As a active supporter of commercial space efforts both within NASA and outside of NASA, as well as a someone who's paying job involves the unmanned Mars program, I will be the first to say that private spaceflight does not negate the importance of publicly supported exploration - they complement each other.

Government's job, in my opinion, is to do those things that private industry can't -- thinks that don't necessarily return an immediate profit (or shouldn't) but are nonetheless good or necessary for our society. For the space program, this means the 'Lewis and Clark' role, where the government funds a risky venture for the benefit of us all, leaving the infrastructure and knowledge for its citizens to follow.

Right now we're at a point where the government has demonstrated the abilities and technology required to get satellites and people to low Earth orbit. Most satellites, except those of actual use to other government agencies, have transitioned to private industry, which has worked hard to drive down prices and increase reliability. Now its time for the government to at least get out of the way, and hopefully help bootstrap (through COTS) the same transformation in manned flight. If there is no profit to be had, then we need to reconsider things, but apparently enough companies think that there is that we should let them have a chance.

Nonetheless, beyond Earth orbit is not there yet. There is not yet an obvious impetus for private individuals and companies to explore Mars or other planets, yet I think most of us (here at least) recognize that it is in the long-term interest of our society. Therefor this is the proper role of government, and something that should be supported -- especially since in the grand scheme of the US Federal Budget, NASA represents a few crumbs.

My hope is, though, that improvements in access to LEO encouraged by private development will truly complement the government programs, and allow the us to do more with the same amount of money.

Actually it does.

The second aspect of my statement focuses particularly on non-gravitational forces on the asteroid, which would not be measured by a free-floating beacon.

Understanding the effects for a small asteroid could inform our understanding of how larger asteroids would behave as well, thus serving to help us better predict contintent-killers like Apophis.

Of course, I'd much rather bring them in closer and mine them, but that would be more difficult, so tracking would probably happen first (and be good practice for eventual capture missions).

As far as allocation of resources go, that really depends. I'd have to see detailed studies on what a mission like this would cost.

Actually, trajectories of small bodies like that are quite interesting. Two things stand out to me (I did some of my graduate work looking at missions to small-ish asteroids like Apophis which is ~300 meters, so bigger than this but smaller than large asteroids).

1. If this is loosely captured by Earth with multi-month orbits it is on the edges of the Earth's sphere of influence where the Earth and the Sun's gravity really interplay in weird ways and small uncertainties in its current state could turn into huge uncertainties later.

2. For a very small asteroid, the surface-area-to-mass ratio is very high, meaning effects of solar pressure and the Yarkovsky effect will cause it to behave very differently. The ability to track an asteroid like this could greatly inform models of these effects.

If you could find many of these and have a spacecraft able to rendezvous and deposit a tracker on new ones as we find them, it could greatly benefit studies of near-Earth objects. Of course, a mission to do that sounds extremely challenging (but very interesting to work on).

Oops. $400M for GRAIL. If it were $400B you might have a better point.

The GRAIL mission costs ~$400B. The NASA budget is ~$17B/year.

If you could fix the economy/budget problems with that amount of money in a politically viable way, GO TELL SOMEONE! Seriously... thats chump change in terms of the federal budget.

My renters insurance and at least specifies that it covers damage from 'aircraft and spacecraft'.

So... possibly yes?

I'm not sure I follow. While NASA is certainly having issues, none of the other programs are particularly stronger.

Russia: Riding the coat-tails of good design decisions many years ago (not that there's anything wrong with that, I wish we had a Soyuz-like design). Soyuz is simple and reliable and they can just keep on flying them without significant development costs. However, as indicated by their recent Mars probe their new development efforts have unfortunately decayed -- GRUNT suffered from not enough money to support decent redundancy and contingency planning.

Chinese: New and developing, and building on Soviet technology. I hope their efforts will be strong and civil-focused, even after the geo-political advantages fade, but in anything but currently being able to reproduce Soviet results with plenty of money, there's nothing I'm too worried about.

Europeans: Here's where you lost me. If your criteria was 'currently being able to fly people' then I could understand (but disagree), but the ESA is essentially a peer to the science mission directorate at NASA, with no manned capability. Considering EU budgets are even more problematic than the US budget I wouldn't say that their taking the lead, though I hope they remain valuable partners.

Personally, I'm tired of all the negativity about the NASA right now. Its been a rough few years, with no one in charge having enough sense to put NASA's manned program on a sustainable course. Now though, even with this SLS nonsense, we're finally on a path to develop robust access capabilities with multiple capsules on multiple launch vehicles. The unmanned programs are shining brightly still, with 3 launches, a comet flyby, the first vehicle in orbit of an asteroid, and the first spacecraft arriving at Mercury this year. We've continued to find more and stronger evidence of water on Mars, and have found ever-more Earth-like exo-planets. Not too shabby for one year.

Is anyone arguing with that? I'm a commercial space proponent and I work on NASA-funded planetary science missions.

The commercial space community states explicitly that NASA should be performing the "Lewis and Clark" job -- in fact thats the exact phrase we use. However, rides to orbit are no longer cutting edge technology, and have a proven opportunity for profit, and this is why we call for the government to stop insisting on its own launchers and use commercially available ones wherever possible, and to foster a market where it is possible to form one.

In planetary science we actively support this model, since Juno, MSL and GRAIL (the three recently launched missions) all launched on commercially purchased launch vehicles (though ULA is a bit of a monopoly so its not the healthiest commercial market).

Its not a replacement for all rockets. Its a replacement for giant rockets that are required to get huge payloads with lots of fuel to space.

The Apollo capsule could have launched easily on many of our current launch vehicles (it was tested on the Saturn I). It was the fuel required to inject towards the moon that required the huge Saturn V.