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> Dragon could do almost everything Orion does with a few enhancements What can Dragon not do that Orion will be able to do? Can Orion go further from Earth?

panick21_ 5y ago
The problem is we don't know exactly. This is not totally public information. Dragon was originally designed for moon missions. We know that the heat shield can do moon reentry. What we don't know is if the avionics can navigate in deep space. However upgrading this shouldn't require much redesign of the core structures. Additionally Orion has a Service Module. This is made by ESA. Dragon would need something along those lines at well. Mostly this is about DeltaV. Dragon has a trunk and with some work likely they could carry additional fuels in the trunk. Dragon has the engines of the required power. SpaceX would have to be asked to provide a design. My estimation is that they could do significantly less then 1 billion $.
simonh 5y ago
Orion is designed for cislunar operations with 21 days of independent operations, while Dragon is capable of up to 10 days. It's supposed to be capable of missions to Mars as well, but as part of a larger vehicular system.
- bryanlarsen 5y ago
  "Red Dragon" was supposed to be capable of missions to Mars, but it was a significantly different design than the current Dragon, and it didn't get past the proposal stage.
  - simonh 5y ago
    And wasn't designed to carry people.
Robotbeat 5y ago
Orion is being qualified for faster reentry. Dragon currently only qualified for LEO reentry. But they both use ablative heatshields which scale in a straightforward way to higher speed reentries. Orion also has more propellant, more delta-v, so it has more post-separation maneuvering capability. Dragon would need either expanded tanks on board or maybe some extra propulsion capability in the trunk or perhaps docking with a small propulsion module (think like how the Apollo command module docked with the LM in Apollo 13 and used that for maneuvering delta-v). Neither of those things are huge. There are a few other things that are relatively minor, like shielding (literally just mass of plastic, very little engineering involved) and extra consumables for longer free flight mission and getting Falcon Heavy fully up to Falcon 9 human rating standards (pretty straightforward as it’s almost identical to Falcon 9 but with 2 side boosters). You could test those things on an uncrewed test flight fairly cheaply. In some ways, it’d be safer than Orion/SLS as the vehicle and spacecraft have a lot more flight history already.
- panick21_ 5y ago
  The Dragon Heat Shield was designed for Moon reentry as far as we know. If they actually had to change the heat shield it would be quite a bit more work.
  - Robotbeat 5y ago
    That’s right. But there’s a bunch of engineering that goes into finally qualifying something for lunar flight. Remember they haven’t been planning to fly dragon the lunar vicinity for several years now since the pivot to Starship, so there are dozens of tiny things that would need to be tweaked to make that demonstrable again. I don’t think it will take SpaceX very long. I think they could do it in about a year from the word “go.” It took them just a few months to design, build, and qualify the bubble cupola window thing for Inspiration 4.
- bryanlarsen 5y ago
  Past NASA administrator Bolden said that NASA would never human rate Falcon Heavy, so SpaceX didn't design Falcon Heavy for human rating. There are a couple of places where the margin is less than the 1.4 that NASA considers to be a requirement for human rating. The walls of the F9 are strong enough to have a 1.4 margin on their own, but adding the force and torsion of 2 extra boosters lowers the margin significantly. Getting those margins up to 1.4 would require a fundamental redesign and that's something SpaceX will never do. They expect Starship to become operational before any Falcon Heavy redesign ever could. But in the opinion of experts Falcon Heavy is considerably safer than the human rated SLS[1] and massively safer than the Shuttle ever was, so human rating Falcon Heavy is just a matter of NASA swallowing their pride and acknowledging that. 1: https://caseyhandmer.wordpress.com/2021/02/24/sls-is-cancellation-too-good/ https://caseyhandmer.wordpress.com/2021/02/24/sls-is-cancell...

panick21_ 5y ago

The problem is we don't know exactly. This is not totally public information. Dragon was originally designed for moon missions. We know that the heat shield can do moon reentry. What we don't know is if the avionics can navigate in deep space. However upgrading this shouldn't require much redesign of the core structures. Additionally Orion has a Service Module. This is made by ESA. Dragon would need something along those lines at well. Mostly this is about DeltaV. Dragon has a trunk and with some work likely they could carry additional fuels in the trunk. Dragon has the engines of the required power. SpaceX would have to be asked to provide a design. My estimation is that they could do significantly less then 1 billion $.

simonh 5y ago

Orion is designed for cislunar operations with 21 days of independent operations, while Dragon is capable of up to 10 days. It's supposed to be capable of missions to Mars as well, but as part of a larger vehicular system.

bryanlarsen 5y ago
"Red Dragon" was supposed to be capable of missions to Mars, but it was a significantly different design than the current Dragon, and it didn't get past the proposal stage.
- simonh 5y ago
  And wasn't designed to carry people.

Robotbeat 5y ago

Orion is being qualified for faster reentry. Dragon currently only qualified for LEO reentry. But they both use ablative heatshields which scale in a straightforward way to higher speed reentries. Orion also has more propellant, more delta-v, so it has more post-separation maneuvering capability. Dragon would need either expanded tanks on board or maybe some extra propulsion capability in the trunk or perhaps docking with a small propulsion module (think like how the Apollo command module docked with the LM in Apollo 13 and used that for maneuvering delta-v). Neither of those things are huge. There are a few other things that are relatively minor, like shielding (literally just mass of plastic, very little engineering involved) and extra consumables for longer free flight mission and getting Falcon Heavy fully up to Falcon 9 human rating standards (pretty straightforward as it’s almost identical to Falcon 9 but with 2 side boosters). You could test those things on an uncrewed test flight fairly cheaply. In some ways, it’d be safer than Orion/SLS as the vehicle and spacecraft have a lot more flight history already.

panick21_ 5y ago
The Dragon Heat Shield was designed for Moon reentry as far as we know. If they actually had to change the heat shield it would be quite a bit more work.
- Robotbeat 5y ago
  That’s right. But there’s a bunch of engineering that goes into finally qualifying something for lunar flight. Remember they haven’t been planning to fly dragon the lunar vicinity for several years now since the pivot to Starship, so there are dozens of tiny things that would need to be tweaked to make that demonstrable again. I don’t think it will take SpaceX very long. I think they could do it in about a year from the word “go.” It took them just a few months to design, build, and qualify the bubble cupola window thing for Inspiration 4.
bryanlarsen 5y ago
Past NASA administrator Bolden said that NASA would never human rate Falcon Heavy, so SpaceX didn't design Falcon Heavy for human rating. There are a couple of places where the margin is less than the 1.4 that NASA considers to be a requirement for human rating. The walls of the F9 are strong enough to have a 1.4 margin on their own, but adding the force and torsion of 2 extra boosters lowers the margin significantly. Getting those margins up to 1.4 would require a fundamental redesign and that's something SpaceX will never do. They expect Starship to become operational before any Falcon Heavy redesign ever could. But in the opinion of experts Falcon Heavy is considerably safer than the human rated SLS[1] and massively safer than the Shuttle ever was, so human rating Falcon Heavy is just a matter of NASA swallowing their pride and acknowledging that. 1: https://caseyhandmer.wordpress.com/2021/02/24/sls-is-cancellation-too-good/ https://caseyhandmer.wordpress.com/2021/02/24/sls-is-cancell...