Polar Exploration On Mars
Phoenix successfully rises from the ashes of the Mars Polar Lander
by Michelle Evans
“Standing by for touchdown. Touchdown signal detected.” With those few excited words from the Jet Propulsion Laboratory Phoenix mission control, America had landed another probe on Mars. And for the first time since the Viking missions in 1976, they had done so successfully using rocket power.
This mission is a major vindication following the debacle of the 1999 Mars Polar Lander mission that failed, most likely due to a single improperly-set computer bit (see, “Mars Exploration: Where Do We Stand,” O.C.Space, March 2000). The backup spacecraft for that mission, aptly named Phoenix, now stands in the high Martian northern polar region, ready for a three-month-long nominal mission to study its environment, poised to possibly answer questions about if Mars has ever had, or might still have, the proper ingredients to support life.
Mars has often been called a graveyard for spacecraft that failed to reach their goals. Between the Russian and U.S. space program, up until Phoenix landed at 16:54 PDT on Sunday, May 25, less than half the probes that made the attempt had survived. Just looking at the American side of the equation gives us better numbers, with six out of seven landing attempts being successful.
With what many would consider long odds, Pete Smith, the Phoenix Principal Investigator from the University of Arizona, Tucson, joked optimistically about the possibilities less than five hours before touchdown. He told us, “There’s a window washer up on the hundredth floor of a building, and he slips off his scaffold. As he’s falling, one of the executives is out on his little balcony; he sees him coming and yells, ‘How ya doing?’ The window washer says, ‘Okay, so far.’” After laughing, Pete continued, “Now, I realize why he gave such a positive answer: that window washer was carrying a parachute; not only a parachute, but he had a rocket pack, and he was able to land safely on the sidewalk and walk away a happy man. So today we’re doing something very similar. It’s okay so far, and we have a parachute and we have a rocket pack, and we’re going to land safely on Mars.”
The public still holds a great fascination with space exploration, especially of Mars, at least when given the chance to know what is happening. It has been over four years since the twin rovers landed and started their investigations, and Spirit and Opportunity still hold the imagination of those who know they are alive and well a couple of hundred million miles from home. Along with Phoenix to the north, we now have three active science stations scattered about the rusty globe.
As with previous landings, the Planetary Society put together a new version of their Planetfest program, to give people a place to go to watch the proceedings as they happened. Several members of the Orange County Space Society gathered with 750 others, watching events unfold. Hosts included Bill Nye, the Science Guy, and Louis Freidman, Executive Director of the society. Special guests included a phone call from Ray Bradbury, and Donna Shirley, former head of the JPL Mars Program Office. While waiting for news from Mars, many different events occurred, the most memorable of which was a tribute to the late Arthur C. Clarke which included a reading from his first novel, The Sands of Mars, published in 1951.
As landing time neared, the auditorium was turned over to a live television feed from JPL. As Phoenix seared through atmospheric entry, popped its parachute, and used its rocket pack to safely and gently touch down on Mars, the crowd cheered, vicariously riding along during the “seven minutes of terror,” as the scientists had so aptly called the final descent to landing.
Cherie and I had been at JPL earlier that day and met Pete Smith of the University of Arizona, and Barry Goldstein, the Phoenix Project Manager at JPL. Now we watched them enjoy the fruits of their labor. At one point in a tense part of the landing sequence some-one remarked that it looked like Barry was going to have a heart attack. Next to him stood a bald man who looked like a doctor. Cherie quipped, “It’s okay, that’s his cardiologist!” In actuality, it was Ed Sedivy, the Lockheed Martin Phoenix leader.
It then took another 90 minutes for the first photos to be returned from the surface. In the meantime, Bill Nye entertained the crowd with his science. When it was mentioned that the mission had cost $420 million, Bill shot back, “and they left it there unlocked!”
