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The "Real Aerospace" Thread 
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Post Re: The "Real Aerospace" Thread
In order to lean this thread back towards a subject it already touched on:

Do you think those people are doing "getting closer to Highland Reusable Launch spacecraft capabilities" right?
Video - Grasshopper Divert | Single Cam (Grasshopper vs. Cows) - Youtube
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Not quite DC-X level stunt yet, but the airspace is limited at that location anyway.

The next Falcon launch ought to 'deliver' interesting results, more likely to be destructive than Grasshopper flights so far. Destructive as in, 1st stage not reusable for another test, soft landing or hard.

PS: I wonder if some of the local cows are getting named after spacecraft, or rocket motors?

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Fri Sep 06, 2013 6:55 am
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Post Re: The "Real Aerospace" Thread
I saw the Grasshopper test videos online and was wondering what they were planning to use it for... I was a little bit surprised to learn that they plan to vertically-land the spent boosters this way. That sounds cool, but I kind of wonder about the reliability of doing it that way. There can't be much of a fuel reserve for landing, if you want to run the system efficiently. And watching the video I have to wonder if any vertical landing can really be safe with rocket engines that put out such huge exhaust plumes. Damage from the exhaust plume near the ground was, if I recall correctly, what destroyed the DCX prototype.

Still, it's nice to see that they're trying, and I have signficiant confidence in the ability of private entrepenuers to make strange-sounding systems work.

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Post Re: The "Real Aerospace" Thread
The padding on the Grasshopper's legs has been smoking away into the wind on pretty much every test video. That radiant heat is indeed quite nasty. It shall remain to be seen if the new bottom-end architecture of Falcon is up to that, but also the aerodynamic loads on the floor and engines poking out of it. Probably the only 'advantage' a Falcon-landing test has over a Grasshopper in terms of excessive heating is that they don't seem to intend to do much hovering around. A quick wiki-read suggests an excessively slow descent damaged the DC-X too. PS: promo photos/drawings of Falcon-sized legs are pretty huge, so eventually those might reach far away from any exhaust-heating issues. They do still have to attatch to the rocket body quite near to the flaming-end tho. In any case, no legs on the first stage-recovery test flights.

Regarding efficiency, I imagine that bit reaps the benefits of having a preformance-upgrade in the engine department. And in the end, what efficiency do we speak of? The per flight cost seems to be competitive, leaving fuel for flying back cuts into the payload at flying cost X. Maybe the lost performance will be an issue when they find difficulty in selling tickets, in a less fortunate future.

Gonna be interesting to see which if any of the expected, or unexpected upgraded hardware exhibits anomalies in the upcoming flight/testflight.

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Fri Sep 06, 2013 11:04 am
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Post Re: The "Real Aerospace" Thread
Mikk wrote:
And in the end, what efficiency do we speak of? The per flight cost seems to be competitive, leaving fuel for flying back cuts into the payload at flying cost X. Maybe the lost performance will be an issue when they find difficulty in selling tickets, in a less fortunate future.

The efficiency hit that comes to mind is in the weight of the landing gear and other additional hardware, and the extra fuel that must be carried; this will reduce the maximum payload that can be carried. But of course the ability to reuse a booster instead of losing it has obvious financial upside.

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Post Re: The "Real Aerospace" Thread
I'm going to take a blind guess, and say that a major point of interest in this case is whether any of the engines will be salvageable afterwards. If they can prove to themselves that even just one portion of the rocket can be reused, then they'll save money, which I'm certain they'd love.

And bear in mind, they're apparently aiming for a water landing, so if the booster can float long enough and they can slow it down enough, they won't need "proper" landing gear.


Fri Sep 06, 2013 11:23 pm
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Post Re: The "Real Aerospace" Thread
Absalom wrote:
And bear in mind, they're apparently aiming for a water landing, so if the booster can float long enough and they can slow it down enough, they won't need "proper" landing gear.


I'm fairly certain they only plan on doing one water landing, and that's just part of the proving process. Show that it can do the powered landing after a launch, but do it somewhere that doesn't have anything to hit if it goes wrong. For production, the plan as I understand it is to fly back and land at (or near) the launch pad. Sea landings are rough on the equipment, and the turnaround time should be a lot faster if it can land on the ground and not need a recovery boat or extensive corrosion protection from the seawater.

