Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE) camera captured this image of Phoenix hanging from its parachute as it descended to the Martian surface. Credit: NASA/JPL/University of Arizona.
[/caption]
Remember this amazing image from 2008? The HiRISE (High Resolution Imaging Science Experiment) camera on the Mars Reconnaissance Orbiter captured the Phoenix lander descending on a parachute to land on Mars’ north polar region. MRO will attempt a repeat performance in August of 2012 when the Mars Science Laboratory rover “Curiosity” will be landing in Gale Crater on Mars. Capturing this event would be epic, especially with MSL’s unique “skycrane” landing system.
“Yes, MRO is planning to image the descent of MSL with both HiRISE and CTX (Context Camera),” Alfred McEwen, HiRISE principal investigator told Universe Today. “For Phoenix we got a bit lucky with HiRISE in terms of the geometry, giving us a high probability of success. It may not work out so well for MSL. What I’d really like is to capture the rover hanging from the skycrane, but the timing may be difficult.”
Again, the word here is epic.
So, how challenging is it for a spacecraft orbiting Mars to try and track another spacecraft coming in?
“If we were not to do anything, the Mars’ orbiting spacecraft may be on the other side of the planet,” said MSL navigation team chief Tomas Martin-Mur, during an interview with UT. “So as soon as we launch, we tell the other spacecraft where we are going to be by the time of entry so they can change their orbits over time, so they will be flying overhead as MSL approaches the planet.”
The orbiters – which also includes NASA’s Mars Odyssey and ESA’s Mars Express – will have to do special maneuvers to be aligned in just the right place – nearby to MSL’s point of entry into Mars’ atmosphere — and they may even have to change the plane of their orbit.
This artist's concept shows the sky crane maneuver during the descent of NASA's Curiosity rover to the Martian surface. Credit: NASA/JPL-Caltech.
“The other thing that we’ll need them to do is to point their UHF antennas towards MSL,” Martin-Mur said. “Normally their antennas will be pointed to take pictures, but they will have to go to a special attitude to point to MSL. This will enable them to try — like they did with Phoenix — to take a picture of the spacecraft as it is coming down to the planet. We are hoping to see the parachute deployed and maybe more.”
“That was a great picture for Phoenix, and we will attempt to repeat that,” Martin-Mur added.
While Odyssey and Mars Express’ cameras may not have the resolving power to capture such an image, MRO’s powerful HiRISE camera does. However it has a narrower field of view, so as much skill and planning as this requires, the team will need a little luck, too. But there’s also the CTX.
“CTX has a much larger field of view and will likely capture it,” McEwen said, “but at 20X lower resolution than HiRISE, which should still be good enough to detect the parachute.”
Here’s a preview of what MSL will be going through during the perilous entry descent and landing:
In June 2000, Martian imaging scientists made a striking discovery — data from NASA’s Mars Global Surveyor spacecraft found gullies on the red planet. Gullies on Earth form when water runs down steep slopes and carves soil out of its way, so the discovery of this geologic feature on Mars was enticing evidence that liquid water existed on or near the surface of Mars.
But gullies have also been spotted in the Mars’ polar regions where the temperature is too cold for water to exist in its liquid form. Adding to the puzzle is the suggestion that the apparent gullies are actually formed by wind or underground gases causing sand and dust to roll down a steep hill and create what looks like a gully formed by Water. So what’s behind the gullies at Mars’ poles?
A gully that looks like it was made by water eroding hard rock. Image credit: NASA/JPL/Malin Space Science Systems
Frozen carbon dioxide — more commonly known as dry ice — isn’t an uncommon feature on Mars. It can freeze out of the carbon dioxide rich atmosphere on Mars and, after a dust storm, be covered by a thin layer of dust or sand. Recently, researchers are looking to this subsurface dry ice as a possible explanation for Martian gullies, particularly at the frozen poles.
The key here is sublimation — the phenomenon of a solid passing directly into its gaseous state. You’ve seen this happen if you’ve ever poured water on dry ice. The water warms the solid dry ice and turn it into a gas. On Mars, it’s possible that changes in temperatures with seasons could be enough to sublimate the frozen carbon dioxide. The expulsion of the gas through the soil on the surface could cause it to roll down a hill like a fluid. The same thing would happen with water coming up from under ground.
Whether or not dry ice sublimation is behind polar gullies became a focus of Yolanda Cedillo-Flores and three colleagues at the Lunar and Planetary Institute in Houston, Texas.