Photographs were slow to arrive, then the floodgate opened. Shots of the lander solar panels, one of three landing legs, then finally one showing the horizon. Phoenix had landed—as intended—on an almost featureless flat plane. Rocks no larger than pebbles, and soil frozen into a regular hexagonal pattern as far as could be seen, just like similar landscapes on Earth. This is the perfect patch of ground from which Phoenix can unstow its robotic arm and start digging for signs of water ice on Mars.
Aboard the lander are 22 small cells which will each eventually be filled with tiny amounts of gathered soil, then experimented upon to see if the right conditions existed on our celestial neighbor so that life may have once gained a foothold there. But for now, that part of the exciting mission lies in the future. A lot of work is yet to be done over the time left before the Sun sets for the Martian arctic winter, freezing the lander and its electronics, silencing it forever.
As things started to finish off at Planetfest, we returned to JPL for the final press conference of the evening, four hours after landing. First up was NASA Administrator Mike Griffin, who told us, “Today you had the chance to watch a team make something that is incredibly hard, look easy.” To explain that difficulty further, Ed Weiler, NASA Associate Administrator for Science Missions Directorate, said, “Doing something to that accuracy is akin to teeing off in Washington and hitting a hole-in-one in Sydney, Australia, 10,000 miles away. That’s not a bad shot!” To which, JPL Director Charles Elachi broke in and said, “You have to remember, that hole is moving!”
It was a jubilant crowd at JPL. Mission members, interspersed with news media, watched the story unfold again on the big screen at the Von Karman auditorium, narrated by those who made it happen.
Elachi put it in perspective by saying, “I’m sure you know throughout history, exploration always required courageous people, and people that have superhuman dedication. Many people thought that this would not be possible. That we would not be able to succeed. All of us knew this was a very risky mission. But tonight this team made history. They will be remembered forever as the first people to explore the polar region of Mars. There’s no telling what discoveries we’ll be seeing over the next 90 days.”
Pete Smith runs the science team in Arizona, and finally has the opportunity to start work now that Lockheed Martin and JPL have safely gotten their Phoenix down onto the hard-packed soil and ice at the Earth-equivalent latitude of the high northern latitudes of Canada, well above the Arctic Circle.
“The science team has been waiting patiently down at the University of Arizona at our Science Operations Center,” Pete told us. “They’re anxious to use their instruments. These instruments that we have provided for the Phoenix mission are really not meant to work on Earth. These are instruments made to work on Mars. And they are anxious to get to the environment where they were designed to be in. So, for the next three months, we’re going to put those instruments in the place they were designed to be, and we’re going to operate those instruments, and we’re going to try and understand what’s the story of this ice that was discovered by [Mars] Odyssey [orbiter]. I think this will change our understanding of Mars and hopefully guide future missions. We see Phoenix as a stepping stone for future investigations of Mars.”
The Planetary Society placed a small package on the Phoenix lander in the form of a special space-qualified mini-DVD. On it is the first library to be sent to another world. Copies of books, photos, and greetings from Earth to some future astronauts are included. One especially poignant recording was made by the late planetary scientist Carl Sagan. In his recording, which now resides affixed to Phoenix, Carl talks to a future generation of explorers who will hopefully find the disc and place it properly in a library for all settlers of the red planet.
“I don’t know why you’re on Mars,” Carl begins. “Maybe you’re there because we recognize we have to carefully move small asteroids around to avert the possibility of one impacting the Earth with catastrophic consequences, and while we’re up in near-Earth space it’s only a hop, skip, and a jump to Mars. Maybe you’re on Mars because we recognize that if there are human communities on many worlds the chances of us being rendered extinct by some catastrophe on one of them is much less. Or maybe you’re on Mars because of the magnificent science that can be done there—the gates of the wonder world are opening in our time.”
Carl stops a moment to collect his thoughts. “Maybe you’re on Mars because we have to be, because there is a deep, nomadic impulse built into us by the evolutionary process. We come, after all, from hunter-gatherers. Ninety-nine point nine percent of our tenure on Earth we’ve been wanderers, and the next place to wander to is Mars. Whatever the reason you’re on Mars is, I’m glad you’re there, and I wish I was with you.”