-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
NASA Announcement for the Moon
- Thread starter Grendal
- Start date
In what sense was the Apollo 10 LEM "man rated"? And how could the other bidders "man-rate" their entries any faster than SpaceX?
Yep, NASA needs to “human rate” any spacecraft that carries humans.
e-FTW
New electron smell
Correct, I was not defending SLS, mainly repeating what I had read in the past that appeared to disqualify Starship from NASA work. ¯\_(ツ)_/¯ And I am at the limit of my knowledge on what that actually entails, so ummm... more coffee?
Excellent question. Apollo 5 took a LEM to orbit (Earth) but no crew onboard. Apollo 9 was crewed and included a LEM, Earth orbit only. Apollo 10 was crewed and went to the Moon with a LEM which then separated from the Command Module with two astronauts onboard the LEM and descended to 50,000 ft above the surface before redocking with the Command Module and returning to Earth.
Apollo program - Wikipedia
I just watched this again and realized I missed something important Scott said about the capabilities (or lack thereof) of what I have dubbed the Starship-L. At about 10:20 in the video Scott says that because the design does not include “aerobraking” capabilities (no canards and no heat shield is shown) he does not expect it to return to Earth but it will likely be left in lunar orbit after it takes humans to the lunar surface and then back to lunar orbit. Then he says that it will have to be refueled in lunar orbit with a Starship tanker. That further complicates the SpaceX mission concept.
So help me understand what Scott means when he says that the Starship-L can’t return to Earth orbit because it cannot do “aerobraking”. I know that when the Apollo capsule was orbiting the Moon and the Command Module engine fired for Transearth Injection the capsule was then captured by Earth’s gravity and then — without making an orbit — used aerobraking to re-enter the atmosphere and land.
But isn’t it possible for a spacecraft to make a Transearth Injection burn on a trajectory that will put it back into a stable orbit around the Earth without entering the atmosphere? Instead of losing delta V by aerobraking, lose it with an orbital insertion burn at a higher altitude and then a second burn to circularize it. That is how the Apollo Command Module entered lunar orbit.
All of this is part of my trying to understand all the reasons behind why SpaceX is proposing a Starship design for the NASA Moon mission that is so different from the design Elon has described for going to Mars.
Moon
Mars
Attachments
Yes it is, but here is a roughly 3 km/s delta V needed if talking LEO (0.68 from lunar transfer to GEO, 2.44 from GEO to LEO).
It's not so different. They pull off (really, don't install) the external parts that aren't needed and use the core that NASA helps fund.
Earth reentry version = Lunar + fins/ strakes/ elonators + heat shield (landing thrusters may be an add on). Stripping weight helps with the fuel requirements throughout the mission.
mongo did a great job in explaining the mechanics. In the larger SpaceX going to Mars - Elon's big goal - aspect to this then just understand this is designing seed money. It is not the build this and here is the contract for six Artemis to Moon landings with a minimum of two astronauts per landing. So this is NASA saying with some money to SpaceX that we see what you're doing and think it is somewhat viable. So continue what you're doing in developing this thing and go ahead and design that Moon lander concept you proposed. The bigger deal for NASA is that they can give SpaceX money for orbital refueling. Which, up until now, those controlling the Congressional purse strings has adamantly said NO to even considering. Congress has said no because they aren't interested in reusability or anything to do with making space cheaper. They are in it for the continued jobs and spending government money in their congressional districts and states. Colonizing Mars is Elon's goal - it is not the American governments goal. They care about American industry and American military industry and a little bit of flouting American greatness in achievements and science - which is sadly very low on the priority list.
So getting any money and consideration for SpaceX is a huge win for the company.
So getting any money and consideration for SpaceX is a huge win for the company.
Thanks for your analysis So do you think that SpaceX is not proposing a version of Starship that can take the astronauts all the way back to Earth because it simply isn’t feasible (due to the amount of fuel required) unless the payload to the lunar surface is so small as to overly constrain the mission?
So true. But what a boost it would be to American science and technology if the government got behind the mission of colonizing Mars and actively participated. Though probably Elon would reject the assistance because he would not want the oversight and additional complications.
Eric Berger analyzes NASA’s push for a Moon landing by 2024. A 2024 Moon landing may sound crazy, but NASA is giving its best shot
QUOTE: “NASA picked three separate designs for a human lander, and all three could launch on commercial rockets to the Moon. Blue Origin's Blue Moon lander could go on the New Glenn or Vulcan rockets. Dynetics' lander is baselined to the Vulcan rocket. However, to fly on commercial rockets, the landers would need to be broken into components and then assembled in lunar orbit. Potentially, these landers could be launched fully assembled on an upgraded SLS rocket (Block 1B), but it is highly unlikely this rocket would be ready by 2024—or even a year or two later. Finally, there is SpaceX's Starship lander. It would be launched to lunar orbit by the company's Super Heavy rocket, where it would rendezvous with astronauts for a lunar landing. Super Heavy is not yet built.”
