This illustration made available by NASA depicts the Ingenuity helicopter on Mars after launching from the Perseverance rover, background left.The Associated Press
According to veterans of NASA’s Mars program, landing on the Red Planet never gets less scary. It only gets more complicated.
That rule certainly holds for the space agency’s latest emissary to Mars, a robotic rover named Perseverance that is about the size of a small SUV. Perseverance is the most capable and autonomous spacecraft ever sent to roam the surface of another world. But when it arrives at Jezero crater at 3:55 p.m. ET on Thursday, it will be doing so in a location that is far more hazardous than any of its predecessors had to contend with.
“Jezero is actually a site that was scientifically interesting to many previous missions and we just couldn’t get there until this point, when our technology was ready to support it,” said deputy project manager Matt Wallace during a news briefing on Wednesday.
Mars mission set to advance search for life beyond Earth
What makes Jezero so attractive to scientists is an ancient river delta whose steep edge towers some 60 metres above the crater floor. Perseverance will attempt to set its wheels down near to that cliff face, where the plan is that it will investigate exposed layers of rock and read the geological history of the site. Over the next two years it will also gather samples that a future mission can pick up and return to Earth in hopes of revealing whether any Martian microbes lived there when the delta formed more than 3.5 billion years ago.
But before that can happen, the spacecraft has to endure its “seven minutes of terror.” The phrase is one that NASA engineers have been using for years to describe the action-packed sequence of events that will, if all goes well, see the rover go from being a high-speed projectile aimed straight at Mars to a working piece of machinery at rest on the planet’s surface – all in less time than it takes to listen to The Beatles’ Hey Jude.
During that interval there is plenty of room for things to go terribly wrong.
For starters, the capsule that carries the rover must survive a peak temperature of about 1,300 C as it rips through the thin Martian atmosphere with an incoming velocity close to 20,000 kilometres an hour. Three minutes later, the capsule will release a supersonic parachute that will have to withstand up to 60,000 pounds of force as it attempts to slow the spacecraft down to less than 600 km/h.
“The parachute has to work,” said Erisa Stilley, a landing systems engineer with the mission. “If it doesn’t, it’s not going to be a very good day for any of us.”
Next, the heat shield must separate, exposing the rover that is stowed behind it. At this point the rover’s radar system is programmed to turn on and try to lock onto the surface just two minutes from touchdown.
All of this should bring Perseverance somewhere within an oval-shaped region called the landing ellipse, which measures 7.7 kilometres long. It includes boulders, small craters, dunes and several kilometres of cliff face that mark the boundary of the delta.
“We’re aiming right at the edge of that delta, and that’s not an accident,” said Allen Chen, who leads the mission’s entry, descent and landing team.
A NEW EXPLOERER ON MARS
NASA’s Perseverance rover is set to land at
3:55 p.m. ET on Thursday. The rover is the
most sophisticated robotic explorer ever sent
to Mars. It will search for signs of past life
and collect samples for return to Earth at a
later date.
THE JOURNEY
Perseverance was launched on July 30, 2020,
and it has been cruising through interplane-
tary space since then. At its current distance
it will take 11 minutes and 22 seconds for
radio signals from the spacecraft to reach
Earth.
Mars at arrival
Flight
trajectory
1.335 AU
1.567 AU
Earth at
arrival
1 AU*
The sun
Earth at
launch
Mars at
launch
*The astronomical unit (AU), a measure of distance, is approximately the average distance between the Earth and the Sun, about 149.6 million km.
THE LANDING
Because of the signal delay between Earth and
Mars, Perseverance is designed to guide itself
safely down to the surface with an automated
navigation system
TERRAIN-RELATIVE
NAVIGATION
1
Camera takes pictures as rover descends
2
Computer compares these to maps of area and adjusts flightpath to avoid hazards
3
Lander lowers rover as close as possible to target site
THE DESTINATION
Jezero Crater was once a deep lake and is
thought to be an ideal location to search for
signs of past life. Perseverance will touch down
somewhere within a 7.7 km long “landing
ellipse” that encompasses part of an ancient
river delta near the crater rim.