A previous study testing whether sublimating dry ice could form gullies, led by Cedillo-Flores, was brilliant in its simplicity. They piled sand into Mars-like slopes then blew air underneath the sand. The sand flowed down the slope, much like a liquid would, and formed was looked very much like a gully.
Recently, the team at the Lunar and Planetary Institute have been testing the possibility of this phenomenon happening on Mars. They used the average daytime and seasonal temperatures of the Martian year to calculate the sublimation rate of dry ice on Mars. Then, they ran models of this event on Martian areas without any sediment as well as those with layers of sand and dust of varying thickness over the average seasonal deposit of dry ice. When simulated spring came, enough heat reached the dry ice that it sublimated and acted like a fluid. Turns out, Mars is just right for seasonal sublimation of frozen carbon dioxide.
They finally came to the conclusion that carbon dioxide sublimation is the likeliest cause behind the gullies forming in Mars’ polar regions.
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.
A Caenorhabditis elegans worm. Credit: Creative Commons
[/caption]
Once the realm of science fiction, the prospect of colonizing other planets is getting closer to reality. The most logical first place, besides the Moon, has always been Mars. Venus is a bit closer, but the scorching conditions there are, well, much less than ideal. There is still technology that needs to be developed before we can send humans to Mars at all, never mind stay there permanently. But now there may be help from an unlikely and lowly companion. – worms.
Ok, not the kind of worms you find in your garden, but tiny microscopic worms called Caenorhabditis elegans (C. elegans). Similar biologically to humans in some ways, they are being studied by scientists at the University of Nottingham in the UK to help see how people are affected by long-duration space travel.
In December 2006, 4,000 of them were sent into orbit aboard the Space Shuttle Discovery. This was followed by another mission in 2009. The scientists found that in space, the worms develop and produce progeny just as they do on Earth. The research has been published in the November 30, 2011 issue of Interface, a journal of The Royal Society.
According to Dr. Nathaniel Szewczyk of the Division of Clinical Physiology in the School of Graduate Entry Medicine, “While it may seem surprising, many of the biological changes that happen during spaceflight affect astronauts and worms and in the same way. We have been able to show that worms can grow and reproduce in space for long enough to reach another planet and that we can remotely monitor their health. As a result C. elegans is a cost-effective option for discovering and studying the biological effects of deep space missions. Ultimately, we are now in a position to be able to remotely grow and study an animal on another planet.”
He added: “Worms allow us to detect changes in growth, development, reproduction and behaviour in response to environmental conditions such as toxins or in response to deep space missions. Given the high failure rate of Mars missions use of worms allows us to safely and relatively cheaply test spacecraft systems prior to manned missions.”
So while a manned space mission to Mars is still a ways off, some lucky worms may get there first, making the voyage of a lifetime, even if they don’t realize it!
NASA’s Curiosity Mars Science Laboratory (MSL) rover blasts off on Nov. 26. NASA's 1 ton Curiosity Mars rover soars skyward lift bound for Mars atop the United Launch Alliance Atlas V rocket at Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida at 10:02 a.m. EST on Nov. 26. Credit: Alan Walters/awaltersphoto.com
[/caption]
NASA’s Curiosity Mars Science Lab (MSL) rover is speeding away from Earth on a 352-million-mile (567-million-kilometer) journey to Mars following a gorgeous liftoff from Cape Canaveral Air Force Station, Florida aboard a United Launch Alliance Atlas V rocket at 10:02 a.m. EST on Nov. 26.
Enjoy the gallery of Curiosity launch images collected here from the Universe Today team and local photographers as well as NASA and United Launch Alliance.
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 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
“We are very excited about sending the world’s most advanced scientific laboratory to Mars,” NASA Administrator Charles Bolden said. “MSL will tell us critical things we need to know about Mars, and while it advances science, we’ll be working on the capabilities for a human mission to the Red Planet and to other destinations where we’ve never been.”
The mission will pioneer a first of its kind precision landing technology and a sky- crane touchdown to deliver the car sized rover to the foothills of a towering and layered mountain inside Gale Crater on Aug. 6, 2012.
Curiosity Mars rover launch. Credit: Mike Deep/David Gonzales
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.
Curiosity Mars rover launch. Credit: Mike Deep/David Gonzales
The robot is equipped with a drill and scoop at the end of its robotic arm to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into analytical laboratory instruments inside the rover.
The 1 ton Curiosity rover sports a science payload that’s 15 times heavier than NASA’s previous set of rovers – Spirit and Opportunity – which landed on Mars in 2004. Some of the tools are the first of their kind on Mars, such as a laser-firing instrument for checking the elemental composition of rocks from a distance, and an X-ray diffraction instrument for definitive identification of minerals in powdered samples.
