Quote from: envy887 on 04/26/2017 01:51 pmNot sure. I know they are doing some protein crystal growth on the ISS, but I haven't heard whether these have generated better results (or even results as good as) than results generated in the best Earth labs. I did hear that the reason centrifugal experiments for the ISS usually cite for cancellation is the need for low vibration environment required by the protein crystal growth experiments.Apparently high quality crystals were grown on Skylab, Shuttle and ISS. But due to a number of reasons this hasn't translated to useful study of unresolvable structures - some of the reasons might be alleviated by commercial transport and a dedicated commercial station would apparently be useful though perhaps not yet viable financially.This is quite far from my field of expertise, but my understanding is that the zero-gravity protein crystal growth application has to some extent become less important with the development of other methods (NMR, for example) for structure determination.(Note that the Nature article that you linked to is almost 20 years old.)
Not sure. I know they are doing some protein crystal growth on the ISS, but I haven't heard whether these have generated better results (or even results as good as) than results generated in the best Earth labs. I did hear that the reason centrifugal experiments for the ISS usually cite for cancellation is the need for low vibration environment required by the protein crystal growth experiments.Apparently high quality crystals were grown on Skylab, Shuttle and ISS. But due to a number of reasons this hasn't translated to useful study of unresolvable structures - some of the reasons might be alleviated by commercial transport and a dedicated commercial station would apparently be useful though perhaps not yet viable financially.
Often times you'll hear people say we should concentrate on Moon/Mars/asteroids etc because we've "done" low earth orbit (LEO), meaning that ~500+ people have been there.To me that really underestimates the commercial potential of LEO as a destination, not just for tourism (although that's what I'll concentrate on here), but for support of ongoing expansion into the solar system. It may only be a few hundred km from the surface, but it's nearly to the other end of the biggest gravity well we have to overcome in the near future.My question is: how do the economics change in the scenario where hundreds of thousands, or even millions of people have been to LEO or beyond, and travel to LEO is simply a more exotic method of travel around the world? (since where you land is largely a matter of departure timing). I'm not an economist/accountant, so this is largely spitballing, I would like to hear more educated assessments of the potential.Say we end up putting hundreds of ISS-volume habitats into orbits 800-1000km altitude, where orbital altitude decay only happens on the order of hundreds of years, you still receive partial radiation protection of Earth's magnetic field. Assume we eventually work out a solution for the space debris problem, and is some form of spin gravity so people can enjoy the novelties of seeing the Earth from space and experiencing zero gravity whilst still having the comforts of being able to bathe and go to the toilet with some sense of normalcy. How we get from here to there:As a ballpark figure, the worldwide ocean cruise industry 2015 carried about 22 million people per year for a total of ~$40Billion USD revenue, giving us an average spend of $1818 per person. Let's say as an aspirational goal, we hope that eventually, 1/1000 of those people would spend 1000x that amount for a trip to orbit for two weeks ($1.8 million ticket price, 22k people per year), and returned to destination of choice because Dragon v2 can land anywhere and be shipped back from anywhere to Cape Canaveral/Brownsville. 7 people at a time (6 passengers, one pilot/staff), 26 flights a year to a given space station: 6*1.8 = 10.8 million revenue per flight. Revenue is $280.8 mil per year per station. Assuming reusable rockets reduces cost to 1/10 of current $70 million/flight = $7 mil per flight.At that rate we're talking 156 spaceflight participants, per space station per year. To service 22k people per year, we need 141 ISS volume space stations or a smaller number of larger ones. Either way, this means space stations themselves are coming off a production line such as Bigelow Aerospace or otherwise. Let's stick with the smaller stations BA 330 type for now.From $10.8 million per flight, lets say $7 million launch costs, $3 million for upkeep/downpayment of the station, and $0.8 million profit. For the station, 26 flights a year gives $78 million/year to pay off the initial launch and ongoing upkeep of the station. Say the initial stations are BA330s launched on a Falcon Heavy for ~$135 million. At this flight rate, the launch of the space station is paid off inside 2 years, and if the station costs $200 million, you've paid off the station itself within 5 years.What about the doubling time? - i.e., how long to fund a second space station from the proceeds of the first? 335/78 = 4.28 years (call it 4.5 so we can calc 4x at 9years). So if we launch the first BA330 in 2018 and need 141 space stations...2018 = 1 commercial space station2027 = 4 stations2036 = 16 stations2045 = 64 stations~2050 = 141 stations So yeah, I know I'm making some optimistic assumptions, but I also think I'm making some pretty conservative ones (i.e. not accounting for any synergistic effects). I guess we can achieve "big" LEO travel rates/settlement, 22k participants per year by at least 2050, if not sooner. Anyone think I'm being too optimistic? too pessimistic?
