Podcast: JPL's Greatest Hits

As I mentioned a few weeks back, I did a second podcast for 365daysofastronomy.org, and it's available today. It's called "JPL's Greatest Hits" and in it, I talk about what I consider to be the "top 10" space exploration missions that have come out of the amazing Jet Propulsion Laboratory since 1958. It's a pretty subjective list, of course, since JPL has done so many great missions and continues to do so today. But it's fun and I hope also informative.

I had planned to do a few supplementary posts for this podcast, but I got distracted by other things the last few weeks, and I forgot! I will probably add a few posts on specific JPL missions in the next few days, and I have also started a new set on my Flickr site to post some images.

Of course you can get plenty of information and images from JPL's own web site, including this summary page listing all JPL missions. But what you can't get from JPL is a way to "fly" those missions yourself using the free Orbiter space flight simulator, which is something I mention only briefly in the podcast itself. Add-on makers have created amazing simulations of many of JPL's spacecraft, including 9 of my top 10. Some of these include extensive documentation and will allow you to simulate the missions from launch to orbital insertion or landing. Many include deployable or operable parts, so you can really learn a lot about these missions by playing with these simulations.

I have tried nearly all of these add-ons in Orbiter at one time or another, but not all of them recently, so I can't guarantee that some of the older ones will work right out of the box with the current version of Orbiter. Check with the Orbiter Forum if you have trouble, or post a comment here. I won't use the DJ-like backwards countdown for this list. All of these free Orbiter add-ons and many, many more are available at Orbit Hangar. John Graves is clearly a champion of planetary exploration simulations for Orbiter!

1. Mars Rovers, add-on by Scott Conklin ("Usonian") - Amazingly complete and detailed! See picture above.
2. Voyager ver. 1.3 by John Graves ("missleman01")
3. Viking Mars mission by John Graves
4. Mariner 10 by John Graves (my #4 is the whole Mariner series in my top-10, but only Mariner 10 is available for Orbiter)
5. Cassini-Huygens Saturn mission by John Graves
6. Galileo Jupiter by John Graves
7. Mars Global Surveyor is not available, but Brian Jones' MRO add-on is great!
8. Surveyor moon landers by Jim Williams
9. Magellan Venus by John Graves
10. Explorer 1 by Jim Williams (there is a newer version by "Bigmac" that I have not tried)

Note also that you can enhance the experience of some of these missions by installing optional high-resolution textures for moons and planets, such as the Saturn moon textures by "Fordprefect," Jupiter moon textures by "McWogs," and the Mercury surface texture by Jim Williams.

More to come in the next few days - please check back, and also let me know if you have any questions or special topics you would like me to discuss.

Super-Cool Spacecraft

The Hubble Space Telescope is a cool spacecraft, and the STS-125 astronauts are busy working on making it better than ever. Despite difficulties with some bolts, yesterday's EVA team removed the workhorse WFPC2 and replaced it with the new WFC3 camera system. Today the second EVA team has replaced RSU's (Rate Sensor Units, part of the telescope's attitude sensing system) and is now working on replacing batteries.

Update: I wasn't following the EVA earlier in the day and I missed the trouble that Mike Good had with installing one of the new RSU's, requiring the installation of an older but refurbished unit that was carried as a backup. Those NASA folks think of everything, but the trouble put them significantly behind schedule and required extending the EVA duration to allow enough time to do the critical battery task. I bet those guys sleep well tonight! Even for well-trained astronauts in great physical shape, a 7.5+ hour space walk has got to be exhausting.

As cool as Hubble is, the Herschel spacecraft that was launched by ESA earlier this week is super-cool. Literally. This advanced telescope for far-infrared and millimeter-wave observations has a supply of liquid helium on board to keep its sensors cooled below 2 K (less than 2 degrees above absolute zero). As an optical engineer, I'm impressed that this Cassegrain telescope has a 3.5 meter primary mirror, the largest yet launched into space (Hubble's primary is 2.4 m in diameter). Using these long wavelengths, Herschel will be able to image very distant, cold, and dust-shrouded objects to investigate the early history of the universe.

Herschel was launched with a companion spacecraft called Planck, which is a microwave observatory designed to study tiny fluctuations in the cosmic microwave background radiation (CMB), allowing scientists to infer the structure of the early universe as early as 380,000 years after the Big Bang (that's only about 0.003% of the estimated age of the universe, 13.5 to 14 billion years). ESA has a lot of online information on both Herschel and Planck.

