Physorg.com has an article (evidently syndicated through AFP) about the ridiculous and dangerous idea of a cosmonaut hitting a golf ball off the space station.
In that article is this line, about how difficult it is to hit the ball the way you want:
The ball thus could quite easily be mis-hit and travel only a couple of metres (a few feet), or be hooked or sliced and sent in entirely the wrong direction.
Um. Um. In space, with no air, what will stop the ball after "a couple of metres"? If it hits a strut or bulkhead, it’ll bounce off and continue on in another direction. And hooking or slicing it will prove difficult, since those shots depend on gravity and air (to be fair, by "hook" and "slice" the author meant the ball might be hit too far to the left or right, but technically those types of motion are due to the ball interacting with air).
Too bad the article has no byline, or I’d email the author. I tried the contact page for AFP, but they want my phone number! No way. Maybe this will filter over to them.
Incidentally, in the comments from my last blog entry is an ongoing conversation about the chances of the ball coming back to hit the station. I first thought yes it will, then I wasn’t so sure. But then I read the article linked above, where Heiner Klinkrad, acting head of space debris at the European Space Agency (ESA), had this to say:
For the ISS, the most probable collision velocity in the worst-case scenario is somewhere at 10 to 11 kilometres (six to 6.5 miles) per second… The international recommendations are that you should not throw out unnecessary objects, and I wouldn’t qualify a golf ball as a mission-related object.
He doesn’t give the odds, and so it’s hard to know how low the chances are of a collision later. But given all the uncertainties, this strikes me as a dangerously foolish stunt. If/when NASA’s people finish their study, I’ll post a synopsis here.
March 7th, 2006 at 10:04 am
“or be hooked or sliced and sent in entirely the wrong direction.”
A hook or slice needs air. A hook or slice is when the ball starts in a direction then curves to the left or right. The change of direction is caused by side by the air flow around the ball hit with a closed or open face causing side spin.
March 7th, 2006 at 10:22 am
To a non-golfer, a hook or a slice means the ball goes left or right (or vice versa). Not an accurate use of terminology, but close enough for hand grenades. Or orbital debris.
It could be mis hit at low speed, and hang around in the vicinity of the ISS just behind it. Would they go retrieve it to try again?
March 7th, 2006 at 10:30 am
Phil: if you have a space flight historian handy, ask him about Voskhod 2. I seem to have read that during his EVA, Leonov jettisoned a camera lens cover that hit the spacecraft a few orbits later.
March 7th, 2006 at 11:06 am
Just give them a fake telephone number (or that of certain adversaries…)
March 7th, 2006 at 11:17 am
Can’t they hit it towards the earth and let it burn up in the atmosphere?
March 7th, 2006 at 11:37 am
What’s the velocity of a golfball? 20 or 30 m/s? I’m too lazy to work it out just now, but I doubt that’s enough delta-V to reach the atmosphere from the ISS. I think the shuttle needs a few hundred metres per sec to de-orbit.
March 7th, 2006 at 12:04 pm
Eli, orbital dynamics don’t work that way. Regular motion doesn’t apply, because of the nature of orbits. Objects are traveling in a circular path, with sideways velocity just canceling downward fall, so the object falls past the side of the Earth, perpetually. A little slower and you fall lower, a little faster and you go higher. Because your path is a circle, changes in velocity don’t apply in the direction you add them, but affect your direction 90 out of plane.
Trying to hit the ball “down” will add velocity 90 deg out of the plane of motion. 1/4 of an orbit later, you are no longer traveling in the same direction, you are pointed 90 degrees “down” from your previous direction, so the golf ball won’t be between the station and Earth any more, it will be in the same altitude from Earth but in front of the Station. 1/4 of an orbit later, it will be above the Station, except any drag that occurred during the previous 1/2 orbit will slow the golf ball and bring it closer to Earth, which means ironically that it will be closer to the station from above. So you hit it down and it hits you in the face. Welcome to orbital dynamics. Read this.
http://www.msnbc.msn.com/id/11102068/page/2/
March 7th, 2006 at 12:24 pm
Leave it to scientists to miss the obvious answer here. The company proposing this stunt has already received far, FAR more publicity than they deserve. Their idea will be rejected, they will pay the Russians zero, and they will have received worldwide publicity that is beyond price.
