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Artemis II

The Pelican

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The Artemis II launch is in progress, NASA's first manned journey to lunar orbit since Apollo in the 1970s.

Anyone who has played Kerbal Space Program will realise that a lunar flyby is an interesting challenge- the game is a spaceflight simulator based on a 1:10 solar system. First you launch your rocket and put your spacecraft in an Earth orbit, then do a burn to move into a transfer orbit, then circularise around the moon, then the reverse to return- it's not too difficult. It removes the risks and difficulties of lunar landing. But NASA have chosen a "free return trajectory" for this particular flight, which avoids the need to do a burn in lunar orbit.

Artemis I did this flight without astronauts and returned safely.

It is interesting to compare Apollo and the Saturn Five, the Space Shuttle and the International Space Station, and the Orion, Crew Dragon and Starliner manned capsules and the SLS/ Falcon rockets, perhaps Starship in a few more years, as the products of different eras of space technology.
 
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JamesT

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The Artemis II launch is in progress, NASA's first manned journey to lunar orbit since Apollo in the 1970s.

Anyone who has played Kerbal Space Program will realise that a lunar flyby is an interesting challenge- the game is a spaceflight simulator based on a 1:10 solar system. First you launch your rocket and put your spacecraft in an Earth orbit, then do a burn to move into a transfer orbit, then circularise around the moon, then the reverse to return- it's not too difficult. It removes the risks and difficulties of lunar landing. But NASA have chosen a "free return trajectory" for this particular flight, which avoids the need to do a burn in lunar orbit.

Artemis I did this flight without astronauts and returned safely.

It is interesting to compare Apollo and the Saturn Five, the Space Shuttle and the International Space Station, and the Orion, Crew Dragon and Starliner manned capsules and the SLS/ Falcon rockets, perhaps Starship in a few more years, as the products of different eras of space technology.
It did look quite impressive taking off. It’s just a shame that SLS seems such a backwards step. Taking the engines that were reusable on the space shuttle and expending them for every launch. When Falcon has been showing how to do reusable rockets for about a decade now.
 

Cloud Strife

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It did look quite impressive taking off. It’s just a shame that SLS seems such a backwards step. Taking the engines that were reusable on the space shuttle and expending them for every launch. When Falcon has been showing how to do reusable rockets for about a decade now.

I can explain this. Basically, the Space Shuttle and Falcon can reuse the engines because they only needed to send the payload to low earth orbit. So, the rockets didn't need to go so far or so fast, and it's also much easier to retrieve/reuse them. On the other hand, retrieving SLS would be massively more difficult because of the sheer size of it, and it needs to be that size so that they can send as much cargo as possible towards the Moon.

The general principle is that reusable engines are doable for LEO, but deep space requires much more power. Starship will apparently deal with this by having a refuelling station in space, but a lot of aerospace engineers are very cynical about the chances of Starship actually working in the way that Elon says it will. I suspect that Starship will end up being like the Space Shuttle: great technology, but nowhere near what was promised, especially the idea of the fuel tanker in space.

From what I've been able to piece together, NASA are adopting the attitude that they're very open to Starship, but only if it proves itself. Until then, they'll continue with tried and tested technology for the purpose of going to the Moon, as they simply can't afford yet another loss of astronauts. If there's a third disaster, then it would pretty much rule out any more involvement with NASA sending humans into anything more than orbit around Earth.
 

Peter Mugridge

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There's an excellent visual representation of the position of the craft relative to both Earth and Moon here:

( No quote because it's visual only but with an added box showing current distances from both and the craft's speed relative to Earth )

 

The Pelican

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The trackers are very impressive, I've found this 2D one from Canada- one of the astronauts is being sent by the Canadian space agency.


The Heavens Above 3D one is great, and looks a lot like the Kerbal Space Program user view while looking at the spacecraft.

It also seems to deal with some issues the 2D view produces- it looked from the 2D view like the insertion burn into the transfer orbit completely reversed the direction the capsule was orbiting, which I don't think actually happened, but was an artifact of compressing a 3D planet into 2D.
 

JamesT

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I can explain this. Basically, the Space Shuttle and Falcon can reuse the engines because they only needed to send the payload to low earth orbit. So, the rockets didn't need to go so far or so fast, and it's also much easier to retrieve/reuse them. On the other hand, retrieving SLS would be massively more difficult because of the sheer size of it, and it needs to be that size so that they can send as much cargo as possible towards the Moon.

The general principle is that reusable engines are doable for LEO, but deep space requires much more power. Starship will apparently deal with this by having a refuelling station in space, but a lot of aerospace engineers are very cynical about the chances of Starship actually working in the way that Elon says it will. I suspect that Starship will end up being like the Space Shuttle: great technology, but nowhere near what was promised, especially the idea of the fuel tanker in space.

From what I've been able to piece together, NASA are adopting the attitude that they're very open to Starship, but only if it proves itself. Until then, they'll continue with tried and tested technology for the purpose of going to the Moon, as they simply can't afford yet another loss of astronauts. If there's a third disaster, then it would pretty much rule out any more involvement with NASA sending humans into anything more than orbit around Earth.
Musk’s roadster was put into an orbit that might reach Mars using a Falcon Heavy, which is effectively three Falcon 9’s strapped together. Two of the three made it back to land safely.

There were a lot of engineers who were sceptical about reusable rockets full stop.

Earth orbit rendezvous was one of the options considered for Apollo and it was the profile chosen for Constellation before that was cancelled. It’s not a completely wacky idea. NASA also need it to work given that Starship is the chosen lander for the Artemis programme.
 

The Pelican

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Nasa are launching Artemis III in 2027- it will dock to the Blue Moon Lunar module (Blue Origin's moon lander) and a SpaceX Starship, representing the Starship-based HLS, or Human Landing System. This mission will help measure whether the two private space companies are able to deliver their vehicles in time. Eventually, the HLS will be refulled for each flight by up to 12 Starships launching from Earth and filling up a tanker, another vehicle based on Starship, which in turn will fill up the HLS.

Wikipedia: (https://en.wikipedia.org/wiki/Artemis_III)
 

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