Starship Artemis Contract & Lunar Starship

[su27k]

https://twitter.com/jeff_foust/status/1483871633332969472

Mark Kirasich describes progress on the HLS award to SpaceX. SpaceX completed five milestones when protests/suits about award were cleared.

[jpo234]

https://twitter.com/thesheetztweetz/status/1486775351246217218

[jpo234]

[getitdoneinspace]

Interesting that the quoted phrase from ASAP explicitly used the plural form for "uncrewed landings". Would be very fun to see several landings to deliver cargo (i.e. science toys, infrastructure, ...) to the surface of the moon prior to a crewed landing when SLS/Orion is ready.

[whitelancer64]

Interesting that the quoted phrase from ASAP explicitly used the plural form for "uncrewed landings". Would be very fun to see several landings to deliver cargo (i.e. science toys, infrastructure, ...) to the surface of the moon prior to a crewed landing when SLS/Orion is ready.

Presumably there will be many Starship landings here on Earth, plus the one demonstration lander on the Moon.

NASA did select Starship as one of several possible providers for CLPS cargo landings for future human missions, but AFAIK there hasn't been a contract for that yet.

[Lee Jay]

Presumably there will be many Starship landings here on Earth, plus the one demonstration lander on the Moon.

I'm trying to envision a way to simulate lunar landings on Earth with Starship.  Could they start the vacuum engines in a near sea-level pressure environment and throttle them to remove 5/6ths of the weight while letting the rest of the engines do their normal landing thing?

[tbellman]

I'm trying to envision a way to simulate lunar landings on Earth with Starship.  Could they start the vacuum engines in a near sea-level pressure environment and throttle them to remove 5/6ths of the weight while letting the rest of the engines do their normal landing thing?

The risk mentioned was specifically "accuracy / stability / hazard avoidance".  To me, that sounds like it is finding a good, flat and boulder-free spot to land on, and actually hitting that spot and not twenty meters off, they are worried about.  So probably more the radar / lidar / optical terrain recognition, not the engines.  I think.

[DanClemmensen]

I'm trying to envision a way to simulate lunar landings on Earth with Starship.  Could they start the vacuum engines in a near sea-level pressure environment and throttle them to remove 5/6ths of the weight while letting the rest of the engines do their normal landing thing?

The risk mentioned was specifically "accuracy / stability / hazard avoidance".  To me, that sounds like it is finding a good, flat and boulder-free spot to land on, and actually hitting that spot and not twenty meters off, they are worried about.  So probably more the radar / lidar / optical terrain recognition, not the engines.  I think.

I would guess that HLS will not need to find a spot as it is landing. Instead, lunar satellites would find candidate spots and a robotic rover would land, do a close-up check, and set up beacons. Such a survey would cost a tiny percentage of the $7 billion Artemis 3 mission cost. For redundancy, find the spot prior to the uncrewed HLS demo and use the spot for that demo, then use the same spot again for the crewed HLS mission.

[tbellman]

I would guess that HLS will not need to find a spot as it is landing. Instead, lunar satellites would find candidate spots and a robotic rover would land, do a close-up check, and set up beacons. Such a survey would cost a tiny percentage of the $7 billion Artemis 3 mission cost. For redundancy, find the spot prior to the uncrewed HLS demo and use the spot for that demo, then use the same spot again for the crewed HLS mission.

Whom do you suggest SpaceX should contract to send a lander with a rover?  Astrobotic with their Peregrine lander?  Blue Origin with their Blue Moon lander?

Potential landing locations will definitely be surveyed from orbit by NASA (or quite possibly already have been photographed by e.g. Lunar Reconnaissance Orbiter) to find a good location, but NASA are not very likely to spend their own money to send a scouting rover to the landing locations in advance.  Avoiding boulders, holes and other terrain misfeatures not identified in advance by LRO, is on the HLS provider.

[whitelancer64]

We have many years of data from the LRO. The Lunar Reconnaissance Orbiter Camera (LROC) can get image resolutions as high as 0.5 m per pixel. At low sun angles, any rocks cast shadows on the ground. These shadows can be used to derive how rough or smooth an area is. That's more than sufficient to find a clear area to land, a rover on the ground isn't needed.

[whitelancer64]

Presumably there will be many Starship landings here on Earth, plus the one demonstration lander on the Moon.