But, since I am supposedly an aspiring scientist myself, can’t the ball be given sufficient delta-V to reach a low enough orbit to begin interacting with atmosphere, and thereby reenter safely after a few orbits?
This assumes the ball can be hit accurately enough, of course.
March 7th, 2006 at 12:27 pm
Grand total of δ ~45 m/s to de-orbit Mir, with a golf ball being hit at ~30 m/s.
March 7th, 2006 at 12:36 pm
The golf clubs are already on board the ISS, which means they paid the lifting fee, and I’m confident the Russians got their money in advance for the whole thing.
Also, folks, remember that the astronaut (really, a cosmonaut) is in a space suit, and I’d be surprised if he’ll hit the ball with a velocity above 10 meters per second. That’s not much, and the orbit of the ball will be very hard to predict in advance. It will have a radio transmitter, so perhaps tracking it will be easy enough, and an orbit determined from that.
March 7th, 2006 at 12:46 pm
First, to go on record, I think this golfball thing is a dumb idea.
BUT in the interest of debate..I read the msnbc article and it seems from that, that hitting the ball “backwards” opposite the direction of the station is the way to go. I haven’t seen anything to suggest they aren’t going to do this.
Space.com reports it will be a 6iron which is historically the easiest club to hit. (Ask any pro teaching lessons this is almost exclusively the club chosen to start with). His feet will be firmly planted, and the tee is specially designed.
Lastly there is a side note on the Space.com report on a specially designed spring loaded tee. Is it at all possible, he doesn’t actually have to “HIT” the ball. It is a stunt after all. So he just takes a swing at it, and a spring activates to push the ball on a well known, controlled trajectory?
Lastly, on a side note, since Force=Mass x Acceleration, would the probable impact forces be about the same in the two events?
SuitSat = Mass High, Acceleration low.
Golfball = Mass Low, Acceleration high.
Just thinking..
March 7th, 2006 at 1:31 pm
This sounds like an incredibly bad idea. Ignoring air resistance and collisions with other space debris, this ball will cross the orbital path of the space station twice per revolution. No matter what delta v (short of that sufficient to either deorbit it or give it escape velocity) they give it, it will spend part of it’s orbit above that of the ISS and part below. Hit it in the same direction as the ISS, hit it backward or hit it to the side, it dosn’t matter. Plus it will cross that path very close in time to the space station being at that crossing point itself. The likelihood of a collision is high.
March 7th, 2006 at 2:47 pm
I just can’t believe that a website supposedly devoted to physics would make that sort of error, except, well there it is in black and white. It’s like the physics site guy is in his cubicle, trying to finish this article that was due like, yesterday, and the guy who writes for the wall street site leans his head in from the next cubicle:”Oh man, that’s ridiculous. What if he slices it?” *Boing* the little light bulb goes off over the physics writer’s head.
Also, orbital makes perfect sense after reading about it, but I certainly had a completely intuitive aka wrong conception of it until now. That’s nuts. I’m not going up on that station, no way! Just forget the whole thing.
March 7th, 2006 at 3:24 pm
This is such a bad idea on so many levels, but there’s one point where this might bring down the ISS that hasn’t as far as I’ve seen been addressed.
When Alan Sheppard tried this on the moon, I distinctly remember ALOT of people in the media and in public office ranting about spending billions “so some clown can golf on the moon”. And it was about that time that NASA started seeing it’s harshest budget cuts. The two events may not have been related, but it sure as heck didn’t help.
And now we’re going to do it again, but this time we’re putting it on TV in 30 second spots? Can anyone honestly say that the money the Russians got for this will be enough to compensate for the public money they stand to lose on the ISS?
