Geoffrey Yo


Director, Exploration Systems Mission Directorate Integration Office, NASA


ith so much of NASA’s attention focused on safely flying its remaining space shuttle missions while trying to field an exploration-oriented successor amid less-than-steller budgets, it might

seem somewhat academic to be planning a lunar outpost that won’t be built for at least a decade – if at all.

But for the

engineers busy designing

the Orion Crew Exploration Vehicle and its Ares 1 launcher

, the work Geoff Yo

der and the rest of the Lunar Architecture Team are doing is critically important to their own task.

As Doug Cooke, NASA deputy associate administrator for exploration systems, recently put it, the near-term design and long-range planning activities for the Constellation program – encompassing the hardware NASA needs to return to the Moon – go hand in hand.

“The transportation system is integrally tied to what we will achieve at the Moon,” Cooke said. “We must think about the objectives of what we will achieve at the Moon as we design the various components in an end-to-end sense.”

NASA rolled out its lunar surface exploration strategy in December 2006 and spent most of 2007 further refining it. A new

iteration is in the works, but no date has been set for its completion and public rollout.


der, an electrical engineer who worked at

Litton Systems for 16 years before joining NASA in 2000, spoke recently

with Space News staff writer Brian Berger

about how that

strategy has evolved in the past year to feature more mobility sooner.

It’s been only a year since NASA rolled out its lunar architecture. Why the update?

When we rolled out the point-of-departure architecture in December 2006, we knew it would be only the first of many phases. December was about making some key early decisions

: outposts first; go to one of the poles; preserve the ability to go to other locations; use solar power but look at other options. From there, we knew we would do follow-on studies. What we focused on during

the second

cycle was digging down deeper to take a closer look at the operations portion.

What’s changed in the past year?

Coming out of what we call the Lunar Architecture Team 1, or LAT 1, we were looking at using the crewed lander missions to assemble our outpost. In the end, we had roughly five modules we would use the crew to assemble and that turned out to be kind of labor intensive. So as part of LAT 2, we looked at using the unmanned cargo-only missions to emplace our initial outpost modules before the crew arrives. It appears more efficient, reduces risk and allows us to get more exploration time on the first couple of crewed missions. We also built in more surface mobility sooner than previously planned.

What kind of mobile assets will the astronauts have at their disposal?

In LAT 1, our thought was we would start with an unpressurized rover, like we had during Apollo, and add a pressurized rover to the mix maybe three years later. Now we are looking at putting a pressurized rover down earlier. This would allow the astronauts to explore far beyond the 10-kilometer range that’s considered the safe walk-back distance in the event the rover breaks down. The pressurized rover we envision would allow the astronauts to venture 20, 30, 100 or perhaps even 200 kilometers from the outpost in a shirt-sleeve type environment. That’s important, because the astronaut can arrive at his destination in better shape because he hasn’t been getting beaten up by his suit along the way. We’d also like the astronaut to be able to get in and out of his suit in under an hour.

What does NASA currently expect to have on the Moon’s surface at the end of the first full year of missions?

Keep in mind these trades are still ongoing. But we expect to have the basic infrastructure in place we will need to maintain the smaller-duration crewed missions. This includes at least one habitation module and an unpressurized rover on the surface for basic transportation. And we’d certainly have basic power systems because that would come with the habitation module. So our thought is to conduct the first un


mission to the surface in the second half of 2019 to validate our landing systems. Then in early 2020, we would launch a second cargo mission to put down additional supplies. After that we are looking at two missions a year, so we would be putting our first crew down before the end of 2020. They’d have the ability to traverse out to the 10 kilometer range.

Does NASA’s emphasis on increased surface mobility

factor into plans for the habitation


Yes. The initial thought coming out of LAT 2 is our outpost would be made up of two or three habitation modules larger than what we talked about initially with the ability to become mobile. They wouldn’t land with anything like the six-legged Athlete robot we’ve been testing, but there would be an

Athlete-type system on the surface that could squat down and pick up the hab module after it has landed and, for example, transport it back to the outpost site where it could be connected to the other modules. We also have looked at using an Athlete-type system to relocate one of the habitation modules maybe 500-1,000 kilometers away from base. We could then use a small pressurized rover to drive to that location and spend maybe 30 days there exploring, or we could send the crew there directly from Earth with another pressurized rover in tow, allowing them to not only explore that new site, but range another 50 to 100 kilometers beyond. They could live in the pressurized rover several days, or even longer if they towed along additional supplies.

What’s next for NASA’s lunar exploration strategy?

The next phase is to refine what we did in LAT 2 to make sure it provides the necessary high-level information for the design of our transportation system. We need to figure out just how big a lander we need to do what we want to do. We also want to make sure we’ve built the right capabilities into the pressurized rover. For example, right now we envision wrapping a water jacket around the pressurized rover to protect the crew from a solar particle event. Are there other ingenious approaches we should examine? We also will

be working with the Science Mission Directorate to figure out some of the science operations in greater detail.

Does NASA’s revised

strategy create any new opportunities for international participation?

Yes, on the robotic side. Remember during the first go-around, NASA said it would take care of the basic transportation system, the communications system and the landers; leaving the rest open. That has not changed. What has changed is that we initially said we would build lunar robotic landers. But when we looked at our whole lunar profile and then looked at the budget, we asked whether we really needed to do these missions. At the same time, other parties had expressed interest in providing a robotic lander. Since it wasn’t in the critical path of our basic transportation system, we’ve decided to leave that open.

Have you identified new opportunities for commercial participation?

We didn’t reduce opportunities for commercial participation between LAT 1 and the second iteration.

What do you see as some of the promising opportunities for commercial involvement?

Some of the commercial folks are talking about a fuel depot in a Lagrange Point 1. I don’t know how promising that is or not. That’s just what some of the commercial entities are looking at. I would think things like rovers and power systems – whether nuclear or something else – would be great opportunities for commercial as well as international participation. Another area prime for commercial involvement is high-bandwidth communications for public engagement-oriented activities.

Do you think the Google Lunar X Prize will spur activity useful to NASA’s Moon plans?

I would hope it would

. That’s what these X Prizes are about, to really get these operations going and spur new ideas. Space commerce and public engagement are the two big areas


X Prize is influencing. When you listen to the talk on the street that’s what you are hearing.