SLS Artemis II - Core Stage 2 Status

[Chris Bergin]

Let's kick off a thread for Artemis-II (yeah, we still will have lots of Artemis-I threads to do including the big launch thread when they rollout).

Philip toured MAF and interviewed SLS Boeing folk, so here's an article from him, extensive as usual. Photos are his, but he took A LOT. Will be a full dump in L2 later. Epic to see MAF in this detail after the last major MAF photo dump during Shuttle.

https://www.nasaspaceflight.com/2022/07/boeing-second-sls-core-march/

https://twitter.com/NASASpaceflight/status/1551602098315427840

[whitelancer64]

There is already an Artemis 2 update thread:

https://forum.nasaspaceflight.com/index.php?topic=54249.0

Is this thread intended to be just for booster processing updates?

[Vahe231991]

There is already an Artemis 2 update thread:

https://forum.nasaspaceflight.com/index.php?topic=54249.0

Is this thread intended to be just for booster processing updates?

Yes, this thread only deals with the status of the core stage for the SLS rocket earmarked for the Artemis 2 mission.

[Rondaz]

Our @esa astronauts @Thom_astro and @Astro_Alex with the second European Service Module that will power the crew of #Artemis II.

https://twitter.com/esaspaceflight/status/1563923808678969349

[Rondaz]

European Service Module was built with hardware contributions from ten @ESA Member State countries: Belgium, Denmark, France, Germany, Italy, Netherlands, Norway, Spain, Sweden, Switzerland.

We got to gaze upon ESM-2, which will power astronauts around the Moon on #Artemis II.

https://twitter.com/AschbacherJosef/status/1563897889600012292

[Rondaz]

More info and flight plan for #Artemis II..

https://twitter.com/esa/status/1563915219784564736

[cplchanb]

Will they orbit the moon a few times or a will they just do a direct slingshot back? It seems like a wasted opportunity if it's the latter. Apollo 8 orbited the moon several times

[Mark S]

Doesn't the ICPS perform the TLI burn? Infographic says that the ESM performs the TLI burn. I would be very surprised if ICPS can only get Orion to high Earth orbit.

I mean technically the moon is in high Earth orbit, and so is JWST, so maybe that's what they mean.

[DistantTemple]

Will they orbit the moon a few times or a will they just do a direct slingshot back? It seems like a wasted opportunity if it's the latter. Apollo 8 orbited the moon several times

The thread title is Artemis TWO. And cplchanb's question was immediately following a graphic of that(Artemis TWO) mission plan..... which doesn't show a full orbit of the moon.
AC in NC you SWITCHED to Artemis ONE!

[Proponent]

Doesn't the ICPS perform the TLI burn? Infographic says that the ESM performs the TLI burn. I would be very surprised if ICPS can only get Orion to high Earth orbit.

I mean technically the moon is in high Earth orbit, and so is JWST, so maybe that's what they mean.

I believe the plan is for ICPS to inject Orion into a highly elliptical orbit in which Orion will remain for 30 or so hours to check out the ECLSS. From that orbit, Orion itself can perform TLI.

[kdhilliard]

Will they orbit the moon a few times or a will they just do a direct slingshot back? It seems like a wasted opportunity if it's the latter. Apollo 8 orbited the moon several times

Artemis 2 does not enter Lunar orbit but instead flies a "hybrid free return trajectory".
See NASA’s First Flight With Crew (NASA, Aug 27, 2018)

10 day mission: First a 115 x 1,800 mile (185 x 2,900 km) 90 minute orbit for initial checkout, then a 235 x 68,000 (380 x 110,000 km) 42 hour high-Earth orbit, both done by ICPS, with the later representing most of the effort toward TLI.  Orion then separates from ICPS to conduct proximity operations.  (ICPS later conducts a disposal burn for atmospheric reentry.)  At perigee, Orion's service module completes the TLI.  Then 4 days out past the Moon and 4,600 miles (7,400) beyond, then 4 days back.

So no lunar orbit, but an interesting start with the high-Earth orbit.

[lrk]

(ICPS later conducts a disposal burn for atmospheric reentry.)

I thought the plan was, at one point, that ICPS would perform its own TLI burn after separating from Orion to deliver secondary smallsat payloads to the moon.  Has this plan changed?

[jadebenn]

(ICPS later conducts a disposal burn for atmospheric reentry.)

I thought the plan was, at one point, that ICPS would perform its own TLI burn after separating from Orion to deliver secondary smallsat payloads to the moon.  Has this plan changed?

I believe that was a casualty of the rendezvous component being added to the mission.

