I really like the idea of five 20-person escapable capsules, one on each tanker flight.
Quote from: redliox on 09/30/2017 04:40 amWhile the bit with the ISS isn't exactly Mars-centric, it now leads me to wonder how they'll handle airlocks and docking.They don't need airlocks. But docking the BFR with the ISS is going to put a lot of mechanical stress on the IDS. The bigger issue is getting NASA to certify BFR for ISS operations, and SpaceX implementing any changes, before ISS is retired. I don't see that ever happening.
While the bit with the ISS isn't exactly Mars-centric, it now leads me to wonder how they'll handle airlocks and docking.
I don't see a way to do this, is there ever a LAS design that involves blowing away the fairing?
I think Vostok and Gemini used ejection seats that blew away a cover which you might refer to as a fairing.
If they do it I see them putting Dragon on the nose of a cargo or tanker BFS. So outside the cargo pod and free to use its abort engines.
So far, it seems to me like the Tanker is the same as the Cargo version and there’s very little practical reason for a long time for SpaceX to build anything but this single type of simpler ship. For Mars or the Moon human transport put a hab in the cargo hold. This has the major advantage that it lets you leave the hab where it’s more useful while returning the ship. Your idea of finding a way to carry a Dragon2 for passenger launches fits with this. I’m assuming just the Dragon2 not the Trunk. If you reoriented the couches? you could mount the Dragon2 in the hold sideways, pointed out the hatch. In an abort the hatch blows off and the D2 fires it’s super Draco’s. In an approach to the ISS the hatch opens normally and it’s slowly pushed out and uses its Draco’s to dock. There’s no exterior mod to the BFR, just D2 mounting hardware wherever most appropriate in the hold. D2 can operate like an emergency abort pod or do normal docking with ISS. It just can’t operate in orbit on its own for long without the trunk.
Early on (2022 - 2030)The safest solution would be construct a crew transfer space station in orbit...Once built and in use...A crew type yet unmanned BFcrew launches first to the transfer station... side docks via the hatch...A Dragon 2 with it's F9 S2 still attached (but vented and inert ed) brings up 7 crew safely and in a proven system.It docks via nose hatch... crew goes aboard station...A station robot arm grapples the D2/S2 assy and swings it over into an empty BFpacman cargo equipped to secure and haul it back down in one piece...It then returns the D2/S2 set cleanly and nearly ready to be put on a used F9 S1 and relaunched...Repeat till BFCrew is manned to required staffing...I think a pair of D2/S2's will fit side by side in a BFpacman cargo... not 100% sure on that...Just saying... NASA or anyone would have a hard time saying no to this idea for early crew missions... Once BFR system has demonstrated it to be safe and reliable... repurpose the transfer station
If you want a crew transfer station, why not the BFS itself? It's pretty much the volume of ISS, in a much more convenient layout. Just fly the Dragon to the BFS and dock directly to it.I don't think this is likely to happen though, I think Elon is going to push for just launching on BFS (after some unmanned testing of course).
Quote from: guckyfan on 09/30/2017 01:17 pmIf they do it I see them putting Dragon on the nose of a cargo or tanker BFS. So outside the cargo pod and free to use its abort engines.If Dragon goes in the nose, how does the BFS renter? There's a lot of heating and pressure on the nose. Can that structure coexist with Dragon?
Just a reminder, What I really wanted to talk about in the OP was a Cargo BFS + Dragon 2 where*The Dragon serves as a LAS at every point, up, down and in LEO (hopefully making 1:100~1:1000 odds of LOC into 1:10,000~1:1000,000) - so it has to be able to return inside (or at least protected by) the Cargo BFS.*The dragon can leave the Cargo BFR and return to it while in LEO, removing any ISS issues but possibly having a bunch of other uses also.
* NASA doesn't need BFR at the ISS. SpaceX doesn't cannot use BFR for the ISS contracts.* NASA payloads or crew will not fly on non-certified launchers.* There is no new station except DSG, and if you have something like BFR, with more space than the ISS and an ECLSS that can support 100 people for 6 months, you don't need a DSG.
(1) * NASA doesn't need BFR at the ISS. SpaceX doesn't cannot use BFR for the ISS contracts.(2) * NASA payloads or crew will not fly on non-certified launchers.(3) * There is no new station except DSG, and if you have something like BFR, with more space than the ISS and an ECLSS that can support 100 people for 6 months, you don't need a DSG.
* It gives you a 100x safety improvement while you are working up the confidence in your vehicle.. and NASA may point blank refuse a vehicle without a LAS for a good long time.* Surely NASA is not so bureaucratic that they cannot separate launching and docking risks.* Probably true, but the same issue may apply to the next station we have not seen yet.Another advantage of this is that you can start with just one variant, the Cargo variant. This also happens to be the most immediately useful and a lot cheaper than the Crew variant.
LAS gives you about a factor of 10 improvement in safety, at best. It can also introduce new failure mechanisms, and is only useful in a fraction of the total mission time. And can easily cost a billion or two to design, build, verify, and operate. Might be cheaper to just fly BFR 1000 times.
I just can't get behind this idea. If a les was needed for the bfs, the very capable engineers at SpaceX would no doubt have found some clever way to design one. They didn't. There's a reason they didn't and I just can't see them ever flying this configuration - it would be tantamount to admitting they aren't confident in their launch vehicle. If they want to be cautious, launch Dragon on F9 and meet on orbit.
Quote from: octavo on 10/07/2017 07:13 amI just can't get behind this idea. If a les was needed for the bfs, the very capable engineers at SpaceX would no doubt have found some clever way to design one. They didn't. There's a reason they didn't and I just can't see them ever flying this configuration - it would be tantamount to admitting they aren't confident in their launch vehicle. If they want to be cautious, launch Dragon on F9 and meet on orbit.This wasn't intended as a long term idea.* It assumes there may be a fair period with just a cargo version, learning how to ramp up to significant flight rates launching com sats. possibly an iteration or two before the passenger version is attempted.* NASA will probably take a long time to accept a crew launcher without a LAS. And they may simply refuse anything that size docking with whatever station they have at the time.* And the passenger version will probably be quite a bit of work, another reason it's arrival could be delayed.
Every real (BF) spaceship needs a (Dragon) shuttle-craft! But in all seriousness, I can only see SpaceX considering this in case NASA does not let them dock the BFS with the ISS (whatever the reason might be). Then they could use a Dragon in the payload bay to shuttle the supplies over to ISS. Otherwise, Dragon would also seem to be quite over-engineered for an "excursion module", with the heavy heatshield, parachutes, detachable trunk, deployable solar, etc. At best, in the long term SpaceX might think about a including a potentially human-tended, Dragon-based "space drone" for all kinds of in-space operations in proximity of the BFS (e.g., overseeing and supplying repair operations, shuttling crew and goods between BFSs and/or space stations where direct docking is not possible, for heatshield inspections, servicing satellites or safing them before capture by a BFS, excursions to asteroid surfaces, etc.).
..... I'm never been so excited for the future of aerospace.
Let's hope that is the case, but bear in mind most of what you wrote could have have been written about the Space Shuttle.
If you desperately want an escape pod on BFS, it would make more sense to build the crew stations into it, and make it part of the OML, F-111 or B-1 style. Something like embedding a Dream Chaser in the nose.On the other hand, a small in-space crew/cargo shuttle could well be handy for docking in tight spaces, and general work.
I still like the idea but I think of it not so much as a quickfix, as a difficult but worthwhile problem for another variant.* Cargo variant* Crew variant (actually, passengers as cargo)* A Shuttle on steroids variant. 6-ish crew, some workspace, lots of cargo.This is a variant for actually doing work in. Also exploration missions where there is not backup and support at the other end, such as an asteroid mission. (Asteroids have the real risk of debris that could damage heatshields as well so there are multiple safety advantages. Additionally the Dragon could be an exploration module)
Quote from: guckyfan on 10/10/2017 12:04 pmIn the medium term a Dragon has no place in a BFS architecture. It means carrying a vehicle with plenty of hypergolic propellant.Please have that conversation here instead: https://forum.nasaspaceflight.com/index.php?topic=43438.0...in fact I will quote it there and reply to it there now.
In the medium term a Dragon has no place in a BFS architecture. It means carrying a vehicle with plenty of hypergolic propellant.
Why there? I am in no way talking about a LES-system but my understanding was that Dragon could become a utility vehicle around BFS. I argued that Dragon is not good for that purpose.
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Just design the cargo version first and launch it at least few dozen times (Ideally a few hundred if the launch rate is as good as advertized) before you ever attempt a manned launch. Once cargo BFR is in operation, you can drop the Falcon 9 for anything that isn't a dragon launch so your stock of F9 rockets will last for a while. The cargo BFR could also be used for in-space breadboard testing of the manned BFS systems since it has downmass capability.
Quote from: Nilof on 10/11/2017 01:15 amJust design the cargo version first and launch it at least few dozen times (Ideally a few hundred if the launch rate is as good as advertized) before you ever attempt a manned launch. Once cargo BFR is in operation, you can drop the Falcon 9 for anything that isn't a dragon launch so your stock of F9 rockets will last for a while. The cargo BFR could also be used for in-space breadboard testing of the manned BFS systems since it has downmass capability.Agreed. That seems like the most reasonable course of action that both gets SpaceX experience and, hopefully, profits from the BFR, yet keeps them in the NASA human space flight world.
