Curiosity and the Curse of Mars
Artists concept of Curiosity rover on Mars. Credit: NASA/JPL-Caltech http://space.com
On November 25th NASA’s $2.5 billion Mars Science Laboratory, the well named Curiosity rover, will launch aboard an Atlas V rocket from Cape Canaveral Air Force Station, carrying the most advanced payload of scientific gear ever used on Mars’ surface. After an almost 9 month journey, it will perform the first-ever precision landing, using the newly developed Sky Crane, at Mars’ Gale Crater. It will spend the next two years investigating whether environmental conditions have ever been favourable for development of microbial life on the red planet. At least, that is the plan.
Approximately two-thirds of all spacecraft destined for Mars fail before completing their missions, some fail before they even begin. Of 38 launches only 19 have succeeded in reaching the planet, a success rate of 50%. Out of 12 attempts to land on the surface, only 7 transmitted data after landing. This high failure rate has been given the name of the Galactic Ghoul or the Martian Curse. After the probable failure of the Russian Phobos-Grunt mission, which, at the time of writing, is still stuck in Earth orbit, ignoring all attempts at communication to reboot the craft, restart its engines and send it on its way, so now all eyes will be on Curiosity & NASA will be holding its breath.
Curiosity Landing
Curiosity is the biggest planetary lander ever built. Weighing 900kg it is twice as long and almost five times heavier than the Mars Exploration Rovers Spirit & Opportunity. Curiosity can’t therefore employ the airbags the smaller, lighter rovers used to land, so after its eight and a half month journey to Mars it will undertake the most complex landing procedure ever attempted. Using the largest heat shield yet flown, Curiosity will enter Mars atmosphere at 21,000km/h. Within 4 minutes, at 10km above the surface, the craft will have slowed to 1,700km/h at which point a 16m parachute will deploy, slowing the lander to 360km/h at 2km above the surface, and that is the easy part! The entry capsule’s back and heat shields will then jettison, fully exposing the rover attached to a Sky Crane fitted with 8 retro rockets. The lander brakes for less than a minute, stopping the Sky Crane 20m above Mars & 3 cables lower Curiosity until its 6 wheels touch the surface and the cables are then released. All this takes just 7, nail biting, minutes. Whereas previous landings were only accurate to within a landing ellipse of 25km by 150km, it is expected that Curiosity will be able to land within10km of it’s target on the floor of Gale Crater.
Mars Science Laboratory Landing Diagram Credit: NASA/JPL-Caltech http://space.com
Gale Crater
Four possible sites were considered for Curiosity’s landing. Mawrth Vallis is rich in clay, Holden Crater has signs of past water activity, and Eberwalde Crater has a huge dried up river delta. Gale Crater , an impact crater measuring 154km across, was eventually chosen as it is 7km deeper than the average, which increases the likelihood of water accumulating there in the past. It also boasts a mound thought to be eroded sediments and sulphate salts and clay minerals.
Prime Mission
Curiosity’s nominal mission is to spend 23 months travelling at least 20km. It’s main goals are to determine if Mars could ever have been habitable, to study the climate and geology, look for organic molecules and signs of biological processes, analyse the atoms, molecules & minerals at the surface, measure carbon, oxygen and phosphorus, study water and carbon dioxide cycles in the atmosphere and finally monitor radiation levels with a view to future manned missions.
Science Payload
To accomplish its mission Curiosity has been packed with an impressive array of instruments. Four cameras, capable of recording high-resolution, high-definition, stereoscopic, colour images and video. A robot arm complete with a microscope camera can gather samples which will then be investigated by the onboard Sample Analysis at Mars (SAM) laboratory that includes three spectrometers. ChemCam employs a laser that can vaporise rocks from 7m away & and analyse them by spectrometry. Alpha-particle X-ray spectrometer (APXS) will reveal the elemental composition of atoms. Radiation assessment detector (RAD) will measure surface radiation. Dynamic albedo of neutrons (DAN) measures ice and water at the surface.
"Curiosity" Mars Science Laboratory. Source: Jet Propulsion Laboratory. http://space.com
Mars or Bust
Man has always been drawn to Mars. The high number of failed missions must be balanced against the high number of missions that have been mounted, more than to any other planet. Visions of martians fuel our science fiction and spark our imagination, while missions and discoveries throw up tantalising cryptic clues that hint at the possibility of life.