[cplchanb]

Will they orbit the moon a few times or a will they just do a direct slingshot back? It seems like a wasted opportunity if it's the latter. Apollo 8 orbited the moon several times

Artemis 2 does not enter Lunar orbit but instead flies a "hybrid free return trajectory".
See NASA’s First Flight With Crew (NASA, Aug 27, 2018)

10 day mission: First a 115 x 1,800 mile (185 x 2,900 km) 90 minute orbit for initial checkout, then a 235 x 68,000 (380 x 110,000 km) 42 hour high-Earth orbit, both done by ICPS, with the later representing most of the effort toward TLI.  Orion then separates from ICPS to conduct proximity operations.  (ICPS later conducts a disposal burn for atmospheric reentry.)  At perigee, Orion's service module completes the TLI.  Then 4 days out past the Moon and 4,600 miles (7,400) beyond, then 4 days back.

So no lunar orbit, but an interesting start with the high-Earth orbit.

Interesting that Orion itself can do TLI while for Saturn V the SIVB was required

[Jim]

Will they orbit the moon a few times or a will they just do a direct slingshot back? It seems like a wasted opportunity if it's the latter. Apollo 8 orbited the moon several times

Artemis 2 does not enter Lunar orbit but instead flies a "hybrid free return trajectory".
See NASA’s First Flight With Crew (NASA, Aug 27, 2018)

10 day mission: First a 115 x 1,800 mile (185 x 2,900 km) 90 minute orbit for initial checkout, then a 235 x 68,000 (380 x 110,000 km) 42 hour high-Earth orbit, both done by ICPS, with the later representing most of the effort toward TLI.  Orion then separates from ICPS to conduct proximity operations.  (ICPS later conducts a disposal burn for atmospheric reentry.)  At perigee, Orion's service module completes the TLI.  Then 4 days out past the Moon and 4,600 miles (7,400) beyond, then 4 days back.

So no lunar orbit, but an interesting start with the high-Earth orbit.

Interesting that Orion itself can do TLI while for Saturn V the SIVB was required

Not really
A.  S-IVB was sending CSM and LM from 100 nmi circular
b.  Going from 68k to 250k is not that much dV.
c.  Orion is not going into lunar orbit
d.  Orion is not making a TEI burn
c.  NRHO is used for the Gateway because Orion can't take payloads to LLO

[whitelancer64]

It appears that this was overlooked -

"Teams have delivered the four RS-25 engines that will help power Artemis II, the first crewed mission of NASA’s Artemis missions and second flight of the Space Launch System (SLS) rocket, to NASA’s Michoud Assembly Facility in New Orleans. Later this fall, the engines will be installed into the Artemis II core stage, which is in the final phase of assembly at Michoud where it was manufactured. Trucks transported the engines in special containers from NASA’s Stennis Space Center near Bay St. Louis, Mississippi, where they were upgraded with new controllers.

Together, the four RS-25 engines will produce more than 2 million pounds of thrust during ascent to help send Artemis II astronauts beyond Earth’s orbit to lunar orbit. Technicians from NASA and Aerojet Rocketdyne, the prime contractor for the engines, will store the engines at Michoud and prepare them for integration into the engine section at the bottom of the rocket’s 212-foot-tall core stage. They will use a pathfinder engine to practice the intricate process of installing each engine on the stage prior to installing the flight engines.

The first engine – Engine E2047 -- of the flight set flew on 15 space shuttle missions, including the final shuttle mission STS-135. The second engine of the set – Engine E2059 -- previously flew on five shuttle missions. The third and fourth engines – E2062 and E2063 – are new engines that include some previously flown hardware.

With the Artemis missions, NASA will land the first woman and the first person of color on the Moon and establish long-term exploration in preparation for missions to Mars. SLS and NASA’s Orion spacecraft, along with the commercial human landing system and the Gateway in orbit around the Moon, are NASA’s backbone for deep space exploration. SLS is the only rocket that can send Orion, astronauts, and supplies to the Moon in a single mission.

Image Credit: NASA/ Michael DeMocker

Last Updated: Sep 29, 2022
Editor: Lee Mohon"

https://www.nasa.gov/exploration/systems/sls/artemis-ii-rocket-engines-arrive-at-nasa-s-michoud-assembly-facility.html

[Vahe231991]

(ICPS later conducts a disposal burn for atmospheric reentry.)

I thought the plan was, at one point, that ICPS would perform its own TLI burn after separating from Orion to deliver secondary smallsat payloads to the moon.  Has this plan changed?

The ICPS is actually designed to enter a heliocentric orbit, circling the Sun until it is destroyed.