Quote from: as58 on 04/27/2017 05:41 amQuote from: envy887 on 04/26/2017 01:51 pmNot sure. I know they are doing some protein crystal growth on the ISS, but I haven't heard whether these have generated better results (or even results as good as) than results generated in the best Earth labs. I did hear that the reason centrifugal experiments for the ISS usually cite for cancellation is the need for low vibration environment required by the protein crystal growth experiments.Apparently high quality crystals were grown on Skylab, Shuttle and ISS. But due to a number of reasons this hasn't translated to useful study of unresolvable structures - some of the reasons might be alleviated by commercial transport and a dedicated commercial station would apparently be useful though perhaps not yet viable financially.This is quite far from my field of expertise, but my understanding is that the zero-gravity protein crystal growth application has to some extent become less important with the development of other methods (NMR, for example) for structure determination.(Note that the Nature article that you linked to is almost 20 years old.)The review article was published in 2015.
Quote from: A_M_Swallow on 04/26/2017 01:42 pmFor crystal growing are we talking weeks or months? Can be as little as a week or more than a month. More detail below.QuoteCan the growing equipment be automated? Or at least remote controlled.The thought that went through my head was this: imagine Chris Rock saying "oh hell no" (but there is a caveat below )QuoteAn unmanned satellite is likely to be much cheaper than a manned spacestation. Docking 10 tonne spacecraft produces a big shock force, followed by the person moving around.There is major vibration during launch, set up and reentry of spacecraft. In between can be very low vibration.The crystals can be quite robust once they have formed, so with appropriate packaging they should be okay during reentry. Many years ago my supervisor would travel internationally to get to a better synchrotron, and he would carry the crystals in his hand luggage, in a little ice pack about the size of two decks of cards (undeclared, because if someone found out he was carrying biological material in hand luggage! haha - difficult to explain what it was for, and if some ignorant customs agent wanted to have a look/poke at the crystals, they're just as likely to destroy them with light/heat exposure and make the entire trip a waste of money). Not sure what he does these days.I'll give a little summary to try and explain why it's so labour intensive: what you start with, when trying to make a protein crystal, is a small vial (maybe 50-100 microliters, so 1-2 drops) of protein in solution that some scientist has spent 6 months to a year of their lives purifying. There's an urban myth about one of the scientists in the early days of crystallography that had spent years getting to the point where he could start crystal experiments - he was so nervous he dropped the vial and spilt it on his lab coat, and spent the next 3 days desperately trying to extract protein out of a square of his lab coat.Anyway, you've got this small amount of very precious solution, and each attempt to grow a crystal uses 1 microliter. I used the hanging drop method which consists of placing a single 1uL drop of solution on a circular glass slide, which is then placed upside down in a sealed chamber to "hang" above another solution which - through vapour diffusion - is meant to help that drop evaporate. The surface tension keeps the drop in place on the top slide where you can focus on it with a microscope. That reduction in volume gradually - hopefully - causes the protein to crystallise. There were about a huge number of variables for what to include in that second solution, including every possible salt combination, changing pH by increments of 0.01, changing the concentrations of various organic chemicals, etc. There was no way you could ever test all the variables, even if you had 100uL (100 attempts) of protein solution, so you would try an initial "semi-randomised" matrix of 20 different combinations, initially based on what might have worked with similar proteins. You then check those each day over the following days/week. Maybe one or two of those would show some kind of crystal growth or not, but once you had some promising leads, you would set up a new batch of crystals, focussing on the specific combinations which worked, but include smaller increments in pH variation, or different salts/concentrations of sodium/potassium etc, and you keep repeating this process iteratively, refining the reagents until you eventually had a promising crystal - or you ran out of protein solution.