Flight controllers will no doubt be haunted by the ghosts of past missions like the ill fated Beagle2 that landed on Mars on Christmas day 2003 was never heard from again. While they will be keeping their fingers crossed during the complex precision landing they should bear in mind that NASA’s Mars exploration program has fared much better than most. The US has achieved success in 13 out of the 20 missions launched, a 65% success rate, and 6 out of 7 an 86% success rate for lander missions (Viking I and II, Pathfinder, MER Spirit and Opportunity, and Phoenix) And when NASA gets it right, it gets it really, really right. Spirit and Opportunity were launched back in June and July 2003 and arrived at Mars in January 2004 on a 90 sol (Mars day) primary mission. Seven years later Opportunity is still going strong having travelled over 21.25 miles across Mars’ surface to date, and Spirit lasted for 6 years 2 months 19 days, over 25 times the original planned mission, travelling a distance of 4.80 miles before contact was lost last year.
For the future, It is probably going to take international cooperation to get humans to Mars While the US, Europe and other space agencies are cautiously aiming for missions in the next 20 or 30 years, entrepreneurs like Elon Musk of SpaceX are actively working to get a manned mission to Mars within 10 to 20 years and setting up permanent human settlements there. To paraphrase President John F. Kennedy, we dream of going to Mars, not because it is easy but because it is hard. I hope we maintain the will to keep the dream alive. Curiosity will lead us forward.
Thank you Rob. I'm really excited about Curiosity too (does it show?) I don't know what I will do with myself for 8 & a half long months between the thrill of the launch on Saturday and that nail biting landing. Then as you say we will have all the science data to look forward to
Thanks for this Jenny, an excellent article. I'm really looking forward to this mission. I hope NASA cover the landing in the same way as they did with Phoenix, which for me was an unforgettable experience. The tension and excitement of the landing was incredible and then we had all that amazing science - right up until the poor thing became an ice cube...
LATEST UPDATE: MSL launch has been delayed to Saturday, Nov. 26 to allow time for the team to remove and replace a flight termination system battery. The new 1 hour & 43 minute launch window opens at 15:02 am U.T.
Just a quick update on poor Phobos-Grunt. If communication isn't established by November 21st then the window for journey to Mars will close. BUT, experts are not ruling out the possibility of sending the probe to our Moon or to an asteroid if communication can be restored before the probe re-enters Earth's atmosphere. So still a slim chance of snatching success from the jaws of defeat. Fingers crossed!
Hi Lee. They reckon the radioscopic thermal generators (RTGs) that power Curiosity will still deliver 80% power to the rover even after 10 years! So in theory Curiosity could be as long lived (or more so) than Spirit & Opportunity (I share your admiration for those two intrepid explorers :)
Looks like an exciting mission especially that landing system. I'll breathe a sigh when its down and transmitting data. I hope its as successful as the wonders known as spirit and opportunity !
Exciting Times - thanks again for a great article ;o)
This is so interesting. In one month it launches, in nine it lands (we hope) and in the years to come... we learn!
That landing procedure does worry me (so much to go wrong) I will not breathe till Curiosity is safely down, but then I think this mission will offer huge returns.
Another great article Jenny! Can't wait to see how Curiousity gets on! I'm with you - little green men as the curse lol ;-) Great job done! :-)
Excellent article Jenny. From an engineering perspective I can't wait to see how Curiosity performs, especially during the tricky landing phase. I'll be glued to my seat, holding my breath at that point. Wondering also, what other potential candidates should be getting the 'Curiosity' treatment, Titan springs to mind, and Europa.
Mike Thanks for this. I think Titan would need a more robust lander, as its dense atmosphere means high pressure. Also very low surface temperature (−179 °C) & chance of rainfall and complex surface features with seas, lakes & rivers of liquid ethane, methane and dissolved N2. One plan to get below Europa's ice surface is to land a probe that could then heat up and melt its way through to the sea or lake below.
Brilliant introduction to this exiting project. Thank you!
Thank you lehndal! I will be watching the launch & the rest of the mission very closely. Curiosity has so much to teach us
Excellent, excellent commentary on the Martian Curse and humankind's attempted invasion of Martian privacy. So one wonders what lies hidden on Mars? Jenny you did great and I bet you will get a cascade of comments just like your previous article did. Space is alive and well on The Urban Times.
Thank you! Part of me would like to believe that the Curse of Mars is actually Martians finding & sabotaging our probes in order to preserve their privacy, & who can blame them ; )
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