March 7th, 2006 at 3:56 pm
How fast will the relative motion of the ball be? I mean, if the astronaut only hits it at 10 m/s, then why isn’t the spacecraft safe?
March 7th, 2006 at 4:05 pm
Jeremy Said:
>I read the msnbc article and it seems from that, that hitting the ball “backwards†opposite the direction of the station is the way to go. I haven’t seen anything to suggest they aren’t going to do this.
Sure, that’s the safest way. It reduces the risk substantially. However, does it reduce the risk enough to make it warranted, given the purpose is to promote some golf club manufacturer and get publicity? How much risk is left, and are the goals worth the risk? That’s what the debate is over. Most people against it think the risk is substantial enough and the goals meaningless enough that it isn’t worth doing. The analysis (if we see it) will quantify the risk, and help make a better assessment. Some people think the goal is not worth doing without any risk. That’s why it’s a sore subject.
>Lastly there is a side note on the Space.com report on a specially designed spring loaded tee. Is it at all possible, he doesn’t actually have to “HIT†the ball. It is a stunt after all. So he just takes a swing at it, and a spring activates to push the ball on a well known, controlled trajectory?
Not likely. That article calls it a “spring-like space tee”. I’m not sure what that means. Is it a spring that the ball sits on? Is it a spring-loaded clip? I would think the latter, but “spring-like” is too vague to make sense of. I suppose it could be done with spring-loaded launcher and a random swing in the vicinity to look good, but that seems overly complex. They’re shooting for a golf shot, not a spring-loaded ejection of a golf ball, after all. I think the special nature of the tee is to hold the ball in place before it’s hit, since gravity isn’t available to do the job.
March 7th, 2006 at 4:16 pm
Frank Sullivan Said:
>How fast will the relative motion of the ball be? I mean, if the astronaut only hits it at 10 m/s, then why isn’t the spacecraft safe?
On the outbound and first pass, it probably is pretty safe, unless it hits a solar array. Those are very flimsy items. Oops, I just put a hole in my power generation device. Oh well, I didn’t want to run the life support at full power anyway. The question is what happens after that. Does the ball’s orbital properties keep it intersecting with the ISS orbit? After all, when you change the orbit of a satellite, it takes two burns to complete the change. The first changes the orbit from a circle to an ellipse, the second recirculizes. This ball will get 1 “burn” that will make the orbit an ellipse. Will it come close enough on subsquent orbits to intersect with the high point at the same altitude as the ISS?
The speed differential will not just be the delta V added by the cosmonaut, but any delta V attributed to differences in the orbits. If the golf ball departs with some sideways motion, then on the next pass it might not be directly in line, but come in at an angle.
I hadn’t thought fully about it, but ruidh’s comments made me reconsider that point. So far the discussions of dynamics have mentioned how the golf ball will slow down behind the ISS, so it will fall inward and speed up. However, by speeding up, it will move outward again. As I said, the orbit will be an ellipse, not a smaller circle. Ergo, the golf ball will be intersecting the ISS orbit (or very close to it) two times an orbit. Sure, the orbit will decay, but how quickly will it decay such that the high point isn’t intersecting with ISS? Will ISS perform a propellant burn to change orbits? Yet more reasons this is a stupid plan.
March 7th, 2006 at 4:45 pm
Looks like orbital dynamics would make an interesting Olympic Games.
Let’s hope no bowling alley ever has enough funds…
March 7th, 2006 at 5:35 pm
So Heiner Klinkrad, acting head of space debris for ESA, says the worst-case scenario could result in a collision velocity of 10 to 11 kilometers per second. That’s faster than orbital velocity, and very close to escape velocity. I’m no orbital mechanic, but I don’t see how that could happen.
The golf ball is given a small initial velocity relative to the station, so its orbit is very similar to the station’s orbit, intersecting it at that initial point. That means the ball and the station could meet on future orbits, but if they meet they should be going at very nearly the same velocity relative to Earth, and therefore a low velocity relative to each other.