Do you assume a stock of unused first stages for crew or do you assume that NASA will be OK with reuse for manned flight?
Getting up and down from that height isn't particularly unsafe with a vehicle the size of BFS, if it has a large hatch and crane as depicted. You just use the crane to lower and raise a large basket (no need for rappelling down the side of the vehicle)
Quote from: biosehnsucht on 10/12/2017 07:29 amGetting up and down from that height isn't particularly unsafe with a vehicle the size of BFS, if it has a large hatch and crane as depicted. You just use the crane to lower and raise a large basket (no need for rappelling down the side of the vehicle)On a vehicle that could be landing on a lean? I think a smaller vehicle and a ladder would be a better idea at first. Once a landing pad is developed then perhaps a crane would work.
Quote from: pathfinder_01 on 10/12/2017 07:42 amQuote from: biosehnsucht on 10/12/2017 07:29 amGetting up and down from that height isn't particularly unsafe with a vehicle the size of BFS, if it has a large hatch and crane as depicted. You just use the crane to lower and raise a large basket (no need for rappelling down the side of the vehicle)On a vehicle that could be landing on a lean? I think a smaller vehicle and a ladder would be a better idea at first. Once a landing pad is developed then perhaps a crane would work.Don't we have enough hi-res imagery of the moon (LRO among others) that we can identify a nearly flat, boulder-free, plane to land on?
I'm not sure landing the BFS itself on the Moon is a good idea since it will have a lot of mass that won't do any good on the moon, e.g. airframe, heat shield, Earth return fuel, tanks, second stage engines. Why waste the fuel needed to get all that mass to a soft landing on the Moon, and then lift it back off?...
I'm not sure landing the BFS itself on the Moon is a good idea since it will have a lot of mass that won't do any good on the moon, e.g. airframe, heat shield, Earth return fuel, tanks, second stage engines. Why waste the fuel needed to get all that mass to a soft landing on the Moon, and then lift it back off?A separate lander with enough structure, engines, and fuel to go up and down and support the crew on the surface sounds more sensible to me. Perhaps a two part lander with living quarters that could remain on the Moon for later incorporation into a larger lunar habitat, and a much lighter launcher just to get the people back to the orbiting BFS. Maybe that could be left in lunar orbit for the next flight to be refueled and reused.Back on topic for a moment: I remain doubtful NASA is going to accept the BFR without an escape system for a very long time, however, there are so few crewed flights, why should SpaceX bother?A related question though is if there will be enough (or any) non-NASA crewed flights that would justify designing and building a crewed version of the BFS. My personal guess is that for a long time the answer will be no.
Fuel is cheap. Vehicles are expensive. Human rated in-space vehicles are really expensive.
Quote from: envy887 on 10/12/2017 04:11 pmFuel is cheap. Vehicles are expensive. Human rated in-space vehicles are really expensive.Actually, fuel on the surface of the Moon is extremely expensive. If the goal is to actually put hardware mass on the Moon and do something with it, carrying a hundred tons of useless stuff along for the ride doesn't sound like a good idea.
I'm sure SpaceX will do the appropriate engineering trades. But it's important to remember that SpaceX optimises for cost. If it turns out cheaper to carry a hundred tons of useless stuff along for the ride then that's what they will do. People will other ideas are welcome to build their own rocket.
Or purchase cargo capacity to the moon and produce propellant to sell to SpaceX. SpaceX would buy it if cheaper than bringing their own propellant. But the propellant would have to be delivered to where SpaceX needs it.
Quote from: guckyfan on 10/13/2017 07:24 amOr purchase cargo capacity to the moon and produce propellant to sell to SpaceX. SpaceX would buy it if cheaper than bringing their own propellant. But the propellant would have to be delivered to where SpaceX needs it.I doubt that lunar-produced propellant would be cheaper to SpaceX than propellant sourced on Earth. The advantage of such propellant is that it enables a greater payload mass to the Moon, so the comparison would be between the additional income to SpaceX from that greater payload against the additional propellant expense to SpaceX. And the former depends on demand - if no-one needs the additional payload capability, they won't pay for it!
