Mercury Flyby 2 |
Mercury Flyby 2 |
Sep 8 2008, 01:00 AM
Post
#16
|
|
Member Group: Members Posts: 544 Joined: 17-November 05 From: Oklahoma Member No.: 557 |
Apparently this is the first time the technique has been used to steer a spacecraft's trajectory. Mariner 4 had solar pressure vanes as an experiment to help control attitude, with mixed results. Mariner 10 successfully adjusted its attitude with solar pressure, which extended its life. But we are talking here about adjusting course.
|
|
|
Sep 8 2008, 12:44 PM
Post
#17
|
|
Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
With the second flyby now just a month away, I have started to dig for events etc for my realtime simulation, and as always I am getting different times for the same events. I guess the closest approach time has not been inked in, but I thought I'd share my initial results anyway.
All times are Spacecraft Event Times in UTC: Mercury closest approach (altitude 200km) on 6 Oct 2008 between 08:40 and 08:42 Horizons currently has closest approach at 06 Oct 2008 08:41:25, resulting in: Entry into Mercury Hillsphere: 05 Oct 2008 20:33:55 Exit from Mercury Hillsphere: 06 Oct 2008 20:48:40 Again according to the Horizons information, the flyby changes the orbital elements as follows: Periapsis: from 47.5 million km to 45.8 million km Apoapsis: from 102.3 million km to 93.8 million km Eccentricity: from 0.36 to 0.34 Inclination: from 6.94 deg to 7.03 deg If anybody has more precise - or updated - information, please share, I will gladly put it on the realtime simulation -------------------- |
|
|
Sep 8 2008, 11:45 PM
Post
#18
|
|
Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
I have from a very reliable source the current best estimate (as of Friday, September 5) of flyby time being 08:40:21.4 UTC. At that time it'll be 200.2 km from Mercury.
My source has different orbital information -- is yours measured with respect to the ecliptic? I could also select "with respect to Earth mean equator" or "with respect to Mercury equator". These are with respect to the ecliptic: Semimajor axis: 7,596,000 before / 6,975,000 after Periapsis radius: 4,720,000 before / 4,523,000 after Eccentricity: 0.38 before / 0.35 after Inclination: 6.9 before / 7.0 after -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
|
|
|
Sep 9 2008, 12:14 AM
Post
#19
|
|
Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
My source has different orbital information -- is yours measured with respect to the ecliptic? Mine are the orbital information for Messenger's orbit around the Sun ... the Solar System Barycenter to be precise ... so maybe that is where the difference comes from. Thanks for the current best estimate. Will work it into the model shortly. Mmmm if your reliable source changes its figures, please post it here :-) -------------------- |
|
|
Sep 12 2008, 08:56 PM
Post
#20
|
|
Member Group: Members Posts: 568 Joined: 20-April 05 From: Silesia Member No.: 299 |
Press Kit: MESSENGER Mercury Flyby 2 (PDF)
-------------------- Free software for planetary science (including Cassini Image Viewer).
http://members.tripod.com/petermasek/marinerall.html |
|
|
Sep 13 2008, 10:54 PM
Post
#21
|
|
Senior Member Group: Members Posts: 1276 Joined: 25-November 04 Member No.: 114 |
Is there a flyby preview video available?
|
|
|
Sep 15 2008, 03:34 AM
Post
#22
|
|
Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
The Messenger website says that there will be (if I read it correctly).
Since I downloaded the images for my realtime simulation anyway (in case that the Solar System Simulator goes down during C/A), here are the images stringed together into a movie for CA +/- 1 hour: http://www.spaceoutreach.com/display.php?i...8nimdaq15025458 But I know there are people on here who can do much more impressive movies -------------------- |
|
|
Sep 25 2008, 09:40 PM
Post
#23
|
|
Member Group: Members Posts: 568 Joined: 20-April 05 From: Silesia Member No.: 299 |
-------------------- Free software for planetary science (including Cassini Image Viewer).
http://members.tripod.com/petermasek/marinerall.html |
|
|
Sep 25 2008, 10:01 PM
Post
#24
|
|
Member Group: Members Posts: 568 Joined: 20-April 05 From: Silesia Member No.: 299 |
-------------------- Free software for planetary science (including Cassini Image Viewer).
http://members.tripod.com/petermasek/marinerall.html |
|
|
Sep 29 2008, 12:35 AM
Post
#25
|
|
Newbie Group: Members Posts: 5 Joined: 25-September 08 Member No.: 4354 |
Great tool, thanks! Not quite as good as the Cassini one but gives a great sense of what will take place |
|
|
Sep 29 2008, 02:49 PM
Post
#26
|
|
Senior Member Group: Members Posts: 1075 Joined: 21-September 07 From: Québec, Canada Member No.: 3908 |
This page shows the part of Mercury that will be imaged during Flyby2.
|
|
|
Sep 30 2008, 03:40 PM
Post
#27
|
|
Member Group: Members Posts: 568 Joined: 20-April 05 From: Silesia Member No.: 299 |
New: Mercury Flyby 2 Instrument Operations.
http://messenger.jhuapl.edu/the_mission/mo...yby_web_sml.mov (17.8 MB) -------------------- Free software for planetary science (including Cassini Image Viewer).
http://members.tripod.com/petermasek/marinerall.html |
|
|
Guest_PhilCo126_* |
Oct 2 2008, 09:25 AM
Post
#28
|
Guests |
That's great Peter!
The second Mercury flyby is slated for 2:40 a.m. MDT on Oct. 6 and the MESSENGER spacecraft will view areas not seen before by the 1974 & 1975 Mariner X flybys.... |
|
|
Oct 2 2008, 03:10 PM
Post
#29
|
|
Senior Member Group: Members Posts: 1018 Joined: 29-November 05 From: Seattle, WA, USA Member No.: 590 |
This page shows the part of Mercury that will be imaged during Flyby2. Nice! What's great about that link is that it clearly shows what was imaged by Mariner 10 and Flyby 1 and what will be imaged in this flyby. It makes it fairly clear that there will be relatively little unimaged surface after this flyby. I sent the Messenger team an e-mail about a month ago telling them I wished they'd show us something like this. They never replied, so maybe I'm vain to imagine this is a response to my request, but I was delighted to see it nonetheless! --Greg |
|
|
Oct 2 2008, 05:59 PM
Post
#30
|
|
Member Group: Members Posts: 715 Joined: 22-April 05 Member No.: 351 |
I hope that someone eventually publishes a map showing coverage by resolution from the flybys. It would visually show how well flybys can cover a world (useful for considering flybys of Galilean satellites, Triton, etc.).
-------------------- |
|
|
Lo-Fi Version | Time is now: 23rd September 2024 - 06:58 AM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |