Nuts, so many things to keep track of (and I’m busy writing a book, dagnappit!), but a job is a job…
Just as it did last October, the MESSENGER spacecraft on its way to the planet Mercury is about to get a gravitational assist from Venus today.
Unlike probes to outer planets, where we need to give them energy (and thus speed) to get them to their targets in a timely fashion, MESSENGER needs to lose energy to drop in closer to the Sun. It’s dipping down low toward Venus, and generously giving the planet some of its momentum. This maneuver lowered the path of the probe and will send it on toward Mercury (where it’ll drop into orbit on March 18, 2011 if all goes well). The closest approach will happen at 4:08 Pacific time (23:08 UT), and I’ll post an update when I learn more.
June 5th, 2007 at 1:06 pm
“This maneuver lowered the path of the probe and will send it on toward Mercury (where it’ll drop into orbit on March 18, 2001 if all goes well). ”
I think you meant 2011, Phil!
CJSF
June 5th, 2007 at 1:17 pm
Oops! I’m having some typo issues with double letters and numbers.
June 5th, 2007 at 1:22 pm
Me tto, haapens aal the time
June 5th, 2007 at 2:27 pm
Are they going to take pictures??
June 5th, 2007 at 3:10 pm
Why will it take so long to go from Venus to Mercury? Will it make several trips around the sun, first? Will it generously give some of its momentum to Sol, too?
June 5th, 2007 at 4:04 pm
How nice to give Venus some energy! Now we need to do the same for Jupiter and Saturn and all those other planets we stole orbital velocity from.
June 5th, 2007 at 4:04 pm
>>Why will it take so long to go from Venus to Mercury? Will it make several trips around the sun, first? Will it generously give some of its momentum to Sol, too?
June 5th, 2007 at 4:06 pm
sorry about that my long reply was truncatted for somereason..any editors to delete both of these? lol
June 5th, 2007 at 4:11 pm
RE: “why will it take so long…”
Down toward the bottom of the page linked at “gravitational assist is an animated gif showing the circuitous route messenger has to take.
Anyone suggest a really good link explaining the gravitational slow-down and how Messenger will finally get in to Mercury orbit?
June 5th, 2007 at 5:35 pm
Man , sometimes I really do hate waiting for my favorite probes to arrive , the amount of years , I’ve been waiting at least four years for this sucker and there is still almost four more to go , It’s still better than the New Horizons wait.
June 5th, 2007 at 10:20 pm
Dusty59 Says: “Anyone suggest a really good link explaining the gravitational slow-down and how Messenger will finally get in to Mercury orbit?”
The Earth is more than halfway out of the sun’s gravitational well. For a spacecraft launched from Earth it takes more energy to cancel orbital momentum and spiral down to Mercury than it takes to leave the solar system completely!
Messenger has to be able to match orbits with Mercury closely enough that it’s small on-board engine can do the final insertion and circularizing maneuvers.
- Jack
June 6th, 2007 at 3:19 am
Though it’ll be a while before Messenger orbits Mercury it’s going to do a few close fly-bys well before then.
June 6th, 2007 at 6:38 am
Is Messenger nuke powered or totally solar?
Eagerly awaiting mercury pics and other instrumental analysis.
Gary 7
June 6th, 2007 at 6:56 am
Michelle Rochon: “Are they going to take pictures??”
At Venus? Yes. According to the MESSENGER website, over 630 of them. Download begins on the 7th (there’s over a CD-ROM’s worth of data).
June 6th, 2007 at 7:23 am
Can I have some momentum?
June 6th, 2007 at 1:36 pm
So what with taking momentum from Venus to boost probes to the outer solar system and giving it back to go further in, how much do we now owe Venus, or does it owe us?
June 6th, 2007 at 4:38 pm
“Can I have some momentum?”
Yes, and you don’t even need a prescription: http://tinyurl.com/2xmps5
June 7th, 2007 at 3:33 pm
Messenger is totally solar not nuclear and another complication not mentioned is that Mercury orbits pretty far out of the ecliptic, though losing energy is the big one.