Curiosity rover bound for Mars punches through Florida clouds. Credit: Ken KremerCuriosity rover launches to Mars on Atlas V rocket on Nov. 26 from Cape Canaveral, Florida. Credit: Mike Killian/Zero-G NewsCuriosity rover launches to Mars on Atlas V rocket on Nov. 26 from Cape Canaveral, Florida. Credit: Mike Killian/Zero-G NewsA United Launch Alliance Atlas V rocket blasts off from Space Launch Complex-41 at 10:02 p.m. EST with NASA’s Mars Science Lab rover Curiosity. Credit: Pat Corkery/ULACredit: NASA/KenThornsleyCuriosity Mars Science Laboratory launches. Credit: ULA
Launch Video – Credit: Matthew Travis/Spacearium
MSL launch. Credit: Julian LeekMSL launch. Credit: Julian Leek
Complete Coverage of Curiosity – NASA’s Next Mars Rover launched 26 Nov. 2011
Read continuing features about Curiosity by Ken Kremer starting here:
Maspalomas station hosts a 15-metre antenna with reception in S- and X-Band and transmission in S-band. It is located on the campus of the Instituto Nacional de Tecnica Aerospacial (INTA), in the southern part of the Canary Islands' Gran Canaria, at Montaña Blanca.Credit: ESA
[/caption]
Editor’s note: Dr. David Warmflash, principal science lead for the US team from the LIFE experiment on board the Phobos-Grunt spacecraft, provides an update on the mission for Universe Today.
As part of an effort to improve communication with the Russian Space Agency’s Phobos-Grunt spacecraft, modifications are being made to a 15-meter dish antenna at Maspalomas station. Located in the Canary Islands off the Atlantic coast of North Africa, the station provides tracking, telemetry, and other functions in support of the European Space Operations Centre (ESOC) of the European Space Agency (ESA).
Last week, ESA succeeded in communicating with Phobos-Grunt on two successive days after a feedhorn antenna was added to an antenna near Perth, Australia similar to the facility in Maspalomas. Although this enabled the downloading of spacecraft telemetry, attempts later in the week to make renewed contact failed. After no attempts were made over the weekend, commands aimed at getting the spacecraft to boost its orbit were sent yesterday, also from Perth, but tracking this morning revealed that the commands had not been executed.
Launched November 9 from the Baikonur Cosmodrome, in Kazakhstan, Grunt is an unpiloted science probe built to travel to Phobos, the larger of Mars’ two small moons. On board is a science payload consisting of numerous instruments designed to elucidate the structure and origin of Phobos, the composition of its surface material, and possibly dust from Mars that may be present as well. A Chinese probe called Yinhuo-1 is to be delivered into orbit around Mars, while the rest of the payload is to land on the Phobosian surface. Some time after landing, a 200 gram sample of the surface is to be deposited into a capsule which then will launch for a journey back to Earth. Also traveling in the return capsule is the Planetary Society’s Living Interplanetary Flight Experiment (LIFE), which I helped to design. As with the Phobosian surface sample, the LIFE experiment will be valuable scientifically, only if the return capsule can be returned to Earth.
Although Phobos-Grunt was delivered into space nearly three weeks ago by a Zenit 2 rocket launch that appeared flawless, an upper stage rocket known as Fregat failed to ignite. This left the spacecraft in a low Earth orbit that improved as a result of the automated maneuvering, but that will decay by mid-January if the altitude is not boosted more significantly. Because a low orbit requires a spacecraft to move more swiftly with respect to the ground, communication is extremely limited due both to time and geometry. By allowing Maspalomas to operate similarly to Perth, but from its different location, both geometric and time factors affecting communication will be improved. Should this result in the spacecraft executing commands to climb to a higher orbit, further communication and diagnosis of spacecraft systems then would become much easier.
The landing site of Viking 1 on Mars in 1977, with trenches dug in the soil for the biology experiments. Credit: NASA/JPL
[/caption]
One of the most controversial and long-debated aspects of Mars exploration has been the results of the Viking landers’ life-detection experiments back in the 1970s. While the preliminary findings were consistent with the presence of bacteria (or something similar) in the soil samples, the lack of organics found by other instruments forced most scientists to conclude that the life-like responses were most likely the result of unknown chemical reactions, not life. Gilbert V. Levin, however, one of the primary scientists involved with the Viking experiments, has continued to maintain that the Viking landers did indeed find life in the Martian soil. He also now thinks that the just-launched Curiosity rover might be able to confirm this when it lands on Mars next summer.
