William Allen, senior engineer at the Jet Propulsion Laboratory, is the mechanical systems design lead on the Mars Science Laboratory (MSL), NASA’s biggest, most expensive, and most capable Mars rover. The rover is set to launch in November 2011.
NASA Tech Briefs: NASA is gearing up for the Mars Science Laboratory to launch in late November. Can you set the stage for us? What is the mission?
William Allen: The Mars Science Laboratory is our next rover that we’re sending to Mars. It’s significantly more capable and massive than the previous rovers that we’ve sent up. It’s nuclear-powered, so we won’t have some of the challenges that we’ve had with solar power. It’s designed to be a science laboratory versus the predecessors that were more like mobile geologists. This’ll actually be a mobile science laboratory. There are 10 instruments on board to facilitate that.
NTB: Can you take us through some of the key capabilities of this Mars Science Laboratory?
Allen: With the size alone, it’ll be able to traverse more difficult terrain. It is designed to drive over objects about 25 inches to thirty inches in size, so that’s different than before. It has a robotic arm, and there is a suite of tools and instruments on the arm itself. For the first time, we will not only collect samples, but we will deposit and analyze the samples within the rover itself.
NTB: What kinds of questions are we trying to answer with this mission?
Allen: Specific questions regarding Martian history, if you will, its current makeup, and its past makeup. The overall Mars program [mission] is to eventually put a person on Mars, so this is the Lewis and Clark effort of pioneering and doing the research to further our knowledge about the planet.
NTB: At the time of this interview (Sept. 2011), what parts of the instrument and spacecraft still need to be finished and integrated?
Allen: Considering it’s a November launch, things are getting down to the wire. The spacecraft is currently being stacked and integrated out in Cape Canaveral as we speak. There are some typical last-minute challenges, but certainly the design is done, and the hardware is fabricated. There might be small things that need fixing or adding, or even things may need to be taken away, at this late hour.
NTB: The rover has to survive a pretty dramatic atmospheric entry and landing. How does the design enable it to withstand that?
Allen: This is something we have a lot of experience with, in terms of entering into another planet’s atmosphere and landing on the surface. It’s about the most difficult space exploration you can do. Orbiting is fairly straightforward, and flybys are fairly straightforward. When landing on another planet, you have to get from about 30,000 miles per hour down to zero, in just a matter of seconds. You’re right. It’s a harsh environment, and it’s a sequence of events and utilizing different technology to enable this.
A heat shield is a primary component of that, much like the shuttle or the reentry capsules that astronauts use here. We have similar equipment on our spacecraft: a heat shield with special materials that withstand high temperatures and deflect the heat away from the actual spacecraft or the rover.
NTB: What are the most exciting possibilities for this mission?
Allen: Personally, my excitement comes when things work: if the rover lands and is functional and driving around, and being able to perform its science. That’s what makes me excited. As a mechanical engineer and designer, that’s my involvement in the program.
NTB: What were the engineering challenges when you were building such a complex rover?
Allen: Because of the size and the number of instruments, it’s an interface nightmare. We’re trying to integrate instruments from different partners, different countries, and different goals. We’re trying to do all that on board, all on one vehicle. Systematically it becomes a challenge to bring all that together. When do you do which science? You have to share all of the resources. We’re restricted in hours of operation based on temperatures. Integrating that and making it work as one vehicle is a significant challenge.
NTB: And what kinds of tools and technologies have been the most helpful when you’re building such a complex instrument?
Allen: We certainly couldn’t do it without the progression of technology. The technology, in fact, that we had when we did the last Mars rovers wouldn’t have helped us do the current Mars rover. With something this complex, we need tools that help us do things in a concurrent fashion. We have a lot of people onboard sharing the same information at the same time. Without that, it would take us four or five times as long.
NTB: How many people are working on this?
Allen: In my area, there were 100 people at its peak on our mechanical design team, and about maybe another 200 engineers. That’s just on the mechanical systems. For the whole project team, the number will be closer to probably 1000 people.
NTB: What’s the key to maintaining order within the groups?
Allen: That’s where management comes in and earns their keep: keeping the troops focused on goals, and supplying them with the right tools and resources to do their job.
NTB: What have your specific, day-to-day work been with the Mars Science Laboratory?
Allen: I serve on a lot of tiger teams, trying to resolve solve systematic problems. Also, I’m in charge of the configuration of the spacecraft, so maintaining that for the design and engineering team is probably the main goal, along with doing the mechanical configuration.
NTB: What do you think will be the biggest challenge in making this mission a success?
Allen: There will be different levels of success, much like the previous rovers. Their design was intended to cover about 90 days, and seven years later, they’re still kicking. So that’s an extraordinary level of success. Here, the MSL is designed to go for about two years. If we’re able to function and process samples and so forth over those two years, it will be considered a success.
NTB: What is the time frame?
Allen: The launch is in November and due to land in the following August. It’ll spend the next two years navigating to places of interest, and taking and processing samples.
NTB: What is the most exciting part of going to work every day?
Allen: It’s probably getting to work on significant and unique things. It’s not every day that something goes up to Mars, and there are not many people in the world doing it. It’s fairly exciting to work on something that unique.
NTB: What would you like to be working on next?
Allen: About a year-long vacation.
NTB: How long have you been at it?
Allen: I’ve been on MSL for 7 years, and I’ve worked on the previous Mars rovers.
NTB: How have the Mars rovers evolved to the model that we’re at today with the MSL?
Allen: They’re certainly a reflection of the growth of technology. We use technology to design and build them, and then we use what technology is available and proven and tested to bring onboard, so it’s kind of a cyclic process. You use technology to design and build these types of things, and the more the technology improves or progresses, the more complicated designs you can do. Even though we’re R&D, we still have to be competitive when we’re spending tax dollars. They don’t fund you just because you have a good idea. You have to have a fiscally sound idea.
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