Star 48b Third-stage Motor, Leaving the solar system Options

[Alan Stern]

"C/A is at 32 RJ"

For comparison, the outermost Galilean moon, Callisto, is at about 26 RJ.

Alan, thanks for all the details. Do you have any idea yet what targets look promising for the Jupiter encounter?

...I will in a couple of weeks.

[Roby72]

Hi Alan, hi all,

after checking the Jupiter encounter date in the Guide8 software I see all Galilean satellites on the left side of the planet, the aim point from NH, I suspect, is on the right side, isnt, it?
Only Himalia could be possible better placed, but I have no depth information currently. I recall that Cassini encounters Himalia a few days ahead of the main Jupiter encounter.



By the way congratulations Alan for the perfect launch of the NH spacecraft and many wishes for a flawless mission !!

Robert

[djellison]

But - that will put them in a good position to image their dark sides in Jupiter shine

Doug

[john_s]

But - that will put them in a good position to image their dark sides in Jupiter shine

Doug

I think Jupiter deserves a dedicated thread, so I just started one here

John.

[RNeuhaus]

Thanks Alan for the detailed info. Indeed, NH will break a new trip record between Earth and Mars with 2 months and 19 days. The old record trip record between Earth and Mars, I think, is held by Mariner IX which took 166 days (5 months and 16 days, at May 30, 1971-Nov 14, 1971). It is a milestone!

Rodolfo

[Guest_AlexBlackwell_*]

We are setting up for our first course correction. Without it we would miss Pluto
by millions of miles. The third stage has no ability to make a course correction
and will therefore miss by this amount.

Alan, was there any deliberate trajectory bias by the LV for any reason, or are the TCMs needed strictly to correct unplanned (albeit very minor) injection errors?

[djellison]

I'd thought the same Alex - the Mars policy of targetting off-target, so that the fact you have a healthy spacecraft to adjust its course back to target means that it isnt going to plough straight into the planet - or perhaps in this case Europa?

Doug

[Guest_AlexBlackwell_*]

I'd thought the same Alex - the Mars policy of targetting off-target, so that the fact you have a healthy spacecraft to adjust its course back to target means that it isnt going to plough straight into the planet - or perhaps in this case Europa?

I'd never heard of any planned Jupiter aimpoint biasing; indeed, I remember Alan posting that New Horizons was a Category III mission for planetary protection purposes.

[djellison]

Ahhh - in that case, it's going to be just residuals from the LV I'd imagine.

Doug

[Guest_AlexBlackwell_*]

Ahhh - in that case, it's going to be just residuals from the LV I'd imagine.

You're probably right, but maybe it's possible that an injection bias was planned for other, operational reasons (e.g., to extend the daily launch window). I guess it's one of those loose ends that niggle away at me.

[Alan Stern]

Alan, was there any deliberate trajectory bias by the LV for any reason, or are the TCMs needed strictly to correct unplanned (albeit very minor) injection errors?

The latter.

[djellison]

It niggled away with me as well, I guess when you're getting THAT much of a kick, even 100m/s could be considered damn accurate - thanks for 'de-niggling' it Alan

Doug

[mchan]

Thanks Alan for the detailed info. Indeed, NH will break a new trip record between Earth and Mars with 2 months and 19 days. The old record trip record between Earth and Mars, I think, is held by Mariner IX which took 166 days (5 months and 16 days, at May 30, 1971-Nov 14, 1971). It is a milestone! 

The NH time of flight is for Earth to Mars orbit. Mars will be far away when NH crosses Mars orbit. For the purpose of records, there are two categories. One is from Earth to a Mars encounter (some arbitrary distance, e.g. 1000 km of Mars surface. Second is from Earth to Mars orbit. For the second case, I would guess the old record was held by Ulysses.

[djellison]

I guess it depends if you want to include the journey for Galileo and Cassini from their last Earth Flybys to Mars orbit. It's cheating, and I don't know the figures, but it would be an interesting comparison.

Doug

[Guest_BruceMoomaw_*]

Even where actual trips from Earth to Mars itself are concerned, Mariner 9 isn't the record holder -- the Atlas-Centaur had so much excess capacity for the much lighter 1969 Mariner Mars flyby craft that they were able to pound them to Mars in only 5 and 4 months, with a leisurely 1-month gap between launches. I imagine this record will stand for a while.