Remember though, Juno is not an imaging mission. Its only camera is there for outreach purposes, will die a quick death once it gets into orbit because of the radiation environment, and thus they didn't spend much money on it.

Juno's mission is to map the gravity field, radiation environment, and magnetic field. It's a (relatively) low-cost mission with a focused science goal, and is thus quite different from a mission like Galileo which produced stunning images of Jupiter and its moons. Similarly, any images we get from the upcoming GRAIL or MAVEN missions will be similarly disappointing. We've got lots of pictures, so new missions are focused on data that is just as useful but less pretty -- at least for the Moon, Mars, and Jupiter.

That's probably because it doesn't have a particularly good camera. We've got lots of good pictures from Galileo -- the purpose of this mission is to map the gravity, magnetic and radiation fields. The mission is power-starved and in a really nightmarish radiation environment, so the only camera is intended solely for outreach purposes, and that one won't last long (7 orbits) within that radiation.

Remember this is not a flagship mission, meant to do anything and everything. It's a relatively cheap mission selected through a competitive process, and thus is highly focused on its particular science goals.

The thing about space (besides that its big) is that it makes almost everything harder. Every spacecraft is power starved, so simply adding power is not usually a possibility -- the key is going to be getting a higher data rate for the same amount of energy, mass and operational complexity compared to radio comm.

Even more importantly: high powered lasers put off a lot of heat. On Earth, we've gotten pretty good at disposing of heat -- convection or conduction work great. Unfortunately, in space, you can only radiate the heat away -- thermal management of a spacecraft is a surprisingly difficult proposition. A high-powered laser makes thermal management all the more difficult, and you'll notice that lasers in space are in fact quite rare for that reason.

This is why an engineering demonstration is important -- it helps us work out these issues without risking a $400M Mars mission. I'm working on the next orbiter (MAVEN) right now, and our job would be much easier if we had laser comms to transmit back a lot of the telemetry we'd like to get.

Bandwidth is an issue. Telemetry is extremely tightly budgeted on a mission like this, and being able to get more back would vastly increase the available science data as well as simplify operations.

And a high-powered laser is not a trivial task. First, all the power comes from solar cells, which are themselves heavy and they try to keep them minimized. Second, when you're pumping a lot of energy through a laser, you end up with a lot of heat that is difficult to discard. You can't bleed it off through convection or conduction, so you have to rely on radiators for everything and those get big and heavy too. This tech development project is incredibly important for trying to work out these kinds of issues.

Now, if you can find a way around the latency issues I'm all ears.

I like SpaceX as much as the next guy, but there's more to the puzzle. Orbital Sciences, Boeing's CST-100, Sierra Nevada's DreamChaser, ESA's and JAXA's resupply vehicles, and even Orion-reborn (to name a few) are all critical to maintaining a foothold on the frontier.

I think what this should teach us (potentially having our only way to get things and people to the ISS grounded) is that no single solution can be depended on. In addition to the sought cost benefits of competition, we need multiple vehicles because none of them will be perfectly reliable and all run a risk of being taken out of service temporarily and leaving a gap if nothing else is available.

ISS, CCDEV, COTS, SLS. There's more to human spaceflight than the space shuttle.

As Alan Stern pointed out on NASA Watch earlier today, this is a very dangerous move for the space science community.

The science program has worked hard to put up firewalls to prevent the manned program from raiding them for funding when the going gets tough. By breaking that firewall in the opposite direction it opens the science directorate to future funding losses when things get bad on the manned side, (as they are sure to when the already obvious failures of SLS come calling).

Between these two massive programs whose budgets keep growing I fear for the interesting smaller programs on boh the manned and unmanned sides...

Are you saying that the diffraction effects allow one to determine source altitude? Azimuth I would imagine is easily distinguishable from using the ears as mere point sensors, as I mentioned in a sibling post.

Very interesting. (not saying that sarcastically).

Easily justified by the presence of a priori information. You know what an airplane sounds like and that unless you're at an airport, one would hope that it's in the air.

