Falkland Islands almost BLITZED from space by plunging European ion-rocket craft The European Space Agency (ESA) has kindly let the planet know that the Gravity field and steady-state Ocean Circulation Explorer – GOCE – has re-entered earth's atmosphere, apparently without incident. Artist GOCE during its mission The demise of the craft was expected, because it ran out of fuel in October: GOCE was …
I live just east of Atlanta and saw 4 objects that faded into view and faded out of view (like a satellite). One accompanied with a bright white flash. The direction of all 4 objects were NNE on a trajectory which I estimate would put it flying about 100 miles east of Toronto. This was seen about 30 minutes ago.
Sometimes I think we waste a aweful lot on getting Sensors, Computing Power, Batts & Solar/Nuke Power, into orbit, then crashing into some part of planet ...
Why not boost them into a higher Orbit to be recycled for other uses, like Lunar Base, or Space Craft, and just putting into say l5 orbit would make them easier to get later ....
I think answer to Junk is a Russian Nuclear powered Electro magnet Satellite, get into orbit, turn it on, whizz around planet couple dozen times, collect all crap in a big ball, prang it into moon, give archeaologists a spacesuit later ...
I notice years ago the "irdium" & other phone system of sats were going to start bringing them down, why didn't they turn want to them around face the network into system, we could have used to control drones, to explore, so much waste ...
Maybe I get carried away with the idea, but I think they should have "tried" to "soft-land" MIR on Moon, for History & a Emergency Habitat, If theres a hole in your spacesuit, it may just need curtains ...
I'm afraid the amount of fuel that the satellite would need to carry just to move to the parking orbit at the end of its life would probably so shorten the amount of life that the satellite has that it would no longer be worth sending the thing up in the first place.
Additionally, the more things up there, the more likely of a collision between 2 spacecraft. Whilst the movie Gravity is obviously hollywood, (please ignore the sensationalist bollocks), and the speed of the "chain reaction" is frankly ridiculous, but the risk of space debris expanding and making the risk to future space missions unacceptable is actually a high risk. So the requirement to deorbit spacecraft now is basically an attempt to safeguard our ability to get off this planet in the future.
"Why not boost them into a higher Orbit to be recycled for other uses..."
Several reasons.
First, most low orbit satellites won't have enough fuel left to be boosted to an altitude that will be stable for long enough to start building L5 stations and moon bases. (Satellites in Geosynchronous Orbits, on the other hand, do get moved upward to a graveyard orbit at the end of their lives.)
Second, recycling old satellites is not likely to be a fruitful exercise. The hardware would be obsolete, aged, and broken - try digging a Soviet TRS-80 clone out of a Chernobyl junk yard and use it to patch your modern computer. Even if you just melt the satellites down for mass, there's not a lot of mass to be had, and it's not in convenient alloys, shapes, or sizes. The popular carbon composites of satellite frames don't recycle well at all.
Third, there's no easy way to collect the satellites. A giant Russian nuclear-powered magnet isn't going to attract the satellites. Partly, satellites don't use a lot of magnetic materials, instead favoring aluminum and carbon composites. And partly, magnetic field strength drops off with the cube of distance. The nuclear-powered magnet that pull your teeth fillings out at 10 meters distance would hardly erase a VHS tape at 100 meters and wouldn't wobble a satellite at 1 kilometer. The alternative is to use an enormous amount of fuel chasing down all the satellites in their different orbits - it's not easy to alter orbital inclination, no matter what the (awesome) movie Gravity showed about hopping around in a manned maneuvering unit.
On that note, Mir would never have made it to the moon. At 130 metric tons and with its thrusters having an exhaust velocity of about 3000m/s (typical of storable liquid propellant rockets), Mir would optimistically have required 260 metric tons of fuel to escape Earth orbit on a lunar trajectory (which requires about 3230m/s). Lunar orbit capture would require another 900m/s, and lunar landing would require about 1800m/s (with gravity losses). So, you're actually looking at a requirement for over 900 tons of fuel to get the 130-ton Mir from Earth orbit to the lunar surface.
The good news is, you can actually shave off a few hundred tons from the fuel requirement because there's no point in spending fuel on the final soft landing maneuver. That savings stems from the bad news: Mir's thrusters are too weak to support Mir's weight against lunar gravity. Even if you were able to somehow deliver 900 tons of fuel to Mir, the end result would be a new and very expensive lunar crater.
Answering your question about Iridium: the issue is that the original Iridium satellites are wearing out. The computers are accumulating radiation damage; the electrical systems are running out of spare parts to replace shorted circuits; the fuel is running out; the reaction wheels are wearing out; etc.
Satellite operators are not ignorant of the potential of keeping old satellites around as spares. That's practiced when it's viable. Old geosynchronous communication satellites may be taken out of service (or applied to less critical services) and then if their new replacement fails suddenly the old satellite can be dropped back into service briefly. The NOAA weather satellites also do that. But there's a point where an old satellite goes from "useful spare wheel" to "hazardous and rough on the operator's insurance policy." At that point, the satellite gets dumped into the atmosphere or moved to a harmless graveyard orbit.
While we're shooting down ideas, here's mine:
Expanding foam.
1. Launch giant can of expanding foam into either low orbit or eccentric orbit, with the periapsis just skimming the atmosphere. Have to be formulated to work in vacuum, of course.
