KENNEDY SPACE CENTER, Fla. — NASA will weigh several factors when it makes a Dec. 16 decision on a plan for its Asteroid Redirect Mission (ARM), including how well each option supports later human missions to Mars, according to the agency official who will make that decision.

In an interview here Dec. 1, NASA Associate Administrator Robert Lightfoot said he will use a “matrix” of variables when deciding between two options for carrying out the robotic portion of ARM.

In one approach, called simply Option A by NASA, a robotic spacecraft would shift the orbit of a small near-Earth asteroid, up to ten meters in diameter, into an orbit around the Moon. The alternative, Option B, would use a robotic spacecraft to grab a boulder a few meters across from a larger asteroid and move that into lunar orbit.

“One of the main things I’m looking for is the extensibility to a martian mission,” Lightfoot said. Hardware proposed for ARM under each option should also be applicable for missions to the moons of Mars or even the martian surface itself, he said. “I want to build as little ‘one-offs’ as we can.”

Another factor will be potential commercial partnership opportunities for the mission. That would include, Lightfoot said, “commercial entities coming in to either help us do this or even take advantage of it once we’ve done it.” Other major factors he said he will consider are the technical and budgetary risks of each option.

Polling Three Gs

On Dec. 16, Lightfoot said he will receive briefings from the teams working on the two options. Also in attendance at the NASA headquarters meeting will be William Gerstenmaier, the associate administrator for human exploration and operations; John Grunsfeld, the associate administrator for science, and Michael Gazarik, the associate administrator for space technology.

Credit: NASA

“Those guys are my advisers as we make these decisions and move forward,” Lightfoot said of the three associate administrators, who he dubbed the “Three G’s” in the interview. “Every one of them has a piece of this mission.”

The ultimate decision, though, belongs to Lightfoot. “I’m actually the decision guy for this one,” he said, but added he would inform NASA Administrator Charles Bolden before making a public announcement. “I want to let Charlie know what we’ve done.”

Lightfoot said a public announcement of which option NASA will pursue could come the same day as the decision, or could slip to Dec. 17, depending on when during the day the decision is made and when Bolden is briefed. “It may not be that afternoon,” he said of the announcement’s timing. “It may be the next morning.”

Once Lightfoot selects an option, NASA will integrate that into planning for the overall ARM concept. The agency has scheduled a mission concept review for ARM in February 2015. That review will examine, among other factors, the budget and schedule for the mission.

Lightfoot said they still had a goal of keeping the robotic mission’s cost at about half of the $2.6 billion estimate from a 2012 report by California Institute of Technology’s Keck Institute for Space Studies that served as the genesis of the ARM mission concept. “We’re pretty sure we can do it for that price,” he said.

The mission concept review will also be used to assign ARM to a single NASA mission directorate. Currently, work on the mission is split among the human exploration and operations, science and space technology mission directorates. “Right now, the budget is put into each mission directorate. It’s spread across all three, so that gets a little complex,” he said.

Assigning ARM to one mission directorate will simplify budgeting, Lightfoot said, and also make things easier for him. “They don’t want me, at my level, leading this and having a weekly meeting on this mission from here on out when I’ve got people perfectly capable of doing this,” he said.