totm dec 2023 Artemis Discussion Thread

[RCgothic]

Sending the lander piecewise via FH, NG or Vulcan is literally 2 of the 3 options Artemis is pursuing.

Falcon Heavy can probably push 30te to TLI with EOR which translates to a 22te lander by the time you get to LLO. In two launches. 4 launches all up.

And if you feel like it, send the ascent and descent stages separately. Now you've got a 44te lander to LLO. In 6 launches all up.

At less booster cost than the *engines* of a single SLS.

82te total to TLI. Twice Saturn V. Just 5 cores expended.

Edited June 23, 2020 by RCgothic

[jinnantonix]

1 hour ago, RCgothic said:

Sending the lander piecewise via FH, NG or Vulcan is literally 2 of the 3 options Artemis is pursuing.

Falcon Heavy can probably push 30te to TLI with EOR which translates to a 22te lander by the time you get to LLO. In two launches. 4 launches all up.

And if you feel like it, send the ascent and descent stages separately. Now you've got a 44te lander to LLO. In 6 launches all up.

At less booster cost than the *engines* of a single SLS.

82te total to TLI. Twice Saturn V. Just 5 cores expended.

And a whole lot of risk, where any failure potentially cans the whole mission.

[RCgothic]

6 hours ago, jinnantonix said:

And a whole lot of risk, where any failure potentially cans the whole mission.

*Gestures at current Artemis plans.*

Edited June 24, 2020 by RCgothic

[magnemoe]

10 hours ago, wumpus said:

Pretty sure they sold Yusaku Maezawa a ticket on the Falcon Heavy before dropping the crew paperwork.  So presumably it is possible, although it would probably put a dent in the schedule (unless you still need SLS.  Starship should be ready before SLS).

Apollo LEM was ~18tons, meaning that it probably can't be fitted with something to circularize once it makes it to LTI (assuming fired from FH).  Also I doubt anyone is going to achieve modern safety levels in 18 tons or less, every gram was sweated there.

How hard would it be to crew rate FH then they have crew rated falcon 9 and dragon capsule? Sounds much easier than to crew rate starliner with vulcan who is an entire new rocket. 

[jinnantonix]

1 hour ago, RCgothic said:

*Gestures at current Artemis plans.*

Just making the point that risk is a factor, not just price.  I think Artemis 3 can be done with 3 launches - 2 x FH and/or Vulcan and 1 x SLS, and this may be preferable to a cheaper solution with 4 or more launches.

19 minutes ago, magnemoe said:

How hard would it be to crew rate FH then they have crew rated falcon 9 and dragon capsule? Sounds much easier than to crew rate starliner with vulcan who is an entire new rocket. 

I doubt that FH, Vulcan or Starliner will be crew rated any time soon.  That is why SLS/Orion continues to be a mandatory component of Artemis.

[RCgothic]

1 hour ago, jinnantonix said:

Just making the point that risk is a factor, not just price.  I think Artemis 3 can be done with 3 launches - 2 x FH and/or Vulcan and 1 x SLS, and this may be preferable to a cheaper solution with 4 or more launches.

I doubt that FH, Vulcan or Starliner will be crew rated any time soon.  That is why SLS/Orion continues to be a mandatory component of Artemis.

Falcon 9 and Falcon Heavy could send Dragon2 to *LLO* and return without crew-rating FH.

SLS does not have the capability to do the same with Orion.

 

Four flights of proven boosters that have flown is not necessarily more risky than 3 flights including a booster that hasn't and continues to be plagued by delays.  And risk isn't just about safety or mission success rate, it's also about schedule.

Will SLS Orion be ready to deliver astronauts to a moon landing in 2024? Probably not.

Could F9/FH be ready to deliver astronauts to a moon landing in 2024? I think they have a higher state of current readiness and an agility and development pace that place them well to deliver.

Edited June 24, 2020 by RCgothic

[kerbiloid]

If scratch the ground but not deorbit, it's '"to the Moon", too, and with dynamic touchdown.

[jinnantonix]

1 hour ago, RCgothic said:

Falcon 9 and Falcon Heavy could send Dragon2 to *LLO* and return without crew-rating FH.

SLS does not have the capability to do the same with Orion.

