SpaceX's 'Grasshopper' vertical takeoff / vertical landing rocket takes its first small leap (video)

[bananas]

Source: Engadget

This test-firing may not match the flame of earlier demonstrations, but SpaceX CEO Elon Musk tweeted out a brief eight-second video of another setup it's testing, the "Grasshopper" reusable vertical takeoff, vertical landing rocket. While the first hop would've been shamed in any interstellar dunk contest, future tests will range in height from a few hundred feet to two miles. The goal is to eventually create a reusable first stage for its Falcon 9 rocket, able to land safely instead of crashing into the sea and damaged beyond repair. Hit the more coverage links for a few more details on the project as well as pictures of it at the Texas test site, or check after the break to see the video.

Read more: http://www.engadget.com/2012/09/22/spacexs-grasshopper-vertical-takeoff-vertical-landing-rocke/

[a geek named Bob]

1. good continuing progress

i'm looking forward to throwing launch parties again.

[SoapBox]

2. I'm no brain surgeon but

cool!

What an interesting concept...and indeed, reusable vs. the booster rocket section tumbling
away into the ocean.

I think it's great.

[HeeBGBz]

3. That was it?

I love space technology, but it looked like it barely lifted up.

I guess I was expecting more of a Harrier or Osprey kind of thing.

[bananas]

6. One step at a time - we're watching history being made.

Harrier and Osprey didn't change history, this will.

[muriel_volestrangler]

7. It would have been good to be able to see it land

rather than be lost in a haze of exhaust ...

[sakabatou]

17. It's an engine test, not a full flight (I think)

[wordpix]

4. I'd rather see the money go to education & clean energy tech

go ahead, flame away

[HubertHeaver]

8. It is going into education.

How do you think the people doing this got so smart?

This project actually creates demand for a specific skill set. That demand filters back to the undergraduate programs and even to the high school level.
Granted the arts and humanities are not on this "cutting edge" but they do go along for the ride.

[ChairmanAgnostic]

11. How AND Why. With more engineering

More science ejumakashun and we WILL