Home Table of Contents What's New Image Index Copyright ScienceViews Search

On Mars: Exploration of the Red Planet. 1958-1978

[358] After the second landing, seven key Viking team members talked about the landing site selection process. Of the lessons they had learned, had they labeled any as especially significant? If later there were a third mission, what would they do differently? All these men had worked toward the same [357] end-safely landing two spacecraft on the Martian surface-but they had viewed the experience from seven different perspectives.
James S. Martin . Support for his decisions from the space agency's top management in Washington figured highly in Martin's recollections. Postponing the Fourth of July landing had probably been one of his most difficult moves. Martin had been "quite horrified" by the first photographs of Chryse, remembering the rough dry river beds and uneven washes he had walked over in Death Valley. And the river bed they had seen on Mars was many times larger, with cliffs hundreds of meters high. It has been his choice to make, and he had wanted a safer site. Martin remarked that even if Viking had safely touched down on the Fourth of July, the landing "would have been lost among the Tall Ships," a reference to the publicity given the bicentennial parade of ships in New York harbor. That historic date had been chosen in 1970 after a preliminary trajectory analysis singled out the first week in July 1976 for a landing, but the Red Planet had not cooperated. The bicentennial was celebrated without a Viking on Mars.
If Martin were going to land a third Viking, he would make some changes. He was unhappy with the data with which they had had to work.. If there were to he a next time, he wanted to equip the lander with a terminal-hazard-avoidance device or a computer-controlled laser guidance system that could evaluate the surface and pick the safest part of a general area in which to land, Both kinds of hardware were available; the latter concept had been used in "smart bombs" in Vietnam. Martin and all his colleagues wanted more information guiding the next Viking on its final approach. A terminal guidance system would eliminate any radar versus photography controversy, Martin suggested, still skeptical about the use of radar.
I'm not convinced that the radar told us anything useful at all. But on the other hand, I believe that it provided an input and a source of information that [we] could not ignore....
I looked at the radar a source of data. I frankly never did.....accept it as an absolute....But I've got to believe that when they get a pass, like at that Northwest Site, and there's something screwy right in the middle of a place that looks just like everything else [in the photographs], the radar is seeing something. For all I know, it was seeing sand dunes....it could have been seeing something perfectly safe, but the fact that it was so different scared me off." 73
A. Thomas Young . Radar played a useful role, Young believed, as he reviewed the background of using radar as an aid in landing site certification, "When we went through the initial selection [process], radar played no role, because we weren't smart enough to know how to use it." But Young and Gerald Sullen had gone to Stanford University to confer with Von Eshleman and Len Tyler.
NASA provided the funds for Tyler and his colleagues to develop the means of interpreting radar data so this tool could be used to evaluate the [358] nature of proposed landing sites on Mars. Young's basic philosophy had been: "Use whatever tools we had available to the maximum extent we could, recognizing that none of them was good enough for absolute site certification." He thought they had probably used this tool before they fully understood what the signals meant. While the technique for interpreting radar data had not matured to the extent that they had absolute confidence in the results, he believed that the radar signals received from the A-1 northwest site did indicate that it was unsafe. Above all, Young commented, they had to be responsible in how they used the data provided them. 74
Gerald A. Soffen . As project scientist, Sullen was interested in the process of scientists at work and concerned that that work be consistently credible. Caught in a philosophical frame of mind after a few days' rest, Soffen said he believed that the crisis over the landing sites had forced them to study the planet with an intensity that would not have existed if Mars had been as bland as Mariner 9 had led them to believe. Talking about the days between 23 June and 21 August, Soffen said:
We learned about Mars in that period. And it is sad to say we will probably never learn as much from the Orbiter pictures...as we did during that intensive period-because we had to, Because people were forced around the clock to do work and integrate their efforts in a way that unfortunately they don't do simply because they are inspired. Inspiration works to a very small extent on any person. What drives us is necessity....
Soffen's observation was that, since only so much data could be collected and since they were working against the clock, the scientists could not retreat into the familiar excuse "I need more data."
Because time was an element that we could not sacrifice, the energies of the people and the brilliance, deduction, the thought, the concerted effort, was as intensive as anything l have ever seen....It was most remarkable. Remarkable because I saw people who otherwise have to take days off, have to take time off, have to relax. Their adrenaline kept them going in a way that l have never seen....That was the moment in which the true concept of a team met its test. It was like an army that was desperately fighting for its life. It was either going to win or it was going to lose. It is not a question of "Maybe I'll survive and they won't." We're all in the same space program.
Soffen believed some important lessons were learned during the search for sites. First of all, they had erred in trusting the Mars maps based on Mariner 9 findings. He suspected that if someone had shown the Landing Site Staff the actual photographs or had verbally described the surface of the planet to them using the raw data, they would not have had such confidence. "But seeing the U.S. Geological Survey maps, the straight lines and real numbers and real elevations, gave it an air of credence...."A second lesson was that real-time decision-making had to be a combination of effort [359] between mission specialists and managers. Before Viking arrived at Mars, Soffen had formed a four-man landing site advisory group-Josh Lederberg, Brad Smith, Toby Owen, and Carl Sagan-to listen to the site certification deliberations and advise Sullen, Young, and Martin. But events moved too last. There was no time to reflect and cogitate; decisions had to be made; Landing Site Staff meetings never followed a neat pattern. 75
Hal Masursky pointed to the same problem. Mosaics, just recently pasted together, were often brought into meetings in progress. There he was, laced with interpreting completely new information on the spot, with ,everyone waiting for his words of wisdom so a decision could be made, "That's hard to do," he noted, "Emotionally and managerially it's not the right way to do it. You need to work, digest, come to conclusions by arguing and then pass on a recommendation," But there was never time. For example, the team would schedule 8 days for the analysis of a particular issue, but the specialists might be able to devote only 10 seconds of wits-gathering to the problem. Pressure from the mission schedule made the scene tense, and too often general scientists, members of the landing site advisory group, for example, had to defer to specialists. Masursky, among others, was not as concerned about the pace as he was with the precipitous nature of their decision-making. But they had committed themselves to the real-time game, and decisions had to be made on schedule. 76
One other observation Soffen made dealt with spheres of influence. Position in the project hierarchy had little to do with power of influence over Jim Martin, "an absolute dictator,'' in Soffen's words. If any one person-regardless of rank-had an idea that made good sense to Martin, he listened and acted accordingly. During early July, it had been Tyler who had held center stage with his radar data. "A week earlier we dismissed what Len Tyler had to say, as though we weren't interested," Sullen recalled. The activity of so many intense individuals working closely together gave the site selection-site certification process a dynamism typical of the entire Viking effort. 77 Such a human endeavor needed discipline.
