As I explained in my last post, I recently had the pleasure of attending Planetfest 2012 in Pasadena, CA. Participants got to watch the landing of the Curiosity rover on Mars. Planetfest was organized by the Planetary Society (http://www.planetary.org/), an association of space enthusiasts like me. The executive director of the society is Bill Nye, the “Science Guy,” whom you may have seen on TV. The Planetary Society’s website has lots of articles and the latest news on planetary exploration. It also has a special section for kids: http://www.planetary.org/explore/for-kids/. Check it out!
Planetfest 2012 was held on the weekend of August 4-5 at the Pasadena Convention Center, which is just 5 minutes away from the Jet Propulsion Laboratory (JPL). That is where Curiosity was built and where Curiosity Mission Control is located. The landing was scheduled for 10:31 pm on Sunday. It followed two days of talks from a variety of speakers, including science fiction writers, journalists, space scientists, engineers, and even Charles Bolden, the head of NASA.
But this information was just a prelude to the dramatic final hour leading up to the landing itself. The auditorium was filled with 2000 people and an overflow room held 1000 more. The dramatic video, “The Seven Minutes of Terror"' tells only part of the complex story behind the events that were about to unfold. Communicating with the rover during entry, descent, and landing (EDL) was almost as complicated as the landing itself. Because of the location of the landing site and the extremely weak signal from Curiosity, NASA used satellites in orbit around Mars to act as data relays. The Mars Odyssey spacecraft was the only one capable of relaying “live” data and it could only get into position for about two of the seven “minutes of terror.”
Because it takes 14 minutes for radio signals to travel from Mars to Earth, Curiosity had to land entirely on its own. All anyone in the control room could do was to sit and watch. About 45 minutes prior to landing the big screen in our auditorium was switched to the NASA TV channel. The first thing we heard was that the spacecraft had separated from its cruise “carrier” and had turned its heat shield towards the Martian atmosphere. This news was greeted with loud cheers, making it hard to follow all the fast-paced action over the next seven minutes. Amid the excitement I managed to hear that the parachute had been deployed and then that “we are in powered flight” – meaning that the rocket pack was operating. Finally there were a few seconds with no commentary until it was announced: “touchdown confirmed.” At that point everyone went wild. To top it all off, the first thumbnail picture showing a wheel on the ground was received within about 30 seconds of landing. This was among the most exciting space events I have ever witnessed – it ranks with the first moon landing.
NASA has released a video entitled “Where were you when Curiosity landed on Mars”, which shows these events as they actually unfolded (http://www.youtube.com/watch?v=zervvVw2dnU). They have also released a high definition video taken by a camera on Curiosity as the spacecraft dropped its heat shield and descended to the surface of Mars (http://www.youtube.com/watch?v=Esj5juUzhpU). It shows the dust kicked up by the rocket engines just prior to touchdown, along with some dramatic sound effects.
Curiosity’s landing site, Gale Crater, was chosen for its rich variety of geological formations. The rocks at the bottom of the crater were formed early in the history of Mars – around the time when life appeared on Earth. Other spacecraft orbiting Mars have determined that these rocks contain clay minerals and other materials that form in fresh water. In the center of Gale Crater is Mount Sharp, a mountain 5.5 kilometres tall that contains layers of rock similar to the Grand Canyon. Scientists intend to drive the rover partway up the mountain and analyze the rocks in each layer. This will help develop a detailed geologic and climatic history of Mars – how it may have changed from a relatively warm and wet environment in the distant past to the cold dry desert that exists today.
Curiosity is by far the largest spacecraft ever to land on another planet. It is the size of a small car and contains a suite of 10 highly sophisticated scientific instruments to analyze the geology and chemistry of Mars. The goal of the mission is to establish how long Mars might have been “habitable,” that is to say whether it ever had conditions favourable to the emergence of life. These conditions are liquid water, organic molecules, and a source of energy. Scientists know that life on Earth emerged because these conditions were present very early in the planet’s history.
In the month since it landed, scientists have been testing and calibrating all of Curiosity’s instruments. It is now making its way to a location called Glenelg, where three different types of rock come together. Curiosity will use its full suite of instruments to analyze these rocks, which may shed light on the question of habitability. For ongoing reports on Curiosity, visit the NASA website at http://mars.jpl.nasa.gov/msl/. This mission will no doubt provide years of exciting discoveries about Mars.
Part of Lorne's Lens on Space