Curiosity about life on Mars
On July 20, 1969 Neil Armstrong uttered one of the most remembered quotes of the 20th century, “That’s one small step for man, one giant leap for mankind….”
Millions of people heard these words as they watched, via grainy black and white television images, Neil Armstrong step from the landing pad of the Lunar Module Eagle onto the surface of the Moon.
With that single step Neil Armstrong became the first human to step foot onto a celestial body other than the Earth. He was joined 14 minutes later by Buzz Aldrin.
To date, 12 people have stepped foot on the Moon. The last Apollo mission was Apollo 17 in December 1972; Apollo 18, 19 and 20 were scrapped due to rising costs.
Curiosity about life on Mars
At 2:21am (AEDT) on November 26, 2011, the Mars Science Laboratory launched from Cape Canaveral in Florida. The payload of this spaceship is not humans. Rather, it’s a remarkable 899 kilogram, six-wheeled Martian rover named Curiosity.
The purpose of Curiosity is to determine the habitability of Mars. The mission , lasting one Martian-year (98 Earth weeks), will begin on August 5, 2012. It’s mission is of scientific significance and perhaps even of human significance.
Curiosity will carrying out the prospecting stage in a step-by-step program of exploration, reconnaissance, prospecting and mining evidence for a definitive answer to, “Has life existed on Mars?”
There are three conditions that are considered crucial for habitability. They are: liquid water, the other chemical ingredients utilized by life (such as nitrogen, phosphorus, sulfur and oxygen), and finally a source of energy.
The landing site for Curiosity, the Gale Crater, was chosen to maximize the chances of answering this question. It was identified as having mineral evidence of a wet history by both NASA’s Mars Reconnaissance Orbiter and the European Space Agency’s Mars Express.
The Gale Crater provides a variety of accessible features for study. Included are clays and sulfate-rich deposits which are good at latching onto organic chemicals and protecting them from oxidation. There are also features that will shield any organic chemicals from the natural radiation.
The natural radiation levels on Mars are higher, due to its lack of a screening atmosphere. The site offers rocks that have become exposed by recent small-crater impacts. One capability of Curiosity’s science payload is to look for these organic chemicals; the carbon-based building blocks of life.
A Tweetup comes to Canberra
Many people will remember what they were doing on “the day that man landed on the moon.” I raced home from primary school to watch the moon-walk live. As an adult I pursued science, physics in my case, as a profession. Many others fired by childhood dreams of being an astronaut or inspired by the astronaut program became scientists and engineers.
I also will remember where I was when the Mars Science Laboratory launched. I was at the Canberra Space Centre in Tidbinbilla attending the #CSIROTweetup. This was a group of 50 science ‘geeks’ who headed to the Australian capital city, Canberra, to tweet about the launch.
NASA has made a tradition of Tweetups to cover it’s most recent launches. The idea was transplanted and organized to Australia by Vanessa (@NessyHill) Hill from CSIRO in Townsville who had attended ISS and GRAIL Tweetups in the US. The event in Canberra was hosted by Glenn (@DSNCanberra) Nagle from the CSIRO run Canberra Deep Space Communication Complex. This is a NASA tracking station that is managed on their behalf by CSIRO.
I found the weekend a most enjoyable experience. Mixing with what can only be described as an eclectic group of people. A group whose joint characteristic was a interest in space exploration. A number had also attended previous #NASATweetups and at least one will attend at least the next launch as well! The idea of a Mars landing Tweetup was discussed with great enthusiasm.
I found three moments particularly memorable. The first was the silence at the precise moment of the launch. The clatter of tweeting keyboards had ceased and I’m sure room full of observers had collectively stopped breathing. The launch was greeted with intake of breaths and elated cheering.
The second was sheltering from drizzling rain under a tin car-port. The group had walked here to near the DSS34 antenna to watch for the spacecraft to come over our horizon. It was hoped that we might see the final burn of the Centaur main engine and the separation of the spacecraft. This final maneuver lofts the spacecraft out of Earth orbit and on its way to Mars. The antennas, DSS34 and DSS45, at Tidbinbilla are the first of NASA’s Deep Space Network to receive communication from the spacecraft.
Cloud obscured any possibility of seeing the burn phase. It was rather profound though watching the dish antenna. Both the tracking dishes ‘staring’ at the horizon. Then synchronously slowly tracking the spacecraft as it above our horizon and across the night sky on its 210 day cruise phase to Mars.
