Comments on: Pluto, ho!

By: Elwood Herring

Elwood Herring — Sun, 22 Jan 2006 15:38:05 +0000

I’d just like to celebrate this occasion by passing on this little-known poem by Stanley G. Weinbaum. It was included in his 1934 book “The New Adam”, and according to the book it was written about Neptune, but I think Pluto is more appropriate. I hope I’m not violating copyright by printing this here but if I am I apologise. I think this poem deserves wider recognition, and it paints a beautifully austere Plutonian landscape.

I am the planet eremite,
The gaunt repulsor of the light
That falls like icy rain at night.
From frigid stars and moons a-cold.
Ye have not seen a world like this -
The blank and oceanless abyss,
The nameless pit and precipice,
The mountain very bleak and old.
Yet ah – my silence murmereth!
Oh inner orbs, ye have not heard
That stillness where there is no death
Because no life hath ever stirred!
“But here God’s very name is dead!”
Wept Heaven’s mighty myriarch,
Then trembling, turned away and fled
For something gibbered in the dark!

Stanley G. Weinbaum 1934 (approx)

By: Justin

Justin — Sun, 22 Jan 2006 05:11:29 +0000

Jack, thanks for the correction on the Titan. You learn something new everyday! So Voyager was sent on its way by about 1.3 million lbs of thrust from the SRM’s, then a second (er, the first) stage with half a million. The difference in speed makes a little more sense now, I suppose.

By: Nigel Depledge

Nigel Depledge — Sat, 21 Jan 2006 08:42:08 +0000

Irishman, thanks for that link. Only scanned the page so far, but it looks good.

By: CousinoMacul

CousinoMacul — Sat, 21 Jan 2006 04:31:18 +0000

btw, don’t you mean “365.2425 days isn’t what it used to be?”

By: CousinoMacul

CousinoMacul — Sat, 21 Jan 2006 04:22:12 +0000

“Nine years sounds like a lot, but Iâ€™ve found of late 365 days isnâ€™t what it used to be!”

Yeah, I just hit 4-0 two weeks ago. I’m told that’s young, and I guess compared to Pluto, it is.

And yes, this is a great time for space exploration.
http://www.savethehubble.com/

â€”Javier

By: Jack Hagerty

Jack Hagerty — Fri, 20 Jan 2006 23:44:23 +0000

Justin sez: “Voyager was launched on a Titan IIIE. It looks like the Titan provided about 2 million lbs of thrust at liftoff (two SRBâ€™s and 1st stage).”

Just to split hairs, the Titan III’s, unlike the Shuttle, took off on the SRB’s only. The hypergolic core vehicle didn’t light until it was well underway, possibly after SRB sep, but I can’t verify that. To split them even further, the strap-ons are actually called “SRM’s” (Solid Rocket Motors), and are designated “Stage 0″ since they light before the first stage.

And an even finer split, only the Titan III C/D/E had the SRM’s. The IIIA and IIIB were the core vehicle only.

- Jack

By: Troy

Troy — Fri, 20 Jan 2006 23:10:08 +0000

Glad to see the probe get off the ground. It is interesting that the DAWN spacecraft to Ceres and Vesta won’t arrive until 2011 (it will be launched in May) and of course the asteroid belt is much closer. (Uses ion propulsion and is an orbiter so it is a much different mission)
This link is in regards to Cassini explaining the sling shot effect in cartoon form, I like it: http://www.planetary.org/saturn/images/gravity-assist_cartoon_578x333.jpg
Nine years sounds like a lot, but I’ve found of late 365 days isn’t what it used to be!

By: CousinoMacul

CousinoMacul — Fri, 20 Jan 2006 20:09:24 +0000

“Yes! That powerful element No. 94 (Pu239) plutonium is finally going home to Pluto.”

I guess that means that the next probe to Uranus will need to be powered by element #92 (U235). Unfortunately the Neptune probe will need a breeder reactor to power it, but its half-life will be so short that there won’t be time to do any meaningful science.

But seriously, I almost went crazy waiting for Cassini to reach its target–this is going to be murder.

By: Tom G.

Tom G. — Fri, 20 Jan 2006 16:34:56 +0000

What a great time for space exploration!
MER Rovers still going, Stardust returns with a bunch of goodies, Cassini doing well at Saturn, orbiters around Mars and MRO on it’s way, now New Horizons on it’s way to Pluto. Way cool!
Oh yeah, we still have a manned program, shuttle that might fly again, and the ISS which might get done somday, but look at the bright side – maybe the CEV will work out and we’ll head back to the moon?

By: Nick

Nick — Fri, 20 Jan 2006 15:48:24 +0000

A gravity assist or brake manuever can never change the speed of the craft relative to the assisting body, when NH goes past Jupiter it will leave having the same speed *relative to Jupiter* that it did when it arrived. Its speed relative to the sun will have increased however. With this in mind it is possible to arrive at a planet and stop there using only that planets gravity. Perhaps by interacting with massive moons it might be possible, but all of the manuevers are easier the more massive the planets are. Since Pluto is not very massive (for a planet) it is doubtful that any manuever with Pluto and Charon will be able to bring the probe into Pluto orbit.

By: Dan

Dan — Fri, 20 Jan 2006 15:40:46 +0000

Marshall, I’m pretty sure the Saturn V was used only for Apollo and Skylab.

