How We Decided


The day after tomorrow- that is, February 18, 2021- the Perseverance rover will attempt to land on the surface of Mars.  It will enter the planetary atmosphere at an acute angle, giving it as much time as possible to experience drag and slow down from orbital velocities.  Because Mars’ air is so thin, and the rover is so heavy, this will fail- in the best case, Perseverance would still be going almost a thousand miles an hour when it impacts the surface.  To help save itself, the craft will deploy a parachute of advanced design, seventy feet across and able to withstand supersonic velocities.  This, too, will fail.  Even with a parachute, there is simply not enough air between Perseverance and the Martian surface to slow it down all the way.  So this is where the rockets kick in.  Once air resistance slows the rover to a bit less than two hundred miles per hour, the heavy heat shield will be jettisoned, and a system of secondary rockets will fire against the direction of motion until it slows to near-hovering.  In a final flourish, the rover will descend from the rocket-boosted frame on coiled springs, until it touches down in the western part of Jezero crater in the northern hemisphere of Mars.


As it happens, Perseverance’s destination was one of the very last things we decided about it- not until the craft itself was fairly thoroughly engineered and designed.  Formally, the decision was made by the mission directorate.  In practice, they follow the consensus of the scientific community, which in turn hashes things out at a series of open-invitation workshops.  Things began with a call for white papers- an open suggestion box, basically.  In 2015, the first workshop narrowed things down from thirty serious proposals to eight candidates.  In 2017, the second workshop further winnowed the list down to three.  And in October of 2018, after three days of presentation, debate, and discussion, the final workshop selected Jezero Crater from these final three candidates using a simple vote of all attendees, and passed on the recommendation to the mission leads.

I haven’t been in the business for very long, so the final workshop was the only one of these where I actually participated.  It wasn’t a close vote as such, and I didn’t break any ties, and technically we were just making a strongly worded suggestion.  Nonetheless, my vote is one of the reasons why the Rover will be going to Jezero Crater instead of Syrtis Major or Gusev, and I think I’m entitled to feel ownership of this mission choice, just a little bit.

(This is, of course, terrifying.)

Having gone through the experience, there were a few surprises worth noting.  The first was how small some of the numbers are here.  The conference was not very large: only thirty proposals, debated by just a few hundred attendees.  I’ve seen book review contests with more entries, and that are read by a wider audience.  Which is to say, this is a situation that was, and is, extremely responsive to individual effort.  In that small a room, populated by people that are philosophically committed to changing their minds when they see good evidence or a good argument, one person can stand up and change the future in a very real way.

The second surprise was the attendance requirements.  Or rather, the lack thereof.  The project is public, paid for by American taxpayers, to whom I am profoundly grateful.  And one way the process reflected that public-spiritedness is that this is not a walled garden.  A small attendance fee (iirc, $40?), and you’re in.  You get a vote, if you want to use it.  A few non-scientists even took us up on this; there’s one retiree (a former schoolteacher, I think) that’s attended every major conference I’ve been to in the last few years, and sets up a small table in the back with his home mineral collection just for fun.  In practice this open-door policy is limited by the obscurity of the event itself; if you don’t move in research circles, you have to be something of a space exploration superfan to hear about it.  Still, as symbols go, you could do worse.

And now that we’re coming up on the day itself, the same kind of public-facing mindset is making me think about why I was persuaded to vote for Jezero Crater, what it means to explore there, and how I’d justify that choice to those of you that made the ongoing discovery of Mars possible in the first place.

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#space #Mars #Perseverance #the power of science #the more you know #apocalypse cw



Not that anyone’s really keeping track, but I do think that this particular crater in the southern ice cap is the most beautiful (recent) impact on Mars.  HiRISE Image ID ESP_057152_0985, -81.485 latitude, 41.358 longitude, impact event in the late summer of 2018.  I keep coming back to it- the beautiful contrast against the ice, the way that the dark sediments of the ejecta blanket in the center almost form wings, the secondary ring of brighter ice all around it where the whoosh of air and dust cleaned the surface, the speckling of secondary impacts throughout.

