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Seriously.

Here is the link to the NASA press release.

And here is the link to the image.

Here are the actual photos: http://messenger.jhuapl.edu/gallery/sciencePhotos/

It has a finite surface area, therefore it feels the solar wind.

Accounting for that force when predicting its trajectory, maybe even aligning the spacecraft to make it additive to thrust rather than subtractive wherever possible, doesn't make it "how they maneuvered".

Much, and possibly most, of the vehicle's maneuvering was done by gravity assist during several flybys of Earth and Venus and Mercury. I just wish the website showed a graphic of the whole thing.

It has a finite surface area, therefore it feels the solar wind.

Accounting for that force when predicting its trajectory, maybe even aligning the spacecraft to make it additive to thrust rather than subtractive wherever possible, doesn't make it "how they maneuvered".

Much, and possibly most, of the vehicle's maneuvering was done by gravity assist during several flybys of Earth and Venus and Mercury. I just wish the website showed a graphic of the whole thing.

Press release doesn't mention that, perhaps just the OP's words? Anyway there's a good QA on how much fuel the solar sails saved.

Then again:

- Mercury's density implies that a metal-rich core occupies at least 60% of the planet's mass, a figure twice as great as for Earth.
- only 45% of the surface of Mercury had been photographed by a spacecraft.
- Mercury has a global internal magnetic field, as does Earth, but Mars and Venus do not.
- At Mercury's poles, some crater interiors have permanently shadowed areas that contain highly reflective material at radar wavelengths.
- the period of time from which the position of the Sun in the sky at a given, fixed Mercury longitude returns to that same position is 176 Earth days.
- 3:2 resonance - 3 planet rotations during 2 orbits around the sun

Given the mysterious material hiding in the cold craters turns out to be water ice, the abundant solar energy on Mercury could be used to separate this into Hydrogen and Water. Both great resources to stay put with operations on the little rock.

http://messenger.jhuapl.edu/why_mercury/index.html

These videos do not require Flash.

As an analogy, think about playing tetherball as a kid. If the ball is already in motion, you have to hit hard enough to cancel all the rotational velocity so it can hit the pole. In the case of a spacecraft, the initial motion is actually the motion of the Earth around the sun -- that's a lot of velocity to make up for.

That's not to say that going to the Sun is impossible. Actually, a recent press release says that NASA will be doing just that in an a mission launching in 2018.

The problem, however, is that the earth is moving quite fast. To get to the sun, a spacecraft has to slow down. A lot. Otherwise, it'll just keep orbiting a little bit closer.

In fact, the early concept for the Solar Probe Plus was to send it to Jupiter (!!!) first in order to slow it down enough. Think of it like using the slingshot effect, only backwards. It seems that's been scrapped in favor of multiple Venus flybys, much like MESSENGER (which is uses a pass by Earth, two by Venus, and three by Mercury before it finally orbits around Mercury).

No, MESSENGER is going into orbit around Mercury next year.

Yeah, it's hard to get to Mercury. That's why MESSENBER has to go though this punkerish orbit involving gravity assists from an Earth flyby, two Venus flybys, three Merc. flybys and a total of five deep space maneuversbefore orbit insertion. You can see the trajectory here. 7 years and 15 orbits of the Sun to go essentially 1 AU away. That's the same amount of time it took Cassini to get to Saturn. The last flyby is at the end of the month.

This is wrong. The GOES satellites are geo-synchronous, meaning they remain at continuous location with respect to the Earth. This also means that they are not in polar orbits. These satellites are similar to the LANL satellites but occupy the western hemisphere. You may be thinking of the DMSP satellites.

GOES is useful at measuring the magnetic fields. It does not, however, measure the ionospheric particles such as is done with the SuperDARN coherent scatter radars or the EISCAT or PFISR incoherent scatter radars. The group at the University of Saskatchewan has also received money to build a new radar which is scheduled to be built on the NE corner of Baffin Island in the Canadian Arctic. It will be their 5th radar.

The current robot mission (New Horizon) to Pluto should provide better answers in the future. The New Horizon mission is going to reach Pluto in 2015, so it should be at the boundary at 2020 or 2025, I am not sure about the exact date in that manner. But it is somewhere along those years.

http://pluto.jhuapl.edu/

We can't know how many sunspots there really are if we're only seeing only half the surface of our star, right?

We see more than half of the surface.

A technique called "helioseismic holography" can detect sunspots on the far side of the sun. There is also a pair of spacecraft called STEREO which are in a solar orbit that lets them see parts of the sun that are not visible from earth.

