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Planetary Exploration Timelines: A Look Ahead to 2016

Posted By Emily Lakdawalla

31-12-2015 16:04 CST

Topics: scale comparisons, mission status

How many planetary exploration missions are there, and where are they? These days, it's hard to keep track, because there are so many. I plan to begin the new year by taking stock of active missions, figuring out what each has set out to do and accomplished so far, but first I want to step back to consider the spread of missions across the solar system as a whole.

I've tried out a variety of ways of visualizing the state of planetary exploration (including Olaf Frohn's monthly orbital diagrams). Below is something I've been working on periodically for a couple of years. (It was inspired by this chart and discussion.) They're still not perfect (and likely contain errors) but they provide a useful place to start, I think. The skinny, gray bars indicate spacecraft in cruise phase; the bars are fat and colored in any calendar quarter in which they're performing their science mission. This chart starts in 2003 and projects out to the end of 2018.

Planetary Exploration Timeline, 2003-2018 (version 2015-12-31)

© Emily Lakdawalla for The Planetary Society

Planetary Exploration Timeline, 2003-2018 (version 2015-12-31)

We are entering 2016 with 15 spacecraft probably actively returning science data from planets, moons, and smaller bodies in the solar system. (I say "probably" because I don't know for sure what the Chinese lunar spacecraft are doing.) Akatsuki is at Venus, Lunar Reconnaissance Orbiter and two Chang'e missions at the Moon, two rovers and five orbiters are active at Mars, Dawn is at Ceres, Rosetta is at 67P, Cassini is at Saturn, and although New Horizons is far past Pluto, it'll be sending back new Pluto science data for most of the year, so I'm counting that as still doing science. Another two missions (Hayabusa2 and Juno) are in their cruise phase; Juno arrives at Jupiter in August. Two (ExoMars Trace Gas Orbiter and OSIRIS-Rex) or three (if you count the Schiaparelli lander separately) will launch this year, with their science starting after 2016. The Voyagers and other heliophysics missions don't show up on this chart.

What missions will end this year? Rosetta is the only one with a specific end date, with its landing on comet Churyumov-Gerasimenko in September. Dawn's primary Ceres mission ends in April; it's likely to be kept at work until it depletes its very little remaining fuel, and may not last out the year. Of the seven active Mars craft, four are operating far longer than they were designed to. There's no particular reason to expect any one of them to die this year, but our luck can only hold out so long. I have arbitrarily chosen to fade out the oldest lander and orbiter (Opportunity and Odyssey) at the end of this year, but there's no way to know what the Mars fleet will look like a year from now.

Step back from the chart and look at the robust fat bands of science being done between 2003 and 2018, and now compare it to a similar chart for the previous 16 years. Yes, this chart is complete, as far as I know. Quite a contrast, eh?

Planetary Exploration Timeline, 1987-2002 (version 2015-12-31)

© Emily Lakdawalla for The Planetary Society

Planetary Exploration Timeline, 1987-2002 (version 2015-12-31)

I have continued working farther into the past, but am not sufficiently certain about the dates and nature of the Soviet Luna missions to be ready to show you that part of the chart. Some of you may be wondering why the Halley missions are not in the main belt / comet section; it's because Halley was in the vicinity of the orbits of Earth and Venus when the encounters happened, and it makes more sense for the bars for those spacecraft to be near Venus, which two of them flew by.

Here's another way of coloring the graphs: according to the agency that launched them. I tried to use a colorblind-safe color scheme on this one, with NASA, Russia, and ESA in shades of blue, and Japan, China, and India in shades of red-orange. I have colored BepiColombo for ESA and Cassini for NASA even though I know those are cooperative missions with JAXA and ESA, respectively -- I need to come up with a better way of signifying those.

Planetary Exploration Timeline, 1987-2002, colored by agency (version 2015-12-31)

© Emily Lakdawalla for The Planetary Society

Planetary Exploration Timeline, 1987-2002, colored by agency (version 2015-12-31)
Planetary Exploration Timeline, 2003-2018, colored by agency (version 2015-12-31)

© Emily Lakdawalla for The Planetary Society

Planetary Exploration Timeline, 2003-2018, colored by agency (version 2015-12-31)

Because of the way I've arbitrarily ended a bunch of missions at the end of 2016, there's a falsely sharp cutoff between 2016 and 2017 that won't precisely reflect reality. But some aspects of that cutoff are true: there are no main belt / comet missions that will be active in 2018 and likely 2017 (depending on how long Dawn's fuel lasts); and no more giant planet missions beginning in 2018. There is a period in the beginning of 2018 when the only planetary target from which NASA or ESA will be returning science data is Mars. That's sobering. So enjoy 2016's bounty of space missions, because we're at peak planetary. And please, advocate to #fundplanetary.

Stay tuned over the coming weeks as I take a focused look at active missions, one by one. Happy 2016!

