Curiosity Mars Science Laboratory (MSL) Spacecraft Cruising to Mars. Guided by the stars, Curiosity has reached the halfway point of its interplanetary cruise phase from the Earth to Mars in between launch on Nov. 26, 2011 and final approach in August 2012. MSL will use the stars to navigate. The spacecraft includes a disc-shaped solar powered cruise stage (on the left) attached to the aeroshell (right). Curiosity and the descent stage are tucked inside the aeroshell. Along the way to Mars, the cruise stage will perform six trajectory correction maneuvers (TCM’s) to adjust the spacecraft's path toward its final, precise landing site on Mars. Credit: NASA/JPL-Caltech
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As of today, NASA’s car sized Curiosity rover has reached the halfway point in her 352 million mile (567 million km) journey to Mars – No fooling on April 1, 2012.
It’s T Minus 126 days until Curiosity smashes into the Martian atmosphere to brave the hellish “6 Minutes of Terror” – and, if all goes well, touch down inside Gale Crater at the foothills of a Martian mountain taller than the tallest in the continental United States – namely Mount Rainier.
Curiosity will search for the ingredients of life in the form of organic molecules – the carbon based molecules which are the building blocks of life as we know it. The one-ton behemoth is packed to the gills with 10 state of the art science instruments including a 7 foot long robotic arm, scoop, drill and laser rock zapper.
The Curiosity Mars Science laboratory (MSL) rover was launched from sunny Florida on Nov. 26, 2011 atop a powerful Atlas V rocket for an 8.5 month interplanetary cruise from the Earth to Mars and is on course to land on the Red Planet early in the morning of Aug. 6, 2012 EDT and Universal Time (or Aug. 5 PDT).
Curiosity’s Position in Space on April 1, 2012 - Halfway to Mars
This roadmap shows Curiosity's flight path through the Solar System - From Earth to Mars during the 8.5 month interplanetary cruise. Credit: NASA/JPL-Caltech
On March 26, engineers at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., successfully ignited the spacecrafts thrusters for the second of six planned trajectory correction maneuvers (TCM’s) to adjust the robot’s flight path during the long journey to achieve a pinpoint landing beside the Martian mountain.
“It is satisfying to get the second maneuver under our belts and know we are headed in the right direction,” said JPL’s Erisa Hines, systems lead for the maneuver. “The cruise system continues to perform very well.”
This maneuver was one-seventh as much as the flight’s first course adjustment, on Jan. 11. The cruise stage is equipped with eight thrusters grouped into two sets of four that fire as the entire spacecraft spins at two rotations per minute. The thruster firings change the velocity of the spacecraft in two ways – along the direction of the axis of rotation and also perpendicular to the axis. Altogether there were more than 60 pulsing maneuvers spaced about 10 seconds apart.
“The purpose is to put us on a trajectory to the point in the Mars atmosphere where we need to be for a safe and accurate landing,” said Mau Wong, maneuver analyst at JPL.
Atlas V rocket and Curiosity Mars rover poised at Space Launch Complex 41 at Cape Canaveral, Florida prior to Nov. 26, 2011 liftoff. Credit: Ken Kremer
Marking another crucial milestone, the flight team has also powered up and checked the status of all 10 MSL science instruments – and all are nominal.
“The types of testing varied by instrument, and the series as whole takes us past the important milestone of confirming that all the instruments survived launch,” said Betina Pavri of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., science payload test engineer for the mission. “These checkouts provide a valuable calibration and characterization opportunity for the instruments, including camera dark images and a measurement of zero pressure in the vacuum of space for the rover weather station’s pressure sensor.”
Ever since it was the first of MSL’s science instruments to be switched on three months ago, the Radiation Assessment Detector (RAD) has been collecting valuable measurements about the potentially lethal radiation environment in space and acting as a stunt double for determining the potential health effects on future human travelers to Mars.
RAD has been collecting data on the recent wave of extremely powerful solar flares erupting from the sun.
Curiosity has another 244 million kilometers to go over the next 4 months.
All hopes ride on Curiosity as America’s third and last generation of Mars rovers.
Devastating and nonsensical funding cuts to NASA’s Planetary Science budget have forced NASA to cancel participation in the 2018 ExoMars lander mission that had been joint planned with ESA, the European Space Agency. ESA now plans to forge ahead with Russian participation.
Stay tuned
Simulated view to Mars over the shoulder of Curiosity on 1 April 2012 - from current location halfway to the Red Planet. Credit: NASA/JPL-Caltech
NASA's Mars rover Curiosity carries a Lincoln Penny on the calibration target to be used by a camera at the end of the robotic arm. The calibration target for the Mars Hand Lens Imager (MAHLI) camera is attached to a shoulder joint of the arm. Inset shows the location of the calibration target. Credit: NASA/JPL-Caltech
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NASA’s huge Curiosity Mars Science Lab (MSL) rover is carrying a vintage Lincoln penny along for the long interplanetary journey to Mars – and it’s not to open the first Martian savings account.
Scientists will use the century old Lincoln penny – minted back in 1909 – as a modern age calibration target for one of Curiosity’s five powerful science cameras attached to the end of the hefty, 7 foot (2.1 meter) long robotic arm.
The car sized rover is on course to touchdown at the foothills of a towering and layered mountain inside Gale Crater in just 161 days on Aug. 6, 2012.
So far Curiosity has traveled 244 million kilometers since blasting off on Nov. 26, 2011 from Florida and has another 322 million kilometers to go to the Red Planet.
The copper penny is bundled to a shoulder joint on the rovers arm along with the other elements of the calibration target, including color chips, a metric standardized bar graphic, and a stair-step pattern for depth calibration.
The whole target is about the size of a smart phone and looks a lot like an eye vision chart in an ophthalmologist’s office. And it serves a similar purpose, which will be to check the performance of Curiosity eyes – specifically the Mars Hand Lens Imager (MAHLI) camera located at the terminus of the robotic arm.
Curiosity’s Calibration Target
Two instruments at the end of the robotic arm on NASA's Mars rover Curiosity will use calibration targets attached to a shoulder joint of the arm. Credit: NASA/JPL-Caltech
MAHLI will conduct close-up inspections of Martian rocks and soil. It can show tiny details, finer than a human hair.
The term “hand lens” in MAHLI’s name refers to the standard practice by field geologists’ of carrying a hand lens during expeditions for close up, magnified inspection of rocks they find along the way. So it’s also critical to pack various means of calibration so that researchers can interpret their results and put them into proper perspective.
MAHLI can also focus on targets over a wide range of distances near and far, from about a finger’s-width away out to the Red Planets horizon, which in this case means the mountains and rim of the breathtaking Gale Crater landing site.
“When a geologist takes pictures of rock outcrops she is studying, she wants an object of known scale in the photographs,” said MAHLI Principal Investigator Ken Edgett, of Malin Space Science Systems, San Diego, which supplied the camera to NASA.
