Donna Shirley Interview (page: 5 / 7) Mars Exploration Program	Print Interview

What were the specific goals of Pathfinder and Sojourner and how were they realized?

Donna Shirley: Pathfinder and Sojourner had really different goals. The way Pathfinder got started was, Mars Observer was going to launch in 1992 and the scientists said, "We're going to be orbiting, we're going to be looking down at the planet with this great complement of instruments. We need something on the ground to validate what we see from orbit." In particular, the weather people said, "Boy, if we had little weather stations all around the planet, and by looking down and comparing with the ground, we can make models that we can use to check out earth models of weather."

The Martian climate is much simpler than earth climate, because earth's is driven by all the water we have. We don't know how to model it, and so they thought if we could model the Martian climate and the Martian atmosphere we could do a better job on earth. So the weather people really wanted this little network. They called it MESUR, Mars Environmental Survey - SUR.

Before we put 20 weather stations on Mars, we'd better figure out how much it's going to cost. The last time we landed on Mars was Viking. That was, in today's dollars, $3.6 billion. Obviously, you can't afford to spend billions of dollars doing this, because we were now in the better, faster, cheaper age. Without the Cold War there's no driver for the big missions. Because the big missions were to flex our missiles and show they were bigger than the Russian's missiles. It was part of, "Hey, I can bomb you if I want to."

So now we have to prove we can land on Mars cheaply. So they started this project called, MESUR Pathfinder, to do one landing on Mars to prove that you could do it cheaply. The Project Manager of MESUR was Tony Spear, who's the Deputy Project Manager of Magellan, which orbited Venus and looked at it with radar. Tony had been looking at how to do really cheap missions.

They put Tony in charge of this MESUR project, which also put him in charge of Pathfinder. And they said, "We've got a new program called Discovery and we'll make Pathfinder the first Discovery mission. You have to build your spacecraft and everything, and all your instruments and everything for $150 million." That was in fiscal year '92 dollars, which turned out for Pathfinder to be $171 million in real year dollars.

So that was where Tony was focused: got to land on Mars cheaply. In the meantime, the funding for MESUR disappeared. So, all that was left was Pathfinder, and it wasn't clear what it was pathfinding for. For a long time I was the Manager of Automation and Robotics at JPL and we were working on rovers. Then I was the manager of a study to do a big rover that was going to explore Mars and gather samples. It was going to be the size of a pickup truck. It could go 100 kilometers, collect samples and bring them back to earth.

We had costed out the mission somewhere between 5 and $10 billion, and when the Cold War ended, that was that. In fact, in 1989 George Bush said, 'We're going back to the moon to stay and then on to Mars." So, all the human exploration people down at Johnson Space Center said, "Hot dog, we're going to start this big human exploration program."

That turned out to be costing hundreds of billions of dollars. The Democratic Congress said to George Bush, "No you're not going back to the moon or to Mars," and cut all the funding for the human program and accidentally cut out all the funding for the robotic Mars program too.

Here we are, no money, and we realize there's no way we're going to send big rovers to Mars. We had been building one-eighth scale models of big rovers, to try out the technology. So we said, "This is probably the biggest thing we'll be able to fly to Mars." By that time we were completely out of money, so I went off to work on Cassini, the big mission to Saturn. I was the Project Engineer. That job was to make sure that the spacecraft, and the operations, and the instruments and the science could all work together.

After about 15 months, Charles Alechi, who's one of the top managers at JPL said, "I think that we should fly small rovers to Mars." He'd seen the technology that my group had developed and he said, "Let's do a demonstration to show that you can build a really small rover -- only seven kilograms, which is less than 20 pounds -- and that can really do science.

He hired a guy named Lonnie Lane, who is a real cowboy, known for being able to do crazy things that nobody else can do. Lonnie put together this demonstration in just a few months of a $2 million rover, named Rocky IV, who could do some science: carry instruments, peck on a rock, and all kinds of things.

