Landing on the moon in 1969 has been considered the most spectacular achievement by mankind
in our quest to explore our solar system, and the universe. But man is now ready to
take another giant leap in space exploration by landing a man on an asteroid.
This is no longer science fiction or the stuff of movies. It is really happening.
NASA currently has a program that is not only exploring the possibility - but astronaut
selection and a training program is already underway. NASA is planning to send humans
far further than they have ever been before by making contact with an asteroid up to 3
million miles away by the end of the next decade.
If the mission goes as planned, it would mark a milestone just as significant as Neil Armstrong’s
‘small step’ on the moon. To go to an asteroid, humans will have to venture for
the first time into “deep space”, where the sun, not the Earth, is the main player.
Asteroids are interesting on many levels. The primary goal is to learn about their hostile
environments and the skills needed to work on their surface. Asteroids are also essentially
an historical record of billions of years of our universe where we can take samples.
NASA hopes that such asteroid missions will provide new scientific information about the
early universe while also providing valuable information for ways of defending the Earth
from collisions with asteroids. Earlier, scientists identified an asteroid more than 460 feet
wide that could come close enough to Earth to collide with our planet in 2040.
Such missions to asteroids could also help test technology needed for future human missions
to other planets. Landing on an asteroid is the next step toward a manned landing on Mars.
Landing on an asteroid however, presents new and different challenges than landing on the
moon did. For one thing, the moon is only 236,000 miles away and remains steady, orbiting
around the earth. An asteroid on the other hand, can be much further away, does not orbit
the earth but orbits our sun in what can be an extraordinarily large orbit. In addition,
an asteroid wobbles and tumbles as it orbits. Added to that is the fact that asteroids have
almost non-existent gravity to hold a spacecraft or astronaut on its surface. The spacecraft
may have to hover around the asteroid and the astronaut may have to spacewalk down to
the surface. An astronaut could become disoriented on an asteroid as it would be so small that
when it rotates or tumbles the sun would appear to spin rapidly across the sky and the horizon
would be only a few hundred yards long. NASA is developing special living quarters,
radiation shields, and other new technology to allow astronauts to live in deep space
for long periods. In zero gravity your bones start to lose their strength (similar to old
age) at a rate of about 1% per month and muscle tissue - including the heart starts to waste
away too. Also, when no longer shielded by the Earth’s magnetic field, the body is
exposed to cosmic rays which can damage DNA which can result in tumors. Space radiation
would raise the risk of cancer and in extreme cases cause nausea and vomiting. Another effect
is the formation of cataracts in the eyes and for good measure the central nervous system
can be damaged too with the brain being especially susceptible, leading to possible degenerative
brain disease. Scientists need this kind of science if we
are ever to send manned missions to other planets. And it is this kind of science that
robots could not provide. By sending astronauts, scientists believe they would learn more about
the psychological effects of long term missions and the risks of working in deep space. It
would also allow astronauts to test kits to convert subsurface ice into drinking water,
breathable oxygen and even hydrogen to top off rocket fuel. All of this would be invaluable
before embarking on a 2 year expedition to Mars. This crew will be more on their own
than any other crew in history. Once on the asteroid, the astronauts will
need some combination of jet packs, spikes or nets so they could travel around the asteroid
without floating off into space. They will also need some way to hold themselves down
on the asteroid. We are still studying how strong the surfaces of asteroids are and whether
they can even hold an astronaut in place. Otherwise, they would launch themselves into
space every time they took a step. A manned mission will aim to rendezvous with
an asteroid up to 3 million miles from the Earth, taking about a year to complete the
entire round trip. The astronauts could stay on the asteroid for up to 30 days. While Apollo
11 took 8 days to go the moon and back in 1969, a typical round-trip mission to a near-Earth
asteroid would last about 200 days. And it would be riskier. Unlike the Apollo 13 mission,
astronauts in trouble would not be days… but weeks or even months away from a return
to the earth. Because of the lack of gravity, traveling to asteroids will cost less fuel
and money than going to the moon. Fuel for the return trip from an asteroid will be substantially
less since there is no need to escape gravity from the asteroid.