We have already seen Pluto from the ground. Adaptive optics rock that way. Here is an article with pictures.

Even more importantly, adaptive optics is a relatively young technology that is getting better. As the GP said, JWST is really expensive. JWST also won't be ready for launch for years yet. It doesn't make sense to pour massive money into a space telescope for visible light when we can already beat Hubble from the ground under some conditions, and we're getting better.

Note that, thanks to New Horizons, Pluto itself will soon be getting a better closeup than anything we can do from the ground or from Earth orbit, at least in the forseeable future.

As if NASA has done much original exploration lately. How long has it been since anybody has been to the Moon?

About the only genuinely ground breaking missions currently on tap are the New Horizons mission to Pluto and the Dawn mission to the asteroids. I am excited about both, but they certainly don't need an agency the current size of NASA to support either or both missions.

The spirit to boldly go where nobody has been before seems to be lost right now with NASA. No astronauts are setting altitude (aka distance) records to explore the depths of the Solar System. Heck, it was Apollo 13... a "failed" mission... that set the all-time distance record for anybody away from the Earth. There just doesn't seem to be any fire in the policy makers to have a difference here. This isn't even a Democrat or Republican issue, as both political parties are to blame.

There are proposals out there, but my understanding is that they need funding and perhaps some new technology like a Saturn V-class vehicle or fancy propulsion technologies like nuclear electric propulsion (combo of nuclear power and electric propulsion) or solar sails.

Oh, my bad, I seemed to remember that both shared the same filters. The WAC was turned on during the first flyby though, allowing to make this false colour mosaic, which means they're still sitting on a real colour picture of the planet.

We can, jackass. There's not always a point.

Here you go.

Easy now. If you look at the details of the images, all of the pictures that have been release have been taken with the Narrow Angle Camera MDIS camera. Details here. The NAC takes black & white photos. In order to get color photos, the pictures need to be taken with the Wide Angle Camera.

IANARS, but I would think they are waiting until they are in orbit before they deploy the WAC, probably due to power requirements. I could be wrong though.

And here is a link to a much better story on the "Messenger website"
http://messenger.jhuapl.edu/news_room/details.php?id=111
and a followup article
http://messenger.jhuapl.edu/news_room/details.php?id=112

And here is a link to a much better story on the "Messenger website"
http://messenger.jhuapl.edu/news_room/details.php?id=111
and a followup article
http://messenger.jhuapl.edu/news_room/details.php?id=112

And when the hell are we going to get coloured images of Mercury? I mean true RGB colours, not remapped colours. I know that Mercury's colours are probably not the most exciting thing ever, but damnit we have yet to see a single damn colour picture of that bloody planet and the Messenger guys are literally sitting on it.

That's my beef with this mission, all they're giving us is the few snapshots they can be bothered to give us, and that's it. And the best they can be bothered to do at updating the maps is this. It makes me mad. If they would just release their raw images like they did Cassini AND Huygens you're have fully updated real colour maps of Mercury all over the place.

Yes, the probe can take color images. The colors on Mercury are quite muted, though. Here's an example.

Here's a link to the homepage for the messenger mission. http://messenger.jhuapl.edu/

And here's a link for the flyby 2 page http://messenger.jhuapl.edu/mer_flyby2.html

Here's a link to the homepage for the messenger mission. http://messenger.jhuapl.edu/

And here's a link for the flyby 2 page http://messenger.jhuapl.edu/mer_flyby2.html

Well as another poster in the above thread pointed out, that's incorrect.

To be "caught", you'd want low relative velocity to Mercury, surely.

And just because you missed it, I'll repost oneTheory's link: http://messenger.jhuapl.edu/the_mission/gravity.html

Ok apparently the rest of the mods are sleeping on the job today. Reading TFA Your first assertion was correct. It's not about slowing down the thing needs to speed up in order to match mercury's orbital velocity of 47.9 km/s which is quite a bit faster than earth's measly 29.8 km/s:

Info on gravity assists for the MESSENGER mission.

There will actually be 6 total flybys (3 of mercury, 2 of venus, 1 of earth) during which the spacecraft will accelerate in order to decrease its orbital period from 365 days (that of earth) to 88 (that of mercury).