I do not understand what he means by “Starship lander...would be launched to lunar orbit by the company's Super Heavy rocket, where it would rendezvous with astronauts for a lunar landing.”
The SpaceX proposal image (see upthread) shows what I am calling the Starship-L landing on the Moon with, I assume, crew on board. I also assumed that the Starship-L would have that crew aboard when it launched from Earth. But what Eric seems to be describing is a mission design where Starship-L launches with no crew and goes into lunar orbit and some other spacecraft takes the crew from Earth to lunar orbit to rendezvous with and transfer to Starship-L for the descent to the lunar surface.
Which seems very complicated and far more expensive than having the crew travel from Earth to the lunar surface and back to Earth orbit in a single vehicle, the Starship-L.
Obviously I’m missing something....
QUOTE: “NASA picked three separate designs for a human lander, and all three could launch on commercial rockets to the Moon. Blue Origin's Blue Moon lander could go on the New Glenn or Vulcan rockets. Dynetics' lander is baselined to the Vulcan rocket. However, to fly on commercial rockets, the landers would need to be broken into components and then assembled in lunar orbit. Potentially, these landers could be launched fully assembled on an upgraded SLS rocket (Block 1B), but it is highly unlikely this rocket would be ready by 2024—or even a year or two later. Finally, there is SpaceX's Starship lander. It would be launched to lunar orbit by the company's Super Heavy rocket, where it would rendezvous with astronauts for a lunar landing. Super Heavy is not yet built.”
I do not understand what he means by “Starship lander...would be launched to lunar orbit by the company's Super Heavy rocket, where it would rendezvous with astronauts for a lunar landing.”
The SpaceX proposal image (see upthread) shows what I am calling the Starship-L landing on the Moon with, I assume, crew on board. I also assumed that the Starship-L would have that crew aboard when it launched from Earth. But what Eric seems to be describing is a mission design where Starship-L launches with no crew and goes into lunar orbit and some other spacecraft takes the crew from Earth to lunar orbit to rendezvous with and transfer to Starship-L for the descent to the lunar surface.
Which seems very complicated and far more expensive than having the crew travel from Earth to the lunar surface and back to Earth orbit in a single vehicle, the Starship-L.
Obviously I’m missing something....
I don't think you are missing anything.
Starship would make a seperate crew launch vehicle redundant, but the other landers need it. So the current plan needs to have seperate launch and lander hardware an Starship is described in terms of that division.
I think the problem with manned Starship launches for NASA is still the lack of an abort system. At least so far AFAIK, SpaceX has never discussed any such system. Using SS itself as the abort system is likely not acceptable to NASA.
Sorry, but what you are describing appears to be different than what Eric describes as the mission plan where a Starship-L (again, my terminology) launches and goes to lunar orbit and then does a “rendevous with astronauts for a lunar landing”. That implies that that Starship-L does not launch with crew, some other vehicle launches with crew and takes them to lunar orbit, right?
So what vehicle is used to take astronauts to the lunar surface and return them to lunar orbit? The SpaceX proposal shows an image of Starship-L on the lunar surface with astronauts.
Is the SpaceX plan plan to use two Starship launches? One launch is an unmanned Starship-L that is sent to lunar orbit. The other launch is a “regular” Starship (for lack of a better term, the design with canards and heat shielding) that launches with crew and does a rendezvous with in lunar orbit with Starship-L. The crew transfers from Starship to Starship-L, descends to the lunar surface and then ascends to lunar orbit for transfer back to Starship and return to Earth.
Both Starships could be refueled in Earth orbit by the Starship-T (tanker) before departing for the Moon to maximize their payload capacity.
I’m not convinced that NASA has the “problem” you describe. Starship is the crew vehicle just like Crew Dragon is the crew vehicle. Crew Dragon can abort by separating from the booster at any time during the initial ascent. I assume that SpaceX plans to provide the same in-flight abort capability to Starship, allowing it to separate from the Super Heavy booster during ascent.
What I described is what Starship could do.
However, the other 2 lander options cannot take crew from Earth to the moon.
So, the program must plan for a separate launch vehicle to get the people to orbit to rendezvous with the lander.
This needs to be accounted for until/ unless Starship is the only down selected lander. Then, there is the option to launch the crew with it also. However, that would mean cancelling the crew launch rocket used in the other scenarios.
Since 2 out 3 prospects require the separate rocket, NASA is keeping a single plan for the moment with the 3 lander option fulfilling the same requirements even if they can do more.
At least that's how I read it.
Thanks @mongo, apologies for my confusion!
Yes the Blue Origin and Dynetics proposals require a lot more hardware than the SpaceX plan.
I remain confused by what Eric Berger wrote: “Starship lander...would be launched to lunar orbit by the company's Super Heavy rocket, where it would rendezvous with astronauts for a lunar landing.”
I don’t understand what he means by “rendezvous for a lunar landing”.
So I read through the 44 comments on Ars Technica responding to the Berger article. None of them singled out the sentence I find confusing, but one person (“Statistical”) did write this:
——————————————————————————————
An interim solution if NASA isn't comfortable with launching people of Starship would be to launch a full (atmospheric) Starship refuel it and then launch a Dragon to meet it in orbit. Tranfer the crew, go directly to lunar surface, return to a direct EDL on Earth.
Alternatively if NASA also isn't comfortable with having cew on Starship for either the launch OR atmospheric flight (landing) OR having crew onboard while it refuels you can do it with 2 starships and a dragon. Like before put a starship in orbit and refuel it. Launch crew on the Dragon transfer to Starship. Make the TLI and LOI. There the Starship would meet the stripped down "Moonship" (HLS) already fueled in NRHO/LLO. The crew transfers goes to the surface, does moon stuff for a couple weeks returns to orbit. Then transfer back to Starship make it back to LEO transfer back to Dragon and land.
———————————————————————————————
That is something like I described earlier today. Requires two different Startships and an F9 with a Crew Dragon.
But it seems to me that the simplest and most cost effective way to do it, if it can’t be done with a single Starship, would be two Starships. One Starship would only be used to get the crew up to LEO and then down from LEO. The other would be the “Starship-L” which would take the crew from LEO to the lunar surface and back to LEO. Such a plan would require two crew transfers between vehicles.
Yes the Blue Origin and Dynetics proposals require a lot more hardware than the SpaceX plan.
I remain confused by what Eric Berger wrote: “Starship lander...would be launched to lunar orbit by the company's Super Heavy rocket, where it would rendezvous with astronauts for a lunar landing.”
I don’t understand what he means by “rendezvous for a lunar landing”.
So I read through the 44 comments on Ars Technica responding to the Berger article. None of them singled out the sentence I find confusing, but one person (“Statistical”) did write this:
——————————————————————————————
An interim solution if NASA isn't comfortable with launching people of Starship would be to launch a full (atmospheric) Starship refuel it and then launch a Dragon to meet it in orbit. Tranfer the crew, go directly to lunar surface, return to a direct EDL on Earth.
Alternatively if NASA also isn't comfortable with having cew on Starship for either the launch OR atmospheric flight (landing) OR having crew onboard while it refuels you can do it with 2 starships and a dragon. Like before put a starship in orbit and refuel it. Launch crew on the Dragon transfer to Starship. Make the TLI and LOI. There the Starship would meet the stripped down "Moonship" (HLS) already fueled in NRHO/LLO. The crew transfers goes to the surface, does moon stuff for a couple weeks returns to orbit. Then transfer back to Starship make it back to LEO transfer back to Dragon and land.
———————————————————————————————
That is something like I described earlier today. Requires two different Startships and an F9 with a Crew Dragon.
But it seems to me that the simplest and most cost effective way to do it, if it can’t be done with a single Starship, would be two Starships. One Starship would only be used to get the crew up to LEO and then down from LEO. The other would be the “Starship-L” which would take the crew from LEO to the lunar surface and back to LEO. Such a plan would require two crew transfers between vehicles.
Last edited:
I was thinking they could use the ISS for the people transfers in those scenarios. The docking adapters are androgynous anyway, so if Starship to Dragon can be done, so can Starship to ISS.
That certainly seems reasonable. But Eric Berger’s article appears to say that the crew transfer will be done in lunar orbit.
e-FTW
New electron smell
Did not read the whole page here, sorry friends!
But I think this all goes back to the “human-rating” aspect of this. I might need to refine my previous comment on this to say that I believe NASA cannot human-rate Superheavy and Starship for launch. But it seems like once a Starship is up there, a rendez-vous, orbit and landing on the Moon is on the table.
Sound about right? Am just armchairing it of course!
But I think this all goes back to the “human-rating” aspect of this. I might need to refine my previous comment on this to say that I believe NASA cannot human-rate Superheavy and Starship for launch. But it seems like once a Starship is up there, a rendez-vous, orbit and landing on the Moon is on the table.
Sound about right? Am just armchairing it of course!
Well the first issue is that while Dragon can accelerate away at several G's, SS can barely manage 1 G fully loaded, that is it can just maintain its own weight so the escape from an exploding 1st stage would be very slow indeed.
The second issue is that while the Dragon escape system is redundant to the Falcon's propulsion system, both 1st and 2nd stage, SS isn't. If there were a problem with the SS itself, e.g. it blew up, there would be no redundancy. Dragon is essentially a 3rd stage that isn't used until already in orbit.
I think NASA would have a serious problem with a launch system that had a VERY slow escape system for a first stage failure and no escape system for a second stage failure.
Similar threads
