electrical systems, communication systems, reaction wheels, etc.) onto the spacecraft, and preparing to receive the science instruments. I am in constant awe of the way in which these teams handle incredibly complex tasks and make them seem simple.

But what is the science team doing? After all don’t we need the data before we can do our work?

Dr. Dave Brain is a Co-Investigator on the MAVEN science team and serves as a science advisor for the Invisible Mars: Science on a Sphere education and outreach project. Dr. Brain is an assistant professor at the University of Colorado Boulder in the Laboratory for Atmospheric and Space Physics and the Department of Astrophysical and Planetary Sciences. (Courtesy Allison Baker)

The science team has not been sitting idle. We are getting ready to use MAVEN data in a variety of ways. But working with spacecraft measurements is not always a straightforward endeavor. An enormous amount of a scientist’s time can be wasted on dealing with unorganized or unnecessarily complicated datasets. More time is left for making new discoveries when data are made easy to acquire and work with. MAVEN faces a particular challenge because data from all its instruments must be considered together in order to answer our main science questions (even the instruments need to work as a team!). But the datasets are fundamentally different. For example, some instruments make measurements at the location of the spacecraft, while others look at the atmosphere far from the spacecraft. These different datasets must all be well organized, and fit together in a way that the science team can easily get to their ‘A-ha!’ moments.

My job right now is to lead an effort to make tools for the science team that solve these challenges. For the past year we have been devising plans for tools that facilitate ‘Intercomparison and Visualization’ of MAVEN data. Over the next few months we will begin developing a web portal to the MAVEN data that will allow MAVEN scientists to view and obtain the spacecraft viewing geometry, data availability, and actual measurements in a variety of different ways. Users will be able to interact directly in the webpage with many of the plots, making our site a ‘first of its kind’ experience. In addition, we are building a ‘toolbox’ of especially useful software routines that can be used with MAVEN data, thus saving the individual scientists precious time developing their own routines. Importantly, both the web page and the software toolbox are tailored to using data from different instruments simultaneously.

Now that we have the tools designed, I’m excited to see them become reality over the coming months as developers and science team members collaborate on specific features and functionality. I am confident that we’re going to provide tools that make the scientist’s analysis tasks easier.

But it’s going to take teamwork.

Friday, September 14, 2012

MAVEN: Mars Atmospheric Loss

When you take a look at Mars, you probably wouldn't think that it looks like a nice place to live. It's dry, it's dusty, and there's practically no atmosphere. But some scientists think that Mars may have once looked like a much nicer place to live, with a thicker atmosphere, cloudy skies, and possibly even liquid water flowing over the surface. So how do you go from something like this--to something like this? NASA's MAVEN spacecraft will give us a clearer idea of how Mars lost its atmosphere, and scientists think that several processes have had an impact.

One way a planet can lose its atmosphere is through a process called "sputtering." In this process, atoms are knocked away from the atmosphere due to impacts from energetic particles. Watch this brief video to learn more: