Though Nasa has spent billions of dollars and countless hours trying to get people into space, what they actually do up there can be an afterthought. Lim wants to change that.
"You're trying to keep people alive and trying to get them beyond low Earth orbit . . . there are experiments that are done, but the science isn't really baked in," Lim said. "But when we head out to somewhere like Mars, and we're going to be there for a while . . . we're going to have to look at designing these missions with an inherent component to science."
With the exception of space suits - and the thin, oxygen-less atmosphere that necessitates them - it is as high-fidelity a mission to Mars as Lim can muster. The Hawaiian mountainside is similar to the landscape scientists think existed on Mars billions of years ago, when the atmosphere was thicker and the planet seethed with volcanic activity.
The "astronauts" tasked with collecting rock samples use instruments that are being developed for real space missions; one heavy backpack contains a spectrometer that is destined to fly to the moon.
Their time in the field is limited to the length of an average astronaut excursion outside the spacecraft: about four hours per day. Their communications to "mission control" (the conference room where Lim and her colleagues are set up) are subject to a five- to 15-minute delay that mimics the actual signal latency between Earth and Mars.
And the science is real. Unlike many other Nasa analog missions, which test gear and operations design on safe, familiar terrain, Lim and her team are exploring a site they have never seen. They are collecting rocks not for practice, but for research - the samples will be studied to understand the relationship between rock types and the microbes that live in them. Some day, the scientists hope their findings will help guide the search for past or present Martian life.
Nasa has been trudging toward its goal of launching a human Mars mission in the 2030s - though at the programme's current pace, it's unlikely to meet that deadline. And about six weeks before the mission's trip to Hawaii, SpaceX founder Elon Musk announced his conceptual plans for a powerful rocket and spacecraft that would help humans colonise the Red Planet. Discussing the news at Nasa's Ames Research Center in Moffett Field, Calif., engineer Amanda Cook shook her head.
"The rocket's the easy part," she said. "It's people who really throw a monkey wrench into things."
This is the guiding principle for the Hawaiian mission, called Basalt, which stands for Biologic Analog Science Associated with Lava Terrains and is also the name of a kind of volcanic rock.
Robots, satellites and space telescopes have produced pioneering, Nobel Prize-winning science - and they don't require food, oxygen or a return trip home. If Nasa is going to put humans on Mars, it needs to be certain the discoveries made are worth the expense and risk of sending them there.
Lim has recruited experts from a wide range of fields to help with her Mars analog mission. Engineers such as Cook are building instruments that astronauts can carry on their backs and in their hands. Computer programmers develop communications software that can inform astronauts without overwhelming them. Geologists establish protocols for quickly analysing rock types and prioritising which ones to sample. The team even includes an ethnographer whose job is to analyse members' interactions and figure out better ways for them to collaborate - a necessity for future Mars astronauts, who will have spent months in cramped, inescapable quarters.