One of my privileges as a student of Mars is that my object of study is not inhumanly large, or inhumanly small, or really very abstract at all.  The underlying theories can be, sure; geology isn’t stamp collecting.  But fundamentally, Mars is a place.  You can point to it, it’s over there, and sometimes we go to it.  The smaller dark speckles here are a meter or two across, the larger dark zone is maybe a couple football fields.  Roughly the size of a decent-sized mall parking lot, to walk across it.  Uneven going, since the rubble can range from dust to boulders, and especially towards the center you might clamber across using your hands as much as your feet at times.  You’d be cautious, since the exposed surfaces are so fresh- newly fractured rocks will surprise you with unexpected jagged edges, and even in the low gravity, stones are constantly shifting underfoot because nothing’s settled yet.  Ice pokes through here and there as you get near the outer perimeter, and when you look up from your study area it dominates the landscape, rows of small hillocks receding in to the distance.  It’s a crisp mix of water and carbon dioxide, rather pitted, with mottled patterns of red-black dust tracing across the surface.  Where it’s clean, it’s more of a matte white than you’re used to from snow on Earth, just enough to throw you a bit.  Especially as it picks up color tones from the alien sky above you: blue at the top of the sky’s arch near the sun, but phasing through soft purples to a dull red at the horizon.  The breeze is brisk, but gossamer; in the thin atmosphere, it can barely move the hairs on your arm, and the familiar sound of wind whistling over the rocks seems to come from far away.

Not really going anywhere with this post.  I just think about it sometimes, is all.


#space #Mars


To: H.R. Haldeman
From: Bill Safire
July 18, 1969


Fate has ordained that the men who went to the moon to explore in peace will stay on the moon to rest in peace.  These brave men, Neil Armstrong and Edwin Aldrin, know that there is no hope for their recovery.  But they also know that there is hope for mankind in their sacrifice.

These two men are laying down their lives in mankind’s most noble goal: the search for truth and understanding.  They will be mourned by their families and friends; they will be mourned by their nation; they will be mourned by the people of the world; they will be mourned by a Mother Earth that dared send two of her sons into the unknown.

In their exploration, they stirred the people of the world to feel as one; in their sacrifice, they bind more tightly the brotherhood of man.  In ancient days, men looked at stars and saw their heroes in the constellations.  In modern times, we do the same, but our heroes are epic men of flesh and blood.

Others will follow, and surely find their way home.  Man’s search will not be denied.  But these men were the first, and they will remain foremost in our hearts.  For every human being who looks up at the moon in the nights to come will know that there is some corner of another world that is forever mankind.


The President should phone each of the widows-to-be.


A clergyman should adopt the same procedure as a burial at sea, commending their souls to “the deepest of the deep,” concluding with the Lord’s Prayer.


It’s a unique kind of pleasure to look back six or seven years in one’s social media history and discover that one’s younger self posted cool things, had neat opinions about unexpected subjects, and was genuinely the sort of person that one likes.  This was one of my favorite autoanthropological discoveries, although being reminded about Hildegard von Bingen was a close second.


#moon #space #death tw #unreality cw #amnesia cw #(personally I find moments like that deeply disturbing) #(oh don’t get me wrong I enjoy re-reading my old posts) #(but while enjoyment is a large part of why I re-read old posts another part is to keep the memories fresh) #(I wish to *never* be surprised by them) #(your past self can only surprise you to the extent they aren’t part of you anymore) #(to me that’s something to mourn‚ not be delighted by) #(but anyway we’re not here for that we’re here for the alternate-universe speech)



Our water-seeking robotic Moon rover just booked a ride to the Moon’s South Pole. Astrobotic of Pittsburgh, Pennsylvania, has been selected to deliver the Volatiles Investigating Polar Exploration Rover, or VIPER, to the Moon in 2023. During its 100-Earth-day mission, the approximately 1,000-pound rover will roam several miles and use its four science instruments to sample various soil environments in search of water ice. Its survey will help pave the way for a new era of human missions to the lunar surface and will bring us a step closer to developing a sustainable, long-term robotic and human presence on the Moon as part of the Artemis program.

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#Moon #VIPER #space #the power of science #proud citizen of The Future #the more you know