Curiosity Mars Science Laboratory Rover - inside the Cleanroom at KSC
Curiosity with robotic arm extended. Calibration target is located at a shoulder joint on the arm. Photo taken just before encapsulation for 8 month long interplanetary Martian Journey and touchdown inside Gale Crater. Credit: Ken Kremer
The target features a collection of marked black bars in a wide range of labeled sizes to correlate calibration images to each image taken by Curiosity.
“If it is a whole cliff face, she’ll ask a person to stand in the shot. If it is a view from a meter or so away, she might use a rock hammer. If it is a close-up, as the MAHLI can take, she might pull something small out of her pocket. Like a penny.”
Edgett donated the special Lincoln penny with funds from his own pocket. The 1909 “VDB” cent stems from the very first year that Lincoln pennies were minted and also marks the centennial of President Abraham Lincoln’s birth. The VDB initials of the coin’s designer – Victor David Brenner — are on the reverse side. In mint condition the 1909 Lincoln VDB copper penny has a value of about $20.
The Lincoln penny in this photograph is part of a camera calibration target attached to NASA's Mars rover Curiosity. Credit: NASA/JPL-Caltech
“The penny is on the MAHLI calibration target as a tip of the hat to geologists’ informal practice of placing a coin or other object of known scale in their photographs. A more formal practice is to use an object with scale marked in millimeters, centimeters or meters,” Edgett said. “Of course, this penny can’t be moved around and placed in MAHLI images; it stays affixed to the rover.”
“Everyone in the United States can recognize the penny and immediately know how big it is, and can compare that with the rover hardware and Mars materials in the same image,” Edgett said.
“The public can watch for changes in the penny over the long term on Mars. Will it change color? Will it corrode? Will it get pitted by windblown sand?”
MAHLI’s calibration target also features a display of six patches of pigmented silicone to assist in interpreting color and brightness in the images. Five of them are leftovers from Spirit and Opportunity. The sixth has a fluorescent pigment that glows red when exposed to ultraviolet light, allows checking of an ultraviolet light source on MAHLI. The fluorescent material was donated to the MAHLI team by Spectra Systems, Inc., Providence, R.I.
Three-dimensional calibration of the MSL images will be done using the penny and a stair-stepped area at the bottom of the target.
“The importance of calibration is to allow data acquired on Mars to be compared reliably to data acquired on Earth,” said Mars Science Laboratory Project Scientist John Grotzinger, of the California Institute of Technology, Pasadena.
Curiosity is a 1 ton (900 kg) behemoth. She measures 3 meters (10 ft) in length and is nearly twice the size and five times as heavy as Spirit and Opportunity, NASA’s prior set of twin Martian robots. The science payload is 15 times heavier than the twin robots.
Curiosity is packed to the gills with 10 state of the art science instruments that are seeking the signs of life in the form of organic molecules – the carbon based building blocks of life as we know it.
NASA could only afford to build one rover this time.
Curiosity MSL location on 27 Feb 2012. Credit: NASA
Curiosity will be NASA’s last Mars rover since the 4th generation ExoMars rover due to liftoff in 2018 was just cancelled by the Obama Administration as part of a deep slash to NASA’s Planetary Science budget.
En route to the Red Planet, Mars rover Curiosity has experienced the strongest solar radiation storm since 2005. No need to be alarmed: Researchers say it’s all part of Curiosity’s job as a ‘stunt double’ for human astronauts.
Earth’s next Mars rover will NOT be made in USA. President Obama has killed NASA funding for the ExoMars Rover joint project by NASA and ESA planned for 2018 Launch and designed to search for evidence of life. Credit: ESA - Annotation: Ken Kremer
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Earth’s next Mars Rover – NOT Made in USA
Just days after President Obama met with brilliant High School students at the 2012 White House Science Fair to celebrate their winning achievements and encourage America’s Youth to study science and take up careers in the Science, Technology, Engineering and Math (STEM) technical fields, the Obama Administration has decided on deep budgets cuts slashing away the very NASA science programs that would inspire those same students to shoot for the Stars and Beyond and answer the question – Are We Alone ?
Last year, the Obama Administration killed Project Constellation, NASA’s Human Spaceflight program to return American astronauts to the Moon. This year, the President has killed NASA’s ExoMars Robotic Spaceflight program aimed at dispatching two ambitious missions to Mars in 2016 and 2018 to search for signs of life.
Both ExoMars probes involved a joint new collaboration with the European Space Agency (ESA) carefully crafted to share costs in hard times and get the most bang for the buck – outlined in my earlier Universe Today story, here.
Expert Scientists and Policy makers have been voicing their opinions.
President Obama meets America’s brightest Young Rocket Scientists
President Barack Obama hosted the winning science fair students from a range of nationwide competitions at the 2nd White House Science Fair on February 7, 2012. The ExoMars missions were eliminated from the NASA budget announced on Feb. 13, 2012.
All of NASA’s “Flagship” Planetary Science missions have now been cancelled in the 2013 Fiscal Year Budget proposed on Feb. 13, and others missions have also been curtailed due to the severe economy.
“There is no room in the current budget proposal from the President for new Flagship missions anywhere,” said John Grunsfeld, NASA’s Associate Administrator for Science at a NASA budget briefing for the media on Feb. 13.
ESA is now looking to partner with Russia as all American participation in ExoMars is erased due to NASA’ s forced pull out.
On Feb. 13, NASA’s Fiscal 2013 Budget was announced and the Obama Administration carved away nearly half the Mars mission budget. Altogether, funding for NASA’s Mars and Planetary missions in the Fiscal 2013 budget would be sliced by $300 million – from $1.5 Billion this year to $1.2 Billion in 2013. NASA was forced to gut the Mars program to pay for the cost overruns of the James Webb Space Telescope.
Mars rover scientist Prof. Jim Bell of Arizona State University and President of The Planetary Society (TPS) told Universe Today that “no one expects increases”, but cuts of this magnitude are “cause for concern”.
NASA’s robotic missions to Mars and other solar system bodies have been highly successful, resulted in fundamental scientific breakthroughs and are wildly popular with students and the general public.
“With these large proposed cuts to the NASA Mars exploration program, there will be a lot of cause for concern,” said Bell.
“The Mars program has been one of NASA’s crown jewels over the past 15 years, both in terms of science return on investment, and in terms of public excitement and engagement in NASA’s mission. It would also represent an unfortunate retreat from the kind of international collaboration in space exploration that organizations like The Planetary Society so strongly support.”
NASA Budget Cuts in Fiscal Year 2013 will force NASA to kill participation in the joint ESA/NASA collaboration to send two Astrobiology related missions to orbit and land rovers on Mars in 2016 and 2018- designed to search for evidence of Life. Credit: ESA - Annotation: Ken Kremer
Bell and other scientists feel that any cuts should be balanced among NASA programs, not aimed only at one specific area.