The system does take a payload hit from all that. I don't remember the exact number, but it's not insignificant. Still, a fully reusable launch system hopefully does make up for it. And it's a useful technique to have on hand when developing even larger and more expensive launch systems in the future, which SpaceX does have plans to do.

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Sun Sep 08, 2013 8:59 pm
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Post Re: The "Real Aerospace" Thread
Plus all you need for a water landing is parachutes... that's how they recovered the shuttle solid rocket boosters.

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Post Re: The "Real Aerospace" Thread
Boosters which were heavy duty rugged construction. OTOH originally SpaceX was required to develop marinized hardware in the early days, due to a certain helmsman, I'm not so sure they pursue the same hardware requirements these days, but perhaps only because nobody's been asking about the status of those 'features' lately. It appears space-grade lithium-aluminium (the tank/fuselage alloy) isn't inherently seawater-resistant.

I've heard talk of early first stages having been part of parachute-arrested recovery experiments. Now if hardware were to be set into the sea softly enough for recovery for any reason (R&D or operation), the question if sea-salvage costs are 'convenient' enough to help in the aim of lowering prices and simplifying the process... I dunno. Supposedly the lightweight legs+ground is a better goal.

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Mon Sep 09, 2013 5:31 am
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Post Re: The "Real Aerospace" Thread
I get that. I'm just saying that if the plan was a water landing, I don't think they'd bother with the vertical landing features.

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Post Re: The "Real Aerospace" Thread
Siber wrote:
I'm fairly certain they only plan on doing one water landing, and that's just part of the proving process. Show that it can do the powered landing after a launch, but do it somewhere that doesn't have anything to hit if it goes wrong. For production, the plan as I understand it is to fly back and land at (or near) the launch pad. Sea landings are rough on the equipment, and the turnaround time should be a lot faster if it can land on the ground and not need a recovery boat or extensive corrosion protection from the seawater.
I might just resort to digging (or renting) myself a lake or pond for the purpose. As long as it's deep enough, and a good deal wider than the rocket's largest dimension, you'll get most of the benefits of the ocean, and more convenience in the fields of environment and recovery (maybe you'll need a dinghy to reach it, but the physical recovery can be done by rope with flotation buoys, and cranes). The one real question would be if it would be practical (I can't, for instance, see doing this in southern California, and I don't recall where SpaceX launches from).

It could be quite expensive for the benefit though, since it would really only be done to avoid adding a little weight to the stage.

Mikk wrote:
Boosters which were heavy duty rugged construction. OTOH originally SpaceX was required to develop marinized hardware in the early days, due to a certain helmsman, I'm not so sure they pursue the same hardware requirements these days, but perhaps only because nobody's been asking about the status of those 'features' lately. It appears space-grade lithium-aluminium (the tank/fuselage alloy) isn't inherently seawater-resistant.
The lithium, I'm sure. It's certainly not the most inert of metals. Though I suppose it might be the sodium or chlorine.

Arioch wrote:
I get that. I'm just saying that if the plan was a water landing, I don't think they'd bother with the vertical landing features.
Mostly true, but they could be using a landing profile that for some reason calls for it (too much velocity in the lower atmosphere for a parachute to both survive and do it's job?).


Mon Sep 09, 2013 4:33 pm
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Post Re: The "Real Aerospace" Thread
An aerial shot of a Grasshopper test (from a little UAV hexacopter that get startlingly close in midair):



I'm not sure which is more impressive: the VTOL rocket, or the amazing capability of the tiny off-the-shelf hexacopter camera platform, and the fact that it's so small and light (and cheap) that they don't appear to be worried about it colliding with the rocket.

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Post Re: The "Real Aerospace" Thread
Arioch wrote:
I'm not sure which is more impressive: the VTOL rocket, or the amazing capability of the tiny off-the-shelf hexacopter camera platform, and the fact that it's so small and light (and cheap) that they don't appear to be worried about it colliding with the rocket.


Playing Tag with rockets.... check!


Tue Oct 15, 2013 1:57 pm
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Post Re: The "Real Aerospace" Thread
In the budget just passed in the US the other day, the SLS heavy launch vehicle and the Orion crew vehicle are funded and back on track.

http://www.nbcnews.com/science/budget-d ... 2D11943948

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Post Re: The "Real Aerospace" Thread
Cut to make room for corporate welfare in 3...2...1...


