# Thread: Progress of New Horizons in the Solar system

1. ## Progress of New Horizons in the Solar system

New Horizons should be around 225,000 miles from Earth. Which is the average distance from Earth to Moon.

Where is everyone getting 9 hours from? Even if I count from the time of last separation, I get well less than that to reach lunar orbit.

Unless they were comparing Apollo 11's actual flight path--which really is a bad comparison.

2. Originally Posted by Lord Jubjub
New Horizons should be around 225,000 miles from Earth. Which is the average distance from Earth to Moon.

Where is everyone getting 9 hours from? Even if I count from the time of last separation, I get well less than that to reach lunar orbit.

Unless they were comparing Apollo 11's actual flight path--which really is a bad comparison.
From the New Horizons Launch Press Kit

After it separates from the third stage, New Horizons will speed from Earth at about 16 kilometers per second, or 36,000 miles per hour – the fastest spacecraft ever launched. New Horizons will reach lunar orbit distance (about 384,000 kilometers or 238,600 miles from Earth) approximately nine hours after launch
*bold mine*

3. 9 hours * 36,000 miles per hour = 324,000 miles

238,600 miles / 36,000 miles per hour = 6 hours and 40 minutes

It separated the third stage 45 minutes into launch.

Am I missing something or has someone confused units?

238,600 miles / 9 hours = 26,500 miles per hour. Will NH slow down that much by the time it reaches lunar orbital distance?

4. Maybe the path it's taking is more of a diagnal across the earth's plane so it has to fly a little further to get to the moons orbit? Not sure..(not sure i'm even typing what I'm thinking correctly lol)

5. ## Re: Progress of New Horizons in the Solar system

Here's an animation of the flight path by someone who should be rather familiar to BAUTers. As you can see, the path is not straight out, hence the additional time needed to cross the Moon's orbit at the current speeds.

6. So the actual route is some 300,000 miles. Makes sense. According to the media release, the speed leaving Jupiter is 72,000 mph. The New Scientist article I reference in another thread is the speed of the probe as it passes through the Jovian system and mentions 75,000 mph. Obviously, it will lose a bit of speed as it passes out of the gravity well.

edit: those speeds should be in kilometers not miles.
Last edited by Lord Jubjub; 2006-Jan-20 at 03:13 PM.

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Actually the whole point of the gravity assist is to gain velocity relative to the sun by stealing momentum off of Jupiter's orbit around the sun. Granted, though, there is no net gain or loss of velocity relative to Jupiter.

8. Will it take any pictures on the Jupiter flyby?

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Originally Posted by Sticks
Will it take any pictures on the Jupiter flyby?

Course! By then they stop the spinning so the instrument platform can target.

10. So the actual route is some 300,000 miles. Makes sense. According to the media release, the speed leaving Jupiter is 72,000 mph. The New Scientist article I reference in another thread is the speed of the probe as it passes through the Jovian system and mentions 75,000 mph. Obviously, it will lose a bit of speed as it passes out of the gravity well.
I think that's 75,000km/h, not miles per hour.

with regards

11. Originally Posted by Sticks
Will it take any pictures on the Jupiter flyby?
that should be great !

12. Originally Posted by Sticks
Will it take any pictures on the Jupiter flyby?
Yes,
AFAIK it will be a flyby more or less the same Cassini did in 2000, but from a lesser distance so we'll have better pictures.

mauro

13. According to wiki, it'll be quite a fair distance from Jupiter at it's closest approach:

The flyby will come within about 43 (&#177;5) Jovian radii of Jupiter and will be the center of a 4-month intensive Jupiter system observation campaign. Primary goals will include Jovian cloud dynamics, which were greatly reduced from the Galileo observation program, and readings from the magnetotail of the Jovian magnetosphere, along which New Horizons will fly.
Source: http://en.wikipedia.org/wiki/New_Horizons

with regards

14. Originally Posted by Omicron Persei 8
Actually the whole point of the gravity assist is to gain velocity relative to the sun by stealing momentum off of Jupiter's orbit around the sun. Granted, though, there is no net gain or loss of velocity relative to Jupiter.
NH will be going at 57000 kmph as it nears Jupiter. As it passes through the system, it will accelerate to 75000 kmph. When it climbs out of the gravity well, it will still be moving at 72000 kmph.