“Certainly no one expects increasing budgets in these austere times, and it is not useful or appropriate to get into a battle of “my science is better than your science” among the different NASA Divisions and Programs.” Bell told me.
“However, it would be unfortunate if the burden of funding cuts were to befall one of NASA’s most successful and popular programs in a disproportionate way compared to other programs. As Ben Franklin said, “We should all hang together, or surely we will all hang separately.”
Bell added that science minded organizations should work with Congress to influence the debate over the coming months.
“Of course, this would only be an initial proposal for the FY13 and beyond budget. Over the winter, spring, and summer many professional and public organizations, like TPS, will be working with Congress to advocate a balanced program of solar system exploration that focuses on the most important science goals as identified in the recent NRC Planetary Decadal Survey, as well as the most exciting and publicly compelling missions that are supported by the public–who ultimately are the ones paying for these missions.”
“Let’s hope that we can all find a productive and pragmatic way to continue to explore Mars, the outer solar system, and our Universe beyond,” Bell concluded.
“The impact of the cuts … will be to immediately terminate the Mars deal with the Europeans,” said Scott Hubbard, of Stanford University and a former NASA planetary scientist who revived the agency’s Mars exploration program after failures in 1999, to the Washington Post. “It’s a scientific tragedy and a national embarrassment.”
“I encourage whoever made this decision to ask around; everyone on Earth wants to know if there is life on other worlds,” Bill Nye, CEO of The Planetary Society, said in a statement. “When you cut NASA’s budget in this way, you’re losing sight of why we explore space in the first place.”
“There is no other country or agency that can do what NASA does—fly extraordinary flagship missions in deep space and land spacecraft on Mars.” Bill Nye said. “If this budget is allowed to stand, the United States will walk away from decades of greatness in space science and exploration. But it will lose more than that. The U.S. will lose expertise, capability, and talent. The nation will lose the ability to compete in one of the few areas in which it is still the undisputed number one.”
Ed Weiler is NASA’s recently retired science mission chief (now replaced by Grunsfeld) and negotiated the ExoMars program with ESA. Weiler actually quit NASA specifically in opposition to the Mars Program cuts ordered by the Office of Management and Budget (OMB) and had these comments for CBS News;
“To me, it’s bizarro world,” Weiler said an interview with CBS News. “Why would you do this? The President of the United States, President Obama, declared Mars to be the ultimate destination for human exploration. Obviously, before you send humans to the vicinity of Mars or even to land on Mars, you want to know as much about the planet as you possibly can. … You need a sample return mission. The president also established a space policy a few years ago which had the concept of encouraging all agencies to have more and more foreign collaboration, to share the costs and get more for the same bucks.”
“Two years ago, because of budget cuts in the Mars program, I had to appeal to Europe to merge our programs. … That process took two long years of very delicate negotiations. We thought we were following the president’s space policy exactly. Congressional reaction was very positive about our activities. You put those factors in place and you have to ask, why single out Mars? I don’t have an answer.”
Space Analysts and Political leaders also weighed in:
“The president’s budget is just a proposal,” said Howard McCurdy, a space-policy specialist at American University in Washington to the Christian Science Monitor.
The cuts “reflect the new reality” in which the economy, budget deficits, and the federal debt have elbowed their way to the top of Washington’s agenda, McCurdy adds.
“You don’t cut spending for critical scientific research endeavors that have immeasurable benefit to the nation and inspire the human spirit of exploration we all have,” said Rep. John Culberson (R-Tex.). Texas is home to NASA’s Johnson Space Center.
Rep. Adam Schiff (D-CA), who represents the district that’s home to the Jet Propulsion Laboratory (JPL), released this statement following his meeting with NASA Administrator Charles Bolden to discuss the agency’s 2013 budget proposal:
“Today I met with NASA Administrator Charles Bolden to express my dismay over widespread reports that NASA’s latest budget proposes to dramatically reduce the planetary science program, and with it, ground breaking missions to Mars and outer planetary bodies like Jupiter’s icy moon Europa, and to inform him of my vehement opposition to such a move.”
“America’s unique expertise in designing and flying deep-space missions is a priceless national asset and the Mars program, one of our nation’s scientific crown jewels, has been a spectacular success that has pushed the boundaries of human understanding and technological innovation, while also boosting American prestige worldwide and driving our children to pursue science and engineering degrees in college.
“As I told the Administrator during our meeting, I oppose these ill-considered cuts and I will do everything in my power to restore the Mars budget and to ensure American leadership in space exploration.”
In an interview with the San Gabriel Valley Tribune, Schiff said, “What they’re proposing will be absolutely devastating to planetary science and the Mars program. I’m going to be fighting them tooth and nail. Unfortunately if this is the direction the administration is heading, it will definitely hurt JPL – that’s why I’m so committed to reversing this.”
NASA still hopes for some type of scaled back Mars missions in the 2016 to 2020 timeframe which will be outlined in an upcoming article.
In the meantime, the entire future of America’s Search for Life on the Red Planet now hinges on NASA’s Curiosity Mars Science Laboratory rover speeding thru interplanetary space and a pinpoint touchdown inside the layered terrain of Gale Crater on August 6, 2012.
Phobos-Grunt plunged to Earth into the Pacific Ocean on Jan 15, 2012 - Crash Zone Map shows orbital track of Phobos-Grunt on Final Orbit before crashing to Earth in the Pacific Ocean west of South America on Jan 15, 2012.
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Story and Crash Zone Map updated 1 p.m. EST Jan 16
Today (Jan. 15) was the last day of life for Russia’s ambitious Phobos-Grunt mission to Mars after a desperate two month race against time and all out attempts to save the daring spaceship by firing up a malfunctioning thruster essential to putting the stranded probe on a trajectory to the Red Planet, failed.
According to the Russian news agency Ria Novosti, the doomed Phobos-Grunt spacecraft apparently plunged into the southern Pacific Ocean today, (Jan. 15) at about 12:45 p.m. EST, 21:45 Moscow time [17:45 GMT] after a fiery re-entry into the Earth’s atmosphere.
“Phobos-Grunt fragments have crashed down in the Pacific Ocean,” Russia’s Defense Ministry official Alexei Zolotukhin told RIA Novosti. He added that the fragments fell 1,250 kilometers to the west of the Chilean island of Wellington.
Universe Today will monitor the developing situation and update this story as warranted. On Jan. 16 Roscosmos confirmed the demise of Phobos-Grunt at 12:45 p.m. EST in the Pacific Ocean – during its last orbit; #1097.
Artist’s concept of Phobos-Grunt re-entry and breakup in the Earth’s atmosphere on Jan 15, 2012
The demise of the Phobos-Grunt spacecraft was expected sometime today, (Jan 15) after a fiery and destructive fall back to Earth, said Roscosmos, the Russian Federal Space Agency, in an official statement released early today before the crash.