Both satellites will operate quite far from Earth, at the Sun/Earth L2 Lagrangian point. They will be established in separate Lissoujous orbits around the L2 point. If you would like to see what this looks like for yourself, you can do so in Orbiter, courtesy of Brian Jones and Papyref, whose latest add-on simulates the Herschel and Planck spacecraft and also provides a special tool for viewing their orbits around the L2 point (screen shot at top). The models and included materials for this add-on are quite detailed. There is one L2 scenario provided, plus two launch-related scenarios (these require additional add-ons for the Ariane 5 launch vehicle and the ESA Kourou launch site.

Super cool!

LRO Preview

There's a cool preview of the LRO (Lunar Reconnaissance Orbiter) mission today on the Planetary Society Blog, written by guest blogger Jim Bell of Cornell University, a participating scientist on the LRO mission. The launch window for LRO opens on June 2.

For Orbiter users who want to preview or follow this mission, Brian Jones has created a great add-on for LRO. As usual, Brian has provided excellent models and user documentation to simulate this upcoming mission in substantial detail. The screen shots above show his Orbiter model in lunar orbit.

Brian has created Orbiter add-ons for a number of real-life space missions that I have tried out and written about in past blog entries. These include MRO, Dawn, Phoenix, Genesis, and Rosetta. I just noticed a more recent add-on that is very interesting, the IEAT (Ion Engine Attitude and Throttle) MFD, an Orbiter control panel that helps with guidance and control of continuous thrust spacecraft such as Dawn. No time to try this out now, but I just downloaded it. I saw a great display on Dawn at JPL's Open House on Saturday, including one of its ion engines.

Electric Rockets 101

There's a good article in the February 2009 issue of Scientific American on electric (or plasma) propulsion systems. It explains the basic principles and the differences between ion drives, Hall thrusters, and magnetoplasmadynamic thrusters (MPDT to their friends). The article does a good job explaining the limitations of each technology and what researchers and engineers are doing to overcome them to improve thrust, efficiency, and long term reliability. These highly efficient propulsion systems will hold the key to faster access to the outer parts of the solar system - an ion drive is already in use on NASA's Dawn mission to the asteroids Vesta and Ceres. The picture above is an Orbiter screen shot I took on a simulated Dawn visit to Ceres.

If you'd like to try an ion drive yourself, you can download Brian Jones' Dawn v.2 add-on for Orbiter and play around with the included scenarios. Also recommended is Asteroid Pack 1.00 which adds Ceres, Vesta, and a few other asteroids to your Orbiter solar system. Because operating with a continuous low-thrust engine is rather different from the usual "burn and coast" method most often used in Orbiter (and in real life), Brian has added some special attitude hold features that are more stable under high time acceleration. He also added a Mars flyby scenario. The real Dawn's Mars flyby is coming up in just a few weeks(February 17). The January 27 entry in the Dawn Journal includes a great explanation of the encounter

Farewell Phoenix

The Mars Phoenix mission is over. It was planned for three months and lasted for five, but as a fixed robotic lander in the north polar region of Mars, there came a point where its solar panels simply could not produce enough power from the low sun to keep it going, even with special power management techniques like selectively shutting down parts of the spacecraft to save power for other systems. So this really isn't a surprise and Phoenix accomplished a lot of good science in its time, doing experiments 149 out of 152 days. The picture above is from Orbiter (the excellent Phoenix add-on by Brian Jones).

If all goes well (including funding), NASA will launch another Mars visitor in fall of 2009, the highly mobile Mars Science Laboratory, a Mars-ready "SUV" with the heart (and brains and instruments) of a planetary scientist. MSL won't be dependent on the sun to keep its wheels rolling, its instruments warm and measuring, and its radios transmitting.

P.S. The Astronomy Picture of the Day for November 12 has a brief summary of the Phoenix mission including some good links.

Small But Interesting Objects

Emily Lakdawalla of the Planetary Society wrote an interesting piece last week, "Things that probably won't ever be called planets, but maybe they should." It's a reasonable sounding approach to the "planet debate" that was triggered by Pluto's "demotion" - "planet" is not a status to aspire to, but simply a name for an object that is smaller than a star, a name that can be qualified as needed with many descriptive words: terrestrial, gas giant, ice giant, dwarf, minor, etc.