15. All those velocities are relative to the sun. Relative to jupiter, it does not change, only in direction. If I understand everything .

16. Originally Posted by Champion_Munch

I think that's 75,000km/h, not miles per hour.

with regards
I think they were quoting CNN miles, not statute miles

I've been trying to summarize the speeds to understand the gravity wells, GA and so-on. I've got incomplete data, so maybe you can all help me fill it in. (since I've scored an incomplete, the following are approximates)

waypoint, T+, speed mph/kps
After stage 3 sep, 0:0:45, 36000/16
Lunar distance, 9:00, 36000/16
Mars distance, 3mon, 36000/16
Closest to jupiter, 12mon, 48000/21
after GA (near-0 Jupiter-G), 13mon, 47000/20
Pluto flyby, 9.5yrs, 47000/20

17. That's what I'm basing my figures on.

18. Originally Posted by NEOWatcher
I've been trying to summarize...

waypoint, T+, speed mph/kps
After stage 3 sep, 0:0:45, 36000/16
Lunar distance, 9:00, 36000/16
Mars distance, 3mon, 36000/16
Closest to jupiter, 12mon, 48000/21
after GA (near-0 Jupiter-G), 13mon, 47000/20
Pluto flyby, 9.5yrs, 47000/20[/quote]
Overtake Voy-2, 79yr, (dist=339 AU)
Overtake Voy-1, 147yr, (dist=627 AU)

19. The figures in the Voyager thread are wrong. NH will never overtake Voyager 1 and will be traveling about the same speed out of the solar system as Voyager 2, so will either never overtake it or will take a very, very long time to do so.

20. Post-launch update

Good news:

Though I haven't seen any actual numbers yet, provisional reports suggest we are very close to our planned trajectory, which is great news for the science team, because less of the spacecraft's fuel will be needed to fine-tune the trajectory to Jupiter, and more will therefore be available to steer us to a Kuiper Belt object after the Pluto encounter. We have also, as they say, "retired a lot of risk" -- the most dangerous part of the mission is over and the spacecraft is in the environment it was born for (as Arthur C. Clarke once wrote, space is a benign environment, at least for ships designed to sail in it). One of the ceremonies at the party was to burn copies of the very detailed contingency plans that had been developed to cover all possible launch failure scenarios. We won't be needing those any more.

21. Would we have been better off waiting the extra couple of years and skipping the Jupiter flyby? Maybe I'm off, but 15,000 extra MPH is going to mean a shorter window of observation for Pluto when it finally arrives...

Any thoughts from someone better connected?

22. Originally Posted by Doodler
Would we have been better off waiting the extra couple of years and skipping the Jupiter flyby? Maybe I'm off, but 15,000 extra MPH is going to mean a shorter window of observation for Pluto when it finally arrives...
Funding agencies really like shorter mission times. Even during deep-space cruise, that's less time for things to go wrong. And a financial consideration enters, in how long they are prepared to pay for the necessary people on the ground (something that NH hibernation should help with) - this is where most of the money goes after launch. Not just operations staff, but engineers familiar enough with the gizmos for long-range troubleshooting.

And for missions this long, there is a certain level of what might delicately be called actuarial risk for key team members, which eventually has to be part of the operations plan. (One of the Galileo instrument principal investigators never got to see the instrument reach Jupiter).

23. Originally Posted by ngc3314
Funding agencies really like shorter mission times. Even during deep-space cruise, that's less time for things to go wrong. And a financial consideration enters, in how long they are prepared to pay for the necessary people on the ground (something that NH hibernation should help with) - this is where most of the money goes after launch. Not just operations staff, but engineers familiar enough with the gizmos for long-range troubleshooting.