The Canberra sites three antenna have a constant 24hour schedule of communicating with all manner of deep space probes. My third moment was the realization that Voyager I was part of that schedule whilst I was there. Imagine this Voyager I was launched in 1977 and is currently at the outer reaches of our solar system and there we were picking up its data signals, a engineering and science wonder!
Finding a place for humans on Mars
There is much to get excited about this Mars mission. Not only from the ‘normal science’ arising from the explorations. It is a large incremental step into uncovering profound insights into Mars’ past and present environments. It is a crucial next step in the program strategy towards missions that ultimately return soil and rock samples to Earth.
For those intrigued by engineering there are two things of note. Firstly the virtuosity of the “sky crane” descent of the lander and secondly the Mars Science Laboratory rover Curiosity.
The lander enters the Mars atmosphere initially much like the Apollo mission re-entered Earth’s atmosphere. It uses atmospheric braking followed by a parachute descent. Then, at about 1.6km to touchdown the parachute shell separates.
A rocket-powered descent-stage lowers the rover to within 20 meters of the surface. The descent-stage then deploys the rover to touchdown on a ‘sky-hook’ of nylon cords . When touchdown is detected the descent-stage then continues, under power, past the rover touchdown area. There was much discussion at the #CSIROTweetup about this novel landing. I think there will be many, the NASA engineers included, who will be holding their breath at this crucial point.
The rover, Curiosity, for the first time lands on it’s own wheels. Curiosity is then ready to begin characterizing the landing site, conduct health checks of various systems and start taking weather measurements. The last two Mars rovers, Spirit and Opportunity landed as rolling ‘airbags'; I find the ‘sky-hook’ a far more elegant and hopefully gentler landing maneuver.
During the descent I am looking forward to the view from the Mars Descent Imager. For the final few minutes of Curiosity’s flight to the surface there will be full-color imaging of the ground. This will provide all wannabe astronauts a real-time experience of riding a spacecraft to a landing on Mars.
For me there is special interest in one group of seemingly trivial experiments. Curiosity will record information about daily and seasonal changes in Martian weather. These instruments are the Rover Environmental Monitoring Station. The team plans on posting daily weather reports from Curiosity.
Information about Martian wind, temperatures, and humidity will provide a way to improve and verify atmosphere modeling of Mars. For the first time the full ultra-violet spectrum of radiation will also be measured. This will strengthen the understanding about the global atmosphere of Mars.
This all contributes to the mission’s evaluation of habitability. These are all crucial steps towards the ultimate missions that land humans on Mars.
This station also showcases some of the international involvement in the science payload of Curiosity. The principle investigators are from he Spanish Centre for Astrobiology and Spanish National Research Council. Whilst the Finnish meterological Institute developed the pressure sensor on this station. Other nations included in the science payload collaborations include Russia, Canada, and France.
Space exploration post the Apollo era
These missions were intended to maximize the scientific aspects of each journey. Ground-breaking research has been carried out on zero-gravity science and engineering,how to build and maintain non-terrestrial habitats and the intricacies of space-travel. Much has been learned about the psychology and physiology of the extended periods of isolation and gravity-free existence that will be necessary for interplanetary exploration.
Despite all these achievements these missions did not seem to generate the same levels of public inspiration as the Apollo moon-shots. They have generated significant professional science and engineering interest. As well there is a core following of ‘space geeks’. This is evidenced, for example, by the the crowd that watched the final shuttle launch and are participating in #NASATweetups and #CSIROTweetups.
There is also a small but growing commercial interest in spaceflight. Virgin Galactic and ShareSpace provide some of the alternative ideas for commercial human spaceflight. For US$200,000 you can book a space flight aboard the Virgin Galactic SpaceShipTwo. Meanwhile Space Exploration Technologies, or SpaceX, will launch its Dragon spacecraft on its second Commercial Orbital Transportation Services demonstration flight on Feb. 7, 2012. Pending completion of final safety reviews, testing and verification, SpaceX might also send Dragon to rendezvous with the International Space Station.
At the same time there are also the established space aspirations of the Europeans, Russia and Japan. Then there is also the emerging push by the Chinese and it would be foolish to discount other pushes by India for example.
Human exploration of Mars may just be what is required to provide that next inspirational step for mankind. With the current pace and breadth of space exploration, there will be somewhere on Earth a 9-15 year old who will in all probability become the first human to step onto Mars. I expect to remember where I was on that memorable day.
I like to think that Mars exploration will fire a new generation to great dreams and achievements.