There has been alot of noise lately about the deflection of the asteroid Apophis in 2029 proposed by the Russian Space Agency as it passes by the Earth within 30,000 kilometers (18,641 miles). While this is a close shave by astronomical distances, experts claim Earth is in no danger.
But others say it’s “too close a shave”:
Apophis will first pass us at close range in just under 20 years. It may almost graze the Earth, missing by only 30,000 kilometres, less than the distance between Earth and the moon. At this point, astronomers have ruled out the possibility that it will hit us.
However, there is a very small chance that it will pass through a 600 metre-wide “gravitational keyhole” as it swings by. That would alter its course and cause it to slingshot back and hit the Earth in 2036. New NASA calculations released in October rate the chance of impact during the second pass at 1 in 250,000.
That still doesn’t sound terribly alarming, but as Dr. William Ailor, of California’s Aerospace Corporation, said Wednesday, “That’s a pretty high probability if you’re betting the planet.”
In April, Ailor chaired the biannual Planetary Defense Conference of the world’s leading asteroid experts.
“There are still issues around how great does the risk have to be before you start planning a (defence) mission like this. But ultimately, everyone agrees that we will have to do this sooner or later,” Ailor said.
Donald K. Yeomans, manager of NASA’s Near-Earth Object Program Office, says the time to make a decision on Apophis will be in late 2012 and early 2013, when it makes another close approach, within about 14 million kilometres of Earth.
“The additional optical and radar data taken then will almost certainly remove any possibility of an Earth collision in April 2036. To my mind it would make sense to wait until 2013, refine the orbit and in the very unlikely event that the impact probability increases, then begin planning possible deflection options,” Yeomans said.
“While Apophis is almost certainly not a problem, I am encouraged that the Russian science community is willing to study the various deflection options that would be available in the event of a future Earth-threatening encounter by an asteroid.”
A variety of deflection methods have been suggested in the past: gravitational tractors; landing a manned mission on Apophis; knocking it off target by ramming it or striking it with nuclear weapons. There is no broad consensus on what might work best.
“There’s also the question of how you design the `campaign’ to attack the asteroid. You’d probably have to launch multiple vehicles, in case some failed,” Ailor said.
Five years ago, Ailor said, the Aerospace Corp. ballparked the cost of such a mission at $80 billion (U.S.). NASA’s current annual budget is a little over $17 billion. Perminov, sounding less than expert on the grasp of details, got the year of impact wrong (2032), couldn’t cite the latest estimates accurately and seriously underestimated the potential cost. But he’s right about the risk.
Ailor points out that the 1908 asteroid that exploded over Tunguska in Siberia was only 30 metres across. It devastated more than 2,000 square kilometres of forest. Apophis is 270 metres in diameter.
What if it hit the Earth directly?
“That’d be a very bad day,” Ailor said.
“Probably not the end of all life as we know it. But a bad day.”
The exploration of asteroid meme has been pushed by the mainstream lately, given that the Augustine Commission review has stressed this as a new path to be taken by NASA, given the funding realities of the original Moon and Mars proposals in 2004 are unrealistic (note: the Flexible Path option that includes asteroid exploration requires a budget increase also).
The Apophis Project requires $80 billion to be pulled off. Surely an international effort, no?
I’m certain that the US would be the prime financial backer of the project however.
As this most probably is leading to this little tidbit of info…
However, another Heavy Lift vehicle came out of the blue in December, via an internal 65 page presentation on NASA’s overview (available on L2) of what it believes can be accomplished via the Flexible Path options, per Augustine Commission.
While the presentation is far-reaching on various mission outlines – including missions to Near Earth Objects (NEOs), GEO Space Telescopes, and manned missions to Mars (all of which will be reported in an upcoming article) – a monster 200 metric ton human rated “Exploration Class” launch vehicle is referenced several times.
“Exploration-Class Rocket: A human-rated system with LEO throw-mass on the order of 200 mt, designed purposely for extremely high reliability and minimum operations cost, rather than being sized directly by an architecture that may change later,” noted the presentation. “200 mt, sized by ‘knee in the curve’ of LV economics. Not driven by the architecture de jour.”
No specific designs are included in the presentation, with a Saturn V schematic shown next to the 200mt references. However, such a vehicle would likely to be a three stage Ares V type heavy lifter. How such a massive vehicle could be afforded is questionable.
For the interim, all eyes remain on the President, who – it is hoped – will show his willingness to help NASA achieve its goals via support for an increased budget.
A generic 200 mT heavy-lift launch vehicle, separate from the architecture that is destined to replace the space shuttle?
How is this to happen, given that the Program of Record, Constellation, is going to be revamped possibly by the cancellation of the Ares 1 rocket, and the Ares V reverting to a ‘Classic’ design that is more ‘shuttle-derived’ due to budgetary considerations?
As stated above, asteroid exploration (NEOs) is a huge part of the Flexible Path option being considered as NASA’s new directive and a 200 mT HLV would be a great tool to have.
Especially if the goal is to put vehicles on the surface of an asteroid in order to move it.
If this is the case, funding for such a beast would have to be international as part of the whole project.