Since the re-entry was uncontrolled, the exact time and location could not be precisely calculated beforehand. Mission Poster for the Russian Phobos-Grunt soil sample return spacecraft that launched to Mars and its moon Phobos on 9 November 2011. The mission did not depart Earth orbit when the upper stage engines failed to ignite. Credit: Roskosmos ( Russian Federal Space Agency)/IKI
The actual crash time of the 13,500 kg space probe was slightly earlier than predicted.
Roscosmos head Vladimir Popovkin had previously stated that perhaps 20 to 30 fragments weighing perhaps 400 pounds (180 kg) might survive and would fall harmlessly to Earth.
The spacecraft burst into a large quantity of pieces as it hit the atmosphere, heated up and broke apart. But the actual outcome of any possible fragments is not known at this time.
Shortly after launching from the Baikonur Cosmodrome on Nov. 9, 2011, the probe became stuck in low Earth orbit after its MDU upper stage engines repeatedly failed to ignite and send the ship on a bold sample return mission to the tiny Martian Moon Phobos.
Phobos-Grunt was loaded with over 11,000 kg of toxic propellants, including dimethylhydrazine and dinitrogen tetroxide, that went unused due to the thruster malfunction and that were expected to be incinerated during the plunge to Earth.
Frictional drag forces from the Earth’s atmosphere had gradually lowered the ship’s orbit in the past two months to the point of no return after all attempts to fire the thrusters and raise the orbit utterly failed.
The audacious goal of Phobos-Grunt was to carry out history’s first ever landing on Phobos, retrieve 200 grams of soil and bring the treasured samples back to Earth for high powered analysis that could help unlock secrets to the formation of Mars, Phobos and the Solar System.
Phobos-Grunt spacecraft being encapsulated inside the nose cone by technicians at the Baikonur Cosmodrome prior to Nov. 9, 2011 blastoff. Credit: Roscosmos
The Holy Grail of planetary science is to retrieve Martian soil samples – and scientists speculated that bits of the Red Planet could be intermixed with the soil of its mini moon Phobos, barely 15 miles in diameter.
The science return from Phobos-Grunt would have been first rate and outstanding.
It’s a sad end to Russia’s attempts to restart their long dormant interplanetary space science program.
The $165 mission was Russia’s first Mars launch in more than 15 years.
Radar image of the Russian Mars orbiter Phobos-Grunt, created with the TIRA space observation radar by researchers at the Fraunhofer Institute in Germany. One can clearly see the extended solar panels (centre) and the tank ring (bottom)
Credit: Fraunhofer FHR
Click to enlarge
Roscosmos had stated that the Atlantic Ocean – to the west of Africa – was at the center of the predicted crash zone. But nothing was certain and the probe had the possibility to crash sooner, perhaps over the Pacific Ocean or South America or later over Africa, Europe or Russia.
Roscosmos had predicted the time of the plunge to Earth to be from 12:50 p.m. EST and 1:34 p.m. EST (1750 to 1834 GMT) or 21:50 to 22: 34 Moscow time on January 15. The last orbit carried the probe over the Pacific Ocean towards South America on a northeasterly heading.
Russia enlisted assistance from ESA and the US in a bid to establish contact with the probe to reorient itself and fire up its engines for a belated journey to the Red Planet. Other than extremely brief signals the efforts proved futile and today’s Pacific plunge is the unfortunate end result.
Hopefully the Russians will not give up in despair, but rather fix the flaws and launch an exciting new Mars mission.
NASA has had better luck with their Mars mission this season.
The Curiosity Mars Science Lab rover is precisely on course to the Red Planet following the Jan 11 firing of the cruise stage thrusters for the first of up to 6 Trajectory Correction Maneuvers – read the details here
Phobos-Grunt imaged while flying over Holland on Dec 28, 2011 by astrophotographer Ralf Vandebergh. Solar panels are deployed. Credit: Ralf Vandebergh
Curiosity Mars Science Laboratory Spacecraft During Cruise. Artist's concept of Curipsity during its cruise phase between launch on Nov. 26, 2011 and final approach to Mars in August 2012. The spacecraft includes a disc-shaped solar powered cruise stage (on the left) attached to the aeroshell (right). Curiosity and the descent stage are tucked inside the aeroshell. Along the way to Mars, the cruise stage will perform several trajectory correction maneuvers to adjust the spacecraft's path toward its final, precise landing site on Mars. Credit: NASA/JPL-Caltech
For a birds-eye view of where it all started, watch the cool close-up launch video, below taken from within the Atlas pad security fence.
Indeed the launch precision was so good that mission controllers at NASA’s Jet Propulsion Lab in Pasadsena, Calif., have announced they postponed the first of six planned course correction burns for the agency’s newest Mars rover by at least a month. The firing had been planned for some two weeks after liftoff.
Curiosity is merrily sailing on a 254 day and 352-million-mile (567-million-kilometer) interplanetary flight from the Earth to Mars that will culminate on August 6, 2012 with a dramatic first-of-its-kind precision rocket powered touchdown inside Gale Crater.
“This was among the most accurate interplanetary injections ever,” said Louis D’Amario of NASA’s Jet Propulsion Laboratory, Pasadena, Calif. He is the mission design and navigation manager for the Mars Science Laboratory.
Video Caption: View from inside the Pad 41 Security Fence at Cape Canaveral. Shot by a Canon 7D still camera during the launch of the Atlas V rocket carrying the MSL Curiosity rover to Mars. Thanks to a sound trigger my camera started firing at three frames per second from just after main engine ignition up until the exhaust plume finally envelops the camera and deadens all sound around it. The frames have been slowed down quite a bit for dramatic effect. Enjoy seeing what it is like for us media personnel who set out our remote cameras for launches at Kennedy Space Center and Cape Canaveral, Florida. Credit: Chase Clark/shuttlephotos.com
As of midday Friday, Dec. 2, the spacecraft had already traveled 10.8 million miles (17.3 million kilometers) and is moving at 7,500 mph (12,000 kilometers per hour) relative to Earth and at 73,800 mph (118,700 kilometers per hour) relative to the sun.
An interesting fact is that engineers deliberately planned the spacecraft’s initial trajectory to miss Mars by about 35,000 miles (56,400 kilometers) so that the Centaur upper stage does not hit Mars by accident. Both Centaur and Curiosity are currently following the same trajectory through the vast void of space and the actual trajectory puts them on course to miss Mars by about 38,000 miles (61,200 kilometers).
The Centaur has not been thoroughly cleaned of earthly microbes in the same way as Curiosity – and therefore cannot be permitted to impact the Martian surface and potentially contaminate the very studies Curiosity seeks to carry out in searching for the “Signs of Life”.
For the 8.5 month voyage to Mars, Curiosity and the rocket powered descent stage are tucked inside an aeroshell and are attached to the huge solar powered cruise stage.
