TRW to build Hubble successor

1 - you don't have to strap a huge-ass engine to it to get it into excape velocity and out of our gravity well. You need a rocket that can go 3,000m/s for 340 seconds ( 11,110 x [1-(1/EXP[ 3,230/3,000])]/25 ) *Based on figs from several sites (here) (here) (here)

fig9.gif

*sorry...couldn't find a nice pic of Excape velocity...but this one's nice too :D

The HST is already in orbit (600kms) and going ~3,200m/s. I agree with you re: the used fuel in orbit, but there are already thousands of chunks of stuff floating in orbit, not to mention satellites in bad orbits that have to be dealt with. A six minute burn won't add much more. I agree that the hubble's 15 years old and wearing down...and that the new telescope will be a boon. I'm not trying to say that we should scrap the new project in favor of the HST. I'm saying..the bloody thing's up there...let's do something more constructive with it than push it into the ocean. Hell...there's even talk about linking it to the ISS as a permanent safe-haven.

You feel that it's lived its life and done good for itself, but it's time to not retire it, but just dump it (into our oceans no less). I feel that it's better to use as much of it as possible...it's already up in orbit, it's already paid for itself several times over, if we can continue using it for even a percentage of its capacity, it's worth keeping up there. I seriously doubt that any moneys dedicated to lenghtening the usefulness of Hubble will stop the TRW or delay it any more than any other projects that NASA is working on will.

As for the Titan Hyugens mission...it's a joint ASI/ESA/NASA mission, launched by NASA. The ESA built the probe (which is taking the pics), but I choose to share the kudos with NASA as well.
 
3,000m/s for 340 seconds
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*sigh* Sometimes I wonder about you.

First off, you're giving an unusable figure. Acceleration is in distance per second squared. But let's say that you're giving a usable figure of final velocity of 3000Kps. Odd that Hubble's already going faster than that, and is in a stable orbit. Oops. Maybe not.



That's 3 kps for 340sec. Think about that number. You know how long a kilometer is. You're talking an engine more powerful than the one that launched Spaceship one. It only burned for 80 seconds. And you're trying to shift 11 tons.

Son, I think the problem is that you just don't understand the numbers involved.
 
Professur said:
*sigh* Sometimes I wonder about you.

First off, you're giving an unusable figure. Acceleration is in distance per second squared. But let's say that you're giving a usable figure of final velocity of 3000Kps. Odd that Hubble's already going faster than that, and is in a stable orbit. Oops. Maybe not.



That's 3 kps for 340sec. Think about that number. You know how long a kilometer is. You're talking an engine more powerful than the one that launched Spaceship one. It only burned for 80 seconds. And you're trying to shift 11 tons.

Son, I think the problem is that you just don't understand the numbers involved.
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and I think tht you've forgotten how to read yourself...

first line after the pretty picture

The HST is already in orbit (600kms) and going ~3,200m/s
+velocity after engine burn = escape velocity...check out the links, Mr. Physics

I might've missed a decimal...maybe it's only 34.0 seconds...I'll recalculate.
 
MrBishop said:
and I think tht you've forgotten how to read yourself...

first line after the pretty picture

The HST is already in orbit (600kms) and going ~3,200m/s
+velocity after engine burn = escape velocity...check out the links, Mr. Physics

I might've missed a decimal...maybe it's only 34.0 seconds...I'll recalculate.
Click to expand...

Ok, lemme try this again. Escape velocity (according to the
first line after the pretty picture
Click to expand...
) is 3000m/s. Hubble is already doing 3200 m/s. So perhaps you want to slow it down? Or do you want 3200m/s + 3000m/s for a total of 6200 m/s?


And I don't see that formula anywhere on either of those links. Not that any orbital equation is going to impress me much when it's completely lacking simple things like the gravitational constant. That's like doing circular geometry and not knowing Pi.

Oh, and just by the by, the gravitational constant is roughly 10m/s². 3000m/s² is 300G. You're suggesting, perhaps, subjecting a 15 year old zero g spacecraft to 300G for 6 minutes? That would solve all our problems, except for where the debris would fall.

If you really think you want to get into a discussion about orbital dynamics with me, lets go. But you might want to read up on Newton and Kepler first. Because only a complete idiot is going to try and brute force anything out of an orbit. You want to nudge it into an elipse. Then you time your bursts in assistance with lunar gravity (you didn't forget that great big hunk of rock that you'll have to pass, did you?) to slingshot it out into a solar orbit. Forget an L point. They're much too far, and too valuable for a junkpile.

Oh, and just a last thought. If this were in any way feasible, don't you think one of the rocket scientists at NASA (who don't want to lose Hubble any more than you do) would have suggested it?
 
Professur said:
Ok, lemme try this again. Escape velocity (according to the ) is 3000m/s. Hubble is already doing 3200 m/s. So perhaps you want to slow it down? Or do you want 3200m/s + 3000m/s for a total of 6200 m/s?