By: Justin

Justin — Fri, 20 Jan 2006 15:39:12 +0000

Tried to pull some numbers together…

Voyager was launched on a Titan IIIE. It looks like the Titan provided about 2 million lbs of thrust at liftoff (two SRB’s and 1st stage). The Atlas used yesterday provided 2.4 million lbs. And it looks like the Atlas might have been 50-100,000 kg less massive, coming in at 570,000 kg at launch (didn’t find specific liftoff mass for Voyager mission, but the maximum takeoff mass of the Titan III was ~630,000 kg). Both launches used a Centaur second stage, although I assume that’s been improved slightly since the ’70′s. New Horizons had a third stage, but I’m not sure about Voyager. Are those slight differences really enough to account for such a difference in spacecraft speed?

By: Marshall

Marshall — Fri, 20 Jan 2006 14:54:54 +0000

Volsen, there are Lagrange points in the Pluto-Charon system just as there are in any two-body system. Unfortunately, parking at one of them is just not an option. The probe will have far too much kinetic energy and far too little reaction mass to do anything but sail on by. And Pluto is simply not big enough to provide for an effective “gravity brake” maneuver.

Stuart, that’s an interesting question of why this probe gets to Jupiter faster than the Voyager. If I’m not mistaken the Voyager probes were launched on Saturn V rockets. A Saturn V is significantly more powerful than the Atlas V launched yesterday. So I suspect that the shorter travel time is mostly due to the New Horizons probe being significantly lower in mass than Voyager. Perhaps the relative alignment of Earth and Jupiter this time vs. 30 years ago makes a difference also.

By: nancy

nancy — Fri, 20 Jan 2006 14:49:58 +0000

Justin said he needed something to keep him busy the next 9 years. Well, how about this:

Feb 28 2006: launch of Space Technology 5 mission (microsats)
March 2006: Mars Reconnaissance Orbiter reaches Mars
May 2006: Launch of Dawn mission to 2 asteroids
Summer 2006: Launch STS 121 shuttle mission (hopefully!)
August 2007: Launch of Mars Phoenix Lander
2008: Launch of Lunar Reconnaissance Orbiter
2009: Launch of Mars Science Laboratory Rover mission
2011: Launch of Jupiter Polar Orbiter mission
2013: Launch of Venus In-Situ Explorer mission
2013: Launch of Lunar South Polar Sample Return mission

These are just a few I could come up with quickly. I’m sure there’s more, and hopefully there will be more human spaceflight missions in that timeframe as well.

Nancy

By: Stuart Greig

Stuart Greig — Fri, 20 Jan 2006 09:04:35 +0000

What always gets me is that it took Voyager how long to get Jupiter and this one gets there in 13 months!

Is this purely down to 30 years of technology advances in propulsion or just a better alignment for a shorter trip? Or is it that Voyager was going deliberately slow (relatively) to get a better look on the way past?

Still amazing!

By: Volsen

Volsen — Fri, 20 Jan 2006 07:47:32 +0000

The centre of gravity in the Pluto-Charon system is in between the two bodies. Is that a Lagrange point? LetÂ´s place the probe there and it can observe and take photos FOREVER

By: Adria

Adria — Fri, 20 Jan 2006 03:21:22 +0000

Hey Phil, do you know how much the trajectory had to be recalculated due to a 3 day delay in launch? If at all? Do they just build that in to the software, an easy fix to make, just in case?

By: yorktank

yorktank — Fri, 20 Jan 2006 01:24:09 +0000

A troll, eh. So does that mean the BA blog has hit the big time?

By: Michelle Rochon

Michelle Rochon — Fri, 20 Jan 2006 00:48:30 +0000

…Hey people, we got a troll.

By: Ray Gray

Ray Gray — Thu, 19 Jan 2006 23:31:53 +0000

Yes! That powerful element No. 94 (Pu239) plutonium is finally going home to Pluto. What a wonder-work the New Horizons Mission really is. Those first two delays reminded me of foul balls during the finish of a tight baseball game. NASA hit the ball out of the ballpark. A nine year wait, after nine innings, will cause the NASA team to consume many bags of mixed nuts. Oh well, “It ain’t over till it’s over”.

By: Daniel Nash

Daniel Nash — Thu, 19 Jan 2006 23:19:53 +0000

The New Horizons plan is to do maneuvering near and/or after Pluto, not in order to observe Pluto more, but rather to move on to one or more Kuiper Belt Object beyond. Or, maybe they are doing both, but the KBOs are the next destination after Pluto, unless NASA drops the mission at that point.

By: Irishman

Irishman — Thu, 19 Jan 2006 22:32:54 +0000

Check out the Basics of Spaceflight manual from Jet Propulsion Labs website.

http://www2.jpl.nasa.gov/basics/bsf4-1.html

By: Nigel Depledge

Nigel Depledge — Thu, 19 Jan 2006 22:17:44 +0000

Volsen – it all depends on the direction of approach, I think. Curse this feeble memory of mine – I once knew a little about gravity-assisted slingshot manoeuvres. I think that the probe will take some orbital energy from Jupiter and some rotational energy, but I’m really not sure.

Anyone have a good link for this?

By: Justin

Justin — Thu, 19 Jan 2006 22:13:10 +0000

From the press kit, when New Horizons reaches Jupiter it will be traveling about 47,000 mph. The flyby increases New Horizons’ speed by 9,000 mph (4 kps). At its closest approach to Pluto, it’ll be down to 31,300 mph. That’s moving pretty fast, but they’re still getting several months of observations. Trying to line up for a breaking maneuver, and trying to actually make a sizable dent in the spacecraft’s speed probably can’t be done effectively with its puny little thrusters.

By: gopher65

gopher65 — Thu, 19 Jan 2006 21:46:28 +0000

weeee! I’ve been waiting for this for a long time:). Good to see that it finally launched successfully.