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| From NASA: "In the shadow of Saturn, unexpected wonders appear.
The
robotic Cassini spacecraft now orbiting
Saturn drifted in giant planet's
shadow for about 12 hours in 2006 and looked
back toward the
eclipsed Sun.
Cassini saw a
view unlike any other.
First, the
night side of Saturn
is seen to be partly lit by light reflected from its own
majestic ring system.
Next, the rings themselves appear dark when
silhouetted against Saturn,
but quite bright when viewed away from Saturn,
slightly scattering sunlight, in this
exaggerated color image.
Saturn's rings light up so much that
new rings were discovered, although they are hard to see in the
image.
Seen in spectacular detail, however, is Saturn's
E ring, the ring created by the newly discovered
ice-fountains of the moon
Enceladus and the outermost ring visible above.
Far in the
distance,
at the left, just above the bright main rings, is the almost ignorable
pale blue dot of Earth." Image Credit: Cassini Imaging Team,
SSI,
JPL,
ESA,
NASA |
“See the dark night has
come down on us
The world is livin' in its dream
But now we
know that we can wake up from this sleep
And set out on the
journey
Find a ship to take us on the way.”
- Gerry Rafferty, “The
Ark,” with apologies to Bill DeYoung
In the early morning hours of
September 15, as I awoke and readied for work, Cassini started its
final plunge into Saturn, its home of 13 years. Launched in October
1997 from a Titan IV-Centaur launch vehicle, the spacecraft had spent
its last few months conducting “dives” into the unexplored region
between the gas giant and its signature rings. But alas, 20 years
dissipated into a matter of seconds, and at 7:55 a.m. EDT JPL
received the last signals from the minivan-sized spacecraft, just
before it turned into a meteor among the high clouds of Saturn. By
that time, I was clocking into work during a challenging week; my job
had been relocated across town due to Hurricane Irma damage. Still,
as I checked out the Cassini updates on social media, I found myself
welling up with tears. Why?
This
was hardly the first time the ending of an uncrewed spacecraft’s
mission had resulted
in a flood of tears and mixed emotions from its supporters,
followers, and even casual fans. In April 2015, NASA’s Messenger
probe finalized its sojourn in space somewhere upon
the surface of Mercury, which had been little-explored prior to its
mission. Space fans mourned the end of the probe that had orbited the
challenging little planet that is closest to our Sun.
Late
last year, ESA’s Rosetta mission came to a close upon
the surface of comet
67P/Churyumov–Gerasimenko; its plucky lander, Philae, had
sacrificed its life there two years earlier after completing most of
its science package in a less-than-optimal landing site. People
identified so much with Rosetta and Philae, partly due to a (frankly
adorable) cartoon promoted by ESA which showed the spacecraft and
lander, each given human qualities and faces, embarking on their
almost-unbelievable explorations of 67P.
As
far back as 1971, one lunar rover’s science and operations team as
far away as the Soviet Union quietly mourned the end of their
pioneering mission, as Lunokhod 1
entered lunar night and, in the words of space historian Jay
Gallentine, “numbly succumbed and slowly froze in place”:
On
the next lunar dawn they tried calling and got no answer. They tried
again and then again. Lunokhod had flatlined. Word went out to every
scientist on the project, informing them not to bother coming down to
Shkolnoye [home of Lunokhod operations]. The crew of Lunokhod, the
quick-sharp brainiacs who drove and drove and drove, packed their
bags and went home. As eulogized by a wistful Vyacheslav Dovgan, "The
operation of the rover on the moon ended in a natural death at a very
old age."
Gallentine
added, “And death so came not because their creation had shed its
will or courage but because it simply could no longer keep itself
warm.” He touched
upon the reason why we
cry at the end of robotic missions that we cannot easily witness –
these machines aren’t human.