For crystal growing are we talking weeks or months?
Can the growing equipment be automated? Or at least remote controlled.
An unmanned satellite is likely to be much cheaper than a manned spacestation. Docking 10 tonne spacecraft produces a big shock force, followed by the person moving around.There is major vibration during launch, set up and reentry of spacecraft. In between can be very low vibration.
All this time you're making judgement calls, and ignoring the salt crystals which form quite happily in a number of different solutions. You develop this weird hatred of pretty crystals - since the salt crystals are always pretty under polarised light, and the protein crystals are dull as, but they're what you want. Even once optimised, you're lucky if you get a crystal more than a couple of mm across, and then you have to be super careful to extract it and package it up without crushing it or dropping it back into the solution.
So yeah, my expectation is that you'll have a crew of scientist astronauts go up, each one with dozens of vials of protein solution to work with (probably hundreds of person-years of work going up in one launch) and the astronauts will just be working continuously to physically set up ever new iterations of crystal experiments, while the scientists on the ground who created to the protein solutions should have some ability to remotely monitor crystal formation - need some sort of system to look at the crystals without bumping them - and decide what the next iteration will be for the astronauts to make up. The whole deal might take 3 months or so.Quote from: Asteroza on 04/26/2017 11:24 pmFor low vibration production environments, sounds like a gateway depot tender/station and a small fleet of freeflyers leading, especially if you are using electric thrusters to counteract drag. Perhaps, but it might be more trouble than it's worth to keep them in separate spacecraft - like I say, they need to be looked at daily, so you don't want to lose a microscope every time you set up an iteration - I would just have a free floating rig inside a BA330 - maybe have magnetic shock absorbers to attach it to the walls, and all orbit adjustments are performed via SEP.{snip}
For low vibration production environments, sounds like a gateway depot tender/station and a small fleet of freeflyers leading, especially if you are using electric thrusters to counteract drag.
The issue with any "kill X and NASA can then do Y" is that killing X won't free up any funds, they get reprogrammed out of NASA.
Quote from: Lar on 04/24/2017 01:56 amThe issue with any "kill X and NASA can then do Y" is that killing X won't free up any funds, they get reprogrammed out of NASA.It'd be awesome if that ever happened, but it doesn't. Constellation was killed, it freed up funds which were used to do other stuff. NASP was killed, it freed up funds which were used to other stuff. Shall I go on? It's a pretty long list.
First of all there are some serious economies of scale in human spaceflight. If you are going to transport 22k per year your not going to do it with spacecraft and space stations with capacities of 7 people. It does not make sense. Instead you would build spacecraft with capacities of at least a hundred people. Spacecraft like the SpaceX ITS. You would probably be building space stations with a capacity of over 1000 people.
Quote from: DarkenedOne on 04/27/2017 05:17 pmFirst of all there are some serious economies of scale in human spaceflight. If you are going to transport 22k per year your not going to do it with spacecraft and space stations with capacities of 7 people. It does not make sense. Instead you would build spacecraft with capacities of at least a hundred people. Spacecraft like the SpaceX ITS. You would probably be building space stations with a capacity of over 1000 people. I think something similar to Skylon flying several times a day from multiple launch sites would be better suited for passenger transport as not everyone is going to be coming and going to the same location at a the same time.
Try and have a small version of the new program going before the old one is cut. Transferring money is easier than simultaneously stopping one program and starting a second.
