<s>
Aqua	O
(	O
EOS	O
PM-1	O
)	O
is	O
a	O
NASA	O
scientific	O
research	O
satellite	B-Application
in	O
orbit	B-Application
around	O
the	O
Earth	O
,	O
studying	O
the	O
precipitation	O
,	O
evaporation	B-Algorithm
,	O
and	O
cycling	O
of	O
water	O
.	O
</s>
<s>
The	O
satellite	B-Application
was	O
launched	O
from	O
Vandenberg	O
Air	O
Force	O
Base	O
on	O
May	O
4	O
,	O
2002	O
,	O
aboard	O
a	O
Delta	O
II	O
rocket	O
.	O
</s>
<s>
Aqua	O
operated	O
in	O
a	O
sun-synchronous	O
orbit	B-Application
as	O
the	O
third	O
in	O
the	O
satellite	B-Application
formation	O
called	O
the	O
"	O
A	O
Train	O
"	O
with	O
several	O
other	O
satellites	B-Application
(	O
OCO-2	O
,	O
the	O
Japanese	O
GCOM	O
W1	O
,	O
PARASOL	O
,	O
CALIPSO	O
,	O
Cloud	O
Sat	O
,	O
and	O
Aura	O
)	O
for	O
most	O
of	O
its	O
first	O
20	O
years	O
;	O
but	O
in	O
January	O
2022	O
Aqua	O
left	O
the	O
A-Train	O
(	O
as	O
Cloud	O
Sat	O
,	O
CALIPSO	O
and	O
PARASOL	O
had	O
already	O
done	O
)	O
when	O
,	O
due	O
to	O
its	O
fuel	O
limitations	O
,	O
it	O
transitioned	O
to	O
a	O
free-drift	O
mode	O
,	O
wherein	O
its	O
equatorial	O
crossing	O
time	O
is	O
slowly	O
drifting	O
to	O
later	O
times	O
,	O
from	O
its	O
tightly	O
controlled	O
orbit	B-Application
.	O
</s>
<s>
Because	O
of	O
a	O
2007	O
anomaly	O
with	O
the	O
Solid	O
State	O
Recorder	O
(	O
SSR	O
)	O
it	O
can	O
only	O
hold	O
two	O
orbits	B-Application
worth	O
of	O
data	O
.	O
</s>
<s>
A	O
recovery	O
procedure	O
was	O
developed	O
and	O
tested	O
through	O
2012	O
,	O
culminating	O
with	O
a	O
December	O
4	O
,	O
2012	O
successful	O
acceleration	O
to	O
2.0767	O
rpm	O
to	O
allow	O
for	O
cross-calibration	O
with	O
the	O
AMSR-2	O
instrument	O
launched	O
in	O
2012	O
aboard	O
the	O
GCOM-W1	O
satellite	B-Application
.	O
</s>
<s>
Moderate	B-Application
Resolution	I-Application
Imaging	I-Application
Spectroradiometer	I-Application
(	O
MODIS	B-Application
)	O
—	O
also	O
measures	O
cloud	O
properties	O
and	O
radiative	O
energy	O
flux	O
,	O
also	O
aerosol	O
properties	O
;	O
land	O
cover	O
and	O
land	O
use	O
change	O
,	O
fires	O
and	O
volcanoes	O
.	O
</s>
<s>
An	O
identical	O
MODIS	B-Application
instrument	O
is	O
also	O
aboard	O
Terra	O
.	O
</s>
<s>
As	O
of	O
2017	O
,	O
some	O
degradation	O
of	O
channels	O
in	O
the	O
MODIS	B-Application
short	O
wave	O
visible	O
bands	O
has	O
been	O
observed	O
by	O
the	O
Ocean	O
Biology	O
Processing	O
Group	O
(	O
OBPG	O
)	O
.	O
</s>
<s>
Humidity	O
Sounder	O
for	O
Brazil	O
(	O
HSB	O
)	O
—	O
VHF	B-Algorithm
band	I-Algorithm
equipment	O
measuring	O
atmospheric	O
humidity	O
.	O
</s>
<s>
Stowed	O
for	O
launch	O
,	O
the	O
satellite	B-Application
fit	O
in	O
a	O
volume	O
of	O
2.68	O
m	O
x	O
2.49	O
m	O
x	O
6.49	O
m	O
.	O
Deployed	O
,	O
Aqua	O
is	O
4.81	O
m	O
x	O
16.70	O
m	O
x	O
8.04	O
m	O
.	O
</s>
