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Correct_Inspection25 t1_j69w4tx wrote

Reply to comment by CurtisLeow in NASA's 'Mega Moon Rocket' aced first flight and is ready for crewed Artemis II launch by sasko12

And the missing 2-3x of disposable Falcon Heavy mass to LTI? SpaceX could have funded the Rad hardened Dragon 7 years ago without NASA funding if they wanted to, but felt Starship was a better investment given the large expense and missing capabilities NASA required of its vendors.

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CurtisLeow t1_j6a0av0 wrote

We are talking about NASA, since this is a thread about NASA's SLS. We're talking about alternatives that NASA could have funded to the SLS. NASA could have paid to human-rate the Falcon Heavy, NASA could have paid to radiation harden Crew Dragon. That would have been a viable alternative to the SLS + Orion, at a far lower cost.

SpaceX absolutely decided to focus on Starship. But it doesn't change that Dragon + Falcon Heavy could have been used as a cheaper alternative to Orion + SLS.

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Correct_Inspection25 t1_j6a7zgp wrote

You said the Falcon Heavy was an alternative for SLS and it wasn’t going to work even if NASA dropped everything and paid SpaceX for everything. 7 years ago couldn’t meet basic SLS TLI payload/Delta V in full disposable mode means hasn’t ever been a viable SLS replacement for pounds to TLI, even if they had red dragon rad hardened at the time. Look at what SpaceX estimated the weight of Red Dragon, Falcon heavy couldn’t have delivered it to TLI fully loaded even for a reduced crew and scope, SpaceX was right to focus on using what they learned from the falcon Heavy’s failures and used the billions of Starship/Raptor NASA money on the next generation of Heavy Lift. https://en.m.wikipedia.org/wiki/SpaceX_Red_Dragon

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CurtisLeow t1_j6ahiea wrote

At one point the SLS was going to launch the Lunar Gateway, the cargo to the Lunar Gateway, the Europa Clipper, and crewed Lunar flyby missions. The vast majority of those missions have switched, at least partially, to the Falcon Heavy.

You may not like it, but the Falcon Heavy's performance is very comparable to the SLS. It's good enough. The Falcon Heavy can't launch Orion into TLI, but it can launch Dragon into TLI. NASA is already paying SpaceX to launch Dragon into TLI, as I've already pointed out, as I've already linked. So nit-picking over performance to the Moon is a distraction from the reality. The Falcon Heavy has almost entirely replaced the SLS.

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Correct_Inspection25 t1_j6ajvw1 wrote

I love the Falcon program and the Merlin’s, but they fell short for economic heavy lift reuse beyond LEO/ and limited apogee GEO kg to orbit/deltaV. Starship and Raptor economics for heavy lift and deep space crewed missions are money better spent than upgrading SpaceX 2010-2012 technology for NASA.

Please provide SpaceX’s claims that the Falcon Heavy could make TLI in 3-4 days fully crewed with 26,000kg? All the articles I can find when asked, SpaceX told NASA and the press in 2018 if they couldn’t replace the SLS/crewed mission scope, and that the fully disposable Falcon Heavy theoretical max payload to TLI was 18,000kg, but without serious modifications, 16,000kg for crewed 3-4 day TLI transit.

Fun fact: This is shortly before SpaceX publicly completely abandoned upgrading the Falcon Heavy (BFR/Red Dragon) program, and announced the new starship architecture and Booster heavy lift program keeping only the Raptor engines in the late fall early winter of 2018.

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