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SpaceX Crew Dragon Splashes Down After Historic Test Flight

scientificamerican.com

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Re: SpaceX Crew Dragon Splashes Down After Historic Test Flight

#81
So I'm a fan of spacex in the sense that they're taking an atraditional approach to space exploration and colonization. However, our current ride to space has been operating reliably since 1978, we've been building and sending large space stations up since the early 70s. Spacex only very recently got their closed cycle engine working, the pinnacle of rocket efficiency, catching up to, again, early 1970s Russian technology. Taking the human out of the loop by automating Dragon is great, but remember, we sent three humans to the moon in, you guessed it, the 70s, with less computing power than my toaster oven. Hats off to the team for what they've done thus far. it's a momentous achievement for the private sector, but they have a ways to go before any kind of groundbreaking achievements. Fantastic marketing though |)

Re: SpaceX Crew Dragon Splashes Down After Historic Test Flight

#82
post #81

So I'm a fan of spacex in the sense that they're taking an atraditional approach to space exploration and colonization. However, our current ride to space has been operating reliably since 1978, we've been building and sending large space stations up since the early 70s. Spacex only very recently got their closed cycle engine working, the pinnacle of rocket efficiency, catching up to, again, early 1970s Russian techn…

Credit also to reinvigorating the world's interest in space exploration, certainly the driving factor in humanity's explorations efforts thus far.

Re: SpaceX Crew Dragon Splashes Down After Historic Test Flight

#83
post #4

This is a better article on the recovery than the one I linked from TechCrunch. I would like to reiterate the point made before which is that SpaceX is on the verge of being in a place that no company has ever been before with regard to space. The are on the cusp of having a capsule that they can send into orbit for days and then return to Earth. They already have rockets capable of putting tons of material into ever…

They are unlikely to do this at this point. The big problem is that while the capsule will be reusable, since NASA killed the propulsive landing for Dragon 2, it now needs to splash down in saltwater and therefore is not considered safe for humans after the first use. This makes Dragon 2:s too expensive for large-scale space tourism. Unless there is suddenly a huge market for this, I think SpaceX would prefer to sell…

They could potentially send a few test attempts with cargo-only or non-NASA missions to test.

Re: SpaceX Crew Dragon Splashes Down After Historic Test Flight

#84
post #53

Earlier quoted context omitted.

If you read the article you’d probably be able to work it out, but essentially: - it marks the return of American human launch capabilities after a several year hiatus from the retirement of the space shuttle - it is being done on by a private company (with government funding), which is unprecedented - dragon crew is intended to be reusable (in opposition to Shuttle/mercury/Gemini/Apollo - the capsule is designed to…

The tower style launch escape system works in flight as well. Here's a video explaining how it works, with footage of it being tested during the Apollo era. https://www.youtube.com/watch?v=AqeJzItldSQ

The video is from Moon Machines. Great series if you're interested in Apollo. https://en.wikipedia.org/wiki/Moon_Machines

Re: SpaceX Crew Dragon Splashes Down After Historic Test Flight

#85
post #16
post #11

Earlier quoted context omitted.

Why did they force the requirement for saltwater splashdown?

I am curious about this as well. Was the propulsion the problem? Did they just want a water landing? Did they specifically want an ocean landing to increase the acceptable margin for error in the splash down location? Is there some specific property to the salt water like buoyancy that is important? Would a landing in fresh water like the Great Lakes (or Lake Victoria if they need something more equatorial) meet NASA…

This is Space X.... let's go for a splash down in a water park in Wisconsin too!

Re: SpaceX Crew Dragon Splashes Down After Historic Test Flight

#86
post #16

Earlier quoted context omitted.

I am curious about this as well. Was the propulsion the problem? Did they just want a water landing? Did they specifically want an ocean landing to increase the acceptable margin for error in the splash down location? Is there some specific property to the salt water like buoyancy that is important? Would a landing in fresh water like the Great Lakes (or Lake Victoria if they need something more equatorial) meet NASA…

> Would a landing in fresh water like the Great Lakes (or Lake Victoria if they need something more equatorial) meet NASA's requirements and allow the capsule to be reusable? I'd guess that one of the big reasons they (and everyone else who does water landings) lands in the ocean, is that it is much more palatable to regulators to create an exclusion zone in the ocean, which people can easily route around. Also, peop…

[deleted]

Re: SpaceX Crew Dragon Splashes Down After Historic Test Flight

#87
post #81

So I'm a fan of spacex in the sense that they're taking an atraditional approach to space exploration and colonization. However, our current ride to space has been operating reliably since 1978, we've been building and sending large space stations up since the early 70s. Spacex only very recently got their closed cycle engine working, the pinnacle of rocket efficiency, catching up to, again, early 1970s Russian techn…

I like how you list all these things and entirely leave out the landing an orbital class rocket, which no private company nor governmental agency has ever done.

They're also pretty much doing it all themselves for a fraction of the price due to vertical integration, which is also unique.

Raptor is a full-flow staged combustion engine. Others have been made, yes, but none have flown. Right now Raptor is the only methalox variety of such an engine to ever reach a test stand.

Re: SpaceX Crew Dragon Splashes Down After Historic Test Flight

#88
post #81

So I'm a fan of spacex in the sense that they're taking an atraditional approach to space exploration and colonization. However, our current ride to space has been operating reliably since 1978, we've been building and sending large space stations up since the early 70s. Spacex only very recently got their closed cycle engine working, the pinnacle of rocket efficiency, catching up to, again, early 1970s Russian techn…

> Spacex only very recently got their closed cycle engine working, the pinnacle of rocket efficiency, catching up to, again, early 1970s Russian technology.

The Raptor is the first functional full-flow staged-combustion methalox engine, and it's already been successfully fired. By some measures, that surpasses both Soyuz technology and the RS-25. Of course, we have yet to see what their true Isp and T/M numbers will turn out to be, but they do plan to use multi-stage (including a refuel in LEO) with separately tuned engines on each. The overall performance (i.e. tons to Moon and beyond) will be very interesting to see.

Re: SpaceX Crew Dragon Splashes Down After Historic Test Flight

#89
post #81

So I'm a fan of spacex in the sense that they're taking an atraditional approach to space exploration and colonization. However, our current ride to space has been operating reliably since 1978, we've been building and sending large space stations up since the early 70s. Spacex only very recently got their closed cycle engine working, the pinnacle of rocket efficiency, catching up to, again, early 1970s Russian techn…

SpaceX lands and reuses orbital class rockets for real-life missions.

Re: SpaceX Crew Dragon Splashes Down After Historic Test Flight

#90
post #39

Earlier quoted context omitted.

The problem is that, unlike ships, they're generally not designed to be water proof. It's not the exterior that's the problem.

I mean, the crew part of it is water proof, right? It has to be air tight... I'm guessing there are things on the "outside" that might still have issues?

The first part of your post reminded me of this quote from Futurama.

Professor Farnsworth: Good Lord! That's over 5000 atmospheres of pressure!

Fry: How many atmospheres can the ship withstand?

Professor Farnsworth: Well, it was built for space travel, so anywhere between zero and one.

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