An earlier doughnut-shape design is now taller and thinner, about 3 feet wide and 4½–feet tall, more like a soda can with landing legs. Julie Arnold, a Moon Express spokeswoman, said it would be a little bigger than the R2-D2 robot from the movie Star Wars.
The change was made so that it could fit in a smaller rocket that Moon Express now plans to use for the first mission. “That’s considered our starter vehicle, our entry-level vehicle, to reach the moon,” Dr. Richards said.
The MX-1E then becomes like a Lego piece, allowing Moon Express to use it as a building block for larger spacecraft.
“Space vehicles and landers have traditionally been custom designed for each purpose,” Dr. Richards said. “What we’ve designed is a common core approach.”
Moon Express’s second mission would use a larger spacecraft that looks like two soda cans, one stacked on top of the other, essentially two MX-1Es. One will be almost the same lander as for the first mission. The second module — without landing legs — is a propulsion stage that would enable the spacecraft to reach the moon’s south pole, where frozen ice persists inside eternally shadowed craters.
Water ice is a valuable resource for future human settlements, even outside of providing water to drink. Water molecules broken up into hydrogen and oxygen could not only provide air for astronauts to breathe, but also rocket propellent. The ice at the bottom of the craters probably preserves molecules from the earliest days of the solar system, which could be a boon for scientists.
That same configuration, called MX-2, could also be sent as far as the moons of Mars. (To land on Mars would require a more complex, more expensive vehicle.) “It can get basically anywhere in the inner solar system,” Dr. Richards said.
Two additional configurations would put together multiple building block propulsion modules in larger moon landers. A propulsion module at the center could serve as a smaller vehicle that could blast off from the moon, bringing back rocks and soil samples to Earth.
The cost of building and launching a MX-1E is less than $10 million, Dr. Richards said. NASA missions, by comparison, typically cost hundreds of millions of dollars.
“We want to collapse the cost of getting to the moon and by doing so, there is going to be a brand new market that is going to emerge,” Dr. Richards said.
He said he hoped that in the years to come, Moon Express would be launching at least twice a year.
Moon Express is not the only company betting on the moon, which has been largely overlooked since the end of NASA’s Apollo missions four decades ago.
The X Prize was intended to spur commercial endeavors, but the pace of progress has been slower and harder than organizers anticipated with the deadline extended two times. There will be no more extensions, X Prize officials have said.
Astrobotic Technology of Pittsburgh dropped out of the competition last year because the 2017 deadline proved unrealistic. It is still developing its Peregrine lander and now plans a 2019 launch, with 11 customers signed up.
“We’re happy with where we’re at,” said John Thornton, Astrobotic’s chief executive. He said Astrobotic is aiming to launch once every two years and then increase the rate to once a year.
Blue Origin, the rocket company created by Jeffrey P. Bezos from his Amazon wealth, has also expressed interest in the moon, proposing a large robotic spacecraft called Blue Moon to ship supplies for a future human settlement on the moon.