Quote from: mikelepage on 08/28/2016 10:02 am(snip)What about the doubling time? - i.e., how long to fund a second space station from the proceeds of the first? 335/78 = 4.28 years (call it 4.5 so we can calc 4x at 9years). So if we launch the first BA330 in 2018 and need 141 space stations...2018 = 1 commercial space station2027 = 4 stations2036 = 16 stations2045 = 64 stations~2050 = 141 stations So yeah, I know I'm making some optimistic assumptions, but I also think I'm making some pretty conservative ones (i.e. not accounting for any synergistic effects). I guess we can achieve "big" LEO travel rates/settlement, 22k participants per year by at least 2050, if not sooner. Anyone think I'm being too optimistic? too pessimistic?First of all there are some serious economies of scale in human spaceflight. If you are going to transport 22k per year your not going to do it with spacecraft and space stations with capacities of 7 people. It does not make sense. Instead you would build spacecraft with capacities of at least a hundred people. Spacecraft like the SpaceX ITS. You would probably be building space stations with a capacity of over 1000 people.
(snip)What about the doubling time? - i.e., how long to fund a second space station from the proceeds of the first? 335/78 = 4.28 years (call it 4.5 so we can calc 4x at 9years). So if we launch the first BA330 in 2018 and need 141 space stations...2018 = 1 commercial space station2027 = 4 stations2036 = 16 stations2045 = 64 stations~2050 = 141 stations So yeah, I know I'm making some optimistic assumptions, but I also think I'm making some pretty conservative ones (i.e. not accounting for any synergistic effects). I guess we can achieve "big" LEO travel rates/settlement, 22k participants per year by at least 2050, if not sooner. Anyone think I'm being too optimistic? too pessimistic?
Quote from: Patchouli on 04/30/2017 11:38 pmQuote from: DarkenedOne on 04/27/2017 05:17 pmFirst of all there are some serious economies of scale in human spaceflight. If you are going to transport 22k per year your not going to do it with spacecraft and space stations with capacities of 7 people. It does not make sense. Instead you would build spacecraft with capacities of at least a hundred people. Spacecraft like the SpaceX ITS. You would probably be building space stations with a capacity of over 1000 people. I think something similar to Skylon flying several times a day from multiple launch sites would be better suited for passenger transport as not everyone is going to be coming and going to the same location at a the same time.There are economies of scale in both flight rate and passenger size, but given the existence of launch windows I think that space travel will favor larger vehicles launched less frequently over smaller launch vehicles launched more frequently.
A launch window to each LEO orbital plane comes around every day, so if each launch site can launch one vehicle per window, then the minimum vehicle size is simply the maximum number of passengers per day divided by the number of launch sites. This is true regardless of the geographic distribution of launch sites.If each launch site can handle more than one launch per day, then stations can be located in orbital planes such that the planes pass overhead at intervals at least as long as the time required to reset the launch site. E.g. if each site can launch every 6 hours then 4 planes each 90 degrees apart can be serviced, each at the same max passenger/day rate as a single plane.For 22,000 passengers/year or 60/day average, assuming the peak is 120/day and 3 launch sites servicing one orbital plane, the minimum vehicle size is 40 passengers/vehicle. But if the 22k/year are going to stations in 4 different planes and can launch 4 vehicles per day, then a 10 passenger/vehicle size is sufficient to handle a peak rate of twice the average rate.
Let's just hope bigelow gets enough time to get any kinks out of their design before ISS comes down. Mid 22's are not that far away. OTOH, bringing ISS down sooner and have NASA use some of the liberated budget to fund a commercial space lab programme might speed up the transition.
Quote from: mikelepage on 04/25/2017 05:47 amHow about zero-g sports? Seriously. It's a forum where audiences are used to paying money to watch experts do something competitively in a specialised space with restricted access.My favourite one is long jump without space suit.Park two spacecrafts (or different parts of same station) so that the airlocks are towards each others, but the distance between them can be adjusted.One airlock contains the athlete(without any spacesuit). The airlocks are opened, and the athlete jumps from one airlock to another through open space. When he enters the another airlock, it's closed and pressurized.The winner is the one who jumps the longest distance between the airlocks, and survives.
How about zero-g sports? Seriously. It's a forum where audiences are used to paying money to watch experts do something competitively in a specialised space with restricted access.