Mars or bust
It’s a question that has teased scientists, dreamers, fantasy writers – yes, and people like us – for centuries: is there, or has there ever been, life on Mars? In the coming year, a 900 kg Nasa-designed rover called Mars Science Laboratory will hopefully deliver a convincing answer. It’s not about bug-eyed monsters, of course; what the scientists are looking for is the unmistakable footprint of microbial life, albeit unimaginably ancient.

To find out, the rover – dubbed Curiosity – will carry the biggest, most advanced suite of instruments for scientific studies ever sent to the Martian surface. It will analyse dozens of samples scooped from the soil and drilled from rocks. . e record of the planet’s climate and geology is essentially written in the rocks and soil – in their formation, structure and chemical composition. The rover’s onboard laboratory will study rocks, soils and the local geologic setting in order to detect chemical building blocks of life (that is, forms of carbon) on Mars, and assess what the Martian environment was like in the past.

To do its job, the rover will rely on a variety of technological innovations, especially for the landing procedure. The spacecraft will descend on a parachute and then, during the final seconds prior to landing, lower the upright rover on a tether to the surface – much like a sky crane. Once on the surface, the rover will be able to roll over obstacles up to 75 cm high and travel up to 90 m per hour. On average, it is expected to travel about 30 m per hour, based on power levels, slippage, steepness of the terrain, visibility and other variables.

The rover will carry a radioisotope power system that generates electricity from the heat of plutonium’s radioactive decay. This power source gives the mission an operating lifespan on Mars’ surface of a full Martian year (that is, 687 Earth days) or more while also providing significantly greater mobility and operational flexibility, enhanced science payload capability, and exploration of a much larger range of latitudes and altitudes than was possible on previous missions to Mars.

Arriving at Mars in 2012, Curiosity will serve as an entrée to the next decade of Mars exploration. It represents a huge step in Mars surface science and exploration capability because it will demonstrate:

• The ability to land a very large, heavy rover on the surface of Mars (which could be used for a future Mars Sample Return mission that would collect rocks and soils and send them back to Earth for laboratory analysis).
• The ability to land more precisely in a 20 km landing circle.
• Long-range mobility on the surface of the red planet (5-20 km) for the collection of more diverse samples and studies.

Curiosity will assess whether Mars ever had an environment capable of supporting microbial life. Determining past habitability on Mars gives Nasa and the scientific community a better understanding of whether life could have existed on the Red Planet and, if it could have existed, an idea of where to look for it in the future.

If all goes according to plan, the mission will launch on 25 November.

It’s about brains, stupid

The rover’s computers (aka brains) are located inside a module called the Rover Compute Element (RCE), and are composed of equipment comparable to a high-end laptop computer. They feature a special memory to tolerate the extreme radiation environment from space and to safeguard against power-off cycles, so the programs and data will not accidentally be erased when the rover shuts down at night.

Onboard memory is roughly eight times better than the computer aboard the twin Mars Exploration Rovers (which, by the way, performed magnificently over a period of several years). The latest rover also carries an inertial measurement unit that provides 3-axis information on its position, which enables the rover to make precise vertical, horizontal and side-toside (yaw) movements. The device is used to support safe traverses and to estimate the degree of tilt the rover is experiencing on the surface of Mars.

One of the rover’s two brains remains asleep, being awakened only if the first brain experiences problems. Just like the human brain, the rover computers monitor its “health”, temperature and other features. This main control loop essentially keeps the rover alive by constantly checking itself to ensure that it is both able to communicate throughout the surface mission and that it remains thermally stable (that is, not too hot or too cold) at all times. It does so by periodically checking temperatures, particularly in the rover body, and responding to potential overheating conditions, recording power generation and power storage data throughout the Mars sol (Martian day), and scheduling and preparing for communication sessions.

"Whenever someone proposes to do something that has never been done before, there will always be sceptics. So when I started SpaceX, it was not surprising when people said we wouldn't succeed. But now that we've successfully proven Falcon 1, Falcon 9 and Dragon, there's been a steady stream of misinformation and doubt expressed about SpaceX's actual launch costs and prices. As noted... by a Chinese government official, SpaceX currently has the best launch prices in the world, and they don't believe they can beat them. This is a clear case of American innovation trumping lower overseas labour rates.

"I recognise that our prices shatter the historical cost models of government-led developments, but these prices are not arbitrary, premised on capturing a dominant share of the market, or 'teaser' rates meant to lure in an eager market, only to be increased later. These prices are based on known costs and a demonstrated track record, and they exemplify the potential of America's commercial space industry.