And I don't see that formula anywhere on either of those links. Not that any orbital equation is going to impress me much when it's completely lacking simple things like the gravitational constant. That's like doing circular geometry and not knowing Pi.

Oh, and just by the by, the gravitational constant is roughly 10m/s². 3000m/s² is 300G. You're suggesting, perhaps, subjecting a 15 year old zero g spacecraft to 300G for 6 minutes? That would solve all our problems, except for where the debris would fall.

If you really think you want to get into a discussion about orbital dynamics with me, lets go. But you might want to read up on Newton and Kepler first. Because only a complete idiot is going to try and brute force anything out of an orbit. You want to nudge it into an elipse. Then you time your bursts in assistance with lunar gravity (you didn't forget that great big hunk of rock that you'll have to pass, did you?) to slingshot it out into a solar orbit. Forget an L point. They're much too far, and too valuable for a junkpile.

Oh, and just a last thought. If this were in any way feasible, don't you think one of the rocket scientists at NASA (who don't want to lose Hubble any more than you do) would have suggested it?
Click to expand...
No...according to what you're reading into what I said..excape velocity is 3000m/s - except that I'm talking about thrust. 25kg/s of mass expelled @ 3,000m/s over and above existing velocity. Hubble wouldn't be going 3,000m/s ... doesn't have to.

eq1-67.gif


where R is not the radius of the Earth, but of the orbit. Don't know where the hell my first link went...I'll try and find it again.

I also never said anything about putting Hubble into any type of orbit, much less a solar orbit.

As for why the scientists at Nasa didn't mention it ... I'm sure that they've discussed it, but splooshing it is cheaper.
 
OK, let's start (again) with Thrust is Acceleration, which is measured in distance divided by time squared. Speed is Acceleration times Time. 25kg/s of mass expelled @ 3,000m/s is neither. It's a Force equation. You need to take your force equation, add in the mass of the object you're trying to force to get your acceleration. Then multiply it by your time to get final velocity.

And it's also eight and a half metric tons of propellent alone. Never mind the guidance, rocket body, grapling equipment, batteries, etc. How do you propose to get it up there? Or pay for it?

Y'know what Bish ... forget it. You're clueless, and too thick to realize it. Take a few classes in orbital dynamics, and go discuss it with someone else. I'm not being paid to teach you.
 
Bish said:
I also never said anything about putting Hubble into any type of orbit, much less a solar orbit.
Click to expand...

Bish said:
Now... if you can tug-boat the Hubble into a controlled downward spiral... why not push it into a higher orbit or outwards? I can understand that retrofitting the hubble with control jets to give it corrective trajectories might be painfully expensive, but giving it a push "thataway" and letting 'er go would be a more honourable end than dumping'er into the oceans, non?
Click to expand...


If you never said anything about putting Hubble into any type of orbit, then where the hell are you taking it?


Bish said:
As for why the scientists at Nasa didn't mention it ... I'm sure that they've discussed it, but splooshing it is cheaper.
Click to expand...


No Shit? Really? It's still fucking broke, you ******* *****. I'm sure NASA was all over boosting a busted satelite higher where it might collide with the ISS. Probably the first idea they came up with.
 
Professur said:
If you never said anything about putting Hubble into any type of orbit, then where the hell are you taking it?
Click to expand...
Me said:
Hubble's got her uses... maybe, instead of splooshing her, they should add in a stronger antanae/signal processor and push her out to the edges of the Solar system...with little side-trips close to some moons and planets. Better use of rocket fuel IMHO
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Orbital Overload: Space Debris Crowds the Not-So-Friendly Skies

By Leonard David
Senior Space Writer
posted: 02 February 2005
06:47 am ET


As dump-sites go, there’s nothing quite like Earth orbit: Totally gone or near-dead spacecraft, spent motor casings and rocket stages, all the way down to pieces of solid propellant, insulation, and paint flakes. Toss in for good measure thousands of frozen bits of still-radioactive nuclear reactor coolant dribbling from a number of aged Russian radar satellites.

Here’s the heavenly clutter count as of December 29, 2004.

There were 9,233 objects large enough to be tracked and catalogued by the USSTRATCOM Space Surveillance Network. Of this total there were 2,927 payloads, along with 6,306 object classed as rocket bodies and debris.

That’s the stats as listed in the January issue of The Orbital Debris Quarterly News, issued by the NASA Johnson Space Center Orbital Debris Program Office in Houston, Texas.

Hardware survivors

A major contributor to orbital debris is an object suddenly breaking up. This can be caused when propellant and oxidizer inadvertently mix; leftover fuel becomes overpressurized due to heating; or when onboard batteries blow their tops. Some spacecraft have been purposely detonated. Explosions can also be indirectly triggered by collisions with fast-moving debris.

An example of fragmentation took place last October. A Russian Proton Block DM auxiliary motor busted up, adding more than 60 pieces of junk to the overall orbital debris scene.

At times some of this high-tech scrap survives its fiery plunge through Earth’s atmosphere. A growing list of these hardware survivors is maintained by The Center for Orbital and Reentry Debris Studies at The Aerospace Corporation in El Segundo, California.

