You do know that these chemicals are manufactured on earth in industrial quantities, while methane isn't?
That means the manufacturing is well understood.
Just don't fire the thing near earth. Mars is already hazardous due to perchorates. Venus is full of sulfuric acid. The moon dust is hazardous, while the lunar water deposits contains chemical poisons. If you really are this worried about this, you should be freaking out about nitrogen oxides from cars - of which some of it is naturally NTO.
Few things would be worse than plans for another hypergolic fueled lander. ...It has no commonality with propellants of any modern western rocket in use or on the drawing board (meaning any use of excess propellant is a no go).
None of that is relevant to the excess propellant issue
Quote from: brickmack on 10/23/2018 11:12 pmNone of that is relevant to the excess propellant issueWas this a reply to me?If so, how is virtually every spacecraft using the same storable propellant type not relevant to the hypothetical excess hypergolic propellant issue?
Quote from: GWH on 10/09/2018 05:17 pmFew things would be worse than plans for another hypergolic fueled lander. ...It has no commonality with propellants of any modern western rocket in use or on the drawing board (meaning any use of excess propellant is a no go).If you limit yourself to launch vehicles and ignore Orion, Dragon, Cygnus, Starliner, Gateway, deep space probes, commercial satellites, space telescopes, or basically everything but launch vehicles that uses chemical propulsion, sure.
I would agree with GWH about not wanting a hypergolic lander, but the problem would not be no commonality with the propellant, but no commonality with the major existing HSF-scaled engines and associated infrastructure (incl. propellant). Even more than that, hypergolic is probably totally unsuitable for ISRU. If we go back to the moon IMO ISRU should be the major goal. We go to stay. We are not just trying to answer a handful of science questions but develop technology towards eventual space settlement.
Quote from: Joseph Peterson on 10/23/2018 11:42 pmQuote from: brickmack on 10/23/2018 11:12 pmNone of that is relevant to the excess propellant issueWas this a reply to me?If so, how is virtually every spacecraft using the same storable propellant type not relevant to the hypothetical excess hypergolic propellant issue?I would guess it has something to do with the fact that none of them are designed to be refueled in orbit, i could be wrong though.
I would agree with GWH about not wanting a hypergolic lander,
but the problem would not be no commonality with the propellant, but no commonality with the major existing HSF-scaled engines and associated infrastructure (incl. propellant).
Even more than that, hypergolic is probably totally unsuitable for ISRU.
If we go back to the moon IMO ISRU should be the major goal. We go to stay. We are not just trying to answer a handful of science questions but develop technology towards eventual space settlement.
Developing Lunar ISRU is a science problem. As of today there are only six sites, the Apollo landing sites, which have been studied enough that they could contain inferred mineral resources. Science needs to be done to measure resources before we can seriously consider creating proven reserves(in other words, functional ISRU).
{snip}Let me be clear. I would prefer to have a propellant that is less toxic than hydrazine. The problem is making the economics work without a $20+ billion NASA exploration budget to create demand in a reasonable time frame.{snip}
(1)-->Let me be clear. I would prefer to have a propellant that is less toxic than hydrazine. The problem is making the economics work without a $20+ billion NASA exploration budget to create demand in a reasonable time frame.(2)--> False. Dragon, Orion, and Starliner all use hydrazine.(3)--> Not totally unsuitable for ISRU, assuming we find the proper mix of elements. That said, the cost of setting up a hydrazine plant and its supply chain is not economically viable compared to shipping propellant to LLO from Earth.(4)--> Developing Lunar ISRU is a science problem. As of today there are only six sites, the Apollo landing sites, which have been studied enough that they could contain inferred mineral resources. Science needs to be done to measure resources before we can seriously consider creating proven reserves(in other words, functional ISRU). Denigrating the amount of science needed to be done by calling it a handful of science questions is improper.
Quote from: Joseph Peterson on 10/24/2018 10:38 pmDeveloping Lunar ISRU is a science problem. As of today there are only six sites, the Apollo landing sites, which have been studied enough that they could contain inferred mineral resources. Science needs to be done to measure resources before we can seriously consider creating proven reserves(in other words, functional ISRU). In principle, hydrolox driven from imported hydrogen with native oxygen resources could be an option to enable hydrolox to play a meaningful role.Oxygen is considerably easier to find, and reasonable simulants from the landing sites could help with development, rather than the considerably harder task of actually locating resources to mine water.A lander like the above, if re-oxygened on the moon could put down some 15 tons of payload, and take off with a similar large payload.(I have not done the maths).
Masten Space Systems are working on the XL-1 lunar lander NET 2021. Its propellant will be MXP-351, a non-toxic storable hypergolic propellant system.The Masten/ULA Xeus lander is due to use H2 and O2 as propellant.
