MESSENGER News Thread, news, updates and discussion Options

[odave]

That rings a bell, but I haven't been able to Google up anything to support what I recalled. Chalk it up to my CRS syndrome...

[Jeff7]

A quick reminder : Messenger is only 13 days to Venus flyby.
http://messenger.jhuapl.edu/

Ah good, it can act as Venus Express Express.

[dvandorn]

Chalk it up to my CRS syndrome...

That's OK, Dave -- just wait until it progresses, as it has with me, to the more advanced form, CRAFT...

-the other Doug

edit -- see, goes to show you, you were referencing a post of mine, and I totally had no memory of it... toD

[tuvas]

Ah good, it can act as Venus Express Express.

Too bad it won't have much of a chance to do any photographing, but it's a good idea...

[RNeuhaus]

Too bad it won't have much of a chance to do any photographing, but it's a good idea...

Yes, Messenger's will fly-by on Venus on the day and night side of Venus and besides, now, Venus is close to conjunction superior to Earth along with Mars.

You can find good details by visiting the following Web Page http://messenger.jhuapl.edu/the_mission/ME...enusFlyby1.html

Minimum altitude (approximate since the surface is not perfectly round) above Venus: 3,040.1 kilometers (1,889.0 miles) on October 24, 2006 8:33 am UTC

Maximum spacecraft speed relative to center of Venus:
12.378 kilometers per second (7.691 miles per second or 27,689 miles per hour)

Rodolfo

[helvick]

You have a typo in the URL there - it should be:
http://messenger.jhuapl.edu/the_mission/ME...enusFlyby1.html

[BPCooper]

You have a typo in the URL there - it should be:
http://messenger.jhuapl.edu/the_mission/ME...enusFlyby1.html

Are the animations mislabeled, or are they from the original flyby dates for Mercury arrival in 2009? They both say Nov. 2 2004 and were updated last year, post launch.

[RNeuhaus]

Are the animations mislabeled, or are they from the original flyby dates for Mercury arrival in 2009? They both say Nov. 2 2004 and were updated last year, post launch.

Why not? The animations is of First Venus Flyby, then again Venus Flyby on June 6,2007, and finally two Mercury flyby (Jan 14,2008 and October 6, 2008) and March 18, 2011 is the Mercury arrival.

Rodolfo

[Holder of the Tw...]

Don't forget the animation for the third Mercury flyby on 30 Sep 2009.

The top right panel on the link for the first Venus flyby clearly states, when you enlarge it, that the spacecraft will be out of communication with earth due to the proximity of the sun in the line of sight.

Things will be better on the second flyby, and you'd think that they should be able to come up with some kind of coordinated activity with Venus Express. After all, two capable spacecraft observing the same object from different vantage points ...

[JRehling]

Yes, Messenger's will fly-by on Venus on the day and night side of Venus and besides, now, Venus is close to conjunction superior to Earth along with Mars.

Actually, they are both close to opposition. Mars will be in superior conjunction next year, and Venus is never in superior conjunction.

[Holder of the Tw...]

Mercury and Venus are in inferior conjunction when they are more or less between the earth and sun. They are in superior conjuction (as Venus is now) when they are pretty much behind the sun as seen from earth. Mars is simply in "conjunction" in this situation, because its conjuctions can only be superior. Mars and other outer planets are in opposition when they transit near midnight, being more or less overhead then.

[RNeuhaus]

Tomorrow between 4-5 am, Messenger will be flying-by over Venus. I am still unclear about the Messenger path after seeing the flyby movies and pictures of Venus 1st Flyby. The pictures show that Messenger is coming from South Pole at about an angle of 60 degree to equotorial line. See the following picture:



The Meessenger approach to Venus side by side and it does not coincide with the above picture which shows that Messenger approach in about 85 degrees from the Sun to Venus.

Orbit Animation
According to the picture which shows Earth, Venus and Mercury orbit around the Sun from the top view.

I am still puzzled that Messenger will approach to Venus from Sun and not by side by side toward with the same orbit direction as Venus.

Rodolfo

[Holder of the Tw...]

Well, the two diagrams do match up. The tick marks are a little more compressed looking in from the sun, but if you carefully trace by the intervals, you'll see in both cases that as viewed from Venus the spacecraft moves in from the sun moving westward and northward, before being flung back south. It still continues west on its departure.

It's necessary to pursue this path, flung backwards from the normal counterclockwise motion of the planets as viewed from north, in order to lose energy relative to the sun, and adjust the orbit inward toward Mercury. It is also necessary to go to high latitudes on Venus in order to adjust to the plane of Mercury's orbit.

[yaohua2000]

2006-10-23 02:21:05 UTC — 1000000 km
2006-10-23 05:24:28 UTC — 900000 km
2006-10-23 08:27:49 UTC — 800000 km
2006-10-23 11:31:05 UTC — 700000 km
2006-10-23 14:34:15 UTC — 600000 km
2006-10-23 17:37:14 UTC — 500000 km
2006-10-23 20:39:59 UTC — 400000 km
2006-10-23 23:42:21 UTC — 300000 km
2006-10-24 02:44:00 UTC — 200000 km
2006-10-24 05:44:07 UTC — 100000 km
2006-10-24 06:01:58 UTC — 90000 km
2006-10-24 06:19:46 UTC — 80000 km
2006-10-24 06:37:31 UTC — 70000 km
2006-10-24 06:55:12 UTC — 60000 km
2006-10-24 07:12:50 UTC — 50000 km
2006-10-24 07:30:24 UTC — 40000 km
2006-10-24 07:47:58 UTC — 30000 km
2006-10-24 08:05:50 UTC — 20000 km
2006-10-24 08:27:26 UTC — 10000 km
2006-10-24 08:34:00 UTC — 9044 km (2992 km above surface)

Note: geometric range, not corrected for light-time

[RNeuhaus]

Well, the two diagrams do match up. The tick marks are a little more compressed looking in from the sun, but if you carefully trace by the intervals, you'll see in both cases that as viewed from Venus the spacecraft moves in from the sun moving westward and northward, before being flung back south. It still continues west on its departure.

It's necessary to pursue this path, flung backwards from the normal counterclockwise motion of the planets as viewed from north, in order to lose energy relative to the sun, and adjust the orbit inward toward Mercury. It is also necessary to go to high latitudes on Venus in order to adjust to the plane of Mercury's orbit.

Good comments, I think a three dimensional graphic would help to view better. Also the above graphic is too small that I seems that after flyby Venus, Messenger would go away from the Venus toward Earth orbit. But, If there is a bigger (smaller scale) in a three dimensional, I would be able to see that after Venus fly-by, Messenger would go toward the South of Venus and little by little going toward on the counterclockwise. For the second fly-by in the June 6, 2007, Messenger will arrive at Venus comming from the North of Venus to South but on the opposite to Venus orbit direction? I see it is for slowing the speed as much as possible with the Venus gravitational pulling (from 13,500 km/sec at Venus 2 fly-by to 7,100 km/sec at Mercury 1 fly-by). But, when Messenger arrives at Mercury, it will be again flying the orbit around the Sun on the counterclockwise.

Rodolfo