But whatever you call them, there are many objects worth exploring here in our solar system, and we have already sent spacecraft to visit many of the "minor" ones. Emily provides a photo album in this post. She also made a collage of all of the visited objects at a common scale, which she posted today. The 1600 x 1200 png file (537 KB) is really cool - it's quite an impressive range of sizes.

This also reminded me that ESA's Rosetta spacecraft will soon be making a flyby of asteroid 2867 Steins on its way to a May 2014 rendezvous with comet 67P/Churyumov-Gerasimenko. The picture above shows Rosetta (add-on by Brian Jones) with Steins as simulated in Orbiter. I'm at 145 km, a bit closer than the intended 800 km distance for next week's flyby.

Hayabusa Visit 2005

I was checking on Orbit Hangar for new Orbiter add-ons, and I noticed one from Brian Jones that I hadn't seen before, a set of Japanese exploration missions based on the JAXA M-V launch vehicle series (MV Missions). These include the Nozomi mission (which failed to reach Mars), the canceled Lunar-A mission, and the partly successful Hayabusa mission that launched from Japan in 2003 and visited asteroid 25143 Itokawa in fall 2005.

As usual, Brian includes a lot of detail in this add-on, including the M-V launch pad area at Uchinoura and the rubbly and potato-like Itokawa itself. There are animations and multiple scenarios including the chance to land on Itokawa to collect a sample for return to Earth, simulating what Hayabusa apparently failed to complete in 2005. I have only played a bit with Hayabusa, not the other two. This add-on is a great value for the price (which is zero, as usual for Orbiter add-ons and Orbiter itself). Nice work, Brian. I'd like to play some more but I have to pack up and go to sleep. I'll be flying over Japan tomorrow en route from Taiwan to SFO (and eventually back to BOS).

Phoenix Has Landed!

Thanks to Brian Jones, his Phoenix add-on, and his real-time web broadcast, I just watched Phoenix enter the atmosphere and land on Mars in really real time. The landing was simulated in Orbiter, but the time in Brian's simulation was Mars time, about 15 minutes ahead of the light-speed-delayed signals received and reported by NASA. In other words, the real Phoenix arrived on Mars when it did so in Brian’s Orbiter simulation. Then like everyone else, we had to wait 15 minutes to find out if the real spacecraft landed safely to the Mars surface when the simulated one did…

It made it! We’ll have to wait a bit for the first pictures but all the telemetry indicated a safe landing with just a quarter-degree tilt. Nice job JPL, University of Arizona, and Brian!

The sample screen here is what I watched – Brian’s video window (with an active chat session), NASA TV, and the mission clock from Arizona’s main Phoenix web site.

Phoenix on Final

It's just under 4 hours until the Mars Phoenix spacecraft will land near the Mars north pole. It probably looks something like this screen shot from Orbiter, though this view is much closer to Mars, about an hour and ten minutes from the simulated landing (and not for the currently projected landing time - correct date, but it's a few hours off).

I hope to follow the entry on the web tonight and possibly also in Orbiter, depending on when we get back from an early dinner with my daughter. A few days ago Brian Jones posted an upgrade to his Phoenix add-on with some corrections that should allow more accurate EDL simulation. See this post for details (the add-on itself is at avsim.com, file phoenix_mission_v3.zip). He will also be streaming his own simulation of the entry and landing in real time at Ustream.

Million Mile Mission

The new Air & Space Magazine arrived yesterday with a cool cover story on a possible mission to visit a near-Earth asteroid using NASA's Constellation program hardware (specifically the Orion spacecraft). While Orion will be considerably roomier than the old Apollo command module, it would seem a bit cramped for a possibly six-month mission, even with only 2 or 3 crew members. Perhaps a Bigelow Sundancer inflatable could somehow be sent along for more living space? But asteroid enthusiasts with good credentials have studied this, and even with only the Orion, astronauts say they would sign up for it in a heartbeat, so who knows? It's definitely not funded at this point, but it surely would make sense to get some sort of practical experience intermediate between the Moon and a two-year Mars mission.

The article includes some nice paintings, but the illustration here was done with a couple of Orbiter add-ons. I can't get the links right now, but if anyone is interested, post a comment and I will find and post them when I have some free time and an internet connection, maybe Sunday in Brussels.

