…what about a modernised version? Similar payload, but with full reuse, potentially. Most of it can be already found in existing hardware.Essentially, Methalox F-1-class Booster, similar to S-IC (S-ID?), but kero swapped out for methane, plus using modernised engines in the same thrust class as F-1. Stage iOS equipped with reuse hardware e.g: legs and Gridfins“S-IIB” second stage, still hydrolox, but using J-2X engines. Similar reentry and landing profile to original F9 US proposal, but it flips over with the help of drogue chutes in the lower atmosphere and uses the centre J-2X (centre one would have a shortened nozzle) to land propulsively.“S-IVC” S3. Same as S-IIB but scaled down to S-IVB scale. Maybe a J-2T-esque upgrade in future upgrades for better performance?Lunar lander could just be Blue Moon or NG’s ALPACA proposal.CSM would just be Orion, or something similar.Obviously, NASA won’t got for it any time soon, because of SLS and the threat of only being able to do science, but I don’t care about that in this scenario. Is it feasible at all?
Fair enough. Does seem a bit overkill. Would probably be similar to if F9 did a ~5 engine landing burn. What about lots of RS-25-class Methalox engines, or maybe 4 outer F-1 class engines, but a few (say 3 or 4) RS-25-class engines in the centre?
…what about a modernised version? Similar payload, but with full reuse, potentially. Most of it can be already found in existing hardware.
but I don’t care about that in this scenario. Is it feasible at all?
F-1 and J-2s don't throttle and hence can't land and have too high of thrust for a proper throttle range
With reuse, it is not the same. Need to lengthen each stage for the additional propellant for boost backs and landing burns and for the additional structural mass for reuse. Also need more thrust now for the higher mass.And for what reason? Apollo (Saturn V) was flags and footprints and not extended stays on the moon with larger crews with more instruments. There is no need to bring back the Saturn V. And NASA is not the one to do it anyways. SLS will likely (>99%) be the last launch vehicle for NASA to manage and operate.
Lots of things are possible (i.e., to not violate the laws of physics or engineering), but why? After you get past physics and engineering, you get to economics. (In the real world, the economics usually drives the engineering).Your proposals require new engine design, which is expensive in time and money. They also require building engine factories, which require more time and money. Engine cost benefits in a big way from economies of scale. Thus, there are large advantages to using multiple instances of the same engine, and that is what SpaceX has done with the Raptor.Here is the evidence: you are looking for a "RS-25-class Methalox engine". A Raptor is exactly that. (Raptor has higher thrust). An RS-25 costs more than $100 million. The goal for Raptor is $250,000. Due to economies of scale, 400 raptors are cheaper than a single RS-25. Even if a Raptor costs $1 million, you can still buy Raptors for three entire Starship Boosters for the cost of a single RS-25. You can buy raptors for twelve Boosters for the cost of the engines on an SLS core.
Your proposal seems to throw everything away except for the dimensions. What would make these dimensions any better than any of the modern designs being worked on now?
NASA is not authorized by law to do this. (Congress authorized NASA to create and fly a Shuttle-Derived heavy lift vehicle; this is not that.) So the first obstacle is not technological but sociological. Who would fund this?Suppose someone began a grass-roots campaign to encourage efforts in this direction. What 'Figures Of Merit' would be used to show this approach is sound?For reference on figures of merit, see page 16 here:https://www.nasa.gov/wp-content/uploads/2015/01/525162main_heft_final_brief_508_20110309.pdfOr suppose some wealthy individual were convinced this was the way to go. What would it look like? (Hint: there are currently more than one such wealthy individual.)Or suppose some entrepreneur, constrained by available venture capital, were convinced this was the way to go. How would they start a company that could eventually do something like this? (Hint: there are currently more than one such entrepreneur.)
The logic behind Shuttle-era "why don't they just bring back Saturn V" was the comparison with the cost/capacity/cadence of STS.But today, even its self-proclaimed reasoning doesn't apply. Today, the comparison would be with SLS. But SLS already has superior rivals.So now you are effectively asking, "Why don't we pay Boeing to redesign SLS, but without the 'Shuttle-derived' requirement?"