Sun Jan 19, 2014 1:42 am
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Post Re: The "Real Aerospace" Thread
Arioch wrote:
In the budget just passed in the US the other day, the SLS heavy launch vehicle and the Orion crew vehicle are funded and back on track.

http://www.nbcnews.com/science/budget-d ... 2D11943948



you think there a link between that and the "colonize mars in 2025" bad idea?


Mon Jan 20, 2014 3:09 pm
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Post Re: The "Real Aerospace" Thread
Karst45 wrote:
you think there a link between that and the "colonize mars in 2025" bad idea?

A manned Mars mission is one of the objectives behind SLS and Orion, but if you're referring to the Mars One nutters, no... there's no connection.

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Post Re: The "Real Aerospace" Thread
Arioch wrote:
Karst45 wrote:
you think there a link between that and the "colonize mars in 2025" bad idea?

A manned Mars mission is one of the objectives behind SLS and Orion, but if you're referring to the Mars One nutters, no... there's no connection.


well am talking about the mission (sorry correction) scheduled for 2023 (after a quick research, yes that indeed mars-one) but from what i heard sound more like a stun for a reality show. Who willingly get send with a 10 year prep to a planet were you can't survive and you just rely on the resource you bring.


I think the first step would have been to set an small autonomous hydroponic garden. just to see if the seed you send can survive and grow on mars, and how fast they do. Also see how much of an ecosystem stability you can get from it.


but this sound more like survivor's mars but instead of being voted out, you just die...


Tue Jan 21, 2014 3:15 pm
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Post Re: The "Real Aerospace" Thread
Karst45 wrote:
well am talking about the mission (sorry correction) scheduled for 2023 (after a quick research, yes that indeed mars-one) but from what i heard sound more like a stun for a reality show. Who willingly get send with a 10 year prep to a planet were you can't survive and you just rely on the resource you bring.

Yes... in my opinion, the people organizing Mars One are either frauds, stupid, insane, or some combination of the three. Regardless of which it is, they won't get anywhere near Mars by 2025.

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Post Re: The "Real Aerospace" Thread
Arioch wrote:
Karst45 wrote:
well am talking about the mission (sorry correction) scheduled for 2023 (after a quick research, yes that indeed mars-one) but from what i heard sound more like a stun for a reality show. Who willingly get send with a 10 year prep to a planet were you can't survive and you just rely on the resource you bring.

Yes... in my opinion, the people organizing Mars One are either frauds, stupid, insane, or some combination of the three. Regardless of which it is, they won't get anywhere near Mars by 2025.


And just to further emphasize the crazy - it's a one way trip. The organizers apparently intend to set up a permanent settlement, no matter the cost. While there's always danger in exploring the unknown, Earth-bound explorers always had the benefit of breathable air, a decent chance of finding potable water, and a real likelihood of something being edible wherever they ended up. This isn't the case for Mars or space exploration in general. You need to bring everything with you.

One mistake on Mars can have much graver consequences than that same mistake on Earth. This will take a lot more planning and investment than the decade timeline they've laid out.


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Post Re: The "Real Aerospace" Thread
I'm gonna be that guy and say space planes are the way to go. Using technology and designs from the late 1940s, there is a company in the UK with a viable space plane design that could be used for space tourism.

I'm afraid I don't remember the name of that company, only that they believe it could be done, and be paying for itself, in 15 or so years of service. The main problem they have is that they themselves aren't capable of building the plane in it's entirety. I may come back to this thread with links!


As for the Mars thing......Ye gads, that's a suicide trip if you're planning on sending more fuel after them or some means of re-supplying!!

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Mon Jan 27, 2014 7:36 am
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Post Re: The "Real Aerospace" Thread
Michael wrote:
I'm afraid I don't remember the name of that company...


I believe you are referring to Skylon.

Here's a discussion topic about it on a forum I belong to. Its last post is from about a year ago:
http://cosmoquest.org/forum/showthread. ... ne-by-2020

Also, the Wikipedia page has some good information:
http://en.wikipedia.org/wiki/Skylon_%28spacecraft%29

I think they've gotten some of the SABRE engine milestones met so far, and they are making steady progress. I'm still on the fence on whether I think it will work or not.