 

So what?  The Artemis 3 mission is to land on the moon and return.  The capability of SLS and Orion to get to LLO is not a necessary part of the successful completion on that mission.

 

Quote

Four flights of proven boosters that have flown is not necessarily more risky than 3 flights including a booster that hasn't and continues to be plagued by delays.  And risk isn't just about safety or mission success rate, it's also about schedule.

Possibly true.  But not necessarily true.  Remember that the Space shuttle was human rated, and SLS is based on that, so it has history.  F9s crew rating is very new.

 

Quote

Will SLS Orion be ready to deliver astronauts to a moon landing in 2024? Probably not.

I disagree.  I think they are on schedule, although any serious unexpected setback will push the deadline to 2025.

 

Quote

Could F9/FH be ready to deliver astronauts to a moon landing in 2024? I think they have a higher state of current readiness and an agility and development pace that place them well to deliver.

I disagree.  You are underestimating the complexity of the mission, and the degree of investment in resources needed to successfully implement.  NASA is committed to Artemis.  There's a lot to be said for having a plan, having a budget, and committing.

[wumpus]

1 hour ago, jinnantonix said:

I disagree.  I think they are on schedule, although any serious unexpected setback will push the deadline to 2025.

I disagree.  You are underestimating the complexity of the mission, and the degree of investment in resources needed to successfully implement.  NASA is committed to Artemis.  There's a lot to be said for having a plan, having a budget, and committing.

How could they possibly be on schedule for 2024?  They would need at least one test flight for SLS, one complete and tested lander, all the gear that needs to go on multiple flights.  Seems like NASA has gone beyond accepting re-use and retropropulsive landings and taken up "Elon time".

According  to the infallible wiki all the lander contracts are listed as "study".  Don't expect "old space" to make a single drawing ready without a contract to design.  I can understand that no NASA employee would ever suggest that such a monumental program would happen in some other administration's tenure (it is entirely possible that NASA only made it to the Moon because they were given the full 8 years [into the Nixon administration] to get to the Moon, not before 1969 when Kennedy could no longer remain in office (assuming he was still alive and won in 1964)).

[tater]

The idea that they could do a crew surface mission in 2024 seems so unlikely as to be comical to me. 3.5 years. We're at best a year out from an uncrewed SLS/Orion mission, and 2 years from a crew mission. So where Orion was 1.5 years ago is where any human landing system needs to be for 2024.

https://www.nasaspaceflight.com/2018/12/crewed-orion-passes-critical-design-review/

^^^ end of December 2018. 1.5 years ago. Orion passes CDR.

What human lander systems have actual hardware, and are in CDR, much less passed CDR?

Edited June 24, 2020 by tater

[jinnantonix]

11 hours ago, tater said:

The idea that they could do a crew surface mission in 2024 seems so unlikely as to be comical to me. 3.5 years.

Unless the chosen HLS contractor has successfully completed an autonomous uncrewed test landing prior to the proposed 2024 Artemis 3 mission, then I would agree that the schedule is unrealistic.  

[tater]

44 minutes ago, jinnantonix said:

Unless the chosen HLS contractor has successfully completed an autonomous uncrewed test landing prior to the proposed 2024 Artemis 3 mission, then I would agree that the schedule is unrealistic.  

I certainly think the best chance of success will involve one of the 3 just flying a test mission ASAP. Honestly not sure which is least likely.

[Lewie]

I am not sure if this falls under politics or not, but I don't believe it does too much so here goes-

I see sls as a giant waste of money, time and resources.  I mean, they are re-using old shuttle parts. The rs-25 engines proved to be quite problematic throughout the life of the shuttle. 

Also, the insane cost of sls. When comping it to rockets like the Falcon 9, Falcon Heavy and the dragon capsule, it really isn't practical. To be honest, it'd probably be for the best of all worlds in NASA helped Space X develop starship. When you look at the costs for Starship andt he sls, starship takes the cake. It just beats sls in pretty much every way.

[Dirkidirk]

15 minutes ago, Lewie said:

I see sls as a giant waste of money, time and resources.  I mean, they are re-using old shuttle parts. The rs-25 engines proved to be quite problematic throughout the life of the shuttle. 