B. Gentry Lee . If Jim Martin were the dictator, as many had suggested, Gentry Lee was the intellectual disciplinarian. From his vantage point as science analysis and mission planning director, Lee noted that "we went into the site certification process with two distinctly different views of how it was going to operate." Many project personnel members-Lee, Martin, and Young among them-did not want to deviate from the previously selected sites unless it were absolutely necessary, since they were relatively certain they had found the best sites available. All the mission operating plans were designed for those targets, with time and money arguing against changes. But a second group, primarily scientists, wanted to search for even better sites during the certification process. Caught between the two were men like Mike Carr and Hal Masursky, who simply wanted to see that the spacecraft landed safely in a scientifically valid location. Probably the only thing that averted open controversy was the terrible nature of the prime Chryse region.
[360] Lee found himself in the role of interlocutor. Even more important, it was his task to ensure that the operational people and the scientists understood each other's needs and limitations. Lee participated in the Landing Site Staff meetings not only to translate for each group the other's goals and problems, but also to make certain that the discussions remained germane to the issues at hand. When they did not, he turned disciplinarian, "trying to get people back where they belonged."
After Lee looked over the photographs of the Martian surface sent back from the two landers, he concluded that if the flight team had seen the sites that clearly before the landings, it would not have certified them as safe. The team had sought zones that were 99 percent "landable," and to Lee the sites they had chosen now appeared to be hazardous at best. "But the thing that we don't know is how much worse the areas may have been that we rejected." Without the rigorous search-certification operation, they would have had no hope of a successful landing. Lee and Martin agreed that a third Viking landing using the same certification tools would have no guarantee of touching down safely. Before another craft was sent to Mars, Lee hoped they would have a better understanding of radar and infrared thermal mapping. He also had hopes that the low-altitude photography planned for the extended Viking mission, with periapsides as low as 300 kilometers, would give them a totally new look at the surface. including hazards of the 15- to 20-meter scale. 78
Michael H. Carr . Mike Carr also had something to say about low-level photography. Commenting on the gap between the 100-meter-resolution orbiter imaging photographs and the lander photographs, the leader of the orbiter imaging team said:
We've got to bring the orbiter down in the extended mission to 200,300, 400 kilometers and use the scan platform for image [motion] compensation. [We must] squeeze the maximum resolution we can out of the orbiter cameras over significant areas, so that we're getting data at a much liner scale in anticipation of the next [mission]....There will only be one next one-a rover. We just can't afford to have it crash.
Even though cameras would be on board any future spacecraft, Carr believed that the site selection team ought to be armed with data at a scale relevant to the lander. Better photography and a clearer understanding of radar and the infrared system would make the job easier. 79 Both Carr and Masursky thought that image-motion compensation was necessary for any future low-altitude orbital photography of Mars, to prevent the images from smearing.
Harold Masursky . The leader of the landing site certification team said he would like to attach a mechanical image-motion compensator to the Viking cameras. With this device, he knew how` he would fly a third mission. The spacecraft would be inserted into low Mars orbit, to take higher resolution site certification pictures. From these low-altitude [361] images, the flight team would be able to avoid hazards of a smaller scale and select key topographical features which the lander could guide itself, using either laser or television. After a site was approved, the orbiter would obtain a higher altitude and release the lander. All the technology Masursky wanted to use was available. What they did not have was NASA's approval for a third flight-and the funds. 80
Coming down to Earth, Masursky commented on the effort made by Martin and Young to maintain the scientific integrity of the Viking missions. No matter what problems came up, the management kept reminding everyone that the primary objective was scientific investigation after a safe landing. With many critical issues facing them daily, Martin and Young never forgot the main goal. 81
Carl Sagan . As a scientist, Sagan was impressed by how "remarkably willing to listen the project manager was." If anything, Sagan had been prepared for resistance to such items as postponing the 4 July landing and taking a closer look at radar data. But Martin had kept an open mind. "It sounds like a reasonable thing for a project manager to do, but that's not always been the case in past missions." 82
Martin and Young had listened. They had not always accepted the advice given them, but considering the immense task they had faced and their success they must have made the right decisions. They had safely landed two out of two spacecraft, and luck had had very little to do with it. Martin would continue to believe that hard work and discipline were better bets than luck. The site selection-site certification process had been time consuming, tension-filled, and seldom an "exact" science, but it had worked-and worked on a planet 348 million kilometers from Earth. With two successful landings behind them, the Viking team could turn to the real reasons for its labors-the scientific examination of the Martian surface and the search for possible life forms on the Red Planet.