Curiosity is not specifically a life-detection mission. Rather, it continues the search for evidence of habitability, both now and in the past. But is it possible that it could find evidence for life anyway? Levin believes it could, between its organics detection capability and its high-resolution cameras.
The major argument against the life-detection claims was the lack of organics found in the soil. How could there be life with no organic building blocks? It has since been thought that any organics were destroyed by the harsh ultraviolet radiation or other chemical compounds in the soil itself. Perchlorates could do that, and were later found in the soil by the Phoenix mission a few years ago, closer to the north pole of Mars. The experiments themselves, which included baking the soil at high heat, may have destroyed any organics present (part of the studies involved heating the soil to kill any organisms and then study the residual gases released as a result, as well as feeding nutrients to any putative organisms and analyzing the gases released from the soil). If Curiosity can find organics, either in the soil or by drilling into rocks, Levin argues, that would bolster the case for life being found in the original Viking experiments, as they were the “missing piece” to the puzzle.
So what about the cameras? Any life would have to be macro, of visible size, to be detected. Levin and his team had also found “greenish coloured patches” on some of the nearby rocks. (I still have a little booklet published by Levin at the time, “Color and Feature Changes at Mars Viking Lander Site” which describes these in more detail). When as a test, lichen-bearing rocks on Earth were viewed with the same camera system using visible and infrared spectral analysis, the results were remarkably similar to what was seen on Mars. Again, since then though, those results have been widely disputed, with most scientists thinking the patches were mineral coatings similar to others seen since then. Of course, there is also the microscopic imager, similar to that on the Spirit and Opportunity rovers, although microorganisms would still be too small to be seen directly.
Regardless, Levin feels that Curiosity just might be able to vindicate his earlier findings, stating “This is a very exciting time, something for which I have been waiting for years. At the very least, the Curiosity results may bring about my long-requested re-evaluation of the Viking LR results. The Viking LR life detection data are the only data that will ever be available from a pristine Mars. They are priceless, and should be thoroughly studied.”
The Mars Science Laboratory is now on an 8.5 month trip to Mars! Watch the successful launch above, and our on-site team of Ken Kremer, Alan Walters, David Gonazales and Jason Rhian will provide all the launch details and more in subsequent, fact- and photo-filled articles.
In the future, planetary protection (where we ensure that missions do not contaminate other words with Earth-borne organisms) will be especially important. Credit: NASA, JPL-Caltech
[/caption]
NASA’s Curiosity Mars rover, the most technologically complex and scientifically capable robot built by humans to explore the surface of another celestial body, is poised to liftoff on Nov. 26 and will enable a quantum leap in mankind’s pursuit of Martian microbes and signatures of life beyond Earth.
“The Mars Science Lab and the rover Curiosity is ‘locked and loaded’, ready for final countdown on Saturday’s launch to Mars,” said Colleen Hartman, assistant associate administrator in NASA’s Science Mission Directorate, at a pre-launch media briefing at the Kennedy Space Center (KSC).
The $2.5 Billion robotic explorer remains on track for an on time liftoff aboard a United Launch Alliance Atlas V rocket at 10:02 a.m. on Nov. 26 from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida.
Atlas V rocket at Space Launch Complex 41 at Cape Canaveral, Florida. An Atlas V rocket similar to this one utilized in August 2011 for NASAS’s Juno Jupiter Orbiter will blast Curiosity to Mars on Nov. 26, 2011 from Florida. Credit: Ken Kremer
NASA managers and spacecraft contractors gave the “Go-Ahead” for proceeding towards Saturday’s launch at the Launch Readiness Review on Wednesday, Nov. 23. The next milestone is to move the Atlas V rocket 1800 ft. from its preparation and assembly gantry inside the Vertical Integration Facility at the Cape.
“We plan on rolling the vehicle out of the Vertical Integration Facility on Friday morning [Nov. 25] ,” said NASA Launch Director Omar Baez at the briefing. “We should be on the way to the pad by 8 a.m.”
The launch window on Nov. 26 is open until 11:14 a.m. and the current weather prognosis is favorable with chances rated at 70 percent “GO”.
“The final launch rehearsal – using the real vehicle ! – went perfectly, said NASA Mars manager Rob Manning, in an exclusive interview with Universe Today. Manning is the Curiosity Chief Engineer at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
“I was happy.”
