Spacecraft Tribute!

[Ho Lam Kerman]

Yesterday, September 15th 2018, was a day of two endings. 

It was both the last day of the Delta-II, and the first anniversary of Cassini-Huygens mission completion.

So, I'll put a little text-based tribute to them both, here in this thread.

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Cassini-Huygens was a mission of firsts. A trailblazer. First mission to orbit Saturn. First soft-landing in the outer solar system. 

Weighing 6 tons when fully fuelled, it is going to be a long time before a mission of this scale is launched again.

Spending 13 years (half a Saturnian year) at Saturn, it observed the changes in the Saturn system over Spring and Summer.

Discovered 7 moons (6 of which are named). Took 453048 images.162 targeted flybys of Saturnian moons. 360 engine burns. 635 GB of data collected. 

Its ride-along sister probe Huygens made the first soft landing in the outer solar system, landing on Titan on January 15th, 2005.

It discovered methane rivers and lakes on Titan. Evidence of salty, liquid water sea heated by hydrothermal vents under Enceladus. Tests of general relativity. Radio occultations of the rings, revealing their composition and particle size.  Verifying spokes in the rings, first confirmed by the Voyagers.

And, on September 15, 2017, it literally tasted the atmosphere of Saturn itself.

1500 km above the cloud tops, Cassini entered the Saturnian atmosphere. Struggling to keep radio contact, signal was finally lost 7:55:46 AM EDT on 15th September 2017. The spacecraft is believed to have broken up 45 seconds after loss of contact.

And so, on that fateful day, the probe was united with the planet it had studied for over a decade.

Ad astra, Cassini-Huygens. We will certainly miss you.

 

 

The Delta-II rocket was a reliable workhorse. 

Launching 54 science missions for NASA, our current understanding of the solar system wouldn't have been possible without it.

It launched 2001 Mars Odyssey, Dawn, Deep Impact, Genesis, Mars Phoenix, MESSENGER, NEAR-Shoemaker, both STEREO spacecraft, both MER rovers Spirit and Opportunity (Hang in there buddy!), WISE, WMAP, Spitzer Space Telescope, all 5 THEMIS spacecrafts, the Fermi Gamma-ray Space Telescope, 24 GPS satellites, 60 Iridium satellites (which are now an endangered species, if you've been paying attention to Scott's science videos), the Kepler spacecraft, and so much more.

Without Delta-II, we wouldn't have had any of this: 

(Asteroid Eros imaged by NEAR-Shoemaker)

(Comet Tempel-1 imaged by Deep Impact)

(Vesta imaged by Dawn)

(Asteroid Mathilde imaged by NEAR-Shoemaker)

(Comet Siding Spring as imaged by WISE)

(CMB as measured by WMAP)

(Polygonal Martian terrain as imaged by Mars Phoenix)

(The sun, as imaged by one of the STEREO spacecraft)

(Heinze 206 as imaged by Spitzer)

(Mercury, as imaged by MESSENGER)

On 15th September 2018 at 13:02 UTC, the final Delta-II launched ICESat-2 out of SLC-2W at Vandenberg Air Force Base in California. The mission went as planned, and earned the launch vehicle a streak of 100 successful missions in a row. Thus ended the illustrious career of the Delta-II.

Ad astra, Delta-II. Goodbye, old friend.

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(Feel free to add your own tributes below, in any format.)

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Edit: I've decided to make this a tribute thread to other spacecraft too, as Dawn and Kepler have come to an end. 

Edited November 3, 2018 by Ho Lam Kerman

[Scotius]

It's hard to add anything Good work.

[YNM]

... And so ends the life of only man-made object around Saturn, and one more of an ICBM-derived rocket design which has flown for 60 years.

[Ho Lam Kerman]

I've decided to make this a tribute thread to other spacecraft too. Incidentally, both were launched by Delta-IIs.

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On October 31st, NASA decommissioned its Kepler spacecraft. Discoverer of 2662 exoplanets. Revolutionised the whole field of exoplanetology- gone were the days of sitting in cold, dark towers, laboriously examining spectroscopy data! Just sit and wait for the discoveries to roll in!

In 2012, Kepler experienced problems with its reaction wheels, rendering it useless. Fortunately, project scientists came up with an ingenious plan to harness the power of the solar wind, and Kepler's hexagonal solar panels to keep it alive.

Designed for 10 observation runs, it was successful beyond anybody's wildest dreams, completing a total of 19 observation runs.

Kepler, the telescope that was raised from the dead, has now died a second and final time, succumbed to fuel run-out. It will forever remain in orbit behind the Earth, lasting until the end of our solar system.

Ad astra, Kepler. Hearts across the globe will sorely miss you as a pioneer in exoplanetology.

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Just one day after Kepler, NASA's Dawn spacecraft has fallen prey to the same tyrannical, inevitable cause.

Launched back in 2007, Dawn was a mission of firsts. First spacecraft to orbit two independent celestial bodies. First spacecraft to orbit either Vesta or Ceres. First spacecraft to visit a dwarf planet. First mission to orbit a dwarf planet, for that matter. All made possible by the use of revolutionary technology, the ion engine.

Dawn has revolutionised out understanding of the asteroids, but has also created new problems for a new orbiter to solve. Occator crater and many other places on Ceres has prominent white patches on them, hypothesised to be mixtures of salts that were left behind after slushy solutions evaporated relatively recently, after it gushed out from underground.

Dawn has also discovered terrain on Vesta that look like gullies, eroded by flowing water. Vesta is believed to be the last of its kind, the last large planetesimal left over after the formation of the solar system.

Dawn has done its job of opening up the time capsules of the earliest chapters of the solar system. Now, it will be left in orbit around Ceres, serving no longer as an outpost for planetary exploration, but as a monument to it. 

Ad astra, Dawn, mission of firsts.

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Feel free to add your own tributes. In any format- be it a poem, a verbal tribute, an image, a song: whatever you like.

Edited November 3, 2018 by Ho Lam Kerman

[Ho Lam Kerman]

15 years ago, two Delta II rockets launched two twins to two opposite places on Mars.

The rover duo was only designed to last for 90 sols.

Opportunity would eventually last 5352 sols.

For 15 years, these rovers would be part of our lives.

They've helped us discover so much. They were our two eyes on Mars.

Hematite blueberries, proving water on Mars. 

Heatshield rock, a wonderful surprise sitting where the heatshield rested.

An entire marathon, on Mars.

Over 220000 pictures.

15 years.

 

They had faced hardships, too.

Driving backward to prevent wheel damage.

Driving on slopes so treacherous the dust started sliding off the solar panels.

Breaking both front wheels.

15 years.

 

Now, they sit silent on Mars, listening to the wind and breathing the dust.

Humanity's last words to the little rover that could were the song I'll Be Seeing You, performed by Billie Holiday.

Ad astra, the little rover that could. You will be dearly missed.