Apophis Tracking Mission Options

[tty]

an atmospheric graze would be fine

I'd rather not. It could break up and some of the pieces might impact. It might even go bang like the Tunguska body though that's unlikely (probably not enough volatiles). Also the IR radiation from an atmospheric graze is fierce. A small body like Apophis would not be too bad, but a graze from a kilometer-size object can incinerate half a continent.

[Thu]

Finally, I'm done!

Just submitted the Apophis mission proposal to The Planetary Society. Anybody has an interest can see my proposal from here http://rapidshare.com/files/52591111/Apoph...rsion_.pdf.html

Wish me luck

[nprev]

Congrats on your proposal, Thu! Unfortunately, I got kind of lost in the pay-me portion of your document hosting service; can you perhaps post a more direct link?

TTY: Do you have any data for the IR effects of a graze? I and many others experienced a very small one (many, many orders of magnitude smaller than Apophis) on Aug 10, 1972. There was no detectable heat, but one hell of a double sonic boom: http://www.youtube.com/watch?v=vBu-yUzWXqg

[Paolo]

Finally, I'm done!

Just submitted the Apophis mission proposal to The Planetary Society. Anybody has an interest can see my proposal from here http://rapidshare.com/files/52591111/Apoph...rsion_.pdf.html

Wish me luck

Great job! I had seen other proposals, but yours until now is the most complete and professional-looking!

[nprev]

Sorry, Thu; I was stuck in stupid mode all day yesterday. Got it downloaded, and it does indeed look terrific; you certainly did your research, and it's incredibly detailed. I hope that your proposal wins, you deserve it!!!

[Phil Stooke]

tty said: "Also the IR radiation from an atmospheric graze is fierce. A small body like Apophis would not be too bad, but a graze from a kilometer-size object can incinerate half a continent."


Can you put any numbers to that? I would think that the flyby would be brief enough that the problem is less severe than you suggest, but the numbers could prove me wrong (as usually happens).

Phil

[tty]

TTY: Do you have any data for the IR effects of a graze?

www.lpi.usra.edu/meetings/impact2000/pdf/3103.pdf


You have to consider that the stagnation temperature for a typical meteorite is actually higher than the the surface of the Sun. Try to visualize a bit of the sun about a kilometer across passing maybe 50 km overhead and staying in sight for perhaps 20 seconds....

[Thu]

Thank you nprev and Paolo for your praise. Initially I planned to design a very simple but a little "dumb" s/c that would carry a lot of chaff (as those used in many fighter aircrafts) and spray over Apophis. That would effectively "paint" the asteroid with radar reflecting material and make it more detectable with radar. But later with more research, this approach turned out to be totally wrong but I still kept the idea of designing the s/c small and simple, but not too dumb like before

[ngunn]

Thu, I enjoyed reading your proposal, which seems full of sensible ideas. Having made a small contribution to the Planetary Society's prize fund I am very interested in the progress of the project. I haven't heard much about how it's going so far. Perhaps Emily can tell us how many submissions have been received to date?

[nprev]

Initially I planned to design a very simple but a little "dump" s/c that would carry a lot of chaff (as those used in many fighter aircrafts) and spray over Apophis. That would effectively "paint" the asteroid with radar reflecting material and make it more detectable with radar.

Interesting idea, but you're right. Not only would that have been horrendously complex in terms of mechanics, but just getting stuff to stick on Apophis would be a major challenge...

Your ranging technique is sound. Thinking in terms of passive backups here (like those that might be desirable in the event of premature EOM), what if the vehicle bus was designed for the best possible radar reflectivity? I doubt if this could add enough to do better ground-based reads during periapsis passes (your LIDAR data was sobering indeed), but perhaps it's still worth a quick thought; maybe it would!

[elakdawalla]

Perhaps Emily can tell us how many submissions have been received to date?

I'm afraid I don't know the number any more exactly than "quite a few." I'll probably be the one posting the next project update, though, so I'll make sure to mention it here when that happens.

--Emily

[ngunn]

That would be great, thanks Emily. I'm glad quite a few people have risen to the challenge and I look forward to reading the update.

[Thu]

Thinking in terms of passive backups here (like those that might be desirable in the event of premature EOM), what if the vehicle bus was designed for the best possible radar reflectivity? I doubt if this could add enough to do better ground-based reads during periapsis passes (your LIDAR data was sobering indeed), but perhaps it's still worth a quick thought; maybe it would!

@nprev, since the idea is only good for periapsis passes which unfortunately happen only once in Jan-2013 during the period till 2017 mentioned in the mission design competition rules.

However, looking further I agree that this is a good idea and it worths a more detailed analysis if we are to send a s/c to Apophis.

[Thu]

A quick update for anybody interested in the Apophis mission design competition by TPS, the judging is going to be a little longer and the current plan calls for an announcement in January 2008. More detail here http://planetarydefense.blogspot.com/2007/...-planetary.html

By the way, based on my proposal Brian Jones from London, UK had made a beautiful animation of the ART s/c mission to Apophis which I uploaded to YouTube http://www.youtube.com/watch?v=mLp3JtrbJsM
May be next time I'll ask for his cooperation in visualizing space missions

[nprev]

Great video, Thu!!! You're rapidly becoming the center of a small-business version of NASA...keep up the terrific work! Will you also submit this vid as part of your proposal package to TPS? I would; it's most compelling.