OP said “in space”. You’re arguing a nuanced point no one else is.

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Once again, Starship delays are irrelevant. It isn't and wasn't ever needed as a launch vehicle for a Moon program, nor was SLS. SLS/Orion, or whatever launch vehicle and capsule are used for Artemis, can't do anything useful until they have a working lander, however long that takes. But once Starship HLS is ready, you might as well make the most of it and replace SLS/Orion. (No other proposed HLS is nearly as far along as Starship, or even under contract to NASA yet. But the same could apply to most any hypothetical HLS, given all of the work that is left to it because of SLS/Orion's shortcomings.)

But since you insist: Orion has been in development since 2006, and SLS since 2011. SLS was based on the earlier Ares and Shuttle. Engines are arguably the most difficult part of a launch vehicle. The core stage engines and boosters for SLS were developed in the 1970s. The upper stage is a repurposed Delta III/IV upper stage using an improved version of an engine first developed in the 1950s. After all of that, SLS still flew nearly 6 years after, and cost twice as much as, what was originally planned.

Starship is a brand new and revolutionary vehicle and should be expected to take longer than SLS to develop. The earliest mention of anything like ITS, BFR, or Starship by SpaceX goes back only to 2012, and even mention of hydrogen fueled "Raptor" engines only goes back to 2009 (since 2012, the fuel has been methane). A Starship design similar its to current form (e.g., switching from carbon fiber to stainless steel) didn't even start until late 2018.

Despite all of that, Starship should make its orbital flight well within a year of SLS. The HLS Starship will of course be extra/different, but that was not contracted until 2021, and even then was delayed (at least on the NASA side) by Blue Origin. Orion has yet to fly with a full life support or any docking systems. SLS will still be using its "interim" upper stage through Artemis III.

I'm not sure what the fixation with radiation hardening is. SpaceX and others have all the access they need to NASA'a data and work on radiaiton. (Furthermore, resillience to radiation is also simpler to brute force with the mass and redundancy afforded by Starship.) SLS itself (and Dragon and Starliner) are not operated beyond LEO, so that is no more an issue than for any other rocket (or LEO capsule). Only Orion (or, as I am proposing a second HLS) and the HLS need to be designed for the deep space environment. Yet again, until the HLS is ready, no one from NASA is landing on the Moon. So even supposing it takes 20 years to get a radiation-hardened HLS, that won't change anything. Whenever the HLS design is ready, we might as well use it for all of Artemis' beyond LEO flight.

The funding models for SLS and Starship are also very different. NASA funding for the HLS is milestone based, and only paid after completing previously agreed upon milestones. SLS is funded in advance through Congress (often getting more than the administration requests). All of Boeing et al's costs are paid for plus a bonus, i.e. cost plus. (In theory, their poor performance should nix the plus part, but that didn't happen.)

Edit: typos

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Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:

|Fewer Letters|More Letters| |-------|---------|---| |BFG|Big Falcon Grasshopper ("Locust"), BFS test article| |BFR|Big Falcon Rocket (2018 rebiggened edition)| | |Yes, the F stands for something else; no, you're not the first to notice| |BFS|Big Falcon Spaceship (see BFR)| |CME|Coronal Mass Ejection| |CST|(Boeing) Crew Space Transportation capsules| | |Central Standard Time (UTC-6)| |ESA|European Space Agency| |EUS|Exploration Upper Stage| |GEO|Geostationary Earth Orbit (35786km)| |HLS|Human Landing System (Artemis)| |ICPS|Interim Cryogenic Propulsion Stage| |ITS|Interplanetary Transport System (2016 oversized edition) (see MCT)| | |Integrated Truss Structure| |Isp|Specific impulse (as explained by Scott Manley on YouTube)| | |Internet Service Provider| |KSP|Kerbal Space Program, the rocketry simulator| |LEO|Low Earth Orbit (180-2000km)| | |Law Enforcement Officer (most often mentioned during transport operations)| |MCT|Mars Colonial Transporter (see ITS)| |NERVA|Nuclear Engine for Rocket Vehicle Application (proposed engine design)| |NRHO|Near-Rectilinear Halo Orbit| |SLS|Space Launch System heavy-lift| |SRB|Solid Rocket Booster| |SSME|Space Shuttle Main Engine| |TLI|Trans-Lunar Injection maneuver| |TMI|Trans-Mars Injection maneuver|

|Jargon|Definition| |-------|---------|---| |Raptor|Methane-fueled rocket engine under development by SpaceX| |Starliner|Boeing commercial crew capsule CST-100| |ablative|Material which is intentionally destroyed in use (for example, heatshields which burn away to dissipate heat)| |apogee|Highest point in an elliptical orbit around Earth (when the orbiter is slowest)|

^(23 acronyms in this thread; )^(the most compressed thread commented on today)^( has 10 acronyms.)
^([Thread #8493 for this sub, first seen 28th Jan 2023, 23:09]) ^[FAQ] ^([Full list]) ^[Contact] ^([Source code])

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.