(I’m not trying to argue that it’s not a stupid idea.)
Is there some mechanism by which the ball’s orbit can tilt over time, so the ball might be in, say, a nearly polar orbit at the same altitude as the station?
March 7th, 2006 at 6:29 pm
Okay, folks. Let’s throttle back a bit from vague terms like “incredibly bad idea” and the like, and look at cold facts. I’m surprised that the discussions along this line are only forming now. I started doing some orbit work on this but got bored.
First off, I think this is dumb for everyone except the golf club company. They’re the only winners in this; that being said, please correct me if any of these assertions are incorrect.
1. This ball hit is going to define a new level of lousy hit. If only the cosmonaut could get a Mulligan. Even if his feet are firmly planeted, the suit and the overall awkwardness will make it one ugly shot.
2. With this lousy shot, the speed the ball leaves the station is the maximum speed that it will strike the station at. Any scenario that has the ball changing speed through atmospheric drag will move the ball’s orbit further from the station.
3. Someone mentioned a “hole in your power generation device” there are already plenty from other debris and space dust. The panels are known to degrade over time, and the station is at a power surplus.
4. The ballistic coefficient (mass/surface area) of the ball and the station are what matters when figuring how much their orbit will be changed by the atmosphere.
5. The station changes its orbit (raising it, for the most part) relatively frequently. A quick web search didn’t reveal the frequency to me, but a maneuver right after the golf play would drop any chance of impact to zero.
6. Future impacts with other orbiting objects are a possibility, but there are about 6,000 objects being tracked in orbit right now, and many others that cannot be tracked. Statistically, the change in odds of anyone or anything getting hit are not changed by adding this ball to the low Earth orbit environment.
March 7th, 2006 at 7:24 pm
First let me remind everyone that the orbit will not be circular, but elliptical. Next, only during the initial moment will the ball have a low relative velocity to the space station – unless the cosmonaut manages to hit the ball in the exact same orbit (not possible because the additional energy will alter that orbit).
Each orbit has high and low points (apogee and perigee) where the velocity of the ball will be different than the initial moment. The orbit of the station also has high and low points. With the station at orbital velociy and the ball slowing due to atmospheric drag, the differential if they do meet again could be much higher than the cosmonaut’s original input creates.
The good news for the ISS is that the chances of hitting on any given orbit will be fairly low, but depending on the resulting orbits, the cumulative probability could be 1:1 given sufficient orbits – or it could be nearly 0 for a very long time.
Still, who would really want to take risk damaging a billion (or two) dollar space craft on a publicity stunt (ok, we already know the answer, don’t we).
jbs
March 7th, 2006 at 7:45 pm
Is this one of those “just a matter of time” sort of things where the chance of collision is 1.0 if given an infinite amount of time? If so, I wonder if it’s possible to calculate the probability based on the expected life time of the space station (i.e., 50% chance it will collide with the ball in the next century, 25% chance that it will collide in the next 750 years, or whatever).
March 7th, 2006 at 8:13 pm
Tom, the max velocity quoted by the guy from ESA surprised me as well. I have no idea how the two orbits could intersect at such a velocity. I’d love to follow up on this, as obviously I think this is important, but unfortunately I have other things to complete right now (the aggravations of a day job…).
March 7th, 2006 at 10:37 pm
Phil, I wrote a message yesterday with URLs to NASA/ESA debris sites.. but your software thought it was spam (maybe too many URLs?). It’s in your bit bucket if you want to retrieve it.
March 7th, 2006 at 11:28 pm
Amara, anything older than a few hours gets deleted. I’m sorry about that, but spam blog (splogs) try to post comments here several hundred (yes really) times a day. Too many linbs (>2) will indeed get tagged as spam.
March 8th, 2006 at 2:06 am
I have not followed this whole golf saga with much atttention. I find it peculiar though. Is there any scientific purpose behind it? Any chance that it might educate the public about science?