2. Deploy foam. Now you have an absolutely huge *blob* of foam in orbit. Low density. High volume.
3. Lots of tiny bits of junk - screws, paint flakes, etc - and some of the larger bits like tools collide during the few years the Blob is in service. Thus they either get embedded, or smashed into an eccentric orbit too.
4. With such a huge cross-sectional area, the blob will eventually (months to a decade or more, depending on orbit) be slowed down by friction and reenter along with the payload of collected debris, to burn up harmlessly. As will any small pieces that break off during collisions.
Spain sized, and less dense than "A fluffy pillow". Collision velocities can be upwards of 20,000mph and you don't want anything spraying off to become smaller, less trackable hazards.
The latter part is _hard_ and why noone's flying fluffy pillows yet.
Yes a blob that size would catch (some of) the small debris up there, screws, paint flakes, etc. But because of its size it would also catch (some) functioning satellites too, and would also be a significant hazard to the ISS and Tiangong-1, so I suspect the blob would rapidly become unpopular.
Manueverable Satellites is a concern to others, and they seem to be planning for SATs that can “fly” about , in formation as well ....
http://www.sst-us.com/missions/snap-1/news/snap-1--the-mission
http://techtransfer.gsfc.nasa.gov/ft_tech_geons.shtm
http://www.russianspaceweb.com/persona.html
or perhaps a story about forcing a SAT into a higher orbit using it’s “steering thrusters”
http://spaceflightnow.com/atlas/av019/111009.html
I feel busting these SAT’s up and spreading the crap everywhere is wrong, it just has to be organised, it’s better than having to pick it up ....
@ lglethal Haven’t bollocks movie, I read the reviews, I think the biggest bit of crap they had to avoid was the plot/script ?
@ cray74 So could MIR be reloaded while it was in use, but after use, let it burn up ? If they
can send a robotic resupply then a robotic- Guidance/Engine could have been done as well ....
Iridium ? http://en.wikipedia.org/wiki/Iridium_Communications
"The founding company went into Chapter 11 bankruptcy nine months later, on August 13, 1999“ and “At one stage there was a threat that the Iridium satellites would have to be de-orbited”
Because 1) phone didn’t work as advertised, and 2) service wasn’t there, but they were going to bring them down on strictly COMMERICIAL grounds, nothing to do with them “wearing out” ..
(Satellites in Geosynchronous Orbits, on the other hand, do get moved upward to a graveyard orbit at the end of their lives.)
Yeah, as long as they don't die unexpectedly first. There are a number of dead birds slowly precessing around the Clarke Belt, requiring whatever's in their way to waste fuel in avoidance manouvres
For the same reason spinning the ISS for gravity is not done and MIR was not used as a Mars-Earth shuttle: Science.
Now, go research the subject for a couple of hours and be less under-informed. Start by finding out how much fuel is needed to get into "higher orbit".
Once you understand the diminishing return of that, look up "space trash" to understand why crashing satellites back to Earth is better than leaving them in orbit.
Exactly, it's like predicting the weather. A commenter above mentioned "120km" as the altitude of doom. True. But sometimes it's a bit higher, say, 130km, depending on atmospheric conditions. Which we don't know exactly at all points of the atmosphere at all times. Hence, you just can't know where a gradually decaying, circular orbit will come down.
Far better to do a big burn at the end of the sat's life, to target the orbit to intersect the Earth at a safe spot.
"NORAD tracks all the (known) crap in orbit"
Down to a given size (about 2cm) - which gives you some time to avoid the larger chunks.
A fleck of paint, let along a single nut or other larger item would give you a _very_ bad day and there would be no warning at all about them.
We have been fairly close to the LEO junk tipping point (think about a room full of mousetraps setting each other off) for a number of years and the amount of crap falling off stuff being launched (let alone what sprays off in collisions amongst existing junk) vastly exceeds the amount of junk deorbiting through atmospheric friction each year.
As for how hard it is to track - earth might be more or less spherical, but its density isn't even, which means the gravitational field isn't even (which means instantaneous speeds vary slightly), PLUS there are variances depending on which wisps of atmosphere you hit or don't hit PLUS there are interations with the earth's magnetic field (which is far from homogenous)
Everything is easy when you can assume a spherical cow, but in real world situations the math gets more complex.
It apparently started it's final decent at c.80Km altitude. If, as is predicted, only some 25% of it's overall mass survives, how much of the charred remnants will remain in low earth orbit, floating around about up there, perhaps not unlike the vast mat(s) of plastic down here in the Pacific ocean?
I am aware that there is ongoing research into how to deal with all the other potentially dangerous crud we have hoisted above us and would ask if any better qualified Regaunauts might have answers to above. Thank you.
It's more like about 25% of it will come down as pieces. The rest will turn into dust in the atmosphere (e.g. vaporise and then condense). None will be left in orbit.
Also as far as dust in the atmosphere goes, the amount of it will be insignificant compared to the natural space dust that lands in the atmosphere every day.
At 80km altitude, anything in orbit will quickly lose velocity due to drag (Air resistance), and hence will lose altitude and de-orbit pretty quickly.
Everything up in orbit around Earth is slowly degrading its Orbit (except in a few key gravitational spots), but until you hit the top of the atmosphere (basically where there is actually enough Air molecules that collisions are likely) that degradation in Orbit is slow. But as soon as you hit the Atmosphere, degredation happens quite quickly, and nothing stays up beyond that point...
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