Thats how its supposed to work. Governments should be doing the things private industry and individuals can't -- in this case development of technologies that have the potential to benefit society as a whole that are expensive enough and uncertain enough to never make a valid business plan or hobby project.

Then, those developments should be fed back to the citizens (and the companies they form), so that when its possible for the private entities to take advantage of it, they can. I work for NASA, and personally I'd much rather SpaceX/Boeing/Lockheed/Orbital build launch vehicles and let us worry about high-risk tech development and exploration.

Well, to be fair, a satellite in an extremely low Earth orbit with significant drag throughout its entire orbit is probably the most difficult place for us to track a live satellite.

The atmosphere is unpredictable, so its constantly rephasing the orbit in ways you can't predict, and when its that low, a ground station has a very brief time to get acquisition, get some data, and send it to the controllers for orbit determination. Compare to a deep space vehicle (say Juno instead of an alien spaceship), where even if you're uncertain by 100s of km you're still within the beam-width of a DSN tracking station, and you only need three stations around the globe to track it at any point in time. Plus the orbital dynamics are known well enough that you should be able to find it again 6 months or a year later pretty easily even if you lose all tracking data from now till then.

That is unless you're worrying about Webb and its partner money sponge SLS soaking up funds from other programs.

Personally, my interests are in seeing CCDEV/COTS, tech development, and planetary science advance. Sadly, unless things (I'll give management the benefit of the doubt and just leave it at luck) improves drastically I can't help but worry as costs keep going up and launch keeps getting delayed.

I think scientific interest would be more along the lines of using it more like GRACE, tracking climatic changes associated with carbon and water ice moving around. Additionally, you couldn't get data from as close to the surface, since you've got to stay out of the atmosphere, just like you do on Earth, making it harder to get 'crust to core' data.

The other problem is that flying these things in formation is *hard*, and around Mars it would be even harder. You depend on tracking data to and from Earth, in addition to the spacecraft-to-spacecraft range, and thats harder to do since its further away. Maintaining data to Earth on a higher-gain antenna while maintaining orbiter point would be difficult, since the pointing constraints are not guaranteed to get along. Plus trying to get them into synchronized orbits is hard enough around the Moon, so Mars sounds potentially nightmarish -- of course, for that you might just have to put them on a common bus and separate them after Mars entry. Additionally, you'd need a bigger motor than GRAIL/GRACE have, in order to achieve Mars orbit.

Given the new development required -- new antennae, figuring out the pointing, a common bus with its own attitude control system and thrusters, and a larger launch vehicle, my WAG for the cost is probably around $800M (compared to ~$495M for GRAIL). Definitely doable under a New Frontiers program. Plus, my experience is with GRAIL and Mars orbiters, so I'd be employed for quite a while and thus like the idea.

Technically, everything is done UTC, and the insertion burn for GRAIL-A is around 22:00 UTC on 31-Dec-2011, and GRAIL-B is after that.

Of course, the people operating it are stationed in Pacific and Mountain time zones (JPL/DSN and Lockheed Martin in Denver), and that places the maneuvers mid-afternoon on those days.

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.