Also, the insane cost of sls. When comping it to rockets like the Falcon 9, Falcon Heavy and the dragon capsule, it really isn't practical. To be honest, it'd probably be for the best of all worlds in NASA helped Space X develop starship. When you look at the costs for Starship andt he sls, starship takes the cake. It just beats sls in pretty much every way.

yes.

[tater]

Agree on the opportunity cost. RS-25 is a fantastic engine, though, just not ideal for a booster, imho. Of course since it can’t start in flight it’s not really good for anything in else. 

[RCgothic]

RS25 only makes sense as a recoverable reused engine. That's the only possible justification for an engine with a marginal cost of $100m. Amortise the cost with multiple reuses.

But it's also pretty hard to recover a sustainer engine.

 

 

To be completely fair to the HLSs, Orion passed CDR 1.5 years ago and will fly with crew in 1.5ish years, and the hold up in its first flight isn't Orion but SLS. Plus it's, you know, Boeing. So that 3 years can probably be shortened with an aggressive schedule. But yes, it's a big ask to get from development contracts to flight in 5 years.

The only actual hardware we can see is Starship.

At a push second stage reuse doesn't absolutely need to work out before the lunar lander mission. It'd probably still be more economical and schedule friendly not expend a load of tankers than launch a lander on SLS. 

But in-flight refuelling absolutely has to work.

Edited June 25, 2020 by RCgothic

[sevenperforce]

On 6/24/2020 at 6:16 AM, RCgothic said:

Falcon 9 and Falcon Heavy could send Dragon2 to *LLO* and return without crew-rating FH.

Small point here -- Falcon Heavy and Falcon 9 can both launch within a short period of time, but not if Falcon 9 is crewed, because pad 39A is the only one that can support FH, and it is the one with the crew access arm.

You could launch crew on F9 and then let them loiter until you could set up FH on 39A but I don't know how many days it would take. It would probably be easier to just crew-rate FH in the first place than it would be to retrofit pad 40 for FH. 

[RCgothic]

14 minutes ago, sevenperforce said:

Small point here -- Falcon Heavy and Falcon 9 can both launch within a short period of time, but not if Falcon 9 is crewed, because pad 39A is the only one that can support FH, and it is the one with the crew access arm.

You could launch crew on F9 and then let them loiter until you could set up FH on 39A but I don't know how many days it would take. It would probably be easier to just crew-rate FH in the first place than it would be to retrofit pad 40 for FH. 

A fair point, but I don't think adding a crew access tower to SLC-40 would be that big a deal.

[sevenperforce]

11 minutes ago, RCgothic said:

A fair point, but I don't think adding a crew access tower to SLC-40 would be that big a deal.

You need more than just a tower -- you need the bunker and the ziplines and uprating for the TEL (it's a different mechanism) and so forth.

[wumpus]

1 minute ago, sevenperforce said:

You need more than just a tower -- you need the bunker and the ziplines and uprating for the TEL (it's a different mechanism) and so forth.

Compared to full CDRs of all the landers and other non-SLS crewed vehicles?  And you get to do it in full parallel?  Sounds like the least of the schedule's issues.

But I don't see a lot of construction upgrading the pad, so I imagine the 2024 schedule only gets lip service.

[RCgothic]

Not needed for the current plan, anyway. Just a fantasy plan in which Orion SLS isn't required.

[tater]

[StrandedonEarth]

Not sure where the Gateway thread went, so I'll put this here...

Canada will be lending a hand (and arm) to Gateway/LOP-G...

https://www.nasaspaceflight.com/2020/06/canadarm3-to-support-gateway/

[kerbiloid]

7 hours ago, StrandedonEarth said:

Canada will be lending a hand (and arm) to Gateway/LOP-G...

US will attach LOP-G to the just another Canadian arm.

or

The next Canadian arm will be equipped with 3rd party LOP-G.

Edited July 2, 2020 by kerbiloid

[tater]

5 hours ago, kerbiloid said:

US will attach LOP-G to the just another Canadian arm.

or

The next Canadian arm will be equipped with 3rd party LOP-G.

Yeah, I hear there's a place people can go in LEO attached to Canadarm 2. Boggles the mind.