UPDATE: The asteroid is actually the core of Comet 67P from Brian Jones' ESA Rosetta add-on which is available on avsim.com (search for rosetta_v3.zip). I edited a Rosettta scenario file to replace the Rosetta with the Orion and to remove the comet's tail (coma) which is implemented as a "spacecraft" landed on the core object. The Orion add-on is a recent CEV version by "Francis Drake" found on his downloads page (Orion CEV 606 at bottom of list). I saw in a forum post that he is working on a newer version with the smaller "service module" shown in more recent Lockmart and NASA graphics, but I don't know the status of that.

Phoenix: Two Weeks Out

The Phoenix Mars spacecraft is just a little over two weeks from landing on Mars (16 days, 11 hours, 20 minutes according the landing countdown clock here). I was reminded of this the other day when I read Phoenix principal investigator Peter Smith's introduction to the "Visions of Mars" mini-DVD that is mounted on the spacecraft. That special DVD was provided by the Planetary Society and is a sort of time capsule, a message to (human?) Martians who may recover and decode it some time in the future. It contains messages, stories, and various other materials, plus a list of thousands of names, including all the members of the Planetary Society (so I'm in there). There's a lot of cool material on the DVD, and you can read and hear some of it on the Planetary Society's web site. I'm listening to Carl Sagan's audio message right now.

As I wrote last summer, if you would like to experience the entry, descent, and landing (EDL) for Phoenix yourself, you can do so in Orbiter with the nice Phoenix add-on by Brian Jones (it's at avsim.com, not Orbit Hangar). The picture above shows the spacecraft about to touch down, having already detached from the parachutes and ejected its landing shroud. Is anyone going to try to follow the EDL in real time on May 25?

P.S. If you want to get up to speed quickly on the Phoenix mission, download the JPL press kit for the Phoenix landing, a 3 MB PDF here.

Dawn's Ion Light

I got a mission status report from JPL on the Dawn mission, which launched successfully back on September 27. The report said that JPL engineers had tested the spacecraft's ion engine for 27 hours this past weekend, a drop in the bucket compared to the 50,000 hours they are expected to thrust over the life of the mission. I wrote about Dawn back in July when it was originally expected to launch, and I simulated some parts of the mission in Orbiter using the excellent add-on package by Brian Jones. The Orbiter picture here shows the ion engine firing in close proximity to Ceres, which Dawn will not actually reach for a few years (2015, after Vesta in 2011).

Phoenix in Orbiter

The Dawn launch has been postponed until September, because the available launch windows in July are limited after this weekend, and they did not want to run the risk of delaying the planned August launch of the Phoenix Mars mission.

Speaking of which, there's a great Orbiter add-on for the Phoenix Mars mission too, courtesy of (you guessed it) Brian Jones (search for phoenix_mission_v2.zip at www.avsim.com). I tried it out the other night, with the dramatic night launch scenario as well as the Mars arrival scenario (I skipped the admittedly vital interplanetary navigation bit for now, though Brian provides helpful notes on using IMFD to navigate to Mars and set up an approach for the planned latitude and longitude).

Starting from the supplied Mars approach scenario (one hour before landing), with basically no user inputs, the spacecraft successfully enters the Mars atmosphere and performs an automated landing, with aeroshields, chutes deployed, landing rockets, the whole nine yards (the whole 8.2296 meters for you metric folks). You can then deploy the solar panels and camera mast and operate the robot arm. Unfortunately you can't drive it around - Phoenix is not a rover. But it's got a long robot arm and it can dig some pretty deep trenches (up to half a meter). There are on-board chemical analysis and atmospheric measurement instruments (and cameras), so hopefully it will dig up something interesting in the arctic regolith.

Dawn in Orbiter

The Dawn mission to Vesta and Ceres can now be flown in Orbiter, thanks to an excellent new free add-on package by Brian Jones (available at avsim.com, registration required). This mission presents some challenges due to the ion engines, which have small thrust but are fired continuously over a long period of time. Most rockets and spacecraft use chemical rockets with relatively large thrust but short burn times. For maneuver calculations, such engines can be considered to produce an impulsive (nearly instantaneous) thrust which quickly changes the spacecraft's velocity and position, allowing the trajectories to be approximated as a series of simple curves (circles, ellipses, hyperbolas, parabolas). Engines are then turned off during the "cruise phase" of the flight. Calculations and guidance to reach other planets are relatively simple in this case (and supported by various Orbiter instruments or MFD's).

Ion engines make it harder. Since the spacecraft is under small but constant acceleration, its path is more of a spiral than a simple conic section. Orbiter doesn't have any good navigation tools for such constant thrust cases (like the Transfer MFD or IMFD which allow you to plan engine burns to get to a certain place at a certain time), but Brian has supplied a few new "autopilot" modes to at least help keep the spacecraft thrusting in a useful direction (e.g., prograde or retrograde). He also has some nice animations as well as solar panels that automatically track the sun.