As it is I wonder about the scientific worth of the ISS, especially considering that for the price of the ISS, we could have put unmanned probes on every sizeable body in the solar system. I regularly read in the media about exciting new scientific discoveries made by unmanned probes. Off the top of my head, I cannot remember ever reading of a single scientific discovery of note being made by the ISS.
And now it has been turned into a billion dollar golf tee.
I have to admit that I half HOPE that the ISS gets hit by the ball and comes down in flames. (Assuming it doesn’t get accidentally shot down by Dick Cheney.)
March 8th, 2006 at 2:14 am
On a more humorous note, I just noticed one of the advertisements at the top of this page. These are apparently put there automatically by software, and I suppose the software recognizes key words on the page and then puts up an advertisement that is relevant to the contents of the page.
Today’s advertisement? “Cure golf slice. Guaranteed to cut seven strokes from your score in only one week.”
Well, I don’t need these guys to tell me how to cure golf slice. There is a simple solution: hit the ball where there’s no air…
March 8th, 2006 at 2:48 am
Lets hope that Dick Cheney Doesn’t get involved – Who knows what he would hit.
March 8th, 2006 at 4:38 am
Casper sayes,” Looks like orbital dynamics would make an interesting Olympic Games.
Let’s hope no bowling alley ever has enough funds…”
Along the same idea, on the ISS, what would a 3D game of snooker be like? Granted it would be ‘indoors’, but I guess those balls would keep going until all dropped into the pockets. A long game I suppose with no chance of the opponet even getting a shot, even if the black ball dropped ‘ in – off ‘. Though he would win, it would not be much of a game.
But it would pass the time when you couldn’t play golf outside during a meteor shower! arrr, sorry ’bout that Phil.
Ivan.
March 8th, 2006 at 5:38 am
Okay, I’m a physics idiot, so someone please tell me where I’m wrong on this. (And I apologize in advance if this has already been hashed over.)
First, I don’t understand this thing about the golf ball going at 18,000m/h. I mean, I do, it’s leaving at the same velocity that the shuttle is going and there’s whatever acceleration the cosmonaut gets on the ball, but isn’t everything up there going at that velocity too? Everything that’s staying in orbit, anyway. It’s not like the Shuttle is standing still and along comes this golf ball at 18,000 m/h, right? Or am I missing something?
Second, I don’t fully undertand orbital mechanics, but don’t orbits decay unless you keep correcting them? And wouldn’t a golf ball’s orbit decay fairly rapidly?
Third, how much force could be involved here? Someone mentioned a camera lens cover that got tossed out and later hit the craft. Did it damage it?
I just *know* I’m wrong about all of this, given my non-background in physics. So go ahead, tell me where. *g*
Hawkeye
March 8th, 2006 at 6:08 am
Hawk-
If the ball and another spacecraft are at the same orbital altitude (circular assumed), then they are traveling at the same speed. If their inclination (angle made when they cross the equator) is different, then at the points they meet, their relative velocities can be very high. An example of the maximum (it’s impossible in this situation) would be an object in a 0 degree inclination, flying directly over the equator, striking an object with a 180 degree inclination, flying directly over the equator in the other direction. That would mean a closing speed of 36,000mph.
Orbits do decay, but the predictability varies quite a bit. I seem to remember that astronauts released a solar array during the first Hubble repair, and it stayed up much longer than people expected. The major variables are the expansion of the atmosphere and the ballistic coefficient of the object. A golf ball has a fairly high ballistic coefficient (compared to a plastic sheet of the same mass), so it could orbit for a while.
As I mentioned before in my 3/7 6:29 post, the differential speed, which translates to force shouldn’t be that high. It’s true that the speed and orbit of the ball will change over time, but while that would increase the collision speed it will also serve to move the ball away from the station.
Orbit mechanics plays with your mind.