Deceleration of Mars Science Laboratory in Martian Atmosphere
Artist's Concept depicts the interaction of NASA's Mars Science Laboratory spacecraft with the upper atmosphere of Mars during the entry, descent and landing (EDL) of the Curiosity rover onto the Martian surface. EDL begins when the spacecraft reaches the top of Martian atmosphere, about 81 miles (131 kilometers) above the surface of the Gale crater landing area, and ends with the rover safe and sound on the surface of Mars some 7 minutes later. During EDL, the spacecraft decelerates from a velocity of about 13,200 miles per hour (5,900 meters per second) at the top of the atmosphere, to stationary on the surface. Credit: NASA/JPL-Caltech
The cruise stage is rotating at 2.05 rounds per minutes and is continuously generating electric power – currently about 800 watts – from the gleaming solar arrays. It also houses eight miniature hydrazine fueled thrusters. The propellant is stored inside titanium tanks.
Atlas V rocket and Curiosity Mars rover poised at Space Launch Complex 41 at Cape Canaveral, Florida prior to Nov. 26, 2011 liftoff. Credit: Ken Kremer/kenkremer.com
The historic voyage of the largest and most sophisticated Martian rover ever built by humans seeks to determine if Mars ever offered conditions favorable for the genesis of microbial life.
Curiosity is packed to the gills with 10 state of the art science instruments that are seeking to detect the signs of life in the form of organic molecules – the carbon based building blocks of life as we know it.
The car sized robot is equipped with a drill and scoop at the end of its 7 ft long robotic arm to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into two distinct analytical laboratory instruments inside the rover.
Popular Science magazine names NASA’s Mars Science Laboratory, Dawn and MESSENGER missions as ‘Best of What’s New’ in innovation in 2011. Artist concept shows mosaic of MESSENGER, Mars Science Laboratory and Dawn missions. Credit: NASA/JPL-Caltech
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A trio of NASA’s Planetary Science mission’s – Mars Science Laboratory (MSL), Dawn and MESSENGER – has been honored by Popular Science magazine and selected as ‘Best of What’s New’ in innovation in 2011 in the aviation and space category.
The Curiosity Mars Science Laboratory was just launched to the Red Planet on Saturday, Nov. 26 and will search for signs of life while traversing around layered terrain at Gale Crater. Dawn just arrived in orbit around Asteroid Vesta in July 2011. MESSENGER achieved orbit around Planet Mercury in March 2011.
Several of the top mission scientists and engineers provided exclusive comments about the Popular Science recognitions to Universe Today – below.
“Of course we are all very pleased by this selection,” Prof. Chris Russell, Dawn Principal Investigator, of UCLA, told Universe Today.
Dawn is the first mission ever to specifically investigate the main Asteroid Belt between Mars and Jupiter and will orbit both Vesta and Ceres – a feat enabled solely thanks to the revolutionary ion propulsion system.
“At the same time I must admit we are also not humble about it. Dawn is truly an amazing mission. A low cost mission, using NASA’s advanced technology to enormous scientific advantage. It is really, really a great mission,” Russell told me.
Vesta is the second most massive asteroid and Dawn’s discoveries of a surprisingly dichotomous and battered world has vastly exceeded the team’s expectations.
Asteroid Vesta from Dawn - Exquisite Clarity from a formerly Fuzzy Blob
NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 24, 2011. It was taken from a distance of about 3,200 miles (5,200 kilometers). Before Dawn, Vesta was just a fuzzy blob in the most powerful telescopes. Dawn entered orbit around Vesta on July 15, and will spend a year orbiting the body before firing up the ion propulsion system to break orbit and speed to Ceres, the largest Asteroid. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
“Dawn is NASA at its best: ambitious, exciting, innovative, and productive,” Dr. Marc Rayman, Dawn’s Chief Engineer from the Jet Propulsion Lab (JPL), Pasadena, Calif., told Universe Today.
“This interplanetary spaceship is exploring uncharted worlds. I’m delighted Popular Science recognizes what a marvelous undertaking this is.”
JPL manages both Dawn and Mars Science Laboratory for NASA’s Science Mission Directorate in Washington, D.C.
Dawn is an international science mission. The partners include the German Aerospace Center (DLR), the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute.
“Very cool!”, John Grotzinger, the Mars Science Laboratory Project Scientist of the California Institute of Technology, told Universe Today.
“MSL packs the most bang for the buck yet sent to Mars.”
Last View of Curiosity Mars Science Laboratory Rover - inside the Cleanroom at KSC.
Curiosity just before Encapsulation for 8 month long interplanetary Martian Journey and touchdown inside Gale Crater. Credit: Ken Kremer
Curiosity is using an unprecedented precision landing system to touch down inside the 154 km (96 miile) wide Gale Crater on Aug. 6, 2012. The crater exhibits exposures of phyllosilicates and other minerals that may have preserved evidence of ancient or extant Martian life and is dominated by a towering mountain.
“10 instruments all aimed at a mountain higher than any in the lower 48 states, whose stratigraphic layering records the major breakpoints in the history of Mars’ environments over likely hundreds of millions of years, including those that may have been habitable for life.”
“It’s like a trip down the Grand Canyon 150 years ago, with the same sense of adventure, but with a lot of high tech equipment,” Grotzinger told me.
MSL also has an international team of over 250 science investigators and instruments spread across the US, Europe and Russia. Curiosity Mars Science Laboratory rover soars to Mars atop an Atlas V rocket on Nov. 26 at 10:02 a.m. EST from Cape Canaveral, Florida. Credit: Ken Kremer
MESSENGER is the first probe to orbit Mercury and the one year primary mission was recently extended by NASA.
Sean Solomon, of the Carnegie Institution of Washington, leads the MESSENGER mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft for NASA.
“Planetary has 3 missions there… Dawn, MESSENGER, and MSL,” Jim Green proudly said to Universe Today regarding the Popular Science magazine awards. Green is the director, Planetary Science Division, NASA Headquarters, Washington
“Three out of 10 [awards] is a tremendous recognition of the fact that each one of our planetary missions goes to a different environment and takes on new and unique measurements providing us new discoveries and constantly changes how we view nature, ourselves, and our place in the universe.”
The First Solar Day
After its first Mercury solar day (176 Earth days) in orbit, MESSENGER has nearly completed two of its main global imaging campaigns: a monochrome map at 250 m/pixel and an eight-color, 1-km/pixel color map. Apart from small gaps, which will be filled in during the next solar day, these global maps now provide uniform lighting conditions ideal for assessing the form of Mercury’s surface features as well as the color and compositional variations across the planet. The orthographic views seen here, centered at 75° E longitude, are each mosaics of thousands of individual images. At right, images taken through the wide-angle camera filters at 1000, 750, and 430 nm wavelength are displayed in red, green, and blue, respectively.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Read more about the Popular Science citations and awards here
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Read continuing features about Curiosity, Dawn and MESSENGER by Ken Kremer starting here:
Mars Science Laboratory, launched three days ago on the morning of Saturday, November 26, is currently on its way to the Red Planet – a journey that will take nearly nine months. When it arrives the first week of August 2012, MSL will begin investigating the soil and atmosphere within Gale Crater, searching for the faintest hints of past life. And unlike the previous rovers which ran on solar energy, MSL will be nuclear-powered, generating its energy through the decay of nearly 8 pounds of plutonium-238. This will potentially keep the next-generation rover running for years… but what will fuel future exploration missions now that NASA may no longer be able to fund the production of plutonium?
