The ISS Marks 10 Years In Space 153
Matt_dk writes to point out the upcoming tenth anniversary of the International Space Station in two days' time. "On 20 November 1998, a Russian Proton rocket lifted off from the Baikonur Cosmodrome for a historic mission: It was carrying the first module of the International Space Station ISS, named Zarya (Russian for 'dawn'). This cargo and control module, which weighs about 20 tonnes and is almost 13 meters long, provides electrical power, propulsion, flight path guidance and storage space. The launch of the module... heralded a new era in space exploration, as, for the first time ever, lasting cooperation in space was achieved between Russia, the US, Europe, Canada and Japan. Over the next ten years, many other modules were brought into orbit, and ISS developed into the largest human outpost in space. Since that time, the building blocks, transported by Russian launch vehicles or the US Space Shuttle, have expanded the ISS to the size of a soccer pitch and a current total mass of about 300 tons."
Lasting? (Score:2, Informative)
Time will tell.
-God
Typical "International" Effort (Score:2, Informative)
As is usually the case, the US has footed over 75% of the bill.
Re:How much does it weigh in space? (Score:1, Informative)
Bzzt! Ton is an imperial unit, but tonne (which the submitter used) is a metric unit (1 tonne = 1000 kg). So the submitter did, in fact, mix up mass and weight.
The GP converted from metric mass to metric weight/force (it would have been clearer to convert from metric mass to imperial weight, but where's the fun in that :>)
Re:How much does it weigh in space? (Score:3, Informative)
Typically though, the word pound refers to force, and the pound mass is sometimes referred to as a slug.
Re:What does it have to show for it ? (Score:5, Informative)
How much technology advancement really has happened and what scientific goals have been accomplished ?
That was all cut to save money. Sadly I'm not kidding. There is a short list here of scientific modules launched. Plenty more were budget cut or just simply won't be launched. The original plan had a hotel load around 2 people, which was fine since there would be like two dozen folks up there (hotel load is how much it takes to keep the place running and human habitable, from navy and submarine terminology). The problem is the life support equipment and "space lifeboat" never was launched, crew endlessly downsized, etc. So, since it only holds about 3 people on a regular basis, and the hotel load is always larger than originally planned, there isn't much time to do anything other than be space janitors / space superintendents. If they could have a staff of 20 up there as originally intended then quite a bit could have been done, but thats not happening.
http://en.wikipedia.org/wiki/International_Space_Station#Scientific_ISS_modules [wikipedia.org]
Part of the problem, as described below, is the only purpose of the shuttle, is to visit the station, and the only purpose of the station, is to be visited by the shuttle. So, since the station has already been downsized to the point of uselessness, and the shuttle is going away, guess what will happen to the station in just a few years?
http://en.wikipedia.org/wiki/International_Space_Station#Future_of_the_ISS [wikipedia.org]
Another part of the problem is the ISS was project managed as a one-time project or one-time stunt. Anyone who's ever spent time in a lab, in the military, or even in front of a computer, knows the original plan is obsolete as soon as it's written. Thats OK, invent a new plan. Except everything relating to ISS project management is a one time stunt. It's a permanent beta releast version 0.99 with no possibility of upgrade. There is no ability to do science if you can't iteratively experiment and try new ideas. And that's not how the ISS was project managed. Therefore it doesn't do science. It's a one time stunt and the stunt is about over.
Too bad, it could have been useful.
Re:How much does it weigh in space? (Score:3, Informative)
No, that is wrong. It is the MASS that is the same in orbit as on the surface of the Earth. The mass of an object is a measure of the amount of matter in it, and this does not change. The weight of an object, however, measures the force due to gravity that is acting upon it. The force of gravity is trying to accelerate you downwards towards the center of the earth, but the Earth's surface is holding you in place[*]. If you step on some scales, then you notice this by your body pushing down and registering a force on the scales. In freefall however, your weight is zero. You could think of it as the set of scales is accelerating at the same rate you are, so you cannot exert a force on it.
The second half, about falling 'around' the Earth, is basically correct. Another analogy is to think of whirling a rock on a piece of string around your head. The rock is going to tend to fly away from you, but it cannot because the tension in the string is holding it in a circle. If you replace the tension in the string with a gravitational attraction instead, then you get the same effect but without the string.
[*] To be more precise, unless you are in freefall, then you are standing on a solid object which is stopping you from accelerating - ie. the solid ground is exerting a force on your feet that exactly cancels out the gravitational force that is acting on your entire body, so overall you do not move, BUT the forces are being applied in different places. Gravity acts upon your entire body, trying to pull every atom in your body with equal force, but the restoring force of the ground that is stopping you from falling into the center of the Earth is acting only on your feet. Hence despite the fact that your overall motion is zero, you still feel a residual gravitational force acting on the rest of your body, so if you raise your arm, gravity is acting upon it and is pushing it back down. The Equivalence Principle states that gravity and acceleration are equivalent, so that the effect of accelerating in a rocket ship in free space at 9.81m/s^2 is precisely equivalent to being on the surface of the earth, so you would weigh the same in this situation. Conversely, if you are at freefall in the vicinity of Earth (and being in orbit is one example where you are in freefall), then you are, in effect, accelerating in such a way as to exactly cancel out the gravitational force and your weight is zero.