March 8th, 2006 at 6:14 am
As long as we know something is not infinitely improbable, then a finite probability calculator, accessorized with a Brownian Motion Generator (say a good hot cup of tea), ought to turn up a satisfactory result in a mere nothingth of a second.
That aside, essentially I agree with Tom. I’ve flown the shuttle simulator software about 30 times, launch, orbit, rendezvous, deorbit, land (only landed successfully once) about 20 years ago. To deorbit, you flip the thing end-for-end (shut the bay doors, dummy!), decline about 23 degrees, then do an OMS burn for between two and three minutes. Shooting the ball both backwards and down is the only way you’re ever going to reach atmosphere, unless you leave the damn ball INSIDE the shuttle where it neither belongs, nor should have ever been. (sigh)
I love space. I’d like to live in an L-5 Colony. People that actually GET there ought not make a mockery of it and jeopardize the chance for all the rest of us to get there in our lifetimes…
March 8th, 2006 at 6:23 am
Hawkeye, I think you’ve got the physics right, as far as I can tell. Everything in and around the ISS is travelling at the same speed. The golf-ball will only have a 10m/s difference in velocity, so the risk to the station is minimal. Its orbit might intersect with something lower down, which in a worst case might be moving at right-angles to the ball, resulting in a velocity difference of tens of km/s.
The orbit will decay from interaction with the very tenuous atmosphere; the ball has a high surface to weight ratio ,so it will decay faster than the station, and it won’t be able to correct its orbit. Somebody around here said 4 years, which sounds reasonable.
Don’t know about the camera lens cover, but if it was dropped it probably had a velocity difference of a few cm/s, so I doubt it would have done any damage.
March 8th, 2006 at 8:18 am
I have a legal question:
Let’s suppose the ball hits and damages something, who is legally responsible, who will have to pay for the repairs? Will it be the golf compagny?
If so, do you think they’ll have to raise the price of their golf balls to cover for the multi-billion dollars loss…?
March 8th, 2006 at 9:13 am
If it were fired exactly “backwards” (yes, unlikely), wouldn’t it enter an elliptical transfer orbit (used to change spacecraft orbits), with apogee at the starting point, and perigee somewhat lower, like deeper into the atmosphere? It wouldn’t just settle into a lower circular orbit without another delta-vee at perigee, right? Of course, that’s a completely ideal situation…
March 8th, 2006 at 9:17 am
I think that in the same way pornography powered the early growth of the internet, boneheaded crap like this is part of the early wave of non-governmental expansion into space. We’ll laugh about it in our Zero-G Hotel in 30 years, at least until an old golf ball comes tearing through our room.
March 8th, 2006 at 10:02 am
aiabx: I think you are wrong, Star Trek powered the growth of the internet. Nerds follows Star Treks and as a sideline Porn.
March 8th, 2006 at 10:55 am
The BA sez: “Tom, the max velocity quoted by the guy from ESA surprised me as well. I have no idea how the two orbits could intersect at such a velocity.”
I have no idea how you’d do this with a single impact, but if you could get the orbit of the golf ball to start precessing such that it winds up with the same altitude and inclination, but opposite nodes at collision, it would hit head-on, which means an impact at ~53,000 ft/sec (~16 Km/sec).
- Jack
March 8th, 2006 at 11:32 am
The more I think about it, the more I think it’s a silly idea only a 6 years old kid would get. Come on.
March 8th, 2006 at 11:46 am
This is why they tried to put all the premed students in *that* physics class.
Thanks, Tom and NelC. Okay, I think I get it. Now if ballistic coeffecient depends on mass to surface area, in a golf ball that should be a lot higher ratio than a solar array (I’m assuming). So you’re saying its orbit would decay faster, right?
And it’s the angle that matters when we consider the speed. That…actually makes sense, which probably means I’m kidding myself about understanding.
*considers*
It still sounds pretty darn unlikely that it’d ever be seen again, I must say. Let alone hit the Shuttle. But it’s a silly stunt all the same.