Pu-238 is a non-weapons-grade isotope of the radioactive element, used by NASA for over 50 years to fuel exploration spacecraft. Voyagers, Galileo, Cassini… all had radioisotope thermoelectric generators (RTGs) that generated power via Pu-238. But the substance has not been in production in the US since the late 1980s; all Pu-238 has since been produced in Russia. But now there’s only enough left for one or two more missions and the 2012 budget plan does not yet allot funding for the Department of Energy to continue production.
Where will future fuel come from? How will NASA power its next lineup of robotic explorers? (And why aren’t more people concerned about this?)
Amateur astronomer, teacher and blogger David Dickinson went into detail about this conundrum in an informative article written earlier this year. Here are some excerpts from his post:
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When leaving our fair planet, mass is everything. Space being a harsh place, you must bring nearly everything you need, including fuel, with you. And yes, more fuel means more mass, means more fuel, means… well, you get the idea. One way around this is to use available solar energy for power generation, but this only works well in the inner solar system. Take a look at the solar panels on the Juno spacecraft bound for Jupiter next month… those things have to be huge in order to take advantage of the relatively feeble solar wattage available to it… this is all because of our friend the inverse square law which governs all things electromagnetic, light included.
Curiosity's MMRTG (about 15 inches high.) Credit: NASA / Frankie Martin
To operate in the environs of deep space, you need a dependable power source. To compound problems, any prospective surface operations on the Moon or Mars must be able to utilize energy for long periods of sun-less operation; a lunar outpost would face nights that are about two Earth weeks long, for example. To this end, NASA has historically used Radioisotope Thermal Generators (RTGs) as an electric “power plant” for long term space missions. These provide a lightweight, long-term source of fuel, generating from 20-300 watts of electricity. Most are about the size of a small person, and the first prototypes flew on the Transit-4A & 5BN1/2 spacecraft in the early 60’s. The Pioneer, Voyager, New Horizons, Galileo and Cassini spacecraft all sport Pu238 powered RTGs. The Viking 1 and 2 spacecraft also had RTGs, as did the long term Apollo Lunar Surface Experiments Package (ALSEP) experiments that Apollo astronauts placed on the Moon. An ambitious sample return mission to the planet Pluto was even proposed in 2003 that would have utilized a small nuclear engine.
A glowing cake of plutonium. (Department of Energy)
David goes on to mention the undeniable dangers of plutonium…
Plutonium is nasty stuff. It is a strong alpha-emitter and a highly toxic metal. If inhaled, it exposes lung tissue to a very high local radiation dose with the attending risk of cancer. If ingested, some forms of plutonium accumulate in our bones where it can damage the body’s blood-forming mechanism and wreck havoc with DNA. NASA had historically pegged a chance of a launch failure of the New Horizons spacecraft at 350-to-1 against, which even then wouldn’t necessarily rupture the RTG and release the contained 11 kilograms of plutonium dioxide into the environment. Sampling conducted around the South Pacific resting place of the aforementioned Apollo 13 LM re-entry of the ascent stage of the Lunar Module, for example, suggests that the reentry of the RTG did NOT rupture the container, as no plutonium contamination has ever been found.
Yet the dangers of nuclear power often overshadow its relative safety and unmistakable benefit:
The black swan events such as Three Mile Island, Chernobyl and Fukushima have served to demonize all things nuclear, much like the view that 19thcentury citizens had of electricity. Never mind that coal-fired plants put many times the equivalent of radioactive contamination into the atmosphere in the form of lead210, polonium214, thorium and radon gases, every day. Safety detectors at nuclear plants are often triggered during temperature inversions due to nearby coal plant emissions… radiation was part of our environment even before the Cold War and is here to stay. To quote Carl Sagan, “Space travel is one of the best uses of nuclear weapons that I can think of…”
Yet here we are, with a definite end in sight to the supply of nuclear “weapons” needed to power space travel…
Currently, NASA faces a dilemma that will put a severe damper on outer solar system exploration in the coming decade. As mentioned, current plutonium reserves stand at about enough for the Mars Science Laboratory Curiosity, which will contain 4.8kilograms of plutonium dioxide, and one last large & and perhaps one small outer solar system mission. MSL utilizes a new generation MMRTG (the “MM” stands for Multi-Mission) designed by Boeing that will produce 125 watts for up to 14 years. But the production of new plutonium would be difficult. Restart of the plutonium supply-line would be a lengthy process, and take perhaps a decade. Other nuclear based alternatives do indeed exist, but not without a penalty either in low thermal activity, volatility, expense in production, or short half life.
The implications of this factor may be grim for both manned and unmanned space travel to the outer solar system. Juxtaposed against at what the recent 2011 Decadal Survey for Planetary Exploration proposes, we’ll be lucky to see many of those ambitious “Battlestar Galactica” –style outer solar system missions come to pass.
Landers, blimps and submersibles on Europa, Titan, and Enceladus will all operate well out of the Sun’s domain and will need said nuclear power plants to get the job done… contrast this with the European Space Agency’s Huygens probe, which landed on Titan after being released from NASA’s Cassini spacecraft in 2004, which operated for scant hours on battery power before succumbing to the -179.5 C° temps that represent a nice balmy day on the Saturnian moon.
So, what’s a space-faring civilization to do? Certainly, the “not going into space” option is not one we want on the table, and warp or Faster-Than-Light drives a la every bad science fiction flick are nowhere in the immediate future. In [my] highly opinionated view, NASA has the following options:
Exploit other RTG sources at penalty. As mentioned previously, other nuclear sources in the form of Plutonium, Thorium, and Curium isotopes do exist and could be conceivably incorporated into RTGs; all, however, have problems. Some have unfavorable half-lives; others release too little energy or hazardous penetrating gamma-rays. Plutonium238 has high energy output throughout an appreciable life span, and its alpha particle emissions can be easily contained.
Design innovative new technologies. Solar cell technology has come a long way in recent years, making perhaps exploration out to the orbit of Jupiter is do-able with enough collection area. The plucky Spirit and Opportunity Mars rovers(which did contain Curium isotopes in their spectrometers!) made do well past their respective warranty dates using solar cells, and NASA’s Dawn spacecraft currently orbiting the asteroid Vesta sports an innovative ion-drive technology.
