I've been in two minds about this asteriod retrieval mission but after reading the Keck report again I've become enthusiastc about it. The original mission video of capturing an asteriod then using Astronauts to collect a sample of it seemed like a large waste of money for a few rock samples. But if you look at from ISRU view point it is definitely a step in right direction.A successful mission would place few hundred mts of oxygen (oxides in rock) and hopeful water within permanent reach of earth. Extracting the water or oxygen may not be easy but it would be to be easier (less difficult) than lunar ISRU and would be permanently in place to experiment on. Any extracted oxygen or water(LOX/LH) would be in ideal location to support lunar missions. At end of the mission the SEP could be refuel for new mission using existing LVs and used again to retrieve another asteroid for a lot less than original $1.25B. A 200KW VASIMR seems better choice of SEP ie 2.4 year round trip compared to 10yrs for 40KW SEP but I'm no expert on SEPs. http://www.adastrarocket.com/AndrewIEPC13-336-Paper.pdf
Here is an update on the ARM mission (slides 13 to 24):http://www.nasa.gov/sites/default/files/files/20140728-Williams-NAC.pdf
Quote from: yg1968 on 08/13/2014 04:45 pmHere is an update on the ARM mission (slides 13 to 24):http://www.nasa.gov/sites/default/files/files/20140728-Williams-NAC.pdfThanks for this. There's a bit I still don't understand about ARM. A stated goal is, "Demonstrate basic planetary defense techniques that will inform impact threat mitigation strategies to defend our home planet." Yet they show an "option B" for redirecting the asteroid to cis-lunar space (see attached). How would picking up a boulder demonstrate any sort of planetary defense technique?
"gravity tractor"
I don't know about that. However, I also think that people complaining about the scientific content (or lack thereof) of the asteroid capture mission are rather missing the point, engineering. It's not Apollo 11, it's Apollo 7, to draw an inexact analogy; it primarily tests a number of technologies and techniques that will be useful to future missions. For example, it obviously demands the development of tools and tactics for working in a near-zero-g environment around a natural rather than a built object, something which has never been done before and which would be useful to future missions to NEAs or to Mars' moons. It also demands the development of a number of technologies which would be useful to a future Mars mission, such as precision automated rendezvous to an unresponsive and unhelpful target, really high-power electric propulsion, and large-scale deep space power production.Hence, the mission should be judged on both the scientific and engineering axes, that is how much does it support developing the technology needed to go further and how much it develops scientific knowledge. Judging it based on either is very incomplete, and I'm a little disappointed that so many people on these forums have been neglecting one or the other (mostly the engineering side). To me, it seems to be very clever in several ways; besides adding science to certain demonstrator missions, thereby increasing the probability of them getting funded, it turns what would otherwise be an early drought in SLS/Orion missions (owing to the lack of most mission-specific hardware) into something that advances the state of the art for later, without the expense needed for a full-scale deep space vehicle or a lunar lander. While I would prefer a non-SLS-based architecture, if it must be used this is an intelligent way to do it, and so I think it's a good idea NASA is working on it.
..and go with the sort of Abundant Chemical architecture that Congress seemed to have envisaged.
Quote from: yg1968 on 08/13/2014 04:45 pmHere is an update on the ARM mission (slides 13 to 24):http://www.nasa.gov/sites/default/files/files/20140728-Williams-NAC.pdfSo, a mission using DRO as a staging point, with a reusable habitat and Chemical and SEP propulsion has become the official baseline for a mission to Mars? If so, I'm very happy with that news (unless I've been sleeping under a rock again).Edit: Took out what could become a political fight.
Congress required NASA to pick an SLS design that could be operational (with MPCV) by end 2016, within the budget available.They then expected NASA to undertake an asteroid mission by ~2025 *which would have demonstrated Deep Space Hab and and EDS* as build up for Mars precursor missions ~2035.
Quote from: MP99 on 08/14/2014 08:04 amCongress required NASA to pick an SLS design that could be operational (with MPCV) by end 2016, within the budget available.They then expected NASA to undertake an asteroid mission by ~2025 *which would have demonstrated Deep Space Hab and and EDS* as build up for Mars precursor missions ~2035.I don't agree with your narrative. Asteroid in 2025 and Mars in 2035 was the administration's directive prior to SLS. SLS was forced in by congress for reasons other than meeting it. This warped the budget and reduced the extent of the administration's plans for investing in maturation of systems necessary for meeting the target, and so the viability of meeting those goals was eliminated. ARM is a downscoped microcosm of the administration's original objective that can fit in the smaller resulting budget envelope in the timeframe.
While this narrative is true, it's a pipe dream to think another (NASA) flagship launch system would be any cheaper. The hand writing was on the wall when Obama "wanted to visit an asteroid by the mid 2020s."
Here is a recent presentation on the ARM at the January NAC HEO Committee:http://www.nasa.gov/sites/default/files/files/2-20150111_ARM_update_NAC_HEOC.pdf
In just the last 2 weeks, Arecibo characterized two ~10m NEAsthat were almost suitable candidates for ARM Option A
Quote from: yg1968 on 01/28/2015 04:09 pmHere is a recent presentation on the ARM at the January NAC HEO Committee:http://www.nasa.gov/sites/default/files/files/2-20150111_ARM_update_NAC_HEOC.pdfMost interesting. Lots to digest. Note they already have the high power ion thrusters, solar array and power systems technology (although I doubt the hardware) ready to go. They've also upped radar resolution from 8m to 4m, and demonstrated full scale capture hardware for option B (boulder, not rubble pile). This looks it could be the first long duration deep space mission (as in beyond Moon orbit in some parts) since the early 1970's. Personally I think flying inside a hollowed out (large) boulder is the way to get around the solar system as it side steps pull what is basically a lot of dumb mass up Earths gravity well for radiation shielding. Pretty much the simplest bit of "ISRU" you can have.