This is a cool add-on, but for maximum value, you should also download Brian's Delta II Missions v.2 (so you can run the Dawn launch mission, maybe even launch this Saturday at the same time as the real launch) and Nighthawk's Asteroid Pack 1.00 (on Orbithangar) in which you can find Ceres, Vesta, and a few other major asteroids to carefully add to sol.cfg (solar system configuration file) in Orbiter. There are a few other requirements, so read the readme files and forum carefully on this one. More pix at Flickr.

Heart of the Sunrise

When I started college in (ahem) September 1970, one of the bands I really liked was Yes. Their music was somehow complex and soothing at the same time, and they held my interest through Close to the Edge, which was perhaps my favorite of theirs (Topographic Oceans was just too much and I never liked much of their later stuff).

So imagine my surprise to find a connection between Yes and Orbiter! I searched for "Brian Jones" over at avsim.com to see what other add-ons he had done (I knew one of them was MRO). But one I hadn't seen was "Yessongs," inspired by the album artwork of Roger Dean (see here, for example). The fish-like space yacht "Schindleria" is really a beauty, especially in the two Venus scenarios, including "Heart of the Sunrise," one of my favorite songs by Yes. And I hope that pointy asteroid never hits the Earth. Nice work, Brian!

Asteroids in the News

The weekly Kurzweil Accelerating-Intelligence News brings its usual roundup of sometimes strange, sometimes wonderful, sometimes scary bulletins from the cutting edge, with brief summaries that point you to the original articles. Retinal implants, self-assembling batteries, quantum computing, interstellar arks, and more. This New Scientist Space article on the threat of near-Earth asteroids is especially interesting.

Although the current estimate (1 in 45,000) for the probability of the 250 meter asteroid Apophis hitting Earth in 2036 may seem small, it is only one of many such asteroids, many of them still unknown (this cool JPL site lets you easily view animated orbital diagrams of potentially hazardous near-Earth objects, or NEO's - see Apophis here, the top picture above). It's not exactly that the sky is falling, but the threat is real, and asteroid impact is one of the few natural disasters that we might have a chance to do something about, if we continue to expand our tracking programs and if we develop the necessary technology.

The necessary technology doesn't require training Bruce Willis for a suicide mission (as in the rather silly Armegeddon) - it could be as (relatively) simple as parking a fairly massive unmanned spacecraft near the asteroid and allowing its tiny but long-acting gravitational pull on the asteroid to slowly "tug" it away from its collision course path. Of course this would have to be started while the asteroid is still quite far from Earth.

There are a few Orbiter add-ons that allow you to install and play around with some asteroids and the spacecraft that have visited or will visit them. One of them is the pictured ESA Rosetta spacecraft add-on by Brian Jones (search for rosetta2.zip at www.avsim.com). Here I have used the scenario editor to place it uncomfortably close to asteroid 2867 Steins (Java applet), which is also included in the add-on. Note that the gravitational effect of a spacecraft on a "body" (planet, moon, asteroid) is most likely not modeled in Orbiter, so you won't be able to try out the gravitational tractor idea yourself (at least not until some Orbiter add-on builder figures out a way).

NOT McNaught

Clouds, trees, and laziness caused me to miss seeing Comet McNaught this past two weeks when it was visible in the northern hemisphere (SpaceWeather.com and this photo gallery reminded me of this sad fact). I wondered if I could simulate a comet in Orbiter (not that this is a good substitute or anything).

Well I did, sort of. I borrowed part of an add-on by Brian Jones, simulating the ESA Rosetta mission (search for rosetta2.zip on Avsim.com). I then played around for a few minutes editing scenario files to place the comet near Earth so it would be visible near sunset at Cape Canaveral. The resulting picture is not very convincing, I admit (it's definitely not McNaught). I was surprised that there are very few Orbiter add-ons that simulate comets and asteroids. There are some, but the focus is on simulating the spacecraft and the flight for missions such as Rosetta and NEAR that have visited such bodies, and the developer typically includes the comet or asteroid as part of the add-on. See Flickr for more.

Mars: Ready for your closeup?