Push to restart plutonium production. Again, it is not that likely or even feasible that this will come to pass in today’s financially strapped post-Cold War environment. Other countries, such as India and China are looking to “go nuclear” to break their dependence on oil, but it would take some time for any trickle-down plutonium to reach the launch pad. Also, power reactors are not good producers of Pu238. The dedicated production of Pu238 requires either high neutron flux reactors or specialized “fast” reactors specifically designed for the production of trans-uranium isotopes…
Based on the realities of nuclear materials production the levels of funding for Pu238 production restart are frighteningly small. NASA must rely on the DOE for the infrastructure and knowledge necessary and solutions to the problem must fit the realities within both agencies.
And that’s the grim reality of a brave new plutonium-free world that faces NASA; perhaps the solution will come as a combination of some or all of the above. The next decade will be fraught with crisis and opportunity… plutonium gives us a kind of Promethean bargain with its use; we can either build weapons and kill ourselves with it, or we can inherit the stars.
Diagram of an RTG. (Source: The Encyclopedia of Science)
Thanks to David Dickinson for the use of his excellent article; be sure to read the full version on his Astro Guyz site here (and follow David on Twitter @astroguyz.) Also check out this article by Emily Lakdawalla of The Planetary Society on how the RTG unit for Curiosity was made.
“There are some people who legitimately feel like this is simply not a priority, that there’s not enough money and it’s not their problem. But I think if you try to step back and look at the forest and not just the individual trees, this is one of the things that has helped drive us to become a technological powerhouse. What we’ve done with robotic space exploration is something that people not just in the U.S., but around the world, can look up to.”
– Ralph McNutt, planetary scientist at Johns Hopkins University’s Applied Physics Laboratory (APL)
Atlas V rocket and Curiosity Mars rover poised at Space Launch Complex 41 at Cape Canaveral, Florida. Curiosity is set to blast off to Mars on Nov. 26, 2011. Credit: Ken Kremer
[/caption]‘Mars Trek – Curiosity’s Search for Undiscovered Life’ has its galaxy wide premiere Saturday morning Nov. 26 at 10:02 a.m. EST – live on NASA TV.
NASA’s quest ‘In Search of Life’ takes a bold leap in less than 12 hours with the Nov. 26 blastoff of “Curiosity”, the most complex and scientifically advanced robotic explorer ever sent to survey the surface of another world. The 103 minute launch window closes at 11:45 a.m. EST.
Curiosity and the United Launch Alliance Atlas V rocket that will thrust her to the Red Planet are poised for liftoff after being rolled out to Space Launch Complex 41 around 8 a.m. this morning under the watchful eyes of ground crews, mission scientists, reporters and photographers.
Universe Today was there – reporting live on all the history making and thrilling events !
Launch day weather remains favorable, with only a 30 percent chance of conditions prohibiting liftoff, said Air Force meteorologists. A low cloud ceiling is the sole concern at this time.
NASA’s Curiosity Mars rover is encapsulated inside the 5 meter payload fairing and loaded atop the Atlas V rocket at Space Launch Complex 41 at Cape Canaveral. Credit: Ken Kremer
The 1.2 million pound booster was pushed 1800 feet along rail tracks by twin diesel powered trackmobiles from the prelaunch preparation and assembly gantry inside the Vertical Integration Facility out to launch pad 41 at Cape Canaveral Air Force Station.
The 197 foot tall booster is equipped with 4 strap on solid rocket motors and generates some 2 million pounds of liftoff thrust according to Vernon Thorp, Atlas Program manager for ULA.
Curiosity is NASA’s next Mars rover and also quite possibly the last US built Mars rover due to severe cuts to NASA planetary science budget.
After an eight and one half month and 354 million mile (570 million km) interplanetary journey, Curiosity will slam into the thin Martian atmosphere at 13,000 MPH and utilize an unprecedented rocket powered pinpoint landing system known as the Sky Crane to touch down with all six wheels deployed inside Gale Crater.
Gale Crater is 154 km (96 mi) in diameter and dominated by a layered mountain rising some 5 km (3 mi) above the crater floor which exhibits exposures of minerals that may have preserved evidence of past or present Martian life.
NASA’s Curiosity Mars rover is rolled out from the Vertical Integration Facility to Launch Pad 41 at Cape Canaveral. Credit: Ken Kremer
Curiosity is packed with 10 state-of-the-art science experiments that will search for organic molecules and clay minerals, potential markers for signs of Martian microbial life and habitable zones.
Atlas V and Curiosity poised at Space Launch Complex 41 at Cape Canaveral, Florida for liftoff to Mars on Nov. 26, 2011. Credit: David Gonzales/Mike Deep
Immediately after touchdown, the 1 ton rover will transmit telemetry so that engineers back on Earth can assess the rover’s status.
“When we first land we want to ascertain the integrity and health of the vehicle and look at the surrounding terrain, said Pete Theisinger, MSL project manager from the Jet Propulsion Laboratory in Pasadena, Calif., at the briefing.
“The rover’s mast will be deployed on the second day and we’ll get pictures.”
“Shortly thereafter we will begin our science investigations. The radiation (RAD) and subsurface hydrogen detection (DAN) instruments will start right away since they are passive.”
The rover will drive inside the first week.
“The cameras will be used to select targets. We will go up to the valuable targets. With the cameras and instruments we will determine which ones to sample” said Theisinger.
“Then we’ll deploy the arm which contains scientific equipment and collect samples with a percussion drill. The samples will be injected into the two science instruments for analysis that are located on the rover.”
“The SAM and ChemMin instruments will look for organic molecules and isotope ratios as well as identify and quantify the minerals in the rock and soil samples. It could be up to 2 to 3 months before we take the first samples,” explained Theisinger.
MSL is powered by a nuclear battery and is expected to operate for a minimum of one Martian year, equivalent to 687 days on Earth. NASA hopes the 6 foot tall rover will last alot longer.
Curiosity atop Atlas V poised at Space Launch Complex 41 at Cape Canaveral, Florida for liftoff to Mars on Nov. 26, 2011. Credit: David Gonzales/Mike Deep
Complete Coverage of Curiosity – NASA’s Next Mars Rover launching 26 Nov. 2011
Read continuing features about Curiosity by Ken Kremer starting here:
Getting the Mars Science Laboratory to the Red Planet isn’t as easy as just strapping the rover on an Atlas V rocket and blasting it in the general direction of Mars. Spacecraft navigation is a very precise and constant science, and in simplest terms, it entails determining where the spacecraft is at all times and keeping it on course to the desired destination.
And, says MSL navigation team chief Tomas Martin-Mur, the only way to accurately get the Curiosity rover to Mars is for the spacecraft to constantly be looking in the rearview mirror at Earth.
“What we do is ‘drive’ the spacecraft using data from the Deep Space Network,” Martin–Mur told Universe Today. “If you think about it, we never see Mars. We don’t have an optical navigation camera or any other instruments to be able to see or sense Mars. We are heading to Mars, all the while looking back to Earth, and with measurements from the Earth we are able to get to Mars with a very high accuracy.”