March 8th, 2006 at 1:49 pm
I have read a few online articles and I’m surprised at the amount
Another says that the golf ball could hit any of “300
of misinformation available. One says that the golf ball will “beam its
position to Earth-bound computers using global positioning transmitters”.
Poppycock.
operational satellites at the same altitude as the ISS”. I don’t think so.
A couple claim that the golf ball could remain in orbit for 3 or 4 years.
That’s not hard to believe since a golf ball actually has a rather low
area to mass ratio. But my wild guesses are: 1) It won’t last more
than 6 months. 2) I doubt Spacecom can actually track it. (I could
be wrong there.)
As to “it’s going to come back and hit the ISS”, 1/2 orbit is 20000Km,
so at 10 m/s, that will take 2000000 seconds. (I know – a zeroth order
approximation.) But that’s 3 weeks and by that time this piece of debris
will be at least a one mile below the ISS due to differential drag.
March 8th, 2006 at 4:58 pm
I finally read the article with the quotes (including the ball stopping only a few meters from the station). The worst case velocities the other quote mentions must be due to something like precession.
Assuming precession can take place quickly (within the four year expected orbit of the ball) the orbits can eventually cross at nearly right angles. I drew a picture (with a back ground supplied by Celestia) of such orbits (click on the word picture).
I don’t know how likely the orbits getting this out of sync is. Imagine two 17000 mph orbits intersecting at a right angle. Top of the head estimate is about 8500 mph closing speed (what’s that, about 4 km/s?).
jbs
jbs
March 8th, 2006 at 5:00 pm
Well the link is disabled (it looks like a link)… the drawing is on my page http://users2.ev1.net/~switchtech/cross_orbit.html.
jbs
March 8th, 2006 at 8:00 pm
i think it’s funny that ALL your google adds are for golf balls and golfing equipment today…..
March 9th, 2006 at 6:03 am
I don’t have the information to rule out precession, though I know that satellites which do precess (POES, the civilian polar-orbiting weather satellite, for example) are launched into very precise orbits to take advantage of the oblateness of the Earth and other factors.
My money is still on the station’s constant orbit maintenance vs. the golf ball’s nonexistent orbit maintenance (drawing ever downward to a burn-up in the atmosphere) make the collision aspect as close to a non-issue as possible (that is, it’s in the noise when compared to the chances of other collisions).
March 10th, 2006 at 4:27 am
John B, two objects moving at 17000 mph at right-angles to each other, by vector addition will have a closing speed of 24000 mph, or 12-ish km/s.
March 10th, 2006 at 4:13 pm
Thanks NelC – I obviously divided by two once too often.
Next time I won’t do the math in my head.
jbs
March 13th, 2006 at 9:06 am
The difference in precession for two objects in almost identical orbits is effectively zero in only 3 months. The ISS is boosted back up about 6 km every 3 months, so once a single reboost occurs, there will never be the slightest chance of a collision.
April 3rd, 2006 at 12:11 am
In all the interesting notes, comments, and discussions above, no one has bothered to address the real concern. If you research a little deeper, to the really, really fine print, you wil notice that before the ball is teed up, they first want to toss out a windmill to add a more realistic obstacle to the course. I always hated that hole too….
April 19th, 2006 at 7:02 am
Can you believe that all the engeneering and work by all countries involved could end up doing something so amazing like hitting a golf ball. Grow up people. The tax payers did not intend to build the ISS for corporate use. I want my money back! what a joke!
Ps. I love golf, and when i find out which company is promoting this stupid stupid idea, I will boycot there products, I suggest all who visit this site do the same….is there any intelligent life out there….hello…hello..?
canuck from Canada
April 20th, 2006 at 7:38 pm
The golf company:
Element 21 Golf.
April 6th, 2009 at 5:05 pm
Ha, I don’t agree with it all but nice none-the-less
October 28th, 2009 at 10:37 am
WOW! You must have worked really hard on this snooker site, I really really like it, in fact it’s ace!