Chandrayaan-2: How will Vikram locate precise landing spot near Lunar South pole
Bengaluru, Sep 06: Of all the phases in India's ambitious Moon mission Chandrayaan-2, the final stages of Vikram lander's soft landing on lunar surface would be most challenging for ISRO.
Launching a craft to orbit around moon is not new for ISRO as it was achieved in Chandrayaan-1 itself. In fact the Indian Space agency went beyond Moon and sent an orbiter to Mars.
Soft
landing
a
probe
on
lunar
surface
is
something
that
ISRO
is
doing
for
the
first
time.
Vikram
lander's
soft
landing
on
lunar
surface
is
the
most
critical,
complex
and
challenging
phase
of
the
entire
Chandrayaan
2
mission.
Even
ISRO
Chairman
K
Sivan
has
acknowledged
that
the
last
15
mins
of
soft-landing
would
be
tense
as
it
is
something
ISRO
has
not
done
before.
This
will
be
the
first
time
that
Indian
scientists
will
attempt
a
soft
landing
on
the
moon,
a
feat
achieved
so
far
by
only
the
US,
Russia
and
China.
Chandrayaan-2 landing time, date, where to watch: Rover roll out time, When will first pictures come
Moon-landing process will be comprised of a series of critical and crucial maneuvers. The Lander Vikram has a unique four-legged design.
Vikram
weighs
1,471
Kg
and
has
an
additional
27
Kg
Pragyan
rover
housed
in
it.
The
lander
separated
from
the
orbiter
on
September
2
and
entered
an
orbit
of
100
km
x
30
km.
After
a
series
of
braking
manoeuvres,
lander's
orbit
was
lowered
to
35
km
x
97
km.
On
September
7,
at
1.40
am
IST,
the
lander
will
start
performing
powered
descent.
From here, the Lander's onboard rocket thrust mechanism would be used in a highly controlled manner. For it to be a success, systems like navigation, guidance, controls, propulsion, sensors and various other things have to work in a precise coordinated manner. Braking the speed of the lander 30 km above till landing on the surface will take about 15 minutes.
The
lander
will
have
five
800N
Liquid
thruster
engines,
touchdown
sensors
and
solar
panels.
First,
all
five
800
N
engines
on
the
Vikram
lander
will
fire
in
tandem
to
decelerate
the
craft.
They
will
keep
firing
until
the
craft
is
just
a
few
meters
above
the
lunar
surface
and
settled
into
a
slow,
steady
approach.
The
Lander
Position
Detection
Camera
will
be
switched
on
to
identify
the
perfect
place
to
land
safely
on
the
ground.
At
this
hovering
stage
of
lander,
about
400
metres
above
the
moon
surface,
two
engines
will
be
ignited.
Chandrayaan 2: Vikram module set for final descent for soft landing on Moon tomorrow
The entire descent stage is fully autonomous. It involves the onboard computer taking continuous input from sensors about its distance, velocity, acceleration, orientation, etc., computing its trajectory and auto-correcting it by orchestrating firing of the engines, until a safe touchdown. At an altitude of 10 metres, the ISRO will carry out the landers parabolic descent for soft landing by igniting the central
engine and using the touchdown sensor at the bottom of the stand.
Hours after touchdown, rover Pragyaan will roll out from inside the lander and carry out probe of the lunar soil.