"Here are the facts: The price of a standard flight on a Falcon 9 rocket is $54 million (about R425 million; correct at the time of going to press - Editor). We are the only launch company that publicly posts this information on our Web site. We have signed many legally binding contracts with both government and commercial customers for this price (or less). Because SpaceX is so vertically integrated, we know and can control the overwhelming majority of our costs. This is why I am so confident that our performance will increase and our prices will decline over time, as is the case with every other technology. "The average price of a full-up Nasa Dragon cargo mission to the International Space Station is $133 million, including inflation, or roughly $115 million in today's dollars, and we have a firm, fixed price contract with Nasa for 12 missions. This price includes the costs of the Falcon 9 launch, the Dragon spacecraft, all operations, maintenance and overhead, and all of the work required to integrate with the Space Station. If there are cost overruns, SpaceX will cover the difference. (This concept may be foreign to some traditional government space contractors that seem to believe that cost overruns should be the responsibility of the taxpayer.)

"The total company expenditures since being founded in 2002 through the 2010 fiscal year were less than $800 million, which includes all the development costs for the Falcon 1, Falcon 9 and Dragon. Included in this $800 million are the costs of building launch sites at Vandenberg, Cape Canaveral and Kwajalein, as well as the corporate manufacturing facility that can support up to 12 Falcon 9 and Dragon missions per year. Th is total also includes the cost of five flights of Falcon 1, two flights of Falcon 9, and one up and back flight of Dragon.

"The Falcon 9 launch vehicle was developed from a blank sheet to first launch in four and half years for just over $300 million. Th e Falcon 9 is an EELV class vehicle that generates roughly one million pounds of thrust (four times the maximum thrust of a Boeing 747) and carries more payload to orbit than a Delta IV Medium.

"The Dragon spacecraft was developed from a blank sheet to the first demonstration flight in just over four years for about $300 million. The spacecraft and the Falcon 9 rocket that carried it were designed, manufactured and launched by American workers for an American company. The Falcon 9/ Dragon system, with the addition of a launch escape system, seats and upgraded life support, can carry seven astronauts to orbit - more than double the capacity of the Russian Soyuz, but at less than a third of the price per seat.

"SpaceX has been profitable every year since 2007, despite dramatic employee growth and major infrastructure and operations investments. We have over 40 flights on manifest representing over $3 billion in revenues.

"These are the objective facts, confirmed by external auditors. Moreover, SpaceX intends to make far more dramatic reductions in price in the long term when full launch vehicle reusability is achieved. We will not be satisfied with our progress until we have achieved this long-sought goal of the space industry.

"For the first time in more than three decades, America last year began taking back international market share in commercial satellite launch. This remarkable turnaround was sparked by a small investment Nasa made in SpaceX in 2006 as part of the Commercial Orbital Transportation Services (COTS) programme. A unique public-private partnership, COTS has proven that under the right conditions, a properly incentivised contractor - even an all-American one - can develop extremely complex systems on rapid timelines and a fixed-price basis, significantly beating historical industry-standard costs.

"China has the fastest-growing economy in the world. But the American free enterprise system, which allows anyone with a better mousetrap to compete, is what will ensure that the United States remains the worldfs greatest superpower of innovation." - ELON MUSK

• Also see PM Breakthrough Awards, "Launching private spaceflight".

Sharpshooter
A Russian-built, neutron-shooting instrument on Curiosity will check for water-bearing minerals in the ground beneath the rover. The instrument, named Dynamic Albedo of Neutrons, or DAN, has two major components: the pulsed neutron generator on the starboard side of the rover (indicated in the picture by red outline), and the detector and electronics module on the port side.

The generator will shoot high-energy neutrons into the ground. If there is hydrogen in the shallow subsurface, the injected neutrons will bounce off the hydrogen atoms with a characteristic decrease in energy. Two detection devices in the detector and electronics module measure the rate and delay time of the refl ected neutrons, yielding information about the amount and depth of any hydrogen. At the mission’s near-equatorial landing area and in the oxidising environment near the Martian surface, most hydrogen is expected to be in the form of water molecules or water-derived hydroxyl ions bound to minerals.

SpaceX takes on the world
Much of the buzz in the corridors of Cape Town’s International Convention Centre in early October was focused on the development of commercial space flight. This was hardly surprising, given the presence of some 2 000-plus delegates attending the 62nd International Astronautical Congress, but what we found interesting were the frequent references to “affordability”. This leads rather neatly to an impassioned statement issued earlier this year by Elon Musk, the South African-born engineer and entrepreneur who founded SpaceX (Space Exploration technologies) in 2002. It’s worth repeating here...

Visit www.popularmechanics.co.za to watch a video showing how Curiosity will be powered for over two years on Mars. Also, see a video showing the major mission events of the Curiosity rover’s landing on Mars.