Planetary Society - Asteroid Tagging Competition

[Astronuc]

Planetary Society Names Winners of $50,000 Asteroid Tagging Competition
http://www.planetarysociety.org/about/press/releases/2008/0226_Planetary_Society_Names_Winners_of.html

Pasadena, CA, —How do you tag and track an asteroid that might be on a collision course with Earth? The first place winners of The Planetary Society's $50,000 Apophis Mission Design Competition presented their innovative solutions at a press conference today in Pasadena, California.

First place went to the team led by SpaceWorks Engineering, Inc. of Atlanta, Georgia in conjunction with SpaceDev, Inc., Poway, California for their mission, entitled Foresight. Mark G. Schaffer served as Principal Investigator. The Foresight team takes home $25,000 in prize money.

The Georgia Institute of Technology, also coincidentally in Atlanta, Georgia, took first place in the student category, winning $5,000. Jonathan Sharma, a student in the Daniel Guggenheim School of Aerospace Engineering, was Principal Investigator for a mission design entitled Pharos.
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NASA and the European Space Agency (ESA) co-sponsored The Planetary Society’s competition and will review the best mission designs offered. The winning designs will also be presented by The Planetary Society to other world space agencies.

The near-Earth asteroid, Apophis, was used as the target for the mission design because it will come closer to Earth in 2029 than the orbit of our geostationary satellites. (That’s close enough to be visible to the naked eye.) If it passes through a small “keyhole” as it travels by Earth, its trajectory could be diverted so that it will impact Earth in 2036. Current estimates do rate the probability of such an impact as very low.

To keep mission costs low, the winning design, Foresight, proposes a simple orbiter with only two instruments and a radio beacon at a cost of $137.2 million. The spacecraft would launch aboard a Minotaur IV, leaving Earth sometime between 2012 and 2014, to arrive at Apophis five to ten months later. It would then rendezvous with, observe, and track the asteroid.
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In continuing coverage from yesterday's briefing, the AP (2/27) reports on the results of the Planetary Society's Apophis Mission Design Competition, which "sought plans for tracking an asteroid so accurately that governments would know whether they needed to deploy some type of mission to deflect it." The competition judged "37 proposals from 20 countries." The AP adds, "The competition was named after the asteroid Apophis, which will come near Earth in 2029."

MSNBC (2/27) adds that Apophis "is currently given a 1-in-45,000 chance of hitting Earth on April 13, 2036." However, "scientists say that they can't yet eliminate the threat entirely because they don't know Apophis' orbit precisely enough." It is possible Apophis could "pass through a small 'keyhole' in outer space" during its next pass by Earth, which would "put it on a path to impact [Earth] on its next pass." MSNBC notes, "The top prize...went to the Foresight team, led by Atlanta-based SpaceWorks Engineering in conjunction with California-based SpaceDev," for their "Foresight" project. The first prize in the student category "went to the Georgia Institute of Technology," where students designed a mission "entitled Pharos."

New Scientist (2/27, Shiga) explains that "Foresight...would put a small spacecraft in orbit around Apophis, where it would send pictures, and" use laser pulses and radio signals to determine the asteroid's trajectory "with an uncertainty of less than seven kilometers." This was half of the competition's required uncertainty of 14 kilometers, judged to be the smallest uncertainty useful for "determin[ing] whether there is a significant chance of a 2036 impact without intervention." Runners up included Spanish company Deimos Space, whose project included a radiometer to "measure heat radiation from the asteroid, which can subtly influence its trajectory," as well as EADS Astruim's APEX (Apophis Explorer) project. New Scientist points out that "NASA has previously said it would not consider mounting a deflection mission until the risk posed by Apophis was better understood." ESA, however, "developing a mission called Don Quijote, which will hit another asteroid with a spacecraft to see if the impact changes the asteroid's trajectory.'

The BBC (2/27, Rincon) notes that, according to advocates of asteroid projects such as these, "Apophis' orbit would need to be changed before 2025 to be sure it misses the Earth." If it did impact Earth, according to NASA estimates, the asteroid "would explode with as much energy as 400 megatons of TNT."

I'm sure this will make the news periodically over the next 21 years.