When approached by NASA in 2018 for potential SLS replacement, they stated to NASA and press questions that the best theoretical max for Falcon Heavy disposable TLI payload is 18,000kg, but only a realistic 16,000kg to lunar orbit for a crewed vehicle. The Mars injection is using the 6 month Holmann transfer window, and remember with crewed missions food/air consumption combined with minimum rad exposure is really important. This means flashlight style month long journeys to lunar orbit doesn’t make sense, and transits need to be between 3-4 days.

I want 4, each placed .25 ly from Sol, each pointing inward, so we can use Sol for a gravitational lens to amplify our knowledge about everything within a 100ly radius.

You said SLS is rad hardened not Artemis (Artemis isn’t even a vehicle, it’s a programme). Orion is “rad hardened” but except for the second stage, SLS doesn’t even leave LEO.

I’ve read the SpaceX submission. They’ve made a few changes to help reduce crew impact in the event of a CME, but the electronics are not rad hardened (radiation hardened CPUs and memory don’t have the performance SpaceX needs)

You also said that Commercial Crew gets an “exemption” because of they’re “short LEO missions”. Hint: they aren’t short

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What would be paused would be SLS / Orion until the problem was identified and fixed. Then the program would continue.

'Exploration' wouldn't stop.

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.

Wait so SLS doesn’t use the Artemis rad hardened crewed vehicle? NASA seemed to indicate the SLS launches Artemis to the moon.

I would re-read the latest SpaceX HLS submission to NASA, it included major changes including rad hardening (including moving tanks of water, supplies and fuel for radiation shielding of humans and key systems).

What orbit does the ISS station occupy? [Hint it’s inside the protection of the Van Allen belts at 240 miles. Max LEO orbit is 1,200 miles in altitude.]

But Apollo 1 was the first fatal accident involving a spacecraft in the pursuit of space exploration, period.

great show!

>2: it makes sense to me because if we can flip/rotates ia particles spin, why don’t we flip an antimatter particle?

"Spin" in particle physics isn't actually the particle spinning. Its just a name for a measure of angular momentum.

>why don’t we flip an antimatter particle?

Not sure what you mean by "flip". If you mean measure the spin, we can. A positron is an antimatter particle, and we can measure their spin.

>you’re probably not fun at parties

Why bother asking the question if you don't want / can't deal with a serious answer?

Dude you want to incur the wrath of the V?!

I had just had a baby and was in the hospital. My husband came in with the things I'd asked him to bring from home. He said "I have bad news. They lost the Shuttle." My brain couldn't comprehend that, so I said, "W-where did it go? They can't find it?" He said, "No, it blew up." In my overly hormonal emotional state, I had to keep switching channels on TV because I couldn't deal with seeing it. Finally I watched it about 10 pm. It looked like something evil had taken it over, with horns sprouting from it (the solud-rocket boosters shooting blindly upward).

Needless to say, I will never forget that.

The comet is called C2022/E3, if you head over to r/astrophotography a few of the guys there have taken some really good pictures

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1: you’re probably not fun at parties 2: it makes sense to me because if we can flip/rotates ia particles spin, why don’t we flip an antimatter particle? 3: you’re probably not fun at parties

SLS was always a place holder until the Obama commercial flight program investments for near earth exploration fully established themselves with their focus on self sustaining privatized profitability. SpaceX is awesome and should be celebrated for its speed, but so far seems to repeat the same missed self imposed overly ambitious timelines even with 50% NASA funding. Remember 6-8 years ago, SpaceX predicted that BFG and Red Dragon would be human rated and ready for deployment in 2020. It’s now 2023, BFR and Red dragon have been completely abandoned for Starship. And in 2023, with billions of NASA co-funding, SpaceX hasnt finished a test crewed vehicle, LSS, new lunar landing thusters, and are expecting to have a successful test launch this year to get to LEO, so figure SLS as something for SpaceX/commercial crewed systems to profit from, it has proved out the new high efficiency lunar injections, started the process of scouting base locations and new rad hardening technologies and permanent lunar presence locations SpaceX and others will use.

These hot, young stars have everything to prove!

Nah, I mean look at the 2 major Shuttle disasters, they just kept on using the same models for years. And mankind's need for exploration has always cost many lives.