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A28 SCIENCE
Thursday 22 November 2018

Mars landing comes down to final 6 minutes of 6-month trip

By MARCIA DUNN kph), at an altitude of 164 a spacesuit, too, if you're
AP Aerospace Writer feet (50 meters) there at the landing site,"
CAPE CANAVERAL, Fla. FIFTEEN SECONDS Grover joked to reporters
(AP) — It all comes down Now in so-called constant while describing the bone-
to the final six minutes of a velocity mode, InSight is dry Martian plain.
six-month journey to Mars. aiming for a 5 mph (8 kph) HELLO? HELLO?
NASA's InSight spacecraft touchdown in a plain near Since departing Earth in
will enter the Martian at- the equator called Ely- May, InSight has been
mosphere at supersonic sium Planitia. There it will shadowed by WALL-E and
speed, then hit the brakes dig deep for heat mea- EVE, the first CubeSats to
to get to a soft, safe land- surements and scope out venture into deep space.
ing on the alien red plains. marsquakes over a full The briefcase-size satellites
After micromanaging ev- Martian year, or two Earth named after the charac-
ery step of the way, flight years. NASA picked this ters in the 2008 animated
controllers will be powerless spot because it should be movie will pass within a
over what happens at the relatively flat and free of few thousand miles (kilo-
end of the road Monday, big rocks that could ham- meters) of Mars, as InSight
nearly 100 million miles (160 per science operations. lands. NASA hopes one or
million kilometers) away. Parking near the equator both relay InSight's radio
The communication lag provides optimal sunlight signals. If the experiment
between Mars and Earth is for solar energy. "It's a very succeeds, flight control-
eight minutes. safe place to land," Grover lers may be able to follow
"By the time we hear any- said at a press conference InSight's descent and land-
thing, the whole thing is al- Wednesday. ing, although with a lag of
ready done," said project This illustration made available by NASA in October 2016 shows TOUCHDOWN! more than eight minutes at
manager Tom Hoffman of an illustration of NASA's InSight lander about to land on the It will be around 2 p.m., best. Otherwise, news will
NASA's Jet Propulsion Labo- surface of Mars. NASA's InSight spacecraft will enter the Martian Mars time, when InSight trickle in from NASA's Mars
ratory. "Either it happened atmosphere at supersonic speed, then hit the brakes to get to a lands. That's 3 p.m. on the orbiters.
soft, safe landing on the alien red plains.
or it hasn't happened." Associated Press U.S. East Coast and noon SAY CHEESE:
Any small last-minute ad- for the JPL flight controllers InSight's first job, just several
justments must be com- up heat. Its heat shield is FORTY-FIVE SECONDS in Pasadena, California. minutes after landing, is
pleted 1 ½ hours before made to withstand the Almost immediately, In- NASA estimates tempera- to take a picture. Ground
touchdown, said Rob Gro- 2,700 degrees Fahrenheit Sight's 12 descent engines tures could be in the teens controllers want to see
ver, lead engineer for the (1,500 degrees Celsius). start firing to further slow or even single digits Fahr- what they're up against.
landing team. Once InSight is down to the lander and keep it enheit (well below zero Big rocks or a hillside could
"All of our efforts to make seven miles (11 kilometers), away from the severed Celsius). Overnight lows interfere with the stationary
sure we're successful all its parachute opens at a back shell, still falling under could reach minus 140 de- lander's geology experi-
happen in the years be- breakneck 860 mph (1,400 the parachute. The lander grees Fahrenheit (minus 96 ments. Once the red dust
fore," he explained. kph). turns itself so its solar panels degrees Celsius.) It's win- settles about 16 minutes af-
A brief rundown of Insight's THREE MINUTES will extend east and west at tertime on Mars. "Probably ter touchdown, the lander
do-or-die entry, descent Shortly after the white nylon touchdown, and its robotic don't need an umbrella, will spread its solar panels
and landing: chute opens with a yank, arm faces south. InSight's but you may need a coat and settle in for its first long
SIX MINUTES BEFORE InSight ditches its heat speed is now 17 mph (27 and definitely recommend winter's nap at Mars.q
TOUCHDOWN shield and unfolds its three
InSight will come in like a legs. After two minutes
12,300-mph (19,800-kph) of descending under the Simulator helps experts understand
arrow, piercing the top of parachute, the spacecraft,
the Martian atmosphere still supersonic, starts using how whales get entangled
about 77 miles (114 kilo- radar to determine speed
meters) above the sur- and altitude, from about 1
face. Engineers are shoot- ½ miles (2 ½ kilometers) up. By WILLIAM J. KOLE whales avoid the loom- the planet, and the spe-
ing for a 12-degree angle Less than a minute remains Associated Press ing threat of extinction. cies' future is bleak be-
of attack, almost parallel until touchdown. With its BOSTON (AP) — A new "If we can see how they cause of heavy mortality
to the ground. Too steep, speed now down to 134 simulator is letting scien- get entangled, it would and poor reproduction in
the spacecraft could burn mph (215 kph), the lander tists use a joystick to swim help us prevent it. The recent years.
up. Too shallow, it could dumps its back shell and a virtual whale across a technology in comput- Werner says the video
bounce back into space. parachute. It is less than a video screen. But this is ers has evolved to a state simulation has helped his
Atmospheric friction slows mile (one kilometer) above no game — it's a serious where we can model team better understand
the spacecraft, but builds the ground. attempt to better un- these things," he said. how whales unwittingly —
derstand how the giant More than eight in 10 and often lethally — wrap
mammals become en- critically endangered themselves in the fishing
tangled in fishing lines. right whales become buoy lines that hang ver-
Tim Werner, a senior sci- ensnared by fishing lines, tically in the ocean.
entist at the New Eng- and nearly six in 10 are Marine biologists say
land Aquarium's Ander- entangled more than entangled whales of-
son Cabot Center for once. ten can't feed, and the
Ocean Life, hopes the Entanglements are a stress weakens them and
technology will lead to leading cause of right makes females less likely
safer fishing gear designs whale deaths. Experts es- to birth calves. This past
and help critically endan- timate there are no more season, not a single new
gered North Atlantic right than 440 animals left on birth was discovered.q