Video shot from the Space Shuttle during launch
io9.com
io9.com
Here's what I would have expected: numbers increasing at a relatively constant rate until separation, then a rapid decrease to zero (and since 1mph ~~ .5m/s, expected decrease at about 20mph/s), then increasing again (maybe with a negative sign) until atmosphere, then a decrease to terminal velocity, then another big decrease when the chutes blow.
So aside from the fact that there is no direction (not even a minus sign), so it's at best a speed counter, there still is something I really don't understand about that number. But... what?
(Edit: fixed dumb math error)
This gives you an idea of the arc:
http://media.tcpalm.com/media/img/photos/2010/04/05/0406_LOC...
You're right about the rest -- a decrease to terminal velocity and then a big decrease as the chutes take effect.
They take some time to completely expand. They're actually deployed in a constricted ("reefed") configuration, and then after several seconds they're allowed to fully open.
They're also trying to slow down a large piece of metal -- the booster rockets are about 150 feet long and weigh about 200,000 pounds (empty weight) each. The chutes produce a lot of force, but they're pulling on a lot of mass too (acceleration = force/mass.)
See also: http://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Boos...
It would be amazing to hear an AMA fron the booster recovery team.
What is the housing that holds these cameras? What type of camera are they and how to they capture and store footage? Are they PTZ?
Edit: If you meant prior to re-entry of Earth's atmosphere, the force of gravity is changing the objects course, thereby affecting acceleration, speed, velocity, etc
this doesnt make sense to me. On the orbit they look like they gaining a distance between each other. Any distance on that altitude would be 150-fold back on earth. How come they landed less than 20m from each other, no idea. Anyone?
I can't since they DID travel through the atmosphere.
Interesting reading here on the details of the booster rockets: http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/s...
Still, though, I feel like I would be hard-pressed to throw two objects from space and have them land within sight of each other.
It was interesting to watch how they gained speed on the orbit while being sucked by Earth gravity, and then quickly hit the breaks when atmosphere/air got thicker... awesome! Must be amazing feeling, given you would have 3000mph-withstand material, to actually "drop" yourself from space to Earth :)
Sort of makes me wonder how much of the sound in that video was real. I really want to believe that's what space sounds like. :)
Edit: Oh, I guess that's his son! A splendid lineage.
Lockheed designed the tank with insulation outside the main shell, and it's never held together very well. I've spoken to retired engineers from another company who designed a competing tank with internal insulation; they're still upset their version didn't get picked. I've never heard a clear explanation as to the specific reasoning for Lockheed or NASA's decisions.
Of particular note, the Columbia disaster was caused by one of those foam pieces breaking off during takeoff and damaging the thermal protective tiles on the shuttle's wing. During re-entry, the edge of the wings reaches a temperature of around 3000 F; damage to the protective tiles basically allowed hot air to burn through the wing.
No thanks!
If we want to keep the maximum acceleration beneath 4g's or so, so that it's uncomfortable in the roller-coaster-thrill-ride sense, not in the 'crap I'm going to die' sense, we'd still need a trebuchet of radius 50,000 m. Even the LHC isn't that long across. :P
I mean, you can in principle get those sorts of speeds, but don't expect a human to easily survive it.
One of the reasons the Concorde never really succeeded was due to the nature of faster than sound travel. A sonic boom doesn't just happen as you pass the sound barrier, but rather trails behind an aircraft the entire time it is traveling over that critical speed. This resulted in the Concorde only being able to travel faster than the speed of sound when it was over water (hence it's primary use for travel between New York and Paris or London).
But what if you could travel where there is no air?
Suborbital space flight means that any place on the globe is a 2 hour flight away. This will happen, and I am confident that I will travel in space before I die.
Suborbital space flight means any place on the globe is a 2 hour flight away, but the fuel costs are pretty high. I expect such a service to one day exist, but I don't expect to be able to afford it.
If we could do it with purely electrical motors, then assuming you pay 10 cents per kilowatt hour and only have a conversion efficiency of 75% into actual lifting power, it would only cost you $0.04/kg energy-wise to get up there. Assuming that you'd need to take an environment of, say, 10,000 kg with you, the marginal cost would still only be about $400. That's something of an ideal case, the "space elevator" proposal. Actually there might even be a possibility to use counterweights somehow to make it even cheaper.
Solid rocket fuel, the numbers are a little harder to come by. It sounds like the active ingredient is usually aluminum. One page on Wikipedia suggests that aluminum has an energy density of 31 MJ/kg (and my calculations based on Wikipedia's "aluminum oxide" page agree) and that only 16% of solid rocket fuel is aluminum. So that's 5 MJ/kg. However, this is a little smaller because it basically needs to push itself up along with you -- it's 1 MJ/kg to bring anything up to space, remember, so 1 kg can lift roughly 5 kg of stuff, but the 1kg of fuel is itself part of that 5 kg. So we're at roughly 4 MJ/kg if you take into account that the fuel more or less has to push its own way up with you. (Not all the way, of course, but I'm too lazy to do the calculation properly and there's wind resistance anyway.)
The first rocketry site on Google says that they'll sell you 20 pounds of rocket fuel (9 kg) for something like 200 bucks, or $22/kg. With the conversion factor of 4 kg lifted / kg fuel, the equivalent number is about 550 times higher -- $5.50 per kg that you want to send into space, and the marginal cost for our 10,000 kg environment is presumably then something like $55,000.
Can we do better by bulk? Google says people sell the main ingredient -- ammonium perchlorate -- at $3,000 per metric ton. Aluminum is a bit pricier, but I can find people selling large chunks at about $500/50kg, adding about $1,500 to the above. Adding in the cost of the plastic binding, the raw fuel components might cost $5/kg. So you're not going to get cheaper with rocket fuel than around $15,000 per flight.
Of course, the spacecraft is going to be the more expensive bit, I'm sure. But that's more complicated because maybe you can amortize that cost over many successful runs. I'm just saying that, even without that, based on fuel alone, it's still going to be an order of magnitude more expensive than a trip to a far-off land. If we had a space elevator we could fix that, maybe -- but not without a massive cord going from us to outer space.
I will add that you can make these numbers cheaper if you don't go into the 'official' outer space region, but just content yourself to fly really high up. People who fly weather balloons can get them to a height where you'd need closer to 0.3 MJ/kg to get to, so you could divide those costs by ~3.
Here is a link to one group that is trying to solve the problem of cheap amateur rocket flights to space: http://www.copenhagensuborbitals.com/
We should build a space colony.