Get the Flash Player to see this video. So, at that point they said, "Hey, we'd like to fly this rover to Mars." Now, all this time the technology people at NASA and the science people at NASA are in two different offices. So, the science people would say, "Okay, we're going to go out and get science." The technology people would develop technology, and they'd say, "Why don't you guys use our technology?" The science people would say, "Well, but it's never flown. We can't take the risk of flying it." So, all this technology would just kind of sit there and never be flown. And, the technology people were really sick of it. They said, "Okay, we're going to pay to fly this rover to Mars, so we can qualify it. And then, in the future science won't be able to say that small rovers don't work."

The logical place to fly it was to hitch a ride on Pathfinder, but Pathfinder was a science mission. And they said, "We don't need no stinkin' technology. We've only got a little bit of money to do this job with, and if you bring along this rover it's going to make our job harder." The total would be almost $250 million, when you count the launch vehicle. The scientists said, "You can't spend $250 million of science money and not do any science, that's ridiculous." So they said, "You've got to fly some science instruments. How about a good camera? We need a weather station?

Get the Flash Player to see this video. We needed something to measure rocks because Viking was never able to see what the rocks were made out of. So, the Germans said, "We'll give you -- we'll donate an alpha proton x-ray spectrometer, which measures the elemental composition of rocks, the chemistry of rocks, if you'll fly it." Free instrument, how can you turn that down? Unfortunately, it had to get to a rock.

When Viking landed, it had a little scoop that could reach out and touch some things that looked like rocks, but mostly they would just crumble, because they were dirt clods. They couldn't really do anything with it. So how do we get this spectrometer to a rock? "Hey, I've got this rover." "No, no, no, we don't want that rover. That rover's too big, and expensive, and heavy, and it's just going to cause us trouble. How about an arm?"

Some scientists did an analysis that said the odds of being able to get the spectrometer to rocks with an arm are not very good. If you land in a place that doesn't have a lot of rocks, you can't reach it. Tony commissioned designing a very small rover on a string, on a tether, so it would get all its power and brains back on the lander. It turned out it would cost quite a bit of money and really wouldn't do much. Finally, Tony accepted that he would fly the rover if we would carry the spectrometer. It took years, but we finally got that deal worked out. It was a barter system. We said, "We'll pay all the costs to integrate the spectrometer and you pay the cost to integrate the rover into the lander," and it worked out about the same.

Get the Flash Player to see this video. So, that's how Sojourner got to go to Mars. And, after a while the press got so interested in Sojourner, I mean, this cute little rover -- "Oh, my gosh, it's so cute," -- that it was really a big selling point for the project. And, kept the project from getting a lot of flack because we had this great little rover, and 'Wow! Rover's never been on Mars before!" So, the rover turned out to be an asset to the project.

We spent $171 million for the spacecraft and 25 for the rover and 55 for the launch vehicle, so a total of $265 million, which is about the same price as the movie, Waterworld. Matt Golenbach, the project scientist says, "It was cheaper than Titanic and had a happier ending."

We landed on Mars and our Outreach Manager, Shek Jiara, who is in charge of educational programs and getting the information out to the public about Mars said, "We're going to get a lot of Web hits." So our Web master set up a bunch of mirror sites. We have our server and then people started to say, "We'll host a site that will mirror what's on your server." Pretty soon all the commercial people, like Sun and SGI and DEC, all started to get interested. Everybody's clamoring to mirror our site.

Get the Flash Player to see this video. By the time we landed on Mars, we were capable of handling 60 million hits. And, we needed every bit of it because it turned out on the 8th of July we got 47 million hits. So, Pathfinder was the defining moment for the Internet. And, somebody wrote a little article they said that -- I think it was in the New York Times -- that the Pearl Harbor speech by Franklin Roosevelt was the defining moment for radio. Landing on the moon was the defining moment for television. And Pathfinder was the defining moment for the Internet.

The Nagano Olympics have now exceeded the number of hits that Pathfinder got, but for the first really big event, Pathfinder was just an order of magnitude more than anybody else. Of course, Nagano was weeks long.

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