The idea that asteroids could be mined for resources has been around for years. Asteroids
are leftovers from the early universe which did not coalesce into planets. Most of the
remnants became the asteroid belt between Mars and Jupiter, but some pieces were pushed
out to roam the solar system. In the past few years NASA and other space agencies have
shifted their attention from the moon and other planets toward asteroids.
NASA’s DAWN spacecraft has revealed that around six per cent of the meteorites that
have hit the Earth had broken off a large 120 mile wide asteroid called VESTA, which
was found to be high in metals and minerals including iron and magnesium. Asteroids also
have been found to contain such substances as hydrogen, carbon, iron and platinum, which
could be used by astronauts to make fuel and equipment.
There are probably 1,500 asteroids that pass near Earth that would be good initial targets.
It is estimated that about 10 percent of them contain water and other valuable minerals.
Experts haven’t chosen a particular asteroid for the deep-space voyage yet, but there are
a few dozen top candidates, most of which pass within about 5 million miles of Earth.
That is 20 times more distant than the moon. Most of the top asteroid candidates are less
than a quarter-mile across. The moon is about 2,160 miles across in diameter. An asteroid
mission would be a Mars training ground, given the distance and alien locale. If humans can’t
make it to near-Earth objects, they can’t make it to Mars. Such missions to asteroids
will also help test technology needed for future human missions to other planets. So
landing on an asteroid is the next step necessary toward a human landing on Mars.
With NASA in the process of identifying possible near-Earth asteroids to explore and with the
goal of visiting an asteroid by 2025, preparations are underway. The plan is to send a robot
explorer mission to the asteroid approximately 5 years before humans arrive, so NASA will
need to make a final selection of which asteroid to explore within the next decade.
NASA is planning to launch its OSIRIS-Rex Explorer spacecraft to an asteroid in 2016.
It will land on an asteroid designated 1999 RQ36 in 2018, after a 2 year voyage. 1999
RQ36 is thought to be a leftover from the formation of our solar system. The spacecraft
will begin six months of comprehensive surface mapping while hovering within 3 miles above
the asteroid. OSIRIS-Rex will gradually move in closer and use a robotic arm to pluck samples
from the asteroid and return to Earth in 2023. Training however is already underway at a
training facility off the coast of Florida called NEEMO (NASA Extreme Environment Mission
Operation). The underwater capsule called Aquarius is a 43 foot long by 20 foot wide
tube anchored in 65 feet of water. The undersea lab serves as a representation of the Deep
Space Habitat (DSH) that will carry the crew over the long journey to and from the asteroid.
Another multi-mission Space Exploration Vehicle (SEV) will accompany the DSH on the journey
to the asteroid and provide an exploration platform that will get in close to the asteroid
and assist crew members during spacewalks. The NEEMO crew is testing whether their work
is more efficient with different vehicles. Mission trainees also are determining whether
they work better in pairs or on solo spacewalks. During training, each “spacewalking” crew
member wears a thruster device to simulate the use of a jet pack. Training at NEEMO aims
to help astronauts figure out how to move around on and collect samples from near-Earth
asteroids with near zero gravity. Since the technology for anchors to attach astronauts
to an asteroid is still in development, NEEMO is evaluating different types of anchoring
and how well astronauts work with them. The sea floor itself is being used to represent
the surface of an asteroid. In some places, fiberglass rock walls stand in for harder
surfaces. For part of the training there is a 50-second, one-way communications delay,
to simulate the average time delay astronauts will face while visiting a near Earth object.
The mission is hoping to use NASA’s Orion spacecraft which sits atop NASA’s Space
Launch System.
The Orion spacecraft will be capable of carrying astronauts on diverse expeditions beyond Earth’s orbit, ushering in a new era of human space exploration.