Last year, for instance, a titanium rocket-motor casing weighing roughly 155 pounds (70 kilograms) was found near San Roque in Argentina. It was identified as debris from a third stage of an American Delta 2 booster that had been orbiting since October 1993.

Similarly, in July a metal pressure sphere and metal fragment fell into Brazil, the likely debris from a second stage of a Delta 2 booster that hurled the Mars Exploration Rover, Opportunity, toward the red planet a year earlier.

Solar max and minimum

So what’s the overall report card on orbiting trash look like over the years?

Fragmentation debris appears to have decreased noticeably in recent years, but unfortunately the true picture is slightly different, said Nicholas Johnson, Program Manager and Chief Scientist of the NASA Orbital Debris Program Office at the Johnson Space Center in Houston, Texas.

"A significant number of fragmentation debris objects have been created during the period and are being tracked by the Space Surveillance Network, but they have not yet been officially cataloged," Johnson told SPACE.com. "This is a bureaucratic issue rather than an environmental one. Meanwhile, spacecraft and rocket bodies continue to accumulate, although for the latter the rate of increase is now small."

There’s another "message" that can be seen in charting out the space junk saga, found in the relative numbers of spacecraft, rocket bodies, and other debris.

Johnson said that that we are nearing solar minimum when reentries -- particularly for small debris -- normally taper off. There was a clear decrease in the population around 1990 during a period of high solar activity. "Unfortunately, the last solar max did not produce a similar result," he said.

Fall of Hubble

So far this month there have been a couple of U.S. Delta rocket stages that have reentered, as well as a Russian Proton motor.

All this is small stuff compared to something big coming in on its own -- like the Hubble Space Telescope. There’s good reason why an eventual "controlled" reentry is being planned for that orbiting eye on the universe.

Orbital debris analysts have figured out the risk to humans down below if Hubble should plow through the Earth’s atmosphere in an uncontrolled manner.

At least two tons (2,055 kilograms) of the estimated 26,000 pounds (11,792 kilograms) of the observatory would survive the plummet from space. Such a fall would produce a debris track that stretches over 755 miles (1,220 kilometers) in length. The analysis suggests that the risk posed to the human population in the year 2020 is 1:250 -- a risk that exceeds NASA’s own safety standard.
 
I like the way the put the word controlled, as in controlled reentry...in quotation marks. As in "Well...we'd like to think that we can control what happens to it after we push it earthwards, but its more of a guestimate."
 
Aw Bish we all know we can plunk that thing down
right on target. It's been done many times before.
A simple procedure actually.

Lets' take bets on the final Circular Error Probability?
 
MrBishop said:
I like the way the put the word controlled, as in controlled reentry...in quotation marks. As in "Well...we'd like to think that we can control what happens to it after we push it earthwards, but its more of a guestimate."
Click to expand...

You're not ignoring the entire top half of that article, are you?


The "controlled" bit refers to the fact that they "control" it by nudging it at a carefully calculated time. Once they've done that, it's up to the accuracy of their equations. If they've not forgotten anything, it'll land where they think it will. If they went and added in metric again, there's no way to stop it. Pretty much like firing a gun at a target a million miles away, and hoping there's no wind.
 
Professur said:
You're not ignoring the entire top half of that article, are you?


The "controlled" bit refers to the fact that they "control" it by nudging it at a carefully calculated time. Once they've done that, it's up to the accuracy of their equations. If they've not forgotten anything, it'll land where they think it will. If they went and added in metric again, there's no way to stop it.
Click to expand...
No..the top half says something about there being huge amounts of crap in orbit, most of it being tracked and some of it occasionally either falling out of orbit or coliding with other pieces of crap also in orbit. Said crap comes from decades of space research and travel, plus dead satelites etc...

They didn't mention how they were going to get rid of all the crap up there though. :shrug:

They did mention that sending down a 13ton object into our atmosphere would reduce it to a mere 2 tons and hopefully they'll hit an ocean (pretty good odds considering how much water we've got down here).

Now... you're going to throw two tons of radioactive materials, sundry metals and plastics etc...into the ocean (See no evil)...and forget about it. Hopefully no one'll notice the dead fish. At the same time, you want to vaporize 11 tons of plastics and metal into our atmosphere...and forget about that too.

You know.. sending it into deep space is starting to sound better and better all the time.
 
It didn't mention how to get the rest of that garbage (which is what it is, garbage) down, because they can't. They can't even slow most of it down, without creating more. The bit I was referring to was how the older stuff keeps blowing up or getting hit and producing even more stuff. As for it going into the ocean and atmosphere ... noone's terribly happy about that. But it's the lesser of evils.

But where did you see 2 tons of radioactive junk? I must have missed that bit.
 
"much like firing a gun at a target a million miles away, and hoping there's no wind"

and very similar to hundreds of ICBM's sitting in silo's all over the world
with 'purported' cep's of 360-730 feet!
 
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