After six months, 426 carefully managed orbital "dips" into Mars' atmosphere, and a few well placed thruster burns, NASA's Mars Reconaissance Orbiter (MRO) reached its near-polar scientific orbit on Monday and will soon (November) be ready to start taking pictures of the Mars surface (and doing a lot of other tasks too). The combination of high resolution sensors and a giant antenna (to enable speedy transmission of all those gigabytes of data back to Earth) means that MRO will return a huge bounty of data on the Martian surface and atmosphere.

I tried to set up MRO's final orbit in Orbiter, but I didn't get the sun-synchronous part right (needs more work but too tired now). The near-polar (planned 92.66 degree inclination) orbit is carefully designed to cross the equator at the same local time on each orbit, providing observations of the surface with nearly constant lighting conditions. The periapsis altitude (low point) of the orbit is about 250 km (and near the south pole), while the apoapsis (high point) is 316 km above the surface (near the north pole). More on the orbit design here (PDF), with general information on the mission here.

P.S. Of course there are no EVA astronauts with MRO at Mars, but I added one for the picture above to show how big this thing is - "bus size" as they say. More pix at Flickr. Note also that the MRO add-on for Orbiter is by Brian Jones, available at avsim.com (file mro.zip).

MRO - Final Approach to Mars

The Mars Reconnaissance Orbiter (MRO) spacecraft is in its final approach to Mars today, and late this afternoon (4:24 pm Eastern time), it will perform an orbital insertion burn to enter an initial high-ecentricity orbit. Over the next 6-7 months, a series of some 500 aerobraking maneuvers will use drag from Mars' thin atmosphere to circularize the orbit to its operational state. You can learn more about MRO and its arrival and follow the JPL mission timeline here.

Thanks to Orbiter add-on developer Brian Jones and Orbiter Forum member "Peter3210," you can simulate the arrival of MRO yourself. Brian's MRO add-on is available at avsim.com (search for mro.zip), and Peter has posted a set of instructions and a starting scenario for simulating the mission from 7 am EST to the insertion burn.

I heard a pretty good report about MRO on NPR this morning (a rare and wondrous thing to hear a space story on the radio, though more likely on NPR than anywhere else). MRO has some amazing instruments on board, and if all goes well, it could return 10 times as much information about Mars over the next few years than all past Mars missions combined.

P.S. at 5:46 pm EST - I parked NASA TV on my tool bar for the last 90 minutes so I could half-watch the JPL control room as the spacecraft's signal was lost and reacquired, both right on time. Early telemetry shows that MRO is in its initial Mars orbit and is healthy. Very cool!

My Stardust Simulation Lands in Utah

NASA's Stardust Comet Sample Return Mission is on track to land (mission timeline here) in Utah early Sunday morning. Thanks to add-on maker Brian Jones, it's possible to simulate the Stardust mission in Orbiter (the add-on has been available for a while on avsim.com). Another Orbiter user (Donald Tinc) has helpfully posted updated orbital elements the last few days as the spacecraft has approached Earth. By text-editing Brian's return scenario file (he also provides a launch scenario and a simulated comet to visit, but I didn't try those parts of the mission myself), I introduced the updated elements from earlier today and simulated Stardust's reentry and landing. Brian also provides a tip in that forum post for an adjustment to a drag factor in the capsule's initialization file. This helps the accuracy of the reentry (without this, my first attempt seemed to skip off the Earth's atmosphere).

If you start with the "close-in" orbital elements, all the course corrections have been incorporated, and the only real control you have is when to separate the return capsule from the "bus" (I followed NASA's timeline) and when to deploy the drogue and main chutes (the separated capsule has no maneuvering thrusters). You can also try (as NASA will do successfully, I'm sure) to maneuver the bus spacecraft after separation to get it to miss the Earth and enter a solar orbit. I need some work on this part, but my landing was pretty good -- at least it was in Utah, about 190 km southwest of Salt Lake City, near the Nevada border (map and other graphics on Flickr). Now I'll really be interested to see where the real spacecraft lands (Update on January 15: it landed safely in the Dugway Proving Grounds near Michael Army Air Field, about 90 km northeast of my simulated landing).

Note that although I did not try it myself, Orbiter is accurate enough to recreate the entire seven-year mission from launch, including three orbits of the Sun and a gravitational "slingshot" around Earth to set up the comet encounter. I just did the easy stuff tonight!

P.S. For an excellent summary of scientific aspects of the Stardust mission, see this new post by Anthony Kendall. This New Scientist graphic is a great visual summary of the successful mission.