Moving around in space is all about changing your velocity. There are a number of ways to effect that change - gravitational slingshot, aerobraking, big sails, thrusters ... Each has advantages and disadvantages. For example, direct thrust may provide the most direct path to your objective, but the fuel requirement may be impractical. The mission designers have chosen a method of getting MESSENGER (about 1000kg of payload) to it's objective with enough fuel on-board to perform it's mission. Many variables have been considered - launch vehicle requirements, time to arrival, duration of mission, required consumables, etc. It's a horribly complex optimization.

The most efficient time/location to make orbital adjustments is apogee or perigee. If you enter into a highly eliptical orbit and wish to circularize at a much lower altitude using only a fractional-Newton thruster, yeah, it'll take a while. MESSENGER has a 650N main thruster, but only about 600kg of propellant. That equates to "not a lot" of thruster time. The main engine has a Specific Impulse (Isp) of 318 seconds. On Earth, you'd get about 318 seconds (5+ minutes) of operation. That gravitational element doesn't really apply out in space, so the available thrust-time will be longer. The NASA PDF indicates that the final orbital insertion burn will consume 30% of the propellant, and will last about 14 minutes. Extrapolating, that indicates that MESSENGER has about 42 minutes of propellant on board.

There's also a nice explanation of the orbital maneuvers on the JHUAPL website, and also a nice PDF showing the orbital insertion cost plots.

Because it is energetically tough to get to Mercury they are trying to get into with as little fuel expenditure as possible, to send as much payload as possible. Since there is no atmosphere, aerobraking is not possible, and thus they are using gravity assists to help reduce the orbital insertion delta-v to a manageable number. Each flyby speeds up the spacecraft a little, to better match Mercury's orbital velocity, and they decided on 3 of these to get the performance they wanted. There is a synodic period (the orbital beat period) between each such opportunity, so it takes a while to complete three flyby gravity assists.

The mission FAQ has more information on this.

Ah, thanks! Very interesting.

Because it is energetically tough to get to Mercury they are trying to get into with as little fuel expenditure as possible, to send as much payload as possible. Since there is no atmosphere, aerobraking is not possible, and thus they are using gravity assists to help reduce the orbital insertion delta-v to a manageable number. Each flyby speeds up the spacecraft a little, to better match Mercury's orbital velocity, and they decided on 3 of these to get the performance they wanted. There is a synodic period (the orbital beat period) between each such opportunity, so it takes a while to complete three flyby gravity assists.

The mission FAQ has more information on this.

To change the orbit to intersect the sun, a tremendous amount of velocity would need to be removed from the current orbit. It would take more propellant to get it to the sun than it took to launch it from the earth in the first place.

It's actually quite difficult to "hit the sun", the Messenger spacecraft will need to do one earth, two Venus, and 3 Mercury flybys over 7 years to "slow down" enough so that it can finally brake into orbit around Mercury with it's insertion motor.

Hopkins and Carnegie are doing something people care about? The government better take back that grant money ASAP!

I had a friend try and tell me that this, and the rest of our space explorations, is a total waste of money.

Personally I'd rather keep throwing things at other planets to learn about them (like MESSENGER, Spirt & Opportunity (Mars Rovers), or New Horizons (First mission to Pluto, launched prior to being "deplanetized"), as opposed to dumping the same funds into our war campaign in the Middle East.

This kind of stuff is a lot more... lasting even though its less tangible.

I had a friend try and tell me that this, and the rest of our space explorations, is a total waste of money.

Personally I'd rather keep throwing things at other planets to learn about them (like MESSENGER, Spirt & Opportunity (Mars Rovers), or New Horizons (First mission to Pluto, launched prior to being "deplanetized"), as opposed to dumping the same funds into our war campaign in the Middle East.

This kind of stuff is a lot more... lasting even though its less tangible.

On the subject, I got all excited to see my house on the "Earth Departure Movie" http://messenger.jhuapl.edu/the_mission/flyby_movie.html.

I was disappointed to see nothing but "Rock".

No ISS, no communication satellites, no Microsoft Nuclear Weapons Array. Nada.

There's a really nice animation on the Flyby 1 page: 10Mb version, 84Mb version.

There's a really nice animation on the Flyby 1 page: 10Mb version, 84Mb version.

There's a really nice animation on the Flyby 1 page: 10Mb version, 84Mb version.

Those are just the approach images, the shots taken up through yesterday that show what the probe saw as it was speeding toward the planet. The close-ups taken today will be downloaded and posted over the coming hours and days. http://messenger.jhuapl.edu/gallery/sciencePhotos/

I'm sure some of the researchers are at McMurdo, and haven't yet gone home to their respective institutions.

