Posted on Sun, Nov. 06, 2011
last updated: November 06, 2011 04:54:23 PM
KEY LARGO, Fla. At 60 feet below the oceans surface, alongside coral, fish and a curious goliath grouper, NASA astronauts and scientists spent seven days testing battery-powered jet packs, booms with magnets, robotic arms on one-man subs and other ways to function in zero gravity.
The Florida Keys underwater world is helping NASA prepare for humankinds first trip to an asteroid.
It would be the first time that human beings have left the Earth/moon system and started to explore the solar system, to explore Mars and beyond, said NASA asteroid expert Paul Abell. Thats a very exciting prospect for us.
Such an endeavor will take billions of dollars and years of effort to learn the unknowns and conquer the challenges and risks. But Abell, based out of the Johnson Space Center in Houston, said the ambitious program is worthwhile for many reasons, including this biggie: planet defense.
Twenty percent of near-Earth asteroids are considered potentially hazardous, Abell said. Dinosaurs were wiped out by a big asteroid impact 65 million years ago. We dont know when or where it will happen again, but it will happen again, and it would be nice to be prepared for that event.
While the goal date to send astronauts to a near-Earth asteroid is more than a decade down the road at 2025, to boldly go where no man or woman has gone before starts with baby steps of which some were just taken in Key Largo.
About 70 people including NASA astronaut Shannon Walker, who recently returned from six months at the International Space Station were in the Keys recently for the 15th NASA Extreme Environment Mission Operations, known as NEEMO. The underwater missions simulate the harsh and confined human conditions of space. Six of the crew live at the Aquarius underwater laboratory, a 400-square-foot habitat that rests on the seabottom about 3.5 miles offshore and has been providing lodging and life support for underwater scientists since 1993.
It was the first NEEMO mission dedicated to asteroids, where the lack of gravity causes many challenges that lunar missions dont have, starting with the inability to simply land a space vehicle on the rotating surface.
And you cant just chip off a piece of rock that you want to analyze and put it in your pocket like you can on the moon, added Steve Chappell, NEEMOs Deputy Mission Manager. On an asteroid, it would fly away.
In real missions, things can go wrong. And they did. The meticulously planned 13 days of operations were delayed three days by thunderstorms and cut short Oct. 26 due to the threat of Hurricane Rina. The crew that lived at the habitat needed 15 hours of decompression time and support staff needed several days to clean up the work site.
Despite losing about half the mission, NEEMO Project Manager Bill Todd said much was learned about what works and doesnt work knowledge that will help the program make progress.
Before Rina was a threat, Todd sat on a dock near NASAs Mobile Mission Control, which arrived from Kennedy Space Center, talking about the uniqueness of this mission.
Going to an asteroid is really in its infancy, he said. Going to the moon was a huge challenge, and this is an even bigger challenge. But its fun and rewarding trying to figure out how we would do it.
In April 2010, the behind-schedule Constellation program was scrapped just months before the last shuttle flight. In tough economic times, President Barack Obama redirected NASA to use limited resources to focus on going further into space. Some saw it as bold, while others saw it as leading to the end of the United States leadership in space.
Obama tried to counter the criticism by setting specific deadlines, calling for the manned mission to a near-Earth asteroid by 2025. If all went according to plan, then it would be off to Mars, with a human mission to orbit the red planet by the mid-2030s followed by a manned Mars landing that the 50-year-old president has said he expects to see in his lifetime.
Exploration of asteroids, which orbit the sun but are too small to be considered planets, are important for scientists beyond planetary defense. They are the leftover building blocks, pristine material, that contain all the secrets of how the solar system was formed, Abell said.
Some asteroids are rich in water and organic material. Scientists would like to figure out how to mine those resources for life support and rocket fuel.
Asteroids could be like supply depots in space waiting for you on your way to Mars, Abell said.
And when it comes to planetary defense from asteroids heading for Earth, humans should not rely on last-minute heroics of blowing it up, as was the case in the blockbuster movie Armageddon.
I certainly would not want to be sent to an asteroid to blow myself up, Abell said.
Instead, he said humans should learn how to deflect them from Earth. And since asteroids can be solid metal or rubble piles, like big bags of sand, different strategies are required for different kinds.
In September, NASA unveiled plans for a super rocket called the Space Launch System that will be made to take astronauts to deep-space destinations millions of miles away.
Also in September, NASA held its first simulation of a human mission to a near-Earth asteroid in northern Arizona during its 14th Desert Research and Technology Studies campaign called D-RATS.
They used the extreme conditions of the Black Point Lava Flow in northern elevations to test vehicles that could hover just off the surface of an asteroid. They were equipped with a 13-foot long robot arm that could support an astronaut.
No one extreme environment on Earth can simulate exactly what the situation would be like on an asteroid. The necessary vehicles and equipment would be ruined in salt water.
But the marine world outside of Aquarius is especially good for astronauts and scientists to simulate zero gravity. They do this by becoming neutrally buoyant and not using flippers.
NEEMO 15s mission was to test general concepts and equipment and conduct tasks that would be simple on Earth but tricky on an asteroid: anchoring, moving from point A to point B, communicating with a 50-second delay and collecting scientific samples.
The six-person submersed crew, which included astronauts from the United States, Japan and Canada and an expert on planetary exploration at Cornell University, quickly discovered that getting around without gravity was difficult. So was trying to perform a task, such as chipping a rock, without being stable.
Walker, commander of the NEEMO mission, learned spacewalks on an asteroid differ from dealing with a lack of gravity at the space station. An asteroid does not come with handholds spaced to correspond with a persons reach or manmade interfaces to connect with foot restraints.
NASA needs to come up with innovative exploration techniques, some of which the NEEMO crew was testing.
Speaking from Aquarius on day 5 of the mission, Walker said they have learned that different techniques are good for different things.
To move a long distance, jet packs to fly from here to there are good, she said. But jet packs are not stable when arriving at a destination. We need some way of anchoring at a site.
One way is using a boom a long, rigid telescopic pole with heavy magnets. While the aquanauts had to move like an inch worm, it worked.
As far as how to anchor a space vehicle to an asteroid, one wild concept is to wrap some kind of rope around the entire mass like a lasso.
The International Space Station is about 100 meters and the asteroid size were talking about going to is about maybe the same size, Abell said.
The NEEMO mission also used two DeepWorker submersibles. They basically are small, one-man submarines that simulate the kind of Space Exploration Vehicle that may someday be used to explore the surface of an asteroid.
Whenever we plan to send astronauts anywhere we send robotic spacecraft ahead of them to look for potential dangerous places or hazards, Abell said.
During NEEMO, an astronaut was tethered by his feet to a robotic arm of the sub for scientific asteroid exploration, using coral and fish to represent rock and other materials found in space. They complete four days of these operations, as well as six spacewalks and a day of scientific research inside the habitat.
Todd said its important to have the astronauts, the ultimate end-users, be involved early in the process to provide their input of what works and doesnt work.
Walker, the astronaut who had the rare opportunity to view Earth from the International Space Station, said the experience underwater also has been fascinating.
You look out the window and have fish look back at you, she said. We also have a big grouper that likes to hang out and come out at night.