<s>
RADCAL	B-Algorithm
(	O
short	O
for	O
RADar	B-Algorithm
CALibration	I-Algorithm
Satellite	I-Algorithm
)	O
was	O
a	O
radar	B-Algorithm
calibration	I-Algorithm
satellite	I-Algorithm
launched	O
and	O
operated	O
by	O
the	O
United	O
States	O
Air	O
Force	O
.	O
</s>
<s>
RADCAL	B-Algorithm
was	O
built	O
by	O
Defense	O
Systems	O
Inc	O
.	O
as	O
United	O
States	O
Air	O
Force	O
Space	O
Test	O
Program	O
payload	O
P92-1	O
.	O
</s>
<s>
Payload	O
included	O
two	O
C	B-Algorithm
Band	I-Algorithm
transponders	O
(	O
operating	O
at	O
the	O
same	O
frequency	O
as	O
space-detection	O
radars	O
)	O
,	O
a	O
Doppler	O
beacon	O
that	O
transmitted	O
at	O
150	O
and	O
400	O
MHz	O
,	O
and	O
a	O
pair	O
of	O
modified	O
Trimble	O
Inc	O
.	O
TANS	O
Quadrex	O
Global	O
Positioning	O
System	O
receivers	O
.	O
</s>
<s>
RADCAL	B-Algorithm
launched	O
into	O
polar	O
orbit	O
at	O
23:30:00	O
UTC	O
on	O
25	O
June	O
1993	O
from	O
Vandenberg	O
Air	O
Force	O
Base	O
's	O
Space	O
Launch	O
Complex	O
5	O
.	O
</s>
<s>
RADCAL	B-Algorithm
was	O
used	O
to	O
calibrate	O
ground-based	O
space	O
tracking	O
radars	O
:	O
they	O
would	O
track	O
it	O
and	O
compare	O
their	O
estimated	O
position	O
to	O
its	O
true	O
position	O
.	O
</s>
<s>
RADCAL	B-Algorithm
was	O
designed	O
to	O
last	O
for	O
three	O
years	O
,	O
but	O
remained	O
operational	O
until	O
May	O
2013	O
.	O
</s>