[hektor]

[woods170]

(ICPS later conducts a disposal burn for atmospheric reentry.)

I thought the plan was, at one point, that ICPS would perform its own TLI burn after separating from Orion to deliver secondary smallsat payloads to the moon.  Has this plan changed?

I believe that was a casualty of the rendezvous component being added to the mission.

That AND the 40 hour check out period (ECLSS related) in HEO. After the PRM and ARB burns the iCPS is done. After separation it is sent into heliocentric orbit. That leaves Orion's own propulsion system to complete TLI 2.  Which leaves Orion with insufficient propellant to enter and leave any kind of safe lunar orbit. Hence the "once around", similar to Apollo 13.


More details here, in Philips' excellent article from 2018(!), when this was still called Exploration Mission 2: https://www.nasaspaceflight.com/2018/12/plan-d-nasa-updates-em-2-baseline/

[Vahe231991]

The latest on the manufacture of the core stage of the SLS rocket slated to launch Artemis 2:
https://www.nasa.gov/exploration/systems/sls/nasa-connects-all-major-structures-of-artemis-ii-moon-rocket-core-stage.html

[Hog]

The latest on the manufacture of the core stage of the SLS rocket slated to launch Artemis 2:
https://www.nasa.gov/exploration/systems/sls/nasa-connects-all-major-structures-of-artemis-ii-moon-rocket-core-stage.html

Dated March 20, 2023.

[arthuroMo]

Next step should be mounting of the engines, and this should start in July according to the March 7th teleconference.

[agusaf]

Why wait?  SpaceX can build 3 full Starship rockets in that amount of time.  I don’t understand why SLS production moves at a snail’s pace when compared to SpaceX.

[eeergo]

No, SpaceX can't build 3 full Starship prototypes (let alone functional Starships) in that amount of time, or even close to that.

Also, SpaceX is supposed to be in a hardware-rich development program that is resulting in a large string of mission failures along the way, no matter how useful or successful you consider those tests to be. This includes significant risks, or even damages, to infrastructure. SLS and Orion are not on that path, and for better or worse you consider that strategy, they have flown in VHEO or DRHO in EFT-1 and EM-1 respectively, in spite of several strong changes of direction regarding mission objectives (driven by political rather than technical powers), with no major technical issues.

However, SLS is driven by constraints that aren't purely technical in nature, and have more to do with a limited-budget architecture where launches are only a means to a (lunar) exploratory aim that needs many more developments behind it.

[arthuroMo]

SpaceX can built many starships that will explode in test flight sure.
NASA need SLS that can safely carry humans.

[agusaf]

Installing four RS-25s on an SLS boat tail is a known procedure. 

[arthuroMo]

Yes it's been done once.

[catdlr]

and flight engines (RS-25) that are dependable.

[whitelancer64]

Yes it's been done once.

And the procedure for installation was modified extensively during that time, including changes that were rolled into the procedures for the next time, Artemis 2.

And the procedure is going to be different for Artemis 3, since engine installation will be done at KSC.

[FutureSpaceTourist]

https://twitter.com/jeff_foust/status/1666444038860419072

NASA's Jim Free says at the AESB/SSB meeting this morning that the Artemis 2 SLS core stage will be shipped to KSC in October, later than planned because of an issue with a supplier. Some work on the stage slated to take place at KSC will be done at Michoud.

[eeergo]

NASA's Jim Free says at the AESB/SSB meeting this morning that the Artemis 2 SLS core stage will be shipped to KSC in October, later than planned because of an issue with a supplier. Some work on the stage slated to take place at KSC will be done at Michoud.

This is largely in line with the schedule reported in the main Updates thread, already back in February (NET 3Q23) and refined a month ago ("early Fall"), with at most 2-3 weeks' worth of delay (which could be mostly moot anyway since some of the work left for KSC can be done at MSFC while they wait, as mentioned by Foust, and CS-2 not being the long pole, it was supposed to dwell in the VAB for a few months once shipped).

Will be interesting to see if it holds though.

[catdlr]

Phillip Sloss provides an update on the core stage processing and engine swap that is taking place.

https://forum.nasaspaceflight.com/index.php?topic=58223.msg2674075#msg2674075

Timestamp:
02:51 SLS Core Stage lift begins for stacking with Boosters
06:29 LVSA moved back where it was before
07:35 Core Stage engine 4, RS-25 engine 2063 will be replaced with engine 2061

[pochimax]

Going to VAB from MPPF

https://twitter.com/NASAGroundSys/status/1912181741260804274

https://twitter.com/RoughRidersShow/status/1912232808858132799