This high accuracy is very important because MSL is using a new entry, descent and landing guidance system which will allow the spacecraft to land more precisely than any previous landers or rovers.
“It is very challenging, and even though it is something similar to what we have done before with the Mars Exploration Rover (MER) mission, this time it will be done at an even higher level of precision,” Martin-Mur said. “That allows us to get to a very exciting place, Gale Crater.”
The Goldstone Antenna, part of the Deep Space Network. Image Credit: JPL
On Earth, we constantly can find exactly where we are with GPS – which is on our cell phones and navigation equipment. But there is no GPS at Mars, so the only way the rover will be able to head to –and through — a precise point in the Red Planet’s atmosphere is for the navigation team to know exactly where the spacecraft is and for them to keep telling the spacecraft exactly where it is. They use the Deep Space Network (DSN) for those determinations from launch, all the way to Mars.
The Deep Space Network consists of a network of extremely sensitive deep space communications antennas at three locations: Goldstone, California; Madrid, Spain; and Canberra, Australia. The strategic placement approximately 120 degrees apart on Earth’s surface allows constant observation of spacecraft as the Earth rotates.
But of course, it’s not as easy as just getting the rocket from Point A to Point B since Earth and Mars are not fixed positions in space. Navigators must meet the challenges of calculating the exact speeds and orientations of a rotating Earth, a rotating Mars, as well as a moving, spinning spacecraft, while all are simultaneously traveling in their own orbits around the Sun.
There are other factors like solar radiation pressure and thruster firings that all have to be precisely calculated.
This artist's concept depicts the rover Curiosity, of NASA's Mars Science Laboratory mission, as it uses its Chemistry and Camera (ChemCam) instrument to investigate the composition of a rock surface. Credit: NASA/JPL
Martin-Mur said even though MSL is a much bigger rover with a bigger spacecraft and backshell than the MER mission, the navigation tools and calculations aren’t much different. And in some ways, navigating MSL might be easier.
“The Atlas V vehicle provides a much more precise launching and can put us in a more precise path than the MER, which used a Delta II,’ Martin-Mur said. “This allows us to use less propellant, proportionally per pound, to get to Mars than the MER rovers did.”
The MER rovers and spacecraft weighed about 1 ton, while MSL weighs almost 4 tons. MSL is allotted 70 kg of propellant for the cruise stage, while the MER rovers each used about 42 kg of propellant.
Interestingly, for the MSL spacecraft to descend through Mars’ atmosphere and land, the spacecraft will use about 400 kg of propellant.
Additionally, Martin-Mur said more precise planetary ephemeris and Very Long Baseline Interferometry measurements are available, enabling the navigation to be able to deliver the spacecraft to the right place in the atmospheric entry interface, so the vehicle finds itself in the range of parameters that it has been designed to operate.
Navigation at Launch
It all starts with years of preparations and calculations by the navigation team, which must calculate all the possible trajectories to Mars depending on exactly when the Atlas V rocket launches with MSL aboard.
In some cases there are literally thousands of launch opportunities and all the possible trajectories must be calculated precisely. The Juno mission, for example, had two-hour daily launch windows with 3,300 possible launch opportunities. For MSL the daily launch windows contain liftoff opportunities in 5 minutes increments. Across the 24 day launch period the team has calculated 489 different trajectories for all the possible launch opportunities.
But ultimately, they will end up using only one.
“This is not something you do on the fly – you prepare all this well in advance so you have time to sit back and assess it and check it,” said another member of the MSL navigation team, Neil Mottinger, who has worked at the Jet Propulsion Laboratory since 1967. He’s worked on navigation for many missions like Mariner, Voyager, the MER, and several international missions.
“The initial function of navigation at launch is to determine the actual spacecraft trajectory well enough so the spacecraft signal will be well within the beam-width of the DSN antennae,” Mottinger told Universe Today.
The Mars Science Laboratory will separate from the rocket that boosted it toward Mars at about 44 minutes after launch, with the navigator’s tracking the spacecraft’s every move.
Mottinger added that without the DSN’s communication capabilities, there are no planetary missions. “The Navigation team does whatever it can to make sure there aren’t any gaps in communication,” he said. “It’s crunch time during the first 6-8 hours after launch to be able to determine the exact position of the spacecraft.”
From the recent problems with the Phobos-Grunt mission, it is evident how difficult it is to track and communicate with a just-launched spacecraft.
The MSL Entry, Descent and Landing Instrument (the black box in the middle left of the photo) is scheduled to launch as part of the Mars Science Laboratory mission. Credit: NASA
Mid-course Corrections
Again, the navigation team has modeled and calculated all the maneuvers and thruster burns for the mission. Once MSL is on its way to Mars, the navigation team will revisit all their models and design the maneuvers to take the spacecraft to the right entry interface at Mars.
“We’ll keep doing orbit determination and re-designing the maneuvers for the spacecraft,” said Martin-Mur. “MSL has 1 lb thrusters – the same size as the MER spacecraft — but our spacecraft is almost four times heavier so the maneuvers we do take a long time – some will take hours.”
For interplanetary navigation, the engineers use distant quasars as landmarks in space for reference of where the spacecraft is. Quasars are incredibly bright, but are at such colossal distances that they don’t move in the sky like nearer background stars do. Martin-Mur provided a list of nearly 100 different quasars that could be used for this purpose, depending on where the spacecraft is.
“It is interesting,” Martin-Mur mused, “with quasars we are using something that is billions of light years away from us, from the very early universe, which are so old that they might not even be there anymore. It is really cool that we are using an object that currently may not exist anymore, but using them for very precise navigation.”
The navigation team also needs to model the solar radiation pressure – the effect the Sun’s radiation has on the spacecraft.
“We know very well, thanks to our friends from the Solar Systems Dynamics group, where Mars is going to be and where the Earth and Sun are,” said Martin-Mur. “But since this spacecraft has not been in space before, what is not known precisely is how solar radiation pressure will affect the surface properties of the spacecraft, and how it will perturb the spacecraft. If we don’t have a good model for that, we could be hundreds of kilometers off as the spacecraft goes from Earth to Mars.”
Powered Descent, Sky Crane & Flyaway for MSL. Credit: NASA/JPL
Arriving at Mars
As the spacecraft approaches Mars, it is very important to know precisely where the spacecraft is. “We need to target the spacecraft to the right entry point,” said Martin-Mur, “and tell the spacecraft where it will enter, so it will be able to find its way to the landing site.”
The MSL Entry Descent and Landing Instrumentation, or MEDLI, will stream information back to Earth as the probe enters the atmosphere, letting the navigators — and the science team – know precisely where the rover has landed.
Only then will the navigation team be able — maybe — to breathe a sigh of relief.