“The folks at KSCs Payload Handling Facility and at JPL’s cruise mission support area (CMSA) – normally a boisterous bunch – worked quietly and professionally thru to T-4 minutes and a simulated fake hold followed by a restart and a recycle (shut down) due to a sail boat floating too close to the range,” Manning told me.
Curiosity rover - Engineering support team working at consoles at JPL. Credit: Rob Manning
Readers may recall that NASA’s JUNO Jupiter orbiter launch in August was delayed by an hour when an errant boat sailed into the Atlantic Ocean exclusion zone.
“This rover, Curiosity rover, is really a rover on steroids. It’s an order of magnitude more capable than anything we have ever launched to any planet in the solar system,” said Hartman.
“It will go longer, it will discover more than we can possibly imagine.”
Curiosity rover explores inside Gale Crater after landing in August 2012. The mast, or rover's "head," rises to about 2.1 meters (6.9 feet) above ground level, about as tall as a basketball player. Credit: NASA, JPL-Caltech
Curiosity is locked atop the powerful Alliance Atlas V rocket that will propel the 1 ton behemoth on an eight and one half month interplanetary cruise from the alligator filled swamps of the Florida Space Coast to a layered mountain inside Gale Crater on Mars where liquid water once flowed and Martian microbes may once have thrived.
Curiosity is loaded inside the largest aeroshell ever built and that will shield her from the extreme temperatures and intense buffeting friction she’ll suffer while plummeting into the Martian atmosphere at 13,000 MPH (5,900 m/s) upon arrival at the Red Planet in August 2012.
The Curiosity Mars Science Lab (MSL) rover is the most ambitious mission ever sent to Mars and is equipped with a powerful 75 kilogram (165 pounds) array of 10 state-of-the-art science instruments weighing 15 times as much as its predecessor’s science payloads.
Curiosity measures 3 meters (10 ft) in length and weighs 900 kg (2000 pounds), nearly twice the size and five times as heavy as NASA’s prior set of twin robogirls – Spirit and Opportunity.
The science team selected Gale crater as the landing site because it exhibits exposures of clays and hydrated sulfate minerals that formed in the presence of liquid water billions of years ago, indicating a wet history on ancient Mars that could potentially support the genesis of microbial life forms. Water is an essential prerequisite for life as we know it.
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.
Oblique View of Gale Crater, Mars, with Vertical Exaggeration
Gale Crater, where the rover Curiosity of NASA's Mars Science Laboratory mission will land in August 2012, contains a mountain rising from the crater floor. This oblique view of Gale Crater, looking toward the southeast, is an artist's impression using two-fold vertical exaggeration to emphasize the area's topography. Curiosity's landing site is on the crater floor northeast of the mountain. The crater's diameter is 96 miles (154 kilometers). The image combines elevation data from the High Resolution Stereo Camera on the European Space Agency's Mars Express orbiter, image data from the Context Camera on NASA's Mars Reconnaissance Orbiter, and color information from Viking Orbiter imagery.
Credit: NASA/JPL-Caltech/ESA/DLR/FU Berlin/MSSS
The car sized rover is being targeted with a first of its kind precision rocket powered descent system to touchdown inside a landing ellipse some 20 by 25 kilometers (12.4 miles by 15.5 miles) wide and astride the towering mountain at a location in the northern region of Gale.
Curiosity’s goal is to search the crater floor and nearby mountain – half the height of Mt. Everest – for the ingredients of life, including water and the organic molecules that we are all composed of.
The robot will deploy its 7 foot long arm to collect soil and rock samples to assess their composition and determine if any organic materials are present – organics have not previously been detected on Mars.
Curiosity will also vaporize rocks with a laser to determine which elements are present, look for subsurface water in the form of hydrogen, and assess the weather and radiation environments
“After the rocket powered descent, the Sky-Crane maneuver deploys the rover and we land on the mobility system, said Pete Theisinger, MSL project manager from the Jet Propulsion Laboratory in Pasadena, Calif., at the briefing.
The rover will rover about 20 kilometers in the first year. Curiosity has no life limiting constraints. The longevity depends on the health of the rovers components and instruments.
“We’ve had our normal challenges and hiccups that we have in these kinds of major operations, but things have gone extremely smoothly and we’re fully prepared to go on Saturday morning. We hope that the weather cooperates, said Theisinger
Missions to Mars are exceedingly difficult and have been a death trap for many orbiters and landers.
“Mars really is the Bermuda Triangle of the solar system,” said Hartman. “It’s the ‘death planet,’ and the United States of America is the only nation in the world that has ever landed and driven robotic explorers on the surface of Mars. And now we’re set to do it again.”
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.
