You almost make it sound like it’s a dying art that may get lost in future government cutbacks and the expansion of commercial space?
OSIRIS-REx samples directly from the surface of the asteroid. For a comet, the sample needs to be taken some depth below the surface to get unaltered volatiles. Based on Philae, there may also be a hard crust that needs to be punched through. As I recall, the other two proposed comet sample return missions essentially shot a sampling mechanism into the surface (one from within an arm and the other as an actual harpoon).
I am asking if it is possible to do useful science by designing the payload only, not the delivery mechanism. We do that already for launchers, but not for cruise and not for orbiters or landers. (yes, some start from commercial buses but they are not off the shelf)Suppose it comes to pass that one of the NASA initiatives for cargo service to Luna actually happens, and it's possible to buy "land X tonnes at location Y without subjecting it to more than these forces". At that point, does it still make sense to design and develop custom lunar landers?If you still don't get what I am asking, do us all a favor and don't be snarky about it. (Ultraviolet9 got it just fine and was able to discuss rationally what some of the issues were without being cavalierly dismissive)
And to win, it's considerable effort on those study contracts.
And that's not even mentioning our current limits in building spacecraft for outer planet missions, where the best we can do, built upon decades of concerted work, isn't good enough for such long lived, hostile environment, missions.
Seven years ago a little bird who worked at JPL told me that they spent on average $500K per Discovery proposal and $750K per New Frontiers proposal. I'm sure it's considerably higher now. If you go back and count how many JPL Discovery proposals there were in the last round, you get a sense of how much internal money JPL spent. That's not counting all the other participants who are doing things like the instrument proposals. I'll just ballpark it and figure that each New Frontiers proposal probably costs $1.5 million to put forth, and each Discovery proposal is probably a million dollars. And that's not including sweat equity.
Quote from: Space Ghost 1962 on 12/23/2017 09:04 pmAnd that's not even mentioning our current limits in building spacecraft for outer planet missions, where the best we can do, built upon decades of concerted work, isn't good enough for such long lived, hostile environment, missions.Huh? Not ONE outer planet mission has failed prior to completing it's primary mission, barring Juno, which still has several months to go. All the others (barring Huygens with lts limited battery life) have had their mission extended, often multiple times.
No, I got it.
Quote from: Dalhousie on 12/24/2017 02:04 amQuote from: Space Ghost 1962 on 12/23/2017 09:04 pmAnd that's not even mentioning our current limits in building spacecraft for outer planet missions, where the best we can do, built upon decades of concerted work, isn't good enough for such long lived, hostile environment, missions.Huh? Not ONE outer planet mission has failed prior to completing it's primary mission, barring Juno, which still has several months to go. All the others (barring Huygens with lts limited battery life) have had their mission extended, often multiple times.Galileo didn’t do too well but these weren’t all New Frontiers missions which is the topic
When we did the decadal, I think we were aware of three potential comet sampling mechanisms, two that were public and one that was proprietary and that we were not allowed to know about, but which was provided to the cost estimators with an NDA. I can only remember one of the two public ones, and it involved a kind of wire brush and scoop mechanism--think of it like a vacuum cleaner with wire brushes up front that would scoop the sample into the collector. The strength of such a mechanism is that it works with multiple samples. If the surface is snow, it scoops it right up. If the surface is hard ice, it scrapes it up. I think the downside is that what you get is an aggregated sample (I'm probably using the wrong word). It's a collection of all the stuff mixed together. What you may want is a small ice core from one spot, and some snow from another spot, and some ice chunks from another spot. So maybe you use this method and you use some other sampling device.
Allow me to comment on my own post...This high cost of proposals is actually an argument for having fewer competitions for Discovery and selecting two each time instead of one. The reason is that if you have a competition every couple of years, then proposers are spending a lot of money each round for a low selection rate.Put it this way: suppose you hold one competition in 2016, and then another competition in 2018, and each time you have 28 proposers and you select one winner each time. For those two competitions the proposers have spent $56 million for two winners over two years. Instead, if you do one competition in 2016 and another in 2020 and you select two winners each time, over four years you've spent $56 million, but selected four winners. It's a more efficient approach and it doesn't kill everybody putting together proposals. Of course, this also assumes that you have the budget to support more missions, and you might not. But NASA is aware that a lot of non-NASA money is being spent for each competition and they want to maximize effectiveness.
Quote from: Blackstar on 12/24/2017 02:08 amAllow me to comment on my own post...This high cost of proposals is actually an argument for having fewer competitions for Discovery and selecting two each time instead of one. The reason is that if you have a competition every couple of years, then proposers are spending a lot of money each round for a low selection rate.Put it this way: suppose you hold one competition in 2016, and then another competition in 2018, and each time you have 28 proposers and you select one winner each time. For those two competitions the proposers have spent $56 million for two winners over two years. Instead, if you do one competition in 2016 and another in 2020 and you select two winners each time, over four years you've spent $56 million, but selected four winners. It's a more efficient approach and it doesn't kill everybody putting together proposals. Of course, this also assumes that you have the budget to support more missions, and you might not. But NASA is aware that a lot of non-NASA money is being spent for each competition and they want to maximize effectiveness.NASA has announced its intention to begin its next Discovery selection in about a year leading to a launch no later than 2025. Any decisions on whether to select one or two missions would likely be made closer to the time of the selection when future funding flows would be better understood.Two popular categories of proposals from the last competition may not be in this new one. With JAXA's Phobos sample return/Deimos multiple flyby MMX mission, these two destinations would seem to be out of the running. From an OPAG presentation this past summer, the outer planets community appears to have concluded that Discovery missions to those destinations don't fit within the budget cap. I expect retries for Venus and more comet and asteroid proposals. Not sure if a meaningful Ceres follow on mission can fit within the budget cap, but there are those main belt comets... And I expect more Mars proposals. The Next Mars Orbiter SDT identified several priority orbital studies, and the Mars community is making noise about stationary landers for sites with current water or ice (with attention to planetary protection) or small rovers to explore the diversity of ancient aqueous sites.
Borderline off topic to bring Musk into this thread, although you guys have a point in that the launch industry may be more competitive and flexible in the coming decade.Well for better or worse it looks like the upcoming Frontier and Discovery missions will be about comets, Titan, and asteroids. Titan was the definite wildcard. Given how all the respective missions, while not the first to visit any of these types of targets, are all doing something unique in their missions.Regarding New Frontiers let's focus the discussion to Dragonfly and CAESAR. They're the finalists and both are pretty ambitious. As for Venus and it's second kick in its asteroid deposit those complaints in the Venus threads. I feel as much for Venus as I do the overlooked Deimos/Phobos missions in the Discovery lineup, but the choice is made and the (space) traveler shall come.
One might almost think someone was seeking to stifle debate.
Quote from: Star One on 12/24/2017 10:14 pmOne might almost think someone was seeking to stifle debate.It's not a debate, it's just a tiresome rehash of every other SpaceX thread on this forum.If launch costs decrease, I'm sure NASA's planetary program will take advantage of it to the extent that it politically can.
Thinking to talk of such missions without considering the wider world especially when the industry is likely to change so greatly over the coming decade or two seems a curious argument to make. Even such a basic element of launch cost which has often been a large factor in such projects cost projections is liable to greatly be impacted. One might almost think someone was seeking to stifle debate.