NASA Tests Heaviest Chute Drop Ever 226
Iddo Genuth writes "NASA and the US Air Force have successfully tested a new super-chute system aimed at reclaiming reusable Ares booster rockets. On February 28, 2009 a 50,000-pound dummy rocket booster was dropped in the Arizona desert and slowed by a system of five parachutes before it crashed to the ground. The booster landed softly without any damage. This was possibly the heaviest parachute drop ever, and NASA is planning to perform even heavier drops of up to 90,000 pounds in the next few months."
Re:Cool - now how much ... (Score:1, Informative)
Well over 350,000 pounds Boeing 767 [wikipedia.org] so don't get any ideas.
Planes would probably break up as well. Great that you attached to the mid section but you'll probably loose either the front 3rd or the rear as the thin cabin torsions apart.
Re:Cool - now how much ... (Score:4, Informative)
Re:1 Question (Score:3, Informative)
Feet, miles and knot based units are the de facto standard in aerospace. The scientists
use SI units, the pilots do not. For a software I wrote I had to use SI units internally
and had to convert those values to feet/miles/knot based ones before passing them into a
pilot specific software. I work in germany (at the DLR if it matters).
Re:1 Question (Score:3, Informative)
An Imperial ton is 2000 lbs(pounds)
1 kg = 2.2 lbs
A metric tonne is therefore 2200 lbs
An Imperial ton is 20 cwt (hundredweight)
A hundredweight is 100 pounds
The US uses pounds because it sounds bigger IMHO
Original NASA press release (Score:4, Informative)
This is pretty old news. If you want up to date news from NASA, subscribe to the RSS feed [nasa.gov].
Re:1 Question (Score:4, Informative)
An Imperial ton is 2000 lbs(pounds)
An Imperial ton is 20 cwt (hundredweight)
A hundredweight is 100 pounds
The US uses pounds because it sounds bigger IMHO
In the US, maybe. In the UK:
An Imperial Ton is 2240 lbs
A Hundredweight is 112 lbs
Sounds like the US uses small measures because it seems like things weigh more/are bigger over there.
Same goes for pints/gallons.
US pint = 16 fl. oz. UK pint = 20 fl oz. No wonder your cars get so few miles/gallon. No wonder your petrol (sorry, gas) is so cheap.
Re:Only one chute (Score:2, Informative)
I'm curious about the engineering reasons for using one really big chute instead of a cluster of smaller ones as on the Apollo command module.
I might have read this wrong, but I read it as a 3 stage system, pilot chute to pull out the drogue, drogue chute, and then a cluster of 3 main chutes.
Re:1 Question (Score:3, Informative)
This is mandated by law. About 5-10 years ago, the courts ruled that pubs selling "pints" of beer could not use a pint glass -- the head reduced the amount of beer the patron was getting to less than the pint they paid for.
This worked out great for me, I picked up 60 or so nice pub pint glasses because so many pubs needed to replace their glasses with ones slightly bigger than a pint.
I'm not impressed yet. (Score:3, Informative)
Sixty years later, NASA manages an extra 10000- lbs. Wake me when they manage 100000 lbs.
Re:1 Question (Score:3, Informative)
England didn't start using the 20 floz pint until 1824. The previous 16 floz unit was defined as 1/8 of the British wine gallon -- about 231 cubic inches -- and had been since 1707. I'm not positive about the force/mass bit, but I'm pretty sure the same 1824 change made a hundredweight 8 stones, making it 112 lbs instead of 100 lbs used in the US or the previous 108 lbs.
Swing Wings (Score:1, Informative)
Swing wings proved to be a combination of too fragile, too prone to mechanical failures, and too much weight to be practical or efficient or economical enough.
In simple terms: a Rube Goldberg contraption.
Re:to hell with parchutes (Score:3, Informative)
They aren't as viable as you might think because flyback stages are expensive to build, expensive to operate and are maintenance intensive.
Not entirely true actually... While they are the heaviest, the generally aren't the most expensive. When it comes to spacecraft, cost varies strongly with complexity and only weakly (if at all) with mass. Generally speaking, the higher you go in a vehicle the more complex the engineering and manufacturing gets because it endures more extreme environments and because the impact of any excess weight grows disproportionately. A pound in the Nth stage is a problem because it is carried all the way to orbit - while a pound in the 1st stage can end up being lost in the noise.
Less than you might think, and frequently it can cost money rather than saving it because of the need to provide landing and refurbishment facilities which a throwaway first stage does not require. This means higher up front costs in engineering the flyback booster and building those facilities, as well as higher ongoing costs.
They key to problem, as always, is flight rate - the more you fly a vehicle, the less it costs. But to make a vehicle that flies often, you need to make it bigger and attractive to a wider variety of customers... Which is one of the key compromises lead to many of the Shuttle's problems.
Re:Cool - now how much ... (Score:3, Informative)
you're saying that planes mostly crash when they meet the ground?
Well all crashes involve the ground (or the water) at some point sure but the question then becomes why they meet the ground (or the water).
Sometimes the pilot is deliberately interacting with the ground (takeoff and landing) but something goes wrong in the interaction
Sometimes the pilot doesn't realise the ground is there (say due to a navigation error or instrument) and therefore hits it even though they still have control over the aircraft.
Sometimes something goes wrong in flight that renders the plane unable to recover sufficiantly to land safely (what is sufficiant recovery to land safely depends to a huge extent on where the incident happened).
A parachute would only help in the last of theese cases (and probablly only a subset of those, a 747 parachuting down in an urban setting would probablly do quite some damage to both itself and what it landed on). The GP is asserting that such cases are a minority of accidents.
Re:Astroid Net? (Score:2, Informative)
there had to be quite a few detonations to get the (small) craft moving anywhere at speed. A single blast won't do it.
now my quote from the wikipedia article on the machine you're talking about
The smallest 4000 ton model planned for ground launch from Jackass Flats, Nevada had each blast add 30 mph (50 km/h) to the craft's velocity.
If you call a 4000 spaceship small, i don't want to know what would be big for you.... As a side note, you're somewhat right, as the nukes had a built in reaction mass that "pushed" the ship. But the part about "blast chambers of precise dimensions" is a bit off too, a huge plain shield of a special material isn't a blast chamber and doesn't have precise dimensions at all (it just has to be huge enough to protect the ship).
Re:Astroid Net? (Score:3, Informative)
Impact energy is roughly proportional to the diameter cubed (volume or mass). All of those tiny asteroids that hit every day just do not add up to all that much. The damage to the earth's biosphere will be roughly proportional to the energy transferred which actually makes a water impact worse than a land impact unless you happen to be under it. For civilization, either can be catastrophic just because of weather effects. An impact like the one in Arizona is small on this scale although no doubt bad for the locals.