JEZERO
CRATER
45km
THE ROVER
Perseverance is outfitted with a suite of cameras
and other instruments. It can drill into Martian
rock and cache the core samples for later collec
tion by a follow-up mission.
INGENUITY
Drone-like helicopter carried on rover’s
belly will demonstrate first powered flight
on another planet
THE LEGACY
More than 30 spacecraft have been sent to
Mars already, starting with the first attempt by
the Soviet Union in 1962. Several have imaged
the planet from space but so far only eight
spacecraft have landed successfully on the
surface. Perseverance is now aiming to
become No. 9. China's Tianwen-1,
which went into orbit around Mars on Feb.
10, will attempt a landing later this spring.
Probe type and duration active on the surface:
Lander
Rover
Hybrid mission
Tianwen-1
Perseverance
InSight (active)
Curiosity (active)
Phoenix
Opportunity
Spirit
Pathfinder/Sojourner
Viking 2
Viking 1
1980
1990
2000
2010
2020
THE GLOBE AND MAIL,
SOURCE: NASA; GRAPHIC NEWS
A NEW EXPLOERER ON MARS
NASA’s Perseverance rover is set to land at 3:55 p.m.
ET on Thursday. The rover is the most sophisticated
robotic explorer ever sent to Mars. It will search for
signs of past life and collect samples for return to
Earth at a later date.
THE JOURNEY
Perseverance was launched on July 30, 2020, and it
has been cruising through interplanetary space since
then. At its current distance it will take 11 minutes and
22 seconds for radio signals from the spacecraft to
reach Earth.
Mars at arrival
Flight
trajectory
1.335 AU
1.567 AU
Earth at
arrival
1 AU*
The sun
Earth at
launch
Mars at
launch
*The astronomical unit (AU), a measure of distance, is approximately the average distance between the Earth and the Sun, about 149.6 million km.
THE LANDING
Because of the signal delay between Earth and Mars,
Perseverance is designed to guide itself safely down
to the surface with an automated navigation system.
TERRAIN-RELATIVE
NAVIGATION
1
Camera takes pictures as rover descends
2
Computer compares these to maps of area and adjusts flightpath to avoid hazards
3
Lander lowers rover as close as possible to target site
THE DESTINATION
Jezero Crater was once a deep lake and is thought to
be an ideal location to search for signs of past life.
Perseverance will touch down somewhere within a 7.7
km long “landing ellipse” that encompasses part of an
ancient river delta near the crater rim.
JEZERO
CRATER
45km
THE ROVER
Perseverance is outfitted with a suite of cameras
and other instruments. It can drill into Martian
rock and cache the core samples for later collec
tion by a follow-up mission.
INGENUITY
Drone-like helicopter carried on rover’s belly will demonstrate first powered flight on another planet
THE LEGACY
More than 30 spacecraft have been sent to Mars
already, starting with the first attempt by the Soviet
Union in 1962. Several have imaged the planet from
space but so far only eight spacecraft have landed
successfully on the surface. Perseverance is now aiming
to become No. 9. China's Tianwen-1, which
went into orbit around Mars on Feb. 10, will
attempt a landing later this spring.
Probe type and duration active on the surface:
Lander
Rover
Hybrid mission
Tianwen-1
Perseverance
InSight (active)
Curiosity (active)
Phoenix
Opportunity
Pathfinder/Sojourner
Viking 2
Viking 1
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020
THE GLOBE AND MAIL,
SOURCE: NASA; GRAPHIC NEWS
A NEW EXPLOERER ON MARS
NASA’s Perseverance rover is set to land at 3:55 p.m. ET on Thursday. The rover is the
most sophisticated robotic explorer ever sent to Mars. It will search for signs of past
life and collect samples for return to Earth at a later date.
THE JOURNEY
Perseverance was launched on July 30, 2020, and it has been cruising through interplanetary
space since then. At its current distance it will take 11 minutes and 22 seconds for radio signals
from the spacecraft to reach Earth.