Our last earthly view
of an unmanned spacecraft is of it leaving the pad surrounded by
glorious yellow and orange
flames, speeding away on its
trajectory to another world in a victorious rumble. They are idealized at that point
as new and “perfect,” and don’t possess the less savory
qualities human explorers can have, such as ego, jealousy, and
greed. They
don’t come back to Earth acting
like celebrities, demanding
ridiculously high
autograph or speaking
fees. As they explore the
solar system and its objects, they retain their “will or
courage” without the very
real shortcomings or
disappointments humans can bring (see “Brothers Under The Skin: 'Island of Clouds' And The Myth of the Astronaut as Hero,”
published in August).
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| From ESA: "At 08:43 UT, 15 October 1997, a Titan
IV-Centaur rocket was launched from Cape Canaveral carrying the
Cassini-Huygens spacecraft." Photo Credit: NASA |
Robotic explorers’ deaths also seem
particularly heroic in that they willfully “plunge” to their
deaths, or peter along until they run out of power and/or cease
communicating. They aren’t capable of having feelings or reserve
about sacrificing their own lives for their journeys, making them
uniquely “selfless.”
Then
there’s the fact that we tend to give non-living things human
characteristics, imposing our hopes and dreams on objects that do not
have thoughts or feelings. How many of us have given our cars human
names, and collegial “pats” on their hoods or steering wheels? We
see untapped promise and potential in things that can bring us closer
to our goals, even if they cannot reciprocate in celebrating the
achievement.
In
keeping with this theme Carl Sagan once wrote, “The unmanned
exploration of the solar system initiated by the United States and
the Soviet Union is a scientific adventure of historic proportions
that will be remembered by our remote descendants after much else of
our epoch has long been forgotten – provided that we are not so
foolish as to destroy ourselves.” He wrote this years before
Cassini-Huygens, Messenger, Rosetta, and a bevy of other deep space
probes were even launched; at that time, Europe hadn’t yet embarked
upon their own deep space explorations – those wouldn’t begin
until Giotto’s famous “night of Halley’s Comet” in 1986.
Sagan’s words summed up the hope given to people by these robotic
missions, provided our own very human flaws didn’t prevent us from
keeping the faith.
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From ESA: "This image of Saturn's northern hemisphere was taken by Cassini on 13
September 2017. It is among the last images Cassini sent back to Earth. The view was taken in visible red light using the Cassini spacecraft
wide-angle camera at a distance of 1.1 million kilometres from Saturn.
Image scale is 64 km." Image Credit: NASA/JPL-Caltech/Space Science Institute
|
Perhaps
the way to best chronicle why we struggle with our emotions at the
end of unmanned space missions is to go to the people who follow
them. The following is a series of responses to the question posed in
this article’s title, as relayed to me on Facebook’s Space
Hipsters group:
“I
can only speak for myself, but when you work on a project like this,
it becomes a part of your life, almost like a family member. If you
know people on the teams, you feel their triumphs as it works (or
fails). The imagery surrounding the Cassini (and Rosetta, etc.)
mission, also touches us, and if the spacecraft is the least bit
anthropomorphized, that also helps us connect to it. It's like saying
goodbye to a favorite car, I would think.” - Carolyn Collins
Petersen
“I
think we also anthropomorphize. It's like how I love my car and will
cry when it dies. Will the car care? No, but to me it will. I can't
speak for others but when you spend so much of your time with
something it's hard not to get attached and know its intricacies and
when you do that it starts to become a living thing.” - Rebecca
Glasser
“It's
a tangible piece of human creativity being sent into the cosmos. We
are at an amazing time in human history, and we are still learning
how to handle these first time events. We have something made by
humans that is now a permanent part of Saturn. Incredible.” -
Nathan Funk
“A
lot of these people have worked together 20 years on this spending
more time together then you do with your families even. Now it's over
and a lot are going to go their separate ways, so it's understandable
how sad that is...” - Brian Macomber
“Rovers
seem more like sentient beings. Spacecraft not so much. But if I saw
a signal disappear...that would remind me of a heartbeat stopping and
it would be hard not to feel sad. I try to focus on all the good and
get ready for the next unmanned mission.” - Tess Simpson
“Saturn
is so far away but Cassini made it seem close.” - Charles Boyer
“...Maybe
it’s the long duration of the mission and the unique beauty and
strangeness of the Saturn system. Cassini has spent thirteen years
orbiting the planet and has sent back amazing images of Saturn, its
rings and moons. It’s been like a long trip to a gorgeous national
park, it was a great ride with incredibly scenic views and you just
hate to see it end and have go back home.” - Michael Mackowski
“Many
of the people on console have gray hair. I'd like to know that story.
