The Mars rovers Spirit and Opportunity are by far one the most successful mission we’ve ever had on another planet. Designed for a total mission time of only 90 days they have gone on to outlive that deadline numerous times over and if it weren’t for an insidious soil trap they’d both still be running today. Whilst Opportunity might still be running a good 7 years after it made planet fall that doesn’t mean that it’s capable of performing all the tasks we want to do and so NASA has been busy designing a replacement rover. It’s quite something to behold and it just recently hit a very important milestone.
The next rover’s official name (dubbed Curiosity in a contest to name it, much like its predecessors) is the Mars Science Laboratory and considering its payload that’s fairly apt. Compared to the Mars Exploration Rovers it’s quite the beast being 5 times more massive and carrying 10 times the scientific payload. To put that in perspective the MSL will be about the same size as the Mini Cooper, the MERs combined would only equal it in length. Such size does present some challenges for getting it down on Mars however, but the guys at NASA have devised a really ingenious way of making sure it arrives safely.
Many are familiar with the way that the MERs made their landing on Mars. They used a combination of aero-breaking (basically parachutes) combined with inflatable bags on the outside that allowed them to bounce over the surface until they landed safely. The MSL is just too heavy for that kind of landing to work so NASA has devised a multi-stage descent that utilizes aero-breaking, retrorockets and a crane system to drop it safely on the surface. I could try and explain it to you but its far more impressive to see in video:
Compared to the way the MERs landed this does seem like an extremely overcomplicated way of landing but given the constraints it’s the best option available. NASA is stepping into unknown territory here so until the landing is confirmed I can see everyone being on tenterhooks.
Keen observers would have noticed something different about the MSL when compared to its MER cousins, most notably the distinct lack of solar panels. The MSL gets all of its power from a radioisotope thermoelectric generator (RTG), the same device that’s powered Mars landers and the extremely long lived Voyager probes. These devices work by using the heat from radioactive decay of an element, usually enriched plutonium, and generating electricity via a thermocouple. The RTG on board Curiosity will generate around 125W of power when its launched, dropping to 100W only after 14 years in service. The mission time frame is slated for just under 2 earth years so the RTG is more than up to the job and there’s the tantalizing possibility that this particular rover could be working for a very long time to come.
The MSL’s payload is simply staggering so I won’t recreate it fully here but there are a few interesting pieces that I’d like to highlight. The first is the MastCam which is a high definition camera that will sit on top of Curosity’s mast. It’s able to take 1.92 megapixel images and 10fps 720p video in true colour, something that other rovers have had to fudge with their black and white cameras with colour filters. There’s also ChemCam which has an infrared laser capable of vaporizing rock at 7 meters then analysing the resulting plasma ball, which is just plain cool (lazers, IN SPACE!).
The milestone I was hinting at earlier was that the MSL has just been sealed up in its payload faring, ready for the trip to Mars:
With its launch window opening in less than two months, the Mars Science Laboratory was matched up with its heat shield at Kennedy Space Center’s Payload Hazardous Servicing Facility on Wednesday, Oct. 5.
The completed MSL rover, a.k.a. “Curiosity,” had already been fitted onto the “back shell powered descent vehicle” — a revolutionary landing mechanism that will first deploy parachutes to slow the capsule’s descent and then use rockets to hover above the Martian surface as it carefully lowers the one-ton rover down on cables before finally launching itself away to fall at a safe distance.
The launch is scheduled to happen between November 25th and December 18th this year with the rover reaching Mars sometime in August next year. After that it will begin its 1 martian year mission, which is just a hair under 700 earth days. With the rover being fitted into the fairing now it signals that NASA has quite a good shot at hitting that launch window, especially when they’re using the tried and true ATLAS V launch system.
Curiosity really is a testament to what NASA is capable of when they put their minds to it. Everything about the new rover is boundary pushing and I’m sure that much like its predecessors it’ll continue to serve NASA and humanity long after its initial mission is completed. It’s going to be agony waiting for the landing confirmation but we’ve got a year and a long trip through space before we have to start worrying about that.