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ESA Plans Test of Asteroid Defense System
vinlud writes "It has been announced by Dutch television ESA has chosen the Don Quijote programme to investigate the possibilities of altering the collision course of asteroids heading for Earth. The program, selected among five other studies, contains two spacecraft: Hidalgo and Sancho. Hidalgo will impact an asteroid of approximately 500 m diameter at a relative speed of at least 10 km/s while Sancho will retreat to a safe distance to observe the impact. An animation of the mission sequence (6.49 Mb) can be downloaded from here."
Better link, maybe?
Beware: In C++, your friends can see your privates!
Perhaps the most famous part of this book is when Don Quixote gallantly charged at windmills, while Sancho watched. In his troubled mind, The windmills were evil Giants, which he sought to destroy to win the favors of his sweethart Dulcinea, wich is a very accurate depiction of what the program is supposed to do.
I find that the depiction, regardless of the obvious fact that in the book it was a hopeless cause; is a romantic metaphore, rather than an endorsement of failure, poor engineering or idealistic but unreachable goals.
As a side note, this book (El ingenioso Hidalgo, Don Quixote de la Mancha) is to the Spanish Language as The Count of Montecristo is to French, Luther's New testament translation is to German, and the works of Shakespeare are to English.
*shower*
Ha Hah!
Show me on the doll where his noodly appendage touched you.
The mission has a very high scientific value, but it will also help in testing technologies required for future deflection missions and raise interest in people for space exploration. The mission will in particular: measure the mass of the asteroid, the ratio of the moments of inertia and the low order harmonics of its gravity field. model the asteroid shape before and after the impact, to detect changes (if any). determine the asteroid internal structure, especially the size the main solid pieces, the average particle size and thickness of regolith and of the debris layers in the space left between the main pieces. constrain the mechanical properties of the asteroid material. measure the orbital deflection of the asteroid as a result of the impact of Hidalgo measure the asteroid rotation state before and immediately after the impact. detect the dissipation of the non-principal axis rotation after the impact. determine the asteroid large scale mineralogical composition.
SHE does throw dice.
Assuming that the Hildalgo probe masses in at 25 kg (the same as Sancho - it might be less) and is moving at 10km/sec
Summing the mass of the instruments won't give you the mass of the whole spacecraft! You neglect the frame, rockets, fuel, fuel containers...
From the executive summary pdf:
Sancho's "final injected mass" 394.0 kg
Hildalgo's "final injected mass" 379.1 kg
Hildalgo's relative arrival velocity: 13.437 km/s
I missed that - thanks! Using the new mass (rounding out to 400 kg gives us 1x10^-7 km/sec. The new velocity would make a slight improvement - 1.3*10^-7 km/sec or 1.3x10^-4 m/sec It's still really small.
This sig seemed like a good idea at the time....
Wouldn't that be "In Soviet Russia, you blow the cataclysm to smitherenes!"
Albuquerque PC
Impact Effects Robert Marcus, H. Jay Melosh, and Gareth Collins
Your Inputs:
Distance from Impact: 100.00 km = 62.10 miles
Projectile Diameter: 500.00 m = 1640.00 ft = 0.31 miles
Projectile Density: 3000 kg/m3
Impact Velocity: 10.00 km/s = 6.21 miles/s
Impact Angle: 45 degrees
Target Density: 3000 kg/m3
Target Type: Competent Rock or saturated soil
Major Global Changes:
The Earth is not strongly disturbed by the impact and remains intact.
The impact does not make a noticeable change in the Earth's rotation period or the tilt of its axis.
The impact does not shift the Earth's orbit noticeably.
Energy: 9.82 x 1018 Joules = 2.35 x 10^3 MegaTons TNT
The average interval between impacts of this size somewhere on Earth is 4.3 x 10^4 years
Crater Size:
Transient Crater Diameter: 4.59 km = 2.85 miles
Final Crater Diameter: 5.63 km = 3.50 miles
The crater formed is a complex crater.
Thermal Radiation: Time for maximum radiation: 0.43 seconds after impact
Visible fireball radius: 3.5 km = 2.2 miles
The fireball appears 7.9 times larger than the sun
Thermal Exposure: 3.60 x 104 Joules/m2
Duration of Irradiation: 6 seconds
Radiant flux (relative to the sun): 6.5
Seismic Effects:
The major seismic shaking will arrive at approximately 20.0 seconds.
Richter Scale Magnitude: 6.9
Mercalli Scale Intensity at a distance of 100 km:
VI. Felt by all. Many frightened and run outdoors. Persons walk unsteadily. Windows, dishes, glassware broken. Knickknacks, books, etc., off shelves. Pictures off walls. Furniture moved or overturned. Weak plaster and masonry D cracked. Small bells ring (church, school). Trees, bushes shaken (visibly, or heard to rustle).
VII. Difficult to stand. Noticed by drivers of motor cars. Hanging objects quiver. Furniture broken. Damage to masonry D, including cracks. Weak chimneys broken at roof line. Fall of plaster, loose bricks, stones, tiles, cornices (also unbraced parapets and architectural ornaments). Some cracks in masonry C. Waves on ponds; water turbid with mud. Small slides and caving in along sand or gravel banks. Large bells ring. Concrete irrigation ditches damaged.
Masonry C. Ordinary workmanship and mortar; no extreme weaknesses like failing to tie in at corners, but neither reinforced nor designed against horizontal forces.
Masonry D. Weak materials, such as adobe; poor mortar; low standards of workmanship; weak horizontally.
Ejecta: The ejecta will arrive approximately 144.2 seconds after the impact.
At your position the ejecta arrives in scattered fragments
Average Ejecta Thickness: 4.6 mm = 0.1822 inches
Mean Fragment Diameter: 3.5 cm = 1.37 inches
Air Blast:
The air blast will arrive at approximately 333.3 seconds.
Peak Overpressure: 19232.2 Pa = 0.1923 bars = 2.7310 psi
Max wind velocity: 38.2 m/s = 85.4 mph
Sound Intensity: 86 dB (Loud as heavy traffic)
So let's see - you're 100 km away - first you experience a 6.9 earthquake, and the red hot 4.6mm fragments arrive 144 seconds later? Great - that's like 250 km per hour... Nice. Anyone in the open is DEAD, and your house might not survive that either. Then after being weakened by a major earthquake and a barrage of highspeed rocks, an 86 mph wind comes to visit.
Great. Sounds pretty crappy to me. I doubt that it would be the end of the world (Except for LA, but who cares?) but I think that even a smallish rock like that would produce some MAJOR damage, and should be avoided at all costs - alomst as much as voting for GW should be avoided.
RS
Shoes for Industry. Shoes for the Dead.
Disintegrate? Where the hell did you get THAT idea from? "Course collection" is what this thing IS doing, it's not Bruce Willis with nuclear bomb.
You don't have much of a change disintegrating 500m asteroid by hitting it with a probe weighting few hundred kilos unless you're doing the ramming at relativistic speeds.