I was there last year to help launch BLAST, which was up in the air at the same time as two other experiments, ANITA and SBI. Wait, that's also 3 simultaneous experiments. Weird record. I guess they didn't count SBI last year since it has pointing issues and they terminated the flight within 12 hours since it was unable to get any science. I felt bad for them. But there were 3 balloons up at the same time (that was a first for Antarctica).

Alan Stern is the precise antithesis of a clueless project manager. He is, in fact, a planetary scientist who continues to actively contribute to the scientific community. He took this job because HIS mission to Pluto, New Horizons, on which he is the principal investigator, did end up on budget and on time, and he thinks that the total amount of science would be maximized if others did the same. He's right. On the astrophysics side there isn't money left for hardly any science at all these days, what with the Hubble-successor James Webb Space Telescope hoovering up any dollar not glued down. What Alan Stern is doing makes sense from the standpoint of maximizing the science return from a fixed yearly budget.

It would be interesting to see a new voyager sent out. In particular, obtain bigger nukes, use bigger rockets (perhaps the ares IV/V), and finally, add ION drives.

Do you mean like New Horizons, which recently passed Jupiter (and took some stunning pictures, too). It's due to fly by Pluto and Charon in 2015, and enter the Kuiper belt shortly after.

Okay, it's not a very good comparison; New Horizons didn't get the gravity boost of the Voyagers and so isn't going as fast; and it doesn't have an engine, so is coasting all the way. An ion drive would have improved the flight time. But it is powered by an RTG, and it has reached solar escape velocity. That makes it one of the only eight man-made objects to do so.

is the contrast between the amazing photos and sophisticated graphics and the Powerpoint 95 quality of the rest of the presentation. This slide (http://pluto.jhuapl.edu/news_center/news/pictures/100907_pressGraphics/files/Stern/SternHi-Res/Stern_11.jpg) could almost be a cat macro.

Polar Lightning and Decadal-Scale Cloud Variability on Jupiter
Kevin H. Baines, NASA Jet Propulsion Laboratory

Io Volcanism Seen by New Horizons: A Major Eruption of the Tvashtar Volcano
John R. Spencer, Southwest Research Institute

Clump Detections and Limits on Moons in Jupiter's Ring System
Mark R. Showalter, Search for Extraterrestrial Intelligence (SETI) Institute

Jupiter Cloud Composition, Stratification, Convection & Wave Motion: A View from New Horizons
Dennis C. Reuter, NASA Goddard Space Flight Center

Io's Atmospheric Response to Eclipse: UV Aurorae Observations
Kurt D. Retherford, Southwest Research Institute

Energetic Particles in the Jovian Magnetotail
Ralph L. McNutt Jr., Johns Hopkins University Applied Physics Laboratory

Diverse Plasma Populations and Structures in Jupiter's Magnetotail
David J. McComas, Southwest Research Institute

New Horizons Mapping of Europa and Ganymede
William M. Grundy, Lowell Observatory

Jupiter's Nightside Airglow and Aurora
G. Randall Gladstone, Southwest Research Institute

We are sending probes to explore the planets, the asteroids and further. Unfortunately science always goes in its own pace, and the amount of investments is small compared to the money that goes to wars. But we are making progress.

Take look at New Horizons, who will explore Pluto and beyond. It will take a few years, but I'm sure it will give images to us from a planet, that no one has ever seen before. And there are several other interesting projects running, not only US-based, but also Japanese (Hayabusa took the first sample of an asteroid) and now even China is making progress in its space program.

Keep up the good hope!

No the movie is already magnified by 2x from the original data. Here is an example of one of the images that went into this movie: http://pluto.jhuapl.edu/soc/data/jupiter/level2/lo r/jpeg/003509/lor_0035099189_0x630_sci_1.jpg

It has already seen Pluto! Twice, even! (one, two)

What are we going all the way there for again?? :-p

It has already seen Pluto! Twice, even! (one, two)

What are we going all the way there for again?? :-p

Before the flyby, the New Horizons science team asked a bunch of us amateurs at http://www.unmannedspaceflight.com/ to search for "pretty pictures", pictures that didn't necessarily have scientific value, but were beautiful and worth taking. Europa Rising and the Io and Europa conjunction were the first two returned. The others I suggested were two double shadow transits, a crescent Callisto emerging from behind a crescent Jupiter, and a crescent Ganymede in front of a crescent Jupiter.
Enjoying my 15 minutes of fame. :)