And for missions this long, there is a certain level of what might delicately be called actuarial risk for key team members, which eventually has to be part of the operations plan. (One of the Galileo instrument principal investigators never got to see the instrument reach Jupiter).
Funding is an issue, I do understand that, but when you're talking about the level of return from that investment, wouldn't a measurably longer observation window serve to aide the cause here? If they're concerned about where and tear on the probe from a longer cruise, then my advice would have been "Thou shalt not assume." Build it as if you missed Jupiter, so you're in a better spot when you can use the boost (it sounds like they did, or they would have simply ruled out a launch after February 2nd).

The personnel part sounds like an issue with multi-tasking. Hiring people to monitor ONE mission for the course of their careers is shortsighted. I can understand a few people on a 24 hour rotation, but then entire team could be rotated to other projects that don't require a full court press while cruising. You do, obviously, have specialists, but I can't imagine except in a mission like Magellan, Cassini or Galileo where you're spending a great deal of time on site observing, that you have a full team on hand all the time.

Also, if you do replace or supplement personnel after the fact, you'd hope the design/build/operations team documented the thing sufficiently that someone who's brought in after the fact can be quickly brought up to speed not only on its specs, but its quirks since its been in operation.

The actuarial issue is a non-starter to me, because it rather selfishly puts a limit on long range/long duration projects. I'm sure there were more than a few people who helped design, build and launch Voyager 2 had shuffled off the mortal coil by the time Uranus and Neptune were in the camera sights, even more now that they're in the top of the ninth in game three, so to speak, out in the heliopause. I can acknowledge how it is seen as delicate out of respect for the individuals who invested themselves on the project, at the same time, there are things which transcend the individual. If this is an actual consideration in mission design, its a very myopic one.

24. PI's update

No unexpected faults occurred during launch, and so far, the checkout procedures that mission control at APL have executed have gone well.

Initial trajectory solutions indicate our launch was almost perfect, needing just perhaps 20 meters/sec or so of makeup delta-V. This is far less than the 100 meter/sec we had budgeted for, meaning we have much more fuel for Pluto and Kuiper Belt encounters than our "3 sigma" planning had to allow for.

25. Shouldn't this be merged with the New Horizons Countdown thread?

26. Originally Posted by ToSeek
And related blog entry.

27. Originally Posted by parallaxicality
Shouldn't this be merged with the New Horizons Countdown thread?
Nah, Countdown applied to the liftoff, we're underway now. Maybe fuse them to a single New Horizons thread, but they're pretty distinct from one another.

28. Originally Posted by Doodler
Nah, Countdown applied to the liftoff, we're underway now. Maybe fuse them to a single New Horizons thread, but they're pretty distinct from one another.
Did not. Look at the first articles. It was about New Horizon's encounter with Pluto.
The launch was but a blip along the way.

yaohua2000 should continue marking NH's progress through the solar system in the original thread. I'll continue marking NH's progress through the solar system in the comprehensive thread, along with the milestones.

29. Originally Posted by Doodler
Would we have been better off waiting the extra couple of years and skipping the Jupiter flyby? Maybe I'm off, but 15,000 extra MPH is going to mean a shorter window of observation for Pluto when it finally arrives...

Any thoughts from someone better connected?
I asked that question here and got a few responses. The principal investigator and some other key people for the mission also post there, so you might keep an eye out for replies from them.

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Originally Posted by ToSeek
The figures in the Voyager thread are wrong. NH will never overtake Voyager 1 and will be traveling about the same speed out of the solar system as Voyager 2, so will either never overtake it or will take a very, very long time to do so.

The Voyagers started slower. So I am guessing that the Voyager probes got better speed increases from the sling shots using the gravity of the gas giants they passed?

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