IF, big IF, the US decided back about 20 years ago to build the RD-180 Russian engines in the US. They could have and had permission from Russia to do so. They could have made a 9-10 RD-180 engine booster that was reusable. This would have met or slightly exceeded Saturn V for a booster, and could have been reusable. Again using modern engines, upper stages could be built using BE-3U's from Blue Origin. Making a reusable upper stage, maybe. The booster idea was discussed by NASA and others when they decided on using the solids and the SSME's in the Constellation program which morphed into the SLS. I have always thought not making the RD-180's in the US was a mistake. We would still be using Atlas V's, and maybe evolved into the Atlas V Phase II program for launching Orion.
New Glenn Block 3 is roughly speaking ORSC Concept RAC 2 come to life.First stage with a cluster of ORSC hydrocarbon/lox engines (9 in this case) that shares that propulsion system with the DOD HLV (Vulcan).High thrust hydrolox stage as the second stage.Composite hydrolox third with a BE-7 (Centaur + RL-10 equivalent)Additional learnings have come in the 15 years since then. Obviously most prominent, a cluster of first stage engines enables VTVL reuse. Commercial can develop systems on their own 2 feet roughly speaking.Quotebut I don’t care about that in this scenario. Is it feasible at all?My brother it is already happening if you believe Blue will succeed in the ~2030 timeframe.
Not just Blue, but just the SpaceX Superheavy booster is more powerful than a Saturn V first stage. If NASA wanted to replicate Saturn V, then they could use a Superheavy booster from SpaceX, and upper stages made from BE-3U Blue Origin engines. A cluster of 10-12 on a second stage, but also 2-3 on a 3rd Stage. I don't believe NASA should try to build their own rockets anymore since SpaceX and Blue Origin are building newer improved rockets as well as them being reusable.
how is this an "advanced concept"?this belongs on the homeless posts thread.https://forum.nasaspaceflight.com/index.php?topic=53586.1040#lastPost
1. Hence the 2 or 3 RS-25-class engines clustered between the four outer F-1 class engines, though the J-2 is another issue. Maybe 1 or 2 BE-3s for propulsive landing instead of the centre engine?2. I suppose, though lengthening each stage could be feasible. Could NG’s second stage be considered for a beefier third stage? (With 1 or 2 BE-3s for landing). Saturn V could be used for more than flags and footprints, certainly in theory. After all, logically, a long-term exploration vehicle should have e more capacity than the Flags & Footprints one, and, 3. Good point, though some money would be saved due to using J-2X, BE-3, Orion, and Blue Moon. All that would be new would be (most of) the first stage engines (we’ll use one Raptor or Raptor-esque instead of 2 or 3 RS-25 class engines, maybe 2 if needed) and the fuselages, fairings and flight computer.4. Suppose someone began a grass-roots campaign to encourage efforts in this direction. What 'Figures Of Merit' would be used to show this approach is sound?Or suppose some entrepreneur, constrained by available venture capital, were convinced this was the way to go. How would they start a company that could eventually do something like this? (Hint: there are currently more than one such entrepreneur.)5. Oh, not Boeing. Deeeeeefinitely not Boeing. Collab between BO, SX, NASA, AR, etc could work, considering where the hardware comes from. Blue Moon & BEs from BO, SX helps with FFSC F-1 class engines, & provides a raptor for S-ID, NASA holds it together like glue, AR does J-2X etc. It would essentially be SLS, but far lower dev costs, lower cost per launch, and 6.cNot just Blue, but just the SpaceX Superheavy booster is more powerful than a Saturn V first stage. If NASA wanted to replicate Saturn V, then they could use a Superheavy booster from SpaceX, and upper stages made from BE-3U Blue Origin engines. A cluster of 10-12 on a second stage, but also 2-3 on a 3rd Stage. 7. I don't believe NASA should try to build their own rockets anymore since SpaceX and Blue Origin are building newer improved rockets as well as them being reusable.
1. no, you are mixing fuels and complicating things.2. not really feasible.3. no savings using tanks, fairings and computers (woefully out dated).4. nobody in their right mind would do this.5. why not Boeing?6. Rockets aren't legos7. NASA has never built their own rockets. Shuttle was reusable.
7. Yeah, always been contractors, but in this sense, “NASA-Built” means NASA-Designed. Again, sorry for confusion
NG Block 3? NG has blocks? (Do you mean New Armstrong or NG / Clipper?)