Mars at arrival
Flight
trajectory
1.335 AU
1.567 AU
Earth at
arrival
1 AU*
The sun
Earth at
launch
Mars at
launch
*The astronomical unit (AU), a measure of distance, is approximately the average distance between the Earth and the Sun, about 149.6 million km.
THE LANDING
Because of the signal delay between Earth and Mars, Perseverance is designed to
guide itself safely down to the surface with an automated navigation system.
TERRAIN-RELATIVE
NAVIGATION
1
Camera takes pictures as rover descends
2
Computer compares these to maps of area and adjusts flightpath to avoid hazards
3
Lander lowers rover as close as possible to target site
THE DESTINATION
Jezero Crater was once a deep lake and is thought to be an ideal location to search for signs of
past life. Perseverance will touch down somewhere within a 7.7 km long “landing ellipse” that
encompasses part of an ancient river delta near the crater rim.
Possible rover path
Search Spots
River canyon
Carved by water which
flowed into the crater
over 3.5 billion years ago
JEZERO
CRATER
45km
Landing Ellipse (approximate)
DELTA
Crater rim
Preferred
landing site
Shoreline of
former lake
Edge of delta
Ancient lake bed
THE ROVER
Perseverance is outfitted with a suite of cameras and other instruments. It can drill into Martian
rock and cache the core samples for later collection by a follow-up mission.
POWER SUPPLY
Relies on the decay of radioactive plutonium to generate electricity
SUPERCAM
Can fire a laser to illuminate rocks and study mineral composition from several metres
SHERLOC
Ultraviolet spectrometer searches for organics and minerals
RIMFAX
Ground-penetrating radar to map geology beneath surface
MASTCAM-Z
Advanced camera
MEDA
Weather station
PIXL
X-ray spectrometer to identify chemical elements
MOXIE
Experiment to demonstrate how astronauts might produce oxygen from Martian CO2 for breathing and fuel
INGENUITY
Drone-like helicopter carried on rover’s belly will demonstrate first powered flight on another planet
THE LEGACY
More than 30 spacecraft have been sent to Mars already, starting with the first attempt by the Soviet
Union in 1962. Several have imaged the planet from space but so far only eight spacecraft have landed
successfully on the surface. Perseverance is now aiming to become No. 9. China’s Tianwen-1,
which went into orbit around Mars on Feb. 10, will attempt a landing later this spring.
Probe type and duration active on the surface:
Lander
Rover
Hybrid mission
Tianwen-1
Perseverance
InSight (active)
Curiosity (active)
Phoenix
Opportunity
Spirit
Pathfinder/Sojourner
Viking 2
Viking 1
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020
THE GLOBE AND MAIL, SOURCE: NASA; GRAPHIC NEWS
Based on orbital images, there is a relatively smooth but narrow area adjacent to the cliff where mission engineers want the rover to set itself down. Such a small target near such an obvious hazard would have been too dangerous for earlier missions to contemplate. But Perseverance comes equipped with a guidance system known as terrain relative navigation, once developed for cruise missiles, that it will used to steer itself toward its landing site – or choose an alternate, if it senses something wrong.
The system calls for the rover to rapidly take photos of the landscape as it speeds downward. A special onboard computer system – the fastest ever sent on an interplanetary mission – will then quickly compare the images to a detailed map of the region that it carries within its memory. This will allow Perseverance to determine precisely where it is above the surface and then use its rockets to direct itself to where it thinks it’s best to land. During the final minute, the parachute will separate and a rocket-powered carriage will hover above the surface, lowering the rover down the final 20 metres or so on a crane.
Along the way, a total of 158 pyrotechnic devices have to fire in a precisely timed sequence to ensure everything that needs to release or be deployed happens at the right moment.
“It’s crazy to imagine that we can do such things,” said Jim Bell, who is part of the rover’s science team. “But that’s what has allowed us to pinpoint this tiny little place to go on the planet with one of the most interesting geologic stories that we could try to go uncover.”
Dr. Bell said he will be watching along with the rest of his team as the rover heads down and tries to become the ninth spacecraft to land successfully on Mars. If it works, dozens of scientists who will be sharing the experience together online will have a moment to collectively exhale. And then their adventure at Jezero can begin.
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