(1) Nah. If you can't do it in a sensible manner, then chose smaller goals you can do in a sensible manner. Doing shoddy quick HSF is just an enormously expensive boondoggle to kill real progress.(2) I think you have missed the point about "no commonality with the major existing HSF-scaled engines" but it might be me. I know Dragon uses hydrazine but is anyone suggesting using the superdraco? I assumed we would have to develop a new engine. Even if it shares the same fuel it would be a different engine. You choose hydrazine for reliability, but the engines that get a hundred times more development will probably be more reliable as well as better performance and less toxic.(3) lets not niggle.(4) Absolutely I support doing science and prospecting.. ASAP and (initially) robotically. You can probably do those fine with existing small hypergolic engines. We don't know how much ice is really there. We know even less about hinted CO. It is totally ridiculous to be pushing for specific enormously expensive HSF architectures before sending something to have a decent poke around at the poles. (Im not accusing you of that, you could accuse me of the same thing. it is a general frustration of mine. It is something I have said over and over on this site.)
Who cares about hypergolic use in spacecraft, its a trivial mass in comparison to the mass needed for significant delta V. For which every crew sized launch vehicle uses either hydrolox of kerolox for, and soon methalox. Hypergolics play a secondary role in these areas. Yes there may be a market for GEO sats but in that realm electric propulsion is becoming more prevalent anyway. It's like if you could make your own fluids for your car, where would you put your efforts, gasoline or motor oil?As for the payload of the proposed lander, the "cargo" is only 5 tonnes but the Orion derived crew capsule is more like 15-20... it should be obvious that if being used for base building a cargo only variant would be developed and capable of 20+ tonnes.
{snip}One problem is creating meaningful oxygen production with a cargo limit of 1 tonne per trip. The only economically viable way I see to do this using the Lockmart design requires heavy modifications and "sacrificing" the spacecraft for tanks.The larger problem is that there simply isn't a market for hydrolox in space, outside of proposals. My preference is to spend the money on doing stuff on the Moon. Once we are doing enough stuff, Lunar propellant or oxidizer production makes economic sense over terrestrial hydrazine production and shipping. Figuring out what stuff makes sense is going to take years, so we should ignore Lunar propellant production for now. Quote from: A_M_Swallow on 10/24/2018 11:55 pmMasten Space Systems are working on the XL-1 lunar lander NET 2021. Its propellant will be MXP-351, a non-toxic storable hypergolic propellant system.The Masten/ULA Xeus lander is due to use H2 and O2 as propellant.MXP-351 shares the same fatal flaw as hydrolox for the purposes of this conversation, no commonality. Keep in mind the point I initially responded to was the claim that using hydrazine risks having unused propellant. As far as I know no spacecraft, let alone commercially viable ones, use MXP-351, meaning no other potential customers.{snip}
Quote from: Joseph Peterson on 10/25/2018 01:42 am{snip}One problem is creating meaningful oxygen production with a cargo limit of 1 tonne per trip. The only economically viable way I see to do this using the Lockmart design requires heavy modifications and "sacrificing" the spacecraft for tanks.The larger problem is that there simply isn't a market for hydrolox in space, outside of proposals. My preference is to spend the money on doing stuff on the Moon. Once we are doing enough stuff, Lunar propellant or oxidizer production makes economic sense over terrestrial hydrazine production and shipping. Figuring out what stuff makes sense is going to take years, so we should ignore Lunar propellant production for now. Quote from: A_M_Swallow on 10/24/2018 11:55 pmMasten Space Systems are working on the XL-1 lunar lander NET 2021. Its propellant will be MXP-351, a non-toxic storable hypergolic propellant system.The Masten/ULA Xeus lander is due to use H2 and O2 as propellant.MXP-351 shares the same fatal flaw as hydrolox for the purposes of this conversation, no commonality. Keep in mind the point I initially responded to was the claim that using hydrazine risks having unused propellant. As far as I know no spacecraft, let alone commercially viable ones, use MXP-351, meaning no other potential customers.{snip}Once the lander is in use and a MXP-351 propellant depot is in orbit then commonality works the other way. New spacecraft are made compatible with the XL-1.
So you want to redesign Orion for MXP-351.{snip}
This thread is about lunar landers.
First and foremost, only LOX/LH2 provides the performance required for a single stage lunar lander operating from the Gateway orbit, where the round trip ∆V is in excess of 5000 m/s.
The key attributes for this single stage, fully reusable crewed lunar lander are:• Capability of delivering a crew of up to 4 from the Gateway to the lunar surface• Capability of delivering 1 metric ton of payload to the surface per mission• Capability of operating on the surface for up to 2 weeks• Capability of returning the crew to the Gateway without maintenance or refueling while on the surface• Total ΔV capability of 5 km/s