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Tue Jan 28, 2014 7:57 am
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Post Re: The "Real Aerospace" Thread
Skylon is discussed in fairly deep detail at NasaSpaceFlight's Advanced Concepts subforum. An (now ex-) employee at Reaction Engines Ltd reads and sometimes posts in that very (series of) thread.


Thu Jan 30, 2014 12:45 am
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Post Yutu: "Goodnight, Humanity"
I have been enjoying a bit of schadenfreude at the recent failures of the Chinese space program; I had a bit of a chuckle when the Mars probe Yinghuo-1 failed to even leave Earth orbit, and raised an eyebrow when the Moon lander Chang'e-3 missed its target landing site by about a thousand miles. And now Chang'e-3's lunar rover, Yutu ("jade rabbit"), is not responding and will probably perish in the cold of the 14-day-long lunar night.

But I must say that the Chinese government has been clever in its handling of the problem, and has managed to elicit an empathetic response by personifying the Yutu rover as a brave little explorer, providing diary messages from the rover to the public.

Gillian Wong, AP wrote:
In the Xinhua diary entry, the Jade Rabbit takes on the tone of a heroic adventurer who has encountered an obstacle that might prove insurmountable, and who is trying to put on a brave face as it pens what might be its final farewell.

“If this journey must come to an early end, I am not afraid,” said the six-wheeled, solar-powered rover. “Whether or not the repairs are successful, I believe even my malfunctions will provide my masters with valuable information and experience.”

The personification of the rover has been a hit with the Chinese public. Parts of the Xinhua report were quoted by an unofficial Chinese microblog account written with the Jade Rabbit’s voice, and the blog was flooded with tens of thousands of sympathetic comments.

As for the rover’s fate, a report Thursday by the state-run Science and Technology Daily newspaper said that would only be clear at the end of the lunar night. Calls to the space program rang unanswered Friday, a public holiday.

On Sunday, the rover said its “masters” — the space program’s engineers, presumably — had found an abnormality in its control mechanism and were working through the night to fix it. It provided no details on what the problem was, but hinted that it was serious.

“Even so, I know I may not make it through this lunar night,” it said, striking a sombre note.

The Jade Rabbit began operating last month after making the first soft landing on the moon by a space probe, Chang’e 3, in 37 years. The moon lander is named after Chang’e, a mythical goddess of the moon, and the rover, after Yutu, or “Jade Rabbit” in English, the goddess’ pet.

In the diary entry, the Jade Rabbit recounted its achievements in the 42 days it spent on the moon, saying it travelled more than 100 metres and collected a large amount of scientific data with a panoramic camera, radar and other equipment.

But in a line clearly written with the aim of tugging at heartstrings, the Xinhua report had the Jade Rabbit appealing to its readers to take care of the space craft that brought it to the moon, Chang’e, in the rover’s absence.

“If I really cannot be fixed, when the time comes, I hope everyone will remember to help me comfort her,” it said.

The rover was designed to roam the lunar surface for three months while surveying for natural resources and sending back data. Then it ran into problems as it was shutting down in preparation for the lunar night when the temperature drops to minus 180 C.

“The sun has already set here and the temperature is falling very quickly. I’ve said a lot today, yet still feel like it’s not enough,” the rover said in its concluding paragraphs. “I’ll tell everyone a secret. Actually, I’m not feeling especially sad. Just like any other hero, I’ve only encountered a little problem while on my own adventure.”

“Good night, planet earth. Good night, humanity.”

http://www.scmp.com/news/china/article/ ... bnormality

Keter wrote:
Skylon is discussed in fairly deep detail at NasaSpaceFlight's Advanced Concepts subforum. An (now ex-) employee at Reaction Engines Ltd reads and sometimes posts in that very (series of) thread.

Here's a link for those interested: http://forum.nasaspaceflight.com/index.php?board=26.0

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Post Re: The "Real Aerospace" Thread
Communist or not, we could probably use a little of that kind of enthusiasm here in the states...


Fri Jan 31, 2014 3:56 pm
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Post Re: The "Real Aerospace" Thread
That's what you get when you steal our technology and replace the expensive metals with lead.


Sat Feb 01, 2014 2:41 am
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