<s>
In	O
orbital	O
mechanics	O
,	O
a	O
porkchop	B-Application
plot	I-Application
(	O
also	O
pork-chop	B-Application
plot	I-Application
)	O
is	O
a	O
chart	O
that	O
shows	O
contours	O
of	O
equal	O
characteristic	O
energy	O
(	O
C3	O
)	O
against	O
combinations	O
of	O
launch	O
date	O
and	O
arrival	O
date	O
for	O
a	O
particular	O
interplanetary	O
flight	O
.	O
</s>
<s>
By	O
examining	O
the	O
results	O
of	O
the	O
porkchop	B-Application
plot	I-Application
,	O
engineers	O
can	O
determine	O
when	O
a	O
launch	O
opportunity	O
exists	O
(	O
a	O
'	O
launch	O
window	O
 '	O
)	O
that	O
is	O
compatible	O
with	O
the	O
capabilities	O
of	O
a	O
particular	O
spacecraft	O
.	O
</s>
<s>
For	O
the	O
Voyager	O
program	O
,	O
engineers	O
at	O
JPL	O
plotted	O
around	O
10,000	O
potential	O
trajectories	O
using	O
porkchop	B-Application
plots	I-Application
,	O
from	O
which	O
they	O
selected	O
around	O
100	O
that	O
were	O
optimal	O
for	O
the	O
mission	O
objectives	O
.	O
</s>
