Total Members Voted: 30
Voting closed: 06/01/2023 07:41 pm
Would you actually NEED a sea level raptor engine for a ship that never lands on earth and only flies in earth's atmosphere once?
Quote from: georgionimo on 04/30/2020 06:42 pmWould you actually NEED a sea level raptor engine for a ship that never lands on earth and only flies in earth's atmosphere once?Yes because it need to take off from Earth.
I am personally really really surprised the Boeing isn't even in the shortlist... Thats the most shocking thing about this to me.
Does anyone have a link for the conops for this lunar starship? Here are my questions:1. How does it get to lunar orbit the first time? Does this always stay between the lunar surface and NRHO once in place? 2. How is it refueled in NRHO? How many launches from Earth does it take to get a tanker to NRHO with sufficient fuel? Thanks
Quote from: mainmind on 04/30/2020 07:17 pmDoes anyone have a link for the conops for this lunar starship? Here are my questions:1. How does it get to lunar orbit the first time? Does this always stay between the lunar surface and NRHO once in place? 2. How is it refueled in NRHO? How many launches from Earth does it take to get a tanker to NRHO with sufficient fuel? ThanksStarting fully fueled in LEO, a 110 t Starship can bring 10 t of payload to NRHO, then to the lunar surface, then back to NRHO without any refueling. It takes a total of 8 launches to fill it in LEO.A refueling tanker takes the same number of launches. So every crew landing will require 8 Starship/Superheavy launches. But it's a fully reusable system throughout (except for the SLS used to launch the crew to NRHO).
Quote from: supersubie on 04/30/2020 07:14 pmI am personally really really surprised the Boeing isn't even in the shortlist... Thats the most shocking thing about this to me.I'm not surprised. NASA wants to spread the money around and Boeing is building SLS.
Reality has finally arrived. It will be interesting to follow this side project for SpaceX. How to handle fast iterations with crew approved design. By looking at the dragon they will probably have to make some major design changes that will prolong time to flight.
Quote from: envy887 on 04/30/2020 07:40 pmQuote from: mainmind on 04/30/2020 07:17 pmDoes anyone have a link for the conops for this lunar starship? Here are my questions:1. How does it get to lunar orbit the first time? Does this always stay between the lunar surface and NRHO once in place? 2. How is it refueled in NRHO? How many launches from Earth does it take to get a tanker to NRHO with sufficient fuel? ThanksStarting fully fueled in LEO, a 110 t Starship can bring 10 t of payload to NRHO, then to the lunar surface, then back to NRHO without any refueling. It takes a total of 8 launches to fill it in LEO.A refueling tanker takes the same number of launches. So every crew landing will require 8 Starship/Superheavy launches. But it's a fully reusable system throughout (except for the SLS used to launch the crew to NRHO).How much could they land on the Moon if it was going to stay there permanently? A lot! Starter base makes sense to me. I'll shut up about it now. Sorry. I really want a nice Moon Base.John
Interesting, special landing thrusters. Certainly useful on the moon.
Quote from: livingjw on 04/30/2020 07:46 pmQuote from: envy887 on 04/30/2020 07:40 pmQuote from: mainmind on 04/30/2020 07:17 pmDoes anyone have a link for the conops for this lunar starship? Here are my questions:1. How does it get to lunar orbit the first time? Does this always stay between the lunar surface and NRHO once in place? 2. How is it refueled in NRHO? How many launches from Earth does it take to get a tanker to NRHO with sufficient fuel? ThanksStarting fully fueled in LEO, a 110 t Starship can bring 10 t of payload to NRHO, then to the lunar surface, then back to NRHO without any refueling. It takes a total of 8 launches to fill it in LEO.A refueling tanker takes the same number of launches. So every crew landing will require 8 Starship/Superheavy launches. But it's a fully reusable system throughout (except for the SLS used to launch the crew to NRHO).How much could they land on the Moon if it was going to stay there permanently? A lot! Starter base makes sense to me. I'll shut up about it now. Sorry. I really want a nice Moon Base.JohnJohn, me too. Me too.I'd love to see them take a Starship to the moon and get it on to it's side.Producing LOx on the moon will simplify logistics.
Quote from: Lars-J on 04/30/2020 05:53 pmInteresting, special landing thrusters. Certainly useful on the moon.Six raptors are way overkill. Six 10kN liquid or gas RCS derived, too small. Other than the 3/4 scale raptor prototype, has there been a hint of smaller methalox engine development?Phil
Quote from: rsdavis9 on 04/30/2020 06:09 pmSo if SS is 400t at landing time.120t vehicle150t payload100t fuel for back to LLO(120t+150t+100t)*moongravity=600kN6 10t GOX/GCH4 thrusters6*10t*earthgravity=588kNPretty close to even.Don't know if 100t to LLO is correct?EDIT: I just checked 3000m/s LLO velocityisp of 370 gives 3 for Mass Fraction360t/120t=3 for mass fractionSo 240t of fuel.I think I did that right.Probably there will be 9 thrusters - angle between visible groups of thrusters looks like 120 degree
So if SS is 400t at landing time.120t vehicle150t payload100t fuel for back to LLO(120t+150t+100t)*moongravity=600kN6 10t GOX/GCH4 thrusters6*10t*earthgravity=588kNPretty close to even.Don't know if 100t to LLO is correct?EDIT: I just checked 3000m/s LLO velocityisp of 370 gives 3 for Mass Fraction360t/120t=3 for mass fractionSo 240t of fuel.I think I did that right.
Quote from: AndrewStrogoush on 04/30/2020 06:21 pmQuote from: rsdavis9 on 04/30/2020 06:09 pmSo if SS is 400t at landing time.120t vehicle150t payload100t fuel for back to LLO(120t+150t+100t)*moongravity=600kN6 10t GOX/GCH4 thrusters6*10t*earthgravity=588kNPretty close to even.Don't know if 100t to LLO is correct?EDIT: I just checked 3000m/s LLO velocityisp of 370 gives 3 for Mass Fraction360t/120t=3 for mass fractionSo 240t of fuel.I think I did that right.Probably there will be 9 thrusters - angle between visible groups of thrusters looks like 120 degreeA question for those who really are rocket scientists: are gas/gas thrusters throttle friendly? I would expect so but don’t really know. Phil
i noticed this:Several Starships serve distinct purposes in enabling human landing missions, each based on the common Starship design. A propellant storage Starship will park in low-Earth orbit to be supplied by a tanker Starship. The human-rated Starship will launch to the storage unit in Earth orbit, fuel up, and continue to lunar orbit.
Also looking forward to the first fan photoshop showing the three landers next to each other in scale. Might give some perspective to those already questioning Lunar Starship's capabilities.