See other posts from December 2015


Read more blog entries about: scale comparisons, mission status


cpushack: 12/31/2015 08:43 CST

"I have colored BepiColombo for ESA and Cassini for NASA even though I know those are cooperative missions with JAXA and ESA, respectively -- I need to come up with a better way of signifying those." Just make them striped, using the appropriate colors.

spaceslinky: 01/01/2016 05:01 CST

There is one more Russian-European Mars mission, "Mars MetNet", with an array of weather sensor impactors. It seems hard to find concrete plans on the launch date... does its omission in your timelines indicate that the mission has been scrapped? (Does anyone even talk about this mission at all...?)

A. Karvajalayas: 01/01/2016 09:38 CST

Thanks for your always very thorough reporting Emily! I want to remind you of a intrepid probe traveling in the Interplanetary Space, 50 years after it was launched: Pioneer 6. Would it still answer with telemetry data, if somebody at/with DSN-facilities contacted it?,_7,_8,_and_9#Time_line_and_current_status

Messy: 01/01/2016 10:51 CST

In the '87-'03 chart, I noticed that you forgot Galileo's magnificent reconnissiance of the MOON, some of those of the Moon from different perspectives have become iconic.

Ralph Lorenz: 01/01/2016 02:09 CST

Great plots ! Do you generate these 'by hand' (photoshop, illustrator or some similar GUI) or is there some clever scripting tool you can use to make diagrams like this ?

Jim Shirey: 01/01/2016 02:41 CST

When are we finally going to officially name "the Moon"? It has always been referred to as Luna by writers forever. It makes no sense to continue calling it "the Moon" when every other bit of solar system material (other than "the Sun" aka "Sol") has a name. I would think it a worthy cause of the Planetary Society to press for naming of the Moon....and the Sun.

Brian Schmidt: 01/01/2016 10:58 CST

These are great charts. I've been interested in when a permanent, active robotic presence is/will be established in different places in space. Mars is safely in that category for orbiters since 1997, possibly for surface missions since 2004. I'd have thought the Moon would've been the same, but Emily's chart suggests otherwise, unless something happens to extend the missions. And nowhere else, so far. My guess is the next long-term missions to Venus and Jupiter will start a permanent presence there, but we'll just have to see.

Jasper : 01/02/2016 05:29 CST

Though the ARTEMIS probes are technically heliophysics spacecraft, their science has been pretty evenly split between planetary/helio objectives. And there are two of them still operating around the Moon!

masanori : 01/02/2016 08:01 CST

I don't understand why what makes Emily choose to end Oppy's & Odyssey's missions at the end of 2016 does not make her choose to end Mars Express's mission at the end of 2016. I mean, apart from NASA's budget issue I have not heard Oppy &/or Odyssey have any problem which can end the mission. Like Mars Express.

David Frankis: 01/03/2016 04:26 CST

Congratulations - this is how it should be (perfection is a meaningless concept here as there will always be design trade-offs to be made). Are the omissions of ICE and Ulysses's Jupiter flyby deliberate?

Sandy: 01/03/2016 06:20 CST

This is a great start - very informative. Thanks.

stargazed: 01/04/2016 06:18 CST

Great charts, I noticed one mistake: BepiColombo is flying to Mercury, not Venus. Thanks!

VoyagerFan: 01/04/2016 09:58 CST

Great graphic ! Thanks. One suggestion: How about a place for the still-active Voyager 1 & 2 ? Maybe rename the bottom zone "Kuiper Belt and Beyond"? Also, we could discuss how thick their lines should be. Yes, they are "in cruise". But they are actively exploring the outer solar system conditions. My vote would be "thick". ;-)

Digi-Destined: 01/04/2016 01:04 CST

Thanks Emily, this is a very visual and informative chart, now I can explain my 6 year old Son the Planetary Exploration past and future. Love it!

David Frankis: 01/04/2016 01:24 CST

I did a bit of digging, and found this thread on UMSF: Unfortunately, the link to the spreadsheet that was the original inspiration is broken, but the discussion is well worth following as it illuminates some of the choices Emily has made.

Emily Lakdawalla: 01/04/2016 04:50 CST

I am really shocked not to have come back from a holiday weekend to find a million corrections to these timelines...maybe they were actually ready for publication! Messy: You're right, and there have been several spacecraft that photographed the Moon, including Nozomi and the Voyagers. I'll have to think about how/whether to incorporate that. I gave up the idea of including Earth imaging because it would make too many timelines start at Earth and just make the whole thing too confusing and spaghetti-like. Ralph: By hand, in Illustrator. Brian: I think it's possible that there will be no gap at the Moon -- I hope LRO will last much longer. Jasper: I *always* forget Artemis. Sigh. David: I have a version of this chart with heliophysics missions included, may need to expand it in the future. Sandy: BepiColombo will fly by Venus first, which is why it starts in that row. VoyagerFanL Voyager 2 is on there but I don't currently include heliophysics missions, which it now is. David: Argh, I should've included a link to that chart which was, as you surmized, the inspiration for this work. Will edit to do that.

Rocketeer_UK: 01/05/2016 03:08 CST

GLXP landers (2017). Beagle 2 (2003). Everyone forgets Beagle 2 *sniffle*...

morganism: 01/09/2016 05:14 CST

Insight launch cancelled due to a vacuum leak. Prob 2 years till launch now...

morganism: 01/09/2016 05:19 CST

oops, forgot to point this out for your orb mech pleasure.

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