Rosetta is on its way! - Page 2

Laguna2 · #31 (**permalink**) 15-November-2007, 01:57 PM

Yes it passed earth at about 230000km following rosettas path. It just kept a greater distance when passing earth. The object is expected to drift farther away from rosetta as rosetta continues its journey. Its course was followed back to where rosetta came from when rosetta was taking its last swing by at mars.

Laguna2 · #32 (**permalink**) 15-November-2007, 02:00 PM

The first, but rapidly excluded, fear was that it could be some debris from rosetta. Possibly a broken solar panel, the philae lander or the foil rosetta is wrapped in.

Laguna2 · #33 (**permalink**) 15-November-2007, 02:09 PM

As i can find no information about this anywhere else I just asked the author for a source...

Laguna2 · #34 (**permalink**) 15-November-2007, 08:17 PM

Nanananana... I got a reply.

Quote:

I'm out of the office.
In urgent matters, please contact ...

01101001 · #35 (**permalink**) 16-November-2007, 08:49 PM

Quote:

Originally Posted by Laguna2

Just read on a German news site that rosetta has a companion, possibly an asteroid.

Planetary Society Weblog: Son of Rosetta

Quote:

On the heels of the news last week that the Rosetta spacecraft was spotted by sky surveys and briefly named among the minor planets as 2007 VN84 came another close approach by a newly discovered near-Earth object, designated 2007 VF189, which had an orbit surprisingly similar to the Rosetta spacecraft, making a close approach to Earth (closer than the Moon, about 250,000 kilometers away) roughly six hours after Rosetta, on November 14.
[...]
In brief: the probability for there to be a random object so close in the sky to Rosetta is 1 in 70; the probability for Rosetta and this object to come close to Earth within 6 hours of each other is 1 in 10; and the probability that they would have velocities within 2.1 km/sec of each other is 1 in 10. Multiplying those together, you get a 1 in 7000 chance for Rosetta and another object to pass so close to each other, at nearly the same speed, near Earth. That's an interesting number, because it's not too likely, but neither is it vanishingly unlikely. Plenty of people bet lots of money on worse odds.

In the end, then, 2007 VF189 is a small, unremarkable Apollo-class object (meaning it's an Earth-orbit-crossing asteroid with an orbital period of longer than one year), and nobody would have paid much attention to it if not for last week's mixup.

Laguna2 · #36 (**permalink**) 17-November-2007, 09:01 AM

Thanks 01101001 for the affirmation.
The only source I could find until yesterday night was Spiegel-Online.

So was Rosetta in fact the object that was held as an incoming asteroid or was it all a mixup with 2007 VF189?

01101001 · #37 (**permalink**) 18-November-2007, 04:36 PM

Quote:

Originally Posted by Laguna2

So was Rosetta in fact the object that was held as an incoming asteroid or was it all a mixup with 2007 VF189?

From reading it sure seems that 2007 VN84 (AKA Rosetta) was discovered and then shortly later 2007 VF189, independently.

The MPML (Yahoo group mpml · A list for asteroid and comet researcher) probably has the whole tale. I have only sampled a couple of entries.

MPML: Discovery Circumstances of 2007 VF189:

Quote:

On the night of the 12th (UT) Andrea sent up to me his usual request to
follow up on objects that Alex Gibbs has discovered at 703 the night
before. When this field came up for validation, the original target was
recovered along with the object that is now known as 2007 VF189.

Maybe MPML: A real asteroid chasing the Rosetta probe? will be the most productive of an answer:

Quote:

After the fuss about 2007 VN84, the online version of the German
weekly "Der Spiegel" now has a story saying that a real asteroid is
chasing Rosetta!
[...]
So I am wondering if all this is maybe just a canard.

Launch window · #38 (**permalink**) 21-November-2007, 07:35 AM

BA blogged Earth from Rosetta
http://www.badastronomy.com/bablog/2...-from-rosetta/

Lord Jubjub · #39 (**permalink**) 03-February-2008, 01:19 AM

Rosetta has recrossed Earth orbit and is heading outward. It will reach Mars orbit around the 1st of May.

Lord Jubjub · #40 (**permalink**) 27-April-2008, 08:55 PM

Just a few days short of the 1st of May, actually. Rosetta will cross Mars orbit over the next 12 hours.

Edit: This crossing is simply a milestone in reaching the first point of interest in this mission. On 5 September, Rosetta will sweep past a small asteroid in the Main Belt.

Manchurian Taikonaut · #41 (**permalink**) 24-June-2008, 05:26 PM

Asteroid Steins

73 days 01 hours

http://www.dmuller.net/rosetta/

01101001 · #42 (**permalink**) 04-July-2008, 03:47 AM

Quote:

Originally Posted by Manchurian Taikonaut

Asteroid Steins

ESA: Rosetta awakes from hibernation for asteroid encounter (3 July 2008):

Quote:

Spacecraft controllers have just awoken Rosetta from hibernation to prepare for its encounter with asteroid (2867) Steins on 5 September. ESA’s comet chaser will study the relatively rare asteroid as it flies by on its way to comet 67/P Churyumov-Gerasimenko.
[...]
In preparation for the fly-by, all the instruments will be checked and tested through the month of July. Between 4 August and 4 September, spacecraft operators will conduct an optical navigation campaign: Steins will be tracked by the on-board cameras and the observations will be used to refine the knowledge of its orbit which has been derived only from ground-based measurements so far.

