WASHINGTON, Feb 18, 2021 (BSS/AFP) – Seven months traveling through
space, a mission that was decades in the making and cost billions of
dollars, all to answer the question: was there ever life on Mars?
NASA’s Perseverance rover prepares for touchdown on the Red Planet
Thursday to search for telltale signs of microbes that might have
existed there billions of years ago, when conditions were warmer and
wetter than they are today.
“Trip to Mars, 99.9% complete,” NASA’s rover account tweeted
Thursday morning, just hours before the landing. “The most dangerous
part comes last: the final seven minutes.”
Over the course of several years, Perseverance will attempt to
collect 30 rock and soil samples in sealed tubes, to be eventually
sent back to Earth sometime in the 2030s for lab analysis.
“It’s of course trying to make significant progress in answering one
of the questions that has been with us for many centuries, namely: are
we alone in the universe?” NASA Associate Administrator Thomas
Zurbuchen said Wednesday.
Perseverance is the largest and most sophisticated vehicle ever sent to Mars.
About the size of an SUV, it weighs a ton, is equipped with a seven
foot (two meter) long robotic arm, has 19 cameras, two microphones,
and a suite of cutting-edge instruments to assist in its scientific
goals.
Before it can embark on its lofty quest, it will first need to
survive the dreaded “seven minutes of terror” — the risky landing
procedure that has scuppered nearly 50 percent of all missions to the
planet.
Shortly after 3:30 pm Eastern Time (2030 GMT), the spacecraft will
careen into the Martian atmosphere at 12,500 miles (20,000 kilometers)
per hour, protected by its heat shield.
It will then deploy a supersonic parachute the size of a Little
League field, before firing up an eight-engined jetpack to slow its
descent even further, and then eventually lower the rover carefully to
the ground on a set of cables.
Its target site, the Jezero Crater, is perilous terrain, but thanks to
new instruments Perseverance is capable of landing with far greater
precision than any robot sent before it.
– Astrobiology dream –
Scientists believe that around 3.5 billion years ago the crater was
home to a river that flowed into a lake, depositing sediment in a
fan-shaped delta.
“We have very strong evidence that Mars could have supported life in
its distant past,” Ken Williford, the mission’s deputy project
scientist said Wednesday.
But if past exploration has determined the planet was once
habitable, Perseverance is tasked with determining whether it was
actually inhabited.
It will begin drilling its first samples in summer, and its
engineers have planned for it to traverse first the delta, then the
ancient lake shore, and finally the edges of the crater.
Perseverance’s top speed of 0.1 miles per hour is sluggish by Earth
standards but faster than any of its predecessors, and along the way
it will deploy new instruments to scan for organic matter, map
chemical composition, and zap rocks with a laser to study the vapor.
“We astrobiologists have been dreaming about this mission for
decades,” said Mary Voytek, head of NASA’s astrobiology program.
Despite its state-of-the-art technology, bringing samples back to
Earth remains crucial because of anticipated ambiguities in the
specimens it documents.
For example, fossils that arose from ancient microbes may look
suspiciously similar to patterns caused by precipitation.
– Flying on another world –
Before getting to the main mission, NASA wants to run several
eye-catching experiments.
Tucked under Perseverance’s belly is a small helicopter drone that
will attempt the first powered flight on another planet.
The helicopter, dubbed Ingenuity, will have to achieve lift in an
atmosphere that’s one percent the density of Earth’s, in a
demonstration of concept that could revolutionize the way we explore
other planets
Another experiment involves an instrument that can convert oxygen
from Mars’ primarily carbon dioxide atmosphere, much like a plant,
using the process of electrolysis to produce 10 grams of oxygen an
hour.
The idea is that humans eventually won’t need to carry their own
oxygen, which is crucial for rocket fuel as well as for breathing.
Perseverance’s two microphones will meanwhile attempt to record the
Martian soundscape for the very first time, after past efforts failed.
The rover is only the fifth ever to set its wheels down on Mars. The
feat was first accomplished in 1997 and all of them have been
American.
That will probably soon change: China’s Tianwen-1 spacecraft entered
Martian orbit last week and is expected to touch down with a
stationary lander and a rover in May.