Artemis III: NASA’s First Human Mission to the Lunar South Pole:https://www.nasa.gov/feature/artemis-iiihttps://twitter.com/NASAArtemis/status/1614023019122364422
Before the crew launch, SpaceX will launch a storage depot to Earth orbit. A series of reusable tankers will carry propellant to the storage depot to fuel the human landing system. The uncrewed Starship human landing system will then launch to Earth orbit and rendezvous with the storage depot to fill its tanks before executing a translunar injection engine burn and traveling approximately six days to NRHO where it will await the Artemis III crew.When both spacecraft have arrived in NRHO, Orion will dock with the Starship human landing system in preparation for the first lunar surface expedition of the 21st century. Once the crew and their supplies are ready, two astronauts will board Starship and two will remain in Orion. Orion will undock and back away from Starship to remain in NRHO for roughly one orbit around the Moon, lasting about 6.5 days. This will match the length of the surface expedition, so as Orion completes its orbit, the two person surface crew will finish their work on the surface in time to launch back up to meet the spacecraft. [...]Using advanced technology including autonomous systems, the crew inside of Starship will land at a carefully selected site within a 100-meter radius. [...]During their time on the Moon, the astronauts will do scientific work inside Starship and conduct a series of moonwalks, exiting Starship to explore the surface. The astronauts will don advanced spacesuits, exit through an airlock, and descend on Starship’s elevator. [...]When their surface expedition is complete, the two astronauts will lift off the surface of the Moon and head back to NRHO in Starship to reunite with their crewmates in Orion. After docking, the crew will spend up to five days in orbit, transferring samples between the vehicles and preparing for the journey back to Earth.When they reach the optimal NRHO departure point, with all four astronauts back in Orion, they will undock and ignite Orion’s engines, slinging the spacecraft past the Moon, and allowing it to coast toward Earth.
That seems an awfully long time to be stuck in the capsule.. the crew who stay onboard are pushing a month. Six days transit, six days waiting, six days loading and six days back ouch. Get me outa this thing
There is some new information in that Artemis III update. For example, HLS-Starship will meet Starship-Depot in Earth orbit and will take about 6 days to get to NRHO. The fact that it takes 6 days to get to NRHO sort of tells you that the Depot will either be in LEO or close to LEO. Some scientific work will be done by the astronauts on Starship while it is on the Moon. Then on the way back, Starship and Orion will spend up to 5 days docked to each other.
It seems like an updated lunar module could do the job. Wikipedia lists the Ascent stage as capable of 2220 m/s and the descent stage as capable of 2500 m/s. Of course, this isn't counting the rocks, rover, cameras, film, astronauts, etc. I think we are past the sortie phase though and we are definitely past film and so the requirements may be different. This just has to get them up and down to their equipment pre-placed on the surface. Sample collection can be done with robotic spacecraft. Doing the numbers myself doesn't exactly recreate that, but it is pretty close. That is basically what is required for NRHO to the surface and back give or take.I think a 15 t+ ascent stage is too big, and that cascades to come up with the 45 t mass. Probably better to keep it at the 30 t at gateway mass so future LVs can lift it all at once (as a precursor to all the fancy in orbit refueling and assembly). A 10 t stage can easily dock that to the gateway after TLI injection leading to a TLI mass of 40 t (maybe a little less). That can be thrown all at once with next generation SHLVs.But my preferred phase split is sort of opposite what is outlined here, instead of the descent stage being two stages with a space tug, the ascent stage should be two stages. The split is then the followingTLI to NRHO and descent: 3000 m/sascent to LLO: 1800 m/sLLO to NRHO: 900 m/sThis allows enough delta-v on lunar launch that, depending on where it is, it can separate from a malfunctioning ascent stage and either reach LLO or reach the surface again. The only phase of flight that doesn't have a backup is then LLO to NRHO, but you aren't going to hit the surface immediately after shutting everything down so it gives enough time for a rescue (probably the next lander docked at the DSG).
At AIAA SciTech, a NASA official says they're expecting to make the award for the second HLS lunar lander in "mid-summer." (As I recall, the solicitation projected an award in June.)
https://spacenews.com/spacex-completes-starship-wet-dress-rehearsal/QuoteThe agency is closely following SpaceX’s Starship tests. “I’m just thoroughly impressed by the scale of these pictures and what the vehicle looks like in an integrated stack,” said Ryan Joyce of NASA’s Langley Research Center, who is working on HLS, during a panel discussion Jan. 23 at the AIAA SciTech Forum, showing several images of Starship development. “We are literally trying to launch skyscrapers here.”NASA’s insight into Starship development includes having astronauts visit to ensure that the vehicle can be safely operated by them. “This is ultimately a vehicle that needs to be operated by the astronauts,” he said. “If you don’t have the conversations with astronauts, as crew members and operators of the spacecraft, during the design phase, you might get far enough along with your design before you find your vehicle is inoperable.”<snip>“It’s very exciting to see the progress being made at SpaceX facilities right now, including at KSC where they’re building a second orbital launch capability,” he said. NASA’s HLS awards leave it up to SpaceX to conduct its lunar lander launches either from KSC or Boca Chica, he noted.
The agency is closely following SpaceX’s Starship tests. “I’m just thoroughly impressed by the scale of these pictures and what the vehicle looks like in an integrated stack,” said Ryan Joyce of NASA’s Langley Research Center, who is working on HLS, during a panel discussion Jan. 23 at the AIAA SciTech Forum, showing several images of Starship development. “We are literally trying to launch skyscrapers here.”NASA’s insight into Starship development includes having astronauts visit to ensure that the vehicle can be safely operated by them. “This is ultimately a vehicle that needs to be operated by the astronauts,” he said. “If you don’t have the conversations with astronauts, as crew members and operators of the spacecraft, during the design phase, you might get far enough along with your design before you find your vehicle is inoperable.”<snip>“It’s very exciting to see the progress being made at SpaceX facilities right now, including at KSC where they’re building a second orbital launch capability,” he said. NASA’s HLS awards leave it up to SpaceX to conduct its lunar lander launches either from KSC or Boca Chica, he noted.
Updated Starship mass to "Earth orbit"Reusable: 150 metric tonsExpended: 250 metric tonshttps://www.spacex.com/vehicles/starship/
Quote from: docmordrid on 01/30/2023 05:30 amUpdated Starship mass to "Earth orbit"Reusable: 150 metric tonsExpended: 250 metric tonshttps://www.spacex.com/vehicles/starship/On the web page it is stated that the payload capacity is 100-250+ t (orbit dependent)Presuming the t means metric ton and the Starship is the standard transport variant.
Quote from: docmordrid on 01/30/2023 05:30 amUpdated Starship mass to "Earth orbit"Reusable: 150 metric tonsExpended: 250 metric tonshttps://www.spacex.com/vehicles/starship/Interesting! I wish we had orbit information for apple to apple comparison. If we assume the 2020 user guide numbers are still good then our three data points for LEO are:100 metric tons - 500km SSO, reuse without tanker refueling.150 metric tons - Reuse to unknown orbit. Unknown if tanker refueling is assumed for recovery.250 metric tons - Expended, presumably mass savings from removing reentry/landing hardware.