Quote from: CuddlyRocket on 10/13/2017 08:40 pmQuote from: guckyfan on 10/13/2017 07:24 amOr purchase cargo capacity to the moon and produce propellant to sell to SpaceX. SpaceX would buy it if cheaper than bringing their own propellant. But the propellant would have to be delivered to where SpaceX needs it.I doubt that lunar-produced propellant would be cheaper to SpaceX than propellant sourced on Earth. The advantage of such propellant is that it enables a greater payload mass to the Moon, so the comparison would be between the additional income to SpaceX from that greater payload against the additional propellant expense to SpaceX. And the former depends on demand - if no-one needs the additional payload capability, they won't pay for it!The mission profile proposed by Elon Musk was refuelling from a tanker in Earth Moon transfer. this would enable them to fly the full payload to the moon if not back. So anyone producing propellant on the moon would compete with the cost of that tanker. Or there is something on the moon valuable enough to justify large return payloads that need more propellant.
Propellant availability on the Moon enables you to send more payload to the Moon. Without such propellant availability, the BFS has to carry sufficient propellant to enable it to return. If propellant is available on the Moon, the BFS doesn't have to carry that amount of return propellant and additional payload can be carried instead.
The mission profile proposed by Elon Musk was refuelling from a tanker in Earth Moon transfer. this would enable them to fly the full payload to the moon if not back. So anyone producing propellant on the moon would compete with the cost of that tanker. Or there is something on the moon valuable enough to justify large return payloads that need more propellant.
Quote from: CuddlyRocket on 10/15/2017 11:28 amPropellant availability on the Moon enables you to send more payload to the Moon. Without such propellant availability, the BFS has to carry sufficient propellant to enable it to return. If propellant is available on the Moon, the BFS doesn't have to carry that amount of return propellant and additional payload can be carried instead.My understanding was that the additional tanker enables BFS to land its full 150t LEO payload on the Moon. To land more it would require adding payload in orbit. I am not sure this would make sense.
I suspect you're going to need more than one tanker flight! The BFS propellant load is more than 1,000t and a tanker can't get much more than 150t of spare propellant into LEO, let alone the high elliptical orbit it is proposed the BFS is in before TLI. You'll probably have to have multiple tanker flights to refuel the tankers that meet the BFS in its high elliptical orbit!Elon was a bit vague on payload to the Moon. I was assuming that a fully refueled BFS wouldn't be able to carry its own return propellant and a full 150t cargo. It's possible I'm wrong about that!
AIUI NASA only has to man-rate it to put their own people on it. If SpaceX want to put there own people on it, it doesn’t matter one lick what NASA thinks about having or not having LAS. FAA will only become interested if it hosts paying customers. If internal employees only, the FAA’s only concern is safety of the public.
There may well be a good argument for the proposals with a Dragon in the BFS nose with a way to blow the nose apart to release it in an emergency. After ascent, the crew could access the rest of the BFS volume.
Quote from: RDoc on 10/24/2017 01:05 amThere may well be a good argument for the proposals with a Dragon in the BFS nose with a way to blow the nose apart to release it in an emergency. After ascent, the crew could access the rest of the BFS volume.I tried to start a discussion about that earlier. What would a well designed, non-kludge solution look like.The nose, with some sort of ejectable nose cone, is no doubt the least controversial for LAS. It is a pity though if you are going to carry a Dragon all that way and not be able to use it for escape during reentry. Reentry may very likely be more dangerous than launch. There are more variables that you will have no control over, such as weather and micrometeoroid damage from months in space.(An ACRV would just be an easy bonus, pretty much for any configuration)
Why wouldn't the Dragon in the nose be usable for an emergency reentry lifeboat?
Im open to a Dragon on the nose that can be used during launch and reentry. Outline it for me. If people get enthusiastic maybe they will start playing around with models to show how the BFS, BFS nose cone and Dragon all fit together.
The problem of being sideways to the plasma is fairly obvious. There are lots of solutions of course, right up to designing a whole new Dragon 3.0 that is fully integrated with the nose cone and halfway to a Dream Chaser... though that is cheating a bit.Im open to a Dragon on the nose that can be used during launch and reentry. Outline it for me. If people get enthusiastic maybe they will start playing around with models to show how the BFS, BFS nose cone and Dragon all fit together.
Quote from: RDoc on 10/24/2017 06:58 pmWhy wouldn't the Dragon in the nose be usable for an emergency reentry lifeboat?The problem of being sideways to the plasma is fairly obvious. There are lots of solutions of course, right up to designing a whole new Dragon 3.0 that is fully integrated with the nose cone and halfway to a Dream Chaser... though that is cheating a bit.Im open to a Dragon on the nose that can be used during launch and reentry. Outline it for me. If people get enthusiastic maybe they will start playing around with models to show how the BFS, BFS nose cone and Dragon all fit together.
I'm assuming the lifeboat would be used if something disastrous happened in orbit, not while actually reentering! I'm pretty doubtful that would be possible with anything like current technology.