The European Space Agency has approved a mission proposal to collide a space probe with an asteroid in order to study techniques to deflect any large asteroid found to be on a collision course with Earth.
On 9 July 2004, the Near-Earth Object Mission Advisory Panel recommended that ESA place a high priority on developing a mission to actually move an asteroid. The conclusion was based on the panel’s consideration of six near-Earth object mission studies submitted to the Agency in February 2003.
Of the six studies, three were space-based observatories for detecting NEOs and three were rendezvous missions. All addressed the growing realisation of the threat posed by Near-Earth Objects (NEOs) and proposed ways of detecting NEOs or discovering more about them from a close distance.
A panel of six experts, known as the Near-Earth Object Mission Advisory Panel (NEOMAP) assessed the proposals. Alan Harris, German Aerospace Centre (DLR), Berlin, and Chairman of NEOMAP, says, “The task has been very difficult because the goalposts have changed. When the studies were commissioned, the discovery business was in no way as advanced as it is now. Today, a number of organisations are building large telescopes on Earth that promise to find a very large percentage of the NEO population at even smaller sizes than visible today.”
As a result, the panel decided that ESA should leave detection to ground-based telescopes for the time being, until the share of the remaining population not visible from the ground becomes better known. The need for a space-based observatory will then be re-assessed. The panel placed its highest priority on rendezvous missions, and in particular, the Don Quijote mission concept. “If you think about the chain of events between detecting a hazardous object and doing something about it, there is one area in which we have no experience at all and that is in directly interacting with an asteroid, trying to alter its orbit,” explains Harris.
The Don Quijote mission concept will do this by using two spacecraft, Sancho and Hidalgo. Both are launched at the same time but Sancho takes a faster route. When it arrives at the target asteroid it will begin a seven-month campaign of observation and physical characterisation during which it will land penetrators and seismometers on the asteroid’s surface to understand its internal structure.
Sancho will then watch as Hidalgo arrives and smashes into the asteroid at very high speed. This will provide information about the behaviour of the internal structure of the asteroid during an impact event as well as excavating some of the interior for Sancho to observe. After the impact, Sancho and telescopes from Earth will monitor the asteroid to see how its orbit and rotation have been affected.
The FuturePundit reaction? Finally a space agency is trying to do something in space that may yield a huge benefit to the human race. We could all die from an asteroid impact and yet little is done to develop defenses against this potential threat. Meanwhile billions are spent every year on the Space Shuttle and International Space Station with little return in scientific knowledge, technological advance, or improved safety for humans down here on Earth. An asteroid detection and deflection system capable of preventing all major asteroid threats to human life offers a far greater potential benefit for humanity than the vast bulk of the programs funded by government space agencies.
"It is just to test a technique: can we change their orbits by running a kinetic energy impactor?" said Matt Genge, an asteroid expert at Imperial College, London.
"Can we change its orbit by less than a centimetre per second? If we ever find an asteroid that is on collision course with Earth, at some point in the future, whether it is 10 orbits away, or 20 orbits away, just giving it a small nudge will make it miss the Earth."
In the proposed mission one space probe would watch while another probe slammed into an asteroid.
Sancho would arrive first and orbit the asteroid for several months. It would deploy some penetrating probes to form a seismic network on the asteroid to examine its structure before and after its sister craft's smashing arrival.Hidalgo would crash into the asteroid at about 22,370 mph (10 kilometers per second).
NASA's Deep Impact mission to Comet Tempel 1 to slam into it on July 4, 2005 (creating fireworks that will be visible from Earth btw) bears some similarity to the ESA mission But while the Deep Impact mission will slam into Tempel 1 at a very simlar speed it does not appear aimed at gathering information about how to do asteroid deflection.
And how. The 770-pound (350-kilogram) probe will hit the comet at 22,300 miles (35, 885 kilometers) per hour and penetrate 16 to 32 feet (5 to 10 meters). Much, but not all of the probe will be vaporized.
Still, it seems likely that the Deep Impact mission will yield information useful for doing asteroid deflection.
For more on the subject of asteroid defenses see my previous post We Should Develop Defenses Against Large Asteroids.
|Share |||Randall Parker, 2004 July 16 12:06 PM Dangers Natural General|