Manchurian Taikonaut · #43 (**permalink**) 26-July-2008, 05:35 PM

Intense preparations for Rosetta's asteroid visit

http://www.esa.int/SPECIALS/Rosetta/SEM4OCXIPIF_0.html

BigDon · #44 (**permalink**) 26-July-2008, 11:21 PM

Thank you for the heads up MT!

01101001 · #45 (**permalink**) 06-August-2008, 11:00 PM

Planetary Society: Planetary News: ESA's Rosetta Has Asteroid Steins in Sight

Quote:

ESA's flagship solar system mission Rosetta is fast approaching the next waypoint on its long journey to comet 67P/Churyumov-Gerasimenko. On September 5 at 18:37 UTC, the spacecraft will zoom past asteroid (2687) Steins, the spacecraft's first scientific target.

Steins has not before been visited by a spacecraft, so everything that is known about it is based on data from Earthbound telescopes. It is believed to be approximately 5 kilometers in diameter, and it is an E-type asteroid, a rare spectral class.

Lots of stuff. Includes a nice timeline of events September 1 to September 6.

Coming up next:

Quote:

Sep 1
00:00 Other science instruments switched on
Sep 2
14:30 Trajectory Correction Maneuver
This and the following two maneuvers may be canceled if optical navigation results indicate that the spacecraft is on the proper course for the encounter.

Launch window · #46 (**permalink**) 20-August-2008, 10:47 AM

Perfect sight: Rosetta cameras track asteroid target

http://www.esa.int/esaCP/SEMC9R6UWJF_index_0.html

ryanmercer · #47 (**permalink**) 20-August-2008, 11:09 AM

Sweet

01101001 · #48 (**permalink**) 02-September-2008, 04:05 AM

Quote:

Originally Posted by 01101001

Planetary Society: Planetary News: ESA's Rosetta Has Asteroid Steins in Sight

Other science instruments have been turned on.

Coming up (times UTC):

Quote:

Sep 2
- 14:30 Trajectory Correction Maneuver
  This and the following two maneuvers may be canceled if optical navigation results indicate that the spacecraft is on the proper course for the encounter.
Sep 4
- 05:00 Trajectory Correction Maneuver
- 16:00 End optical navigation campaign
  The data must be returned to Earth quickly if the final Trajectory Correction Maneuver is to be performed.
Sep 5
- 05:00 Trajectory Correction Maneuver
- 08:00 Attempt to put cameras into tracking mode
- 17:57 Begin spacecraft flip
  The spacecraft must rotate into a particular orientation in order to track Steins throughout the flyby while also keeping sensitive parts of the Philae lander out of direct solar illumination. The flip takes about 20 minutes to complete; during this time, the cameras should still be tracking the asteroid.
- 18:18 Entry into Asteroid Fly-By Mode
  The spacecraft will now perform automatic tracking of the asteroid based upon information from the navigation cameras.
- 18:27 End telemetry from Rosetta
  The geometry of the flyby will result in the spacecraft's high-gain antenna pointing away from Earth. Earth will be out of communication with Rosetta for about an hour.
- 18:35 Rosetta views Steins at "zero phase"
  Rosetta will pass almost directly between the Sun and Steins, an unusual geometry that provides immensely valuable data on the way that the asteroid's surface reflects sunlight. The entire "globe" of Steins will be fully lit by the Sun.
- 18:37 Asteroid (2687) Steins Closest Approach (800 kilometers)
- 19:37 End Asteroid Fly-By Mode; start high-gain antenna rotation
  Control of the spacecraft's orientation will be handed back from the optical navigation system to the spacecraft's internal sequences. At the same time, the high-gain antenna will begin to rotate back towards Earth. The rotation will take 25 minutes to complete. It is possible that the spacecraft will remain out of communication with Earth for 22 of those minutes, until 22:02.
- 20:25 Resume telemetry transmission with Earth
  NASA's Goldstone radio antenna will receive Rosetta's communications.
- 21:25 Earliest possible start of scientific data reception on Earth
  The first five hours of downlink will contain data from the OSIRIS and VIRTIS instruments. Then two more hours of VIRTIS, followed by data from the rest of the science instruments.
Sep 6
- 14:01 End first downlink

Edit: New Planetary Society Weblog entry: Rosetta's zeroing in on Steins (September 2)

01101001 · #49 (**permalink**) 03-September-2008, 03:04 AM

A few links:
ESA Rosetta Mission
ESA Rosetta Blog
ESA Rosetta Flyby Timeline
Daniel Muller's (dmuller) Rosetta Real-Time Simulation, with Steins flyby countdown
Universe Today: Countdown to Asteroid Flyby