Growing older with your mission. These missions take decades. The end
of your mission seems like forever and then there it is. Just like
life.” - Laura Bluhm
“These
brave little spacecraft carry our hopes and dreams aloft with them. I
think we anthropomorphize them as ‘our children’ in many ways. We
bring them into the world and send them on their way. If and when
they prosper, we are ‘proud of them’ and we rejoice in whatever
influences we as humans have had on their successes. When it's time
to say good-bye, it's almost like losing a child, or at the very
least, a very close friend. That is a very human experience.” -
Bruce Moody
“I
think for me, Cassini has sent back these stunningly beautiful photos
for so long; Cassini served as an extension to my eyes and my vision,
allowing me to see what I'd never have been able to see without that
extension; helping me to imagine what form life on other worlds would
take, just giving all of us so much more to think with. Now that's
gone, and maybe never in my lifetime will I have the opportunity to
see something 'out there' so hauntingly beautiful again. I
think about all the great astronomers and scientists who have lived
before our time who would have given anything to see what ordinary
people have seen because of Cassini, and I feel humbled and awestruck
and sad and proud of our people who made this happen all at the same
time.” - Lois Huneycutt
“I
think it’s okay to be sad for the loss of a spacecraft. In a
perfect world, at the end of its mission, a history-making spacecraft
like Cassini would be brought back to Earth to be placed in a museum,
where it can inspire future generations of scientists and engineers,
as well as provide lessons on the condition of interplanetary craft
after 20 years in space. The science that was achieved by Cassini’s
grand finale was certainly more important than Cassini’s
preservation, but it’s okay to be sad that a great orbiter is now
gone.” - Robert Pearlman
“Cassini
brought us all such incredible photos! The average person may not
care about the science (which was truly incredible!), but looking at
all the photos Cassini gave us, [they were] just so beautiful. And it
lasted so long, it became a kind of celebrity in its own right. How
many memes, and cartoons and articles have we seen over its 20 year
mission?
“What
happens, I think, is that we all personalize the spacecraft, and then
it becomes a friend (if you will). Cassini gave us so much, and for
so long, that everybody felt they had a personal connection to this
mission. And she dared to do mighty things! She traipsed around the
most majestic planetary system in our neighborhood, and she
courageously made new, bold discoveries with each orbit! And so
now, here we are, Cassini has taken her final plunge into Saturn. And
so we truly grieve at her passing, but we delight in her
accomplishments.” - Jamie Rich
*****
Sources:
1.
Gallentine, J. (2015). Infinity
Beckoned: Adventuring Through the Inner Solar System, 1969-1989.
Lincoln, NE: University of Nebraska Press.
2. Murray, B. (Ed.). (1983). The
Planets: Readings from Scientific American. New York, NY:
W.H. Freeman and Company.
Many
thanks to the Space Hipsters group for its participation.
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| From ESA, one final view: "This monochrome view is the last image taken by the imaging cameras on
the Cassini spacecraft before the mission concluded on 15 September. It
looks toward the planet's night side, lit by reflected light from the
rings, and shows the location at which the spacecraft would enter the
planet's atmosphere hours later. The view was acquired on 14 September 2017 at 19:59 GMT (spacecraft
event time). The view was taken in visible light using the Cassini
spacecraft wide-angle camera at a distance of 634,000 km from Saturn." Image Credit: NASA/JPL-Caltech/Space Science Institute |
