At times I feel like Cassini
Not the French Astronomer
Who discovered the gap between Saturn’s rings
And four of the planet’s moons

But the robot named for him
That, for 20 years sailed through space
Became for a time a satellite of Saturn
Did important work
Then dived and died on command.

A necessary obliteration 
to protect possible life (on Titan
On Enceladus)
from this-worldly radiation
And bacterial contamination.

Nothing lasts. 
Battery spent
One final image
Nothing’s good enough
To earn immortality on this earth.

(Nor on Saturn, apparently.)
No mission or life ever completes.
Knowledge opens new mysteries.
Discoveries define the undiscovered.

Heroism cannot save itself.
I mean Cassini
Who died in 1712
After sailing through space for 87 years

From Genoa to Paris
Directed the Paris Observatory
Looked at heaven through his telescope
Then went there.