Simply put, humans are incredible sensor platforms, able to synthesize information from both simple and complex sources. Nonetheless, your ears are essentially two point sensors, so while you can distinguish quite a bit by hearing alone, azimuth by differencing the volume to each ear (of course there's a front-to-back ambiguity), distance by expected volume, and change in distance by Doppler shifts, you're still limited by basic physics. Of course if you're needing to distinguish up and down locations by sound alone, you can always cock your head and get quite a bit more that way.

Of course, I'm no expert in biology -- I'm more interested in sensor systems, thus my tendency to analyze human senses in those terms.

I would venture that the 2d limitations of natural human sonar have more to do with the fact that our ears are in a horizontal plane and thus can't distinguish up/down variations. Except in special circumstances, the air through which the sound is travelling is not going to be stratified enough to make a difference.

Given that, this is likely to sidestep that limitation, since it appears far more directional, and mounted on a hand, which is more natural to tilt than ones head.

The problem is that the only way to be 100% sure (or even 10% sure) of an impact risk is to send something out there to track it with proper radio science measurements.

Generally the approach any mission should take is not to prevent an impact, which implies that you will have something approaching good knowledge of whether or not it would pass through a keyhole, but rather to reduce the probability of impact. Because the center of the distribution from your knowledge (largely gaussian) is going to be offset from the keyhole, you need to nudge the asteroid further in that same direction to move it out past a 5-sigma or 6-sigma or 7-sigma ellipse, whatever your desired goal is.

The annoying truth about dealing with anything in deep space is that its all probabilistic. You never really know where anything is, and you always have to quote your certainty values.

I wonder if they've looked at predicting how this will play out with the new program in place -- they have the basic problem that they're affecting what they're observing, and thus will change what will happen.

If the algorithms predict crimes in certain areas, you'll end up with officers in the area, likely preventing a crime before it even happens. That is, the potential criminal will notice the police presence and decide its not a good time. Thus there would be some feedback from the prediction method back onto itself.

I can think of three ways it could go:
1. Predictable "waves" that roll across the city
2. Predictable but chaotic patterns reminiscent of a complex cellular automata or fractal
3. The software nullifies itself.

Anyone have any other thoughts or know if they've studied this problem?

Airbags scale by a factor of ~2.5 with mass. MSL is much larger than the MERs. Thus it can't be landed with airbags and fit on top of a launch vehicle.

The skycrane, ridiculous as it may seem, is probably really the best way to get something the size of MSL to the ground. Whether or not they wouldn't have been better off selecting a couple of MER sized machines is a different question...

I like how Boeing, ULA and ATK are listed as having no experience. This is neglecting the fact that no-experience applies less and less to SpaceX. You'd think being able to get a completely new good-sized vehicle flying with two successul test flights would speak to their capabilities.

When will these people realize that the old way of building spaceships hasn't produced a new vehicle in 30 years! Claiming NASA has the experience to build something new is disingenuous -- this is not to put the blame on NASA employees, but rather to point out that the current contracting structure, with its tendency to produce a One-Design-To-Rule-Them-All, and then have it be meddled with by congress, has proven to not be up to the task without Apollo-like external influences. I have trouble believing that any new NASA-designed launch vehicle would actually make it all the way to completion.

And their arguments are based largely on a miscomprehension of what is meant by 'commercial space'. It does not mean independence from a government market -- in fact only the wildest flights of fancy claim that an HSF market could exist without government demand. It means changing the contracting methods to something less prone to the abuses of cost-plus contracting, and allowing the companies that build new spaceships to sell their services to others as well. I really wish that we had chosen a less inflammatory name for the concept when it got pushed into the Obama budget -- I fear that the name makes the whole process sounds scarier than it actually is.

The problem with that is recognizing what code is going to be reused by others and what isn't.

I'm an aerospace engineer who writes a lot of code (and does so on the taxpayer's dime), and it is a struggle to find the right balance between getting something functional for the immediate task, and recognizing what will be useful for others later. Since its much more difficult to write the second variety (particularly if it needs to be generalized for as-yet unknown tasks,) its just as important to perform some tasks the quick way as it is to do others the right way. Otherwise I am wasting precious resources.