totm dec 2023 Artemis Discussion Thread

[kerbiloid]

Spoiler

  

1 hour ago, Nightside said:

Except possibly to serve as a petri dish if a crew becomes infected after departure.

When you realise that you forgot you hanky on the Earth.

Spoiler

 

 

[kerbiloid]

I was reading about the docking ports, particularily of the NASA standard (i.e. the androgynous one).

I may get it wrong, but afair, unlike the old male-female designs of Soyuz, etc, the NASA docking port currently doesn't provide fluid transfer, only electric contacts.

Ok, ISS can be provided with liquid supplies by Progresses.

But what about LOP-G? Old ports are obviously not an option, while the modern ones can't feed it?
How are they going to refuel it with RCS fuel and water?

[jinnantonix]

I wonder if the Dragon XL might have flexible hoses that could be man-handled by the crew through the ports across the HALO to the PPE and lander.  Hypergolics too toxic?

[tater]

 

[jinnantonix]

10 hours ago, tater said:

 

How else are they going to operate mining equipment in the darkness of polar craters?  Mirrors?  I don't think so.

[RCgothic]

Tim Dodd, The Everyday Astronaut, posted this earlier.

One error that's been caught already is that there are parts for 7SRBs, not 35.

 

[Flavio hc16]

8 hours ago, RCgothic said:

Tim Dodd, The Everyday Astronaut, posted this earlier.

One error that's been caught already is that there are parts for 7SRBs, not 35.

*boosters segments"

[tater]

*blink*

So Gateway, because SLS/Orion is incapable of real lunar mission, but Gateway because 24/7 comms! And polar! And "sustainable!" And ISRU experiments, because polar water! Except maybe now a landing plane change because?

Epic fail if true,

[RealKerbal3x]

49 minutes ago, tater said:

So Gateway, because SLS/Orion is incapable of real lunar mission, but Gateway because 24/7 comms! And polar! And "sustainable!" And ISRU experiments, because polar water! Except maybe now a landing plane change because?

Epic fail if true,

Watching Tim's video yesterday, I realised something: Artemis lunar operations are essentially designed so that the HLS vehicles make up for SLS/Orion's performance deficiencies. Orion can't reach low lunar orbit, so they put Gateway in a high elliptical orbit and left the landers to get the rest of the way down to the surface. 

Basically, NASA are insisting on using an underpowered rocket and spacecraft for their chosen mission profile, and then forcing commercial providers to make up for it. I'd say having a well-balanced and interconnected system is a part of being sustainable, and this certainly isn't that. 

[tater]

8 minutes ago, RealKerbal3x said:

Watching Tim's video yesterday, I realised something: Artemis lunar operations are essentially designed so that the HLS vehicles make up for SLS/Orion's performance deficiencies. Orion can't reach low lunar orbit, so they put Gateway in a high elliptical orbit and left the landers to get the rest of the way down to the surface. 

Basically, NASA are insisting on using an underpowered rocket and spacecraft for their chosen mission profile, and then forcing commercial providers to make up for it. I'd say having a well-balanced and interconnected system is a part of being sustainable, and this certainly isn't that. 

This has been true since forever.

The initial complaint about SLS/Orion, long before SpaceX was a significant force, and before Vulcan and NG were on the table (much less SS), was that it was "a rocket to nowhere."

Not cost, not schedule slip, assuming it had met every milestone and cost estimate and flew in 2016—still a rocket to nowhere.

No mission it could do. ARM was made up for it. Fly a probe to an asteroid, and secure a decent sized sample! Great idea. Bring sample to a distant lunar orbit—wait, what? Why? Just bring it HOME to Earth! Send astronauts to distant lunar orbit to pick it up, silly! But why? Because it costs more! (?)

if you're going to build a giant rocket without a specific mission, it better be a jack of all trades. For all the problems with Shuttle, for LEO it was just that.

[sh1pman]

Is landing on equator easier than South Pole? I don’t quite get it, why would they change the landing site?

[sevenperforce]

2 minutes ago, sh1pman said:

Is landing on equator easier than South Pole? I don’t quite get it, why would they change the landing site?

Equatorial landings have lower dV requirements, which is increasingly important because LOP-G seems less and less likely to be ready in time for A3.

[sh1pman]

8 minutes ago, sevenperforce said:

Equatorial landings have lower dV requirements

I thought that landing from circular polar orbit should cost about the same regardless of landing spot. 

[tater]

1 minute ago, sh1pman said:

I thought that landing from circular polar orbit should cost about the same regardless of landing spot. 

Yeah, but still more than a sensible mission direct to LLO, then the surface.

[sevenperforce]

16 hours ago, sh1pman said:

I thought that landing from circular polar orbit should cost about the same regardless of landing spot. 

The lander has lots of dV -- it's Orion that is lacking. 

[tater]

The whole reuse thing (sorry repeating a post from the other thread) makes little sense to me, honestly, at least with these tiny landers and no surface base.

A base is critical, else these landers are a mess and need disposal anyway. They will be covered with dust the first day (inside).

Better:

1. Land a hab unit that stays on the surface.

2. Use something like Dynetics to land a pressurized rover.

3. Land crew. Crew moves to hab with minimal surface interaction in s suit NOT for general EVA. That suit has a disposable cover, and it stored in the hab for egress to the lander. Hab contains EVA suits that stay in a dedicated airlock, keeping the hab as clean as possible (shower?).

[tater]

Alternately, you need something akin to what is so trivial in KSP in prop depots in game.

You have a facility, Gateway in this case. It includes a prop depot for the landers and transfer stages. The crew and reupply vehicles then have enough excess capacity that they fill up the prop depot with that extra mass they carry. This pretty much requires something perhaps more like ISS, where the station has some continuous use, so it's getting resupplied often, anyway. The props are then increased incidentally to that normal delivery schedule. Imagine if ISS had been storing props as small tanks, every launch of Dragon would then either have some important stuff in the trunk, or if no trunk cargo needed—a prop tank is delivered. Or a few sizes such that the payload to ISS is always maximized with any excess being props.

That's never going to happen with Gateway, though, since at best Orion can bring props for one segment of a lander system. Maybe it can build a prop depot for the ascent stage?

[kerbiloid]

First Buran was following the Shuttle design, now the Shuttle-derived SLS is following the Buran's Energy.

Spoiler

 

[tater]

JB clarifies:

 

[RCgothic]

 

 

 

 

 

 

 

 

[RCgothic]

 

 

[Guest]

https://www.nasa.gov/sites/default/files/atoms/files/artemis_plan-20200921.pdf

Here is the PDF of the plans

Artemis 1: 2021

Artemis 2: 2023

Artemis 3: 2024

Let's see if that sticks

Commercial landers will still plan to land in 2021.

Viper will launch before Artemis 1

The first Gateway element before Artemis 2

Interesting

[RCgothic]

I'd say SpaceX is likely to continue development whether or not they get NASA funding. Blue might. Dynetics would perhaps struggle.

 

[tater]

SpaceX has, and Blue Origin will have the ability to launch test  articles at cost. Dynetics is using Vulcan, so any test is 3 Vulcan launches, making it pretty difficult.

[tater]

LOL (relevant to all the companies, and pretty much all of them have some skin in the Artemis game, so here seems like a good place to put it):