I'm trying to envision a way to simulate lunar landings on Earth with Starship.  Could they start the vacuum engines in a near sea-level pressure environment and throttle them to remove 5/6ths of the weight while letting the rest of the engines do their normal landing thing?

It would likely be a lot easier to make something more akin to the LLTV, rather than trying to do it with a full scale Starship vehicle.

[su27k]

See HLS BAA Attachment A20 for a discussion of characterization of Lunar landing site.

Although I think it's a good idea for SpaceX to use the unmanned landing opportunity to do some additional reconnaissance from lunar orbit.

[DanClemmensen]

I would guess that HLS will not need to find a spot as it is landing. Instead, lunar satellites would find candidate spots and a robotic rover would land, do a close-up check, and set up beacons. Such a survey would cost a tiny percentage of the $7 billion Artemis 3 mission cost. For redundancy, find the spot prior to the uncrewed HLS demo and use the spot for that demo, then use the same spot again for the crewed HLS mission.

Whom do you suggest SpaceX should contract to send a lander with a rover?  Astrobotic with their Peregrine lander?  Blue Origin with their Blue Moon lander?

Potential landing locations will definitely be surveyed from orbit by NASA (or quite possibly already have been photographed by e.g. Lunar Reconnaissance Orbiter) to find a good location, but NASA are not very likely to spend their own money to send a scouting rover to the landing locations in advance.  Avoiding boulders, holes and other terrain misfeatures not identified in advance by LRO, is on the HLS provider.

I suggest that NASA's IM-1 or IM-2 missions should land at  potential HLS landing sites. These little Nova-C landers carry little rovers that should be adequate. If NASA is unwilling to pay for a reconnaissance mission that will improve the changes of success of the $5 billion Artemis 3 mission, then maybe SpaceX would consider a separate Nova-C mission. Nova-C launches on F9, so they could get a discount on the launcher. Besides, it would be great to get pictures from the surface of the historic first crewed landing in 50 years. 

[Jim]

Presumably there will be many Starship landings here on Earth, plus the one demonstration lander on the Moon.

I'm trying to envision a way to simulate lunar landings on Earth with Starship.  Could they start the vacuum engines in a near sea-level pressure environment and throttle them to remove 5/6ths of the weight while letting the rest of the engines do their normal landing thing?

It would likely be a lot easier to make something more akin to the LLTV, rather than trying to do it with a full scale Starship vehicle.

Why?  It isn't going to be piloted for landings.   Did MSL or M2020 need such a test vehicle?  Or Surveyor?

[Jim]

I would guess that HLS will not need to find a spot as it is landing. Instead, lunar satellites would find candidate spots and a robotic rover would land, do a close-up check, and set up beacons. Such a survey would cost a tiny percentage of the $7 billion Artemis 3 mission cost. For redundancy, find the spot prior to the uncrewed HLS demo and use the spot for that demo, then use the same spot again for the crewed HLS mission.

Whom do you suggest SpaceX should contract to send a lander with a rover?  Astrobotic with their Peregrine lander?  Blue Origin with their Blue Moon lander?

Potential landing locations will definitely be surveyed from orbit by NASA (or quite possibly already have been photographed by e.g. Lunar Reconnaissance Orbiter) to find a good location, but NASA are not very likely to spend their own money to send a scouting rover to the landing locations in advance.  Avoiding boulders, holes and other terrain misfeatures not identified in advance by LRO, is on the HLS provider.

I suggest that NASA's IM-1 or IM-2 missions should land at  potential HLS landing sites. These little Nova-C landers carry little rovers that should be adequate. If NASA is unwilling to pay for a reconnaissance mission that will improve the changes of success of the $5 billion Artemis 3 mission, then maybe SpaceX would consider a separate Nova-C mission. Nova-C launches on F9, so they could get a discount on the launcher. Besides, it would be great to get pictures from the surface of the historic first crewed landing in 50 years. 

No need for such scout landers.   Apollo didn't need them.  The HLS vehicle can do it itself.  See MSL or M2020.

[clongton]

No need for such scout landers.   Apollo didn't need them.  The HLS vehicle can do it itself.  See MSL or M2020.

Terrain mapping technology from orbit is good enough these days to preclude the need for ground surveillance. HLS will have to be able to hover and maneuver anyway for optimal touchdown spot. What is needed is sufficient fuel onboard to enable that. That's a design consideration. Like Jim said - scout landers are not needed.

[DanClemmensen]

No need for such scout landers.   Apollo didn't need them.  The HLS vehicle can do it itself.  See MSL or M2020.

Terrain mapping technology from orbit is good enough these days to preclude the need for ground surveillance. HLS will have to be able to hover and maneuver anyway for optimal touchdown spot. What is needed is sufficient fuel onboard to enable that. That's a design consideration. Like Jim said - scout landers are not needed.

I know that missions can succeed without on-surface surveys. The survey mitigates risk to the mission and risk to the crew. The idea is to spend a bit more money to reduce an avoidable risk. I remember listening as the Apollo 11 LEM was landing and needed to find a spot without a big rock on it. From
    https://en.wikipedia.org/wiki/Apollo_11#Landing

When Armstrong again looked outside, he saw that the computer's landing target was in a boulder-strewn area just north and east of a 300-foot-diameter (91 m) crater (later determined to be West crater), so he took semi-automatic control.[122][123] Armstrong considered landing short of the boulder field so they could collect geological samples from it, but could not since their horizontal velocity was too high. Throughout the descent, Aldrin called out navigation data to Armstrong, who was busy piloting Eagle. Now 107 feet (33 m) above the surface, Armstrong knew their propellant supply was dwindling and was determined to land at the first possible landing site.[124]

Armstrong found a clear patch of ground and maneuvered the spacecraft towards it. As he got closer, now 250 feet (76 m) above the surface, he discovered his new landing site had a crater in it. He cleared the crater and found another patch of level ground. They were now 100 feet (30 m) from the surface, with only 90 seconds of propellant remaining. Lunar dust kicked up by the LM's engine began to impair his ability to determine the spacecraft's motion. Some large rocks jutted out of the dust cloud, and Armstrong focused on them during his descent so he could determine the spacecraft's speed.[125]

[clongton]

<snip>

That was 53 years ago. It's a lot different now.
Camera technology today is several orders of magnitude better than what Apollo had. Orbiting cameras back then had difficulty seeing rocks on the surface the size of a Volkswagen, while orbital surveys today are capable of resolving small rocks on the surface the size of a tennis ball. It is simply not necessary to send a ground survey mission to determine whether or not the selected site can be safely landed on.

[DanClemmensen]

<snip>

That was 53 years ago. It's a lot different now.
Camera technology today is several orders of magnitude better than what Apollo had. Orbiting cameras back then had difficulty seeing rocks on the surface the size of a Volkswagen, while orbital surveys today are capable of resolving small rocks on the surface the size of a tennis ball. It is simply not necessary to send a ground survey mission to determine whether or not the selected site can be safely landed on.

Perhaps I miss-read the landing site paper linked by Su27 below  (Attachment_A20_Lunar_Landing_Site_Characterization_White_Paper.pdf). It looked to me like reliable resolution was about one meter, not "tennis ball". I don't think you want to risk putting a landing foot down on a 1-meter tippy rock.

Despite all its other overwhelming advantages, Starship HLS has one disadvantage: No downward-looking window for the pilot. This means reliance on cameras, and that apparently makes it a little bit harder for even a highly-trained astronaut to do a semi-manual landing. This is all about risk reduction. It's not a yes/no choice.

At this point I think NASA will choose to land without an on-surface survey, and I think the landing will succeed.

[Jim]

Despite all its other overwhelming advantages, Starship HLS has one disadvantage: No downward-looking window for the pilot. This means reliance on cameras, and that apparently makes it a little bit harder for even a highly-trained astronaut to do a semi-manual landing. This is all about risk reduction. It's not a yes/no choice.

At this point I think NASA will choose to land without an on-surface survey, and I think the landing will succeed.

no, no and no.

A.  What says the landing is going to be piloted at all?  See MSL, M2020 and every F9 first stage.  Not to mention the intend of every uncrewed Starship returning to earth. 

B.  And even if piloted, what says cameras are not good enough?

C.  There is no "risk reduction" required.  Landers already use cameras for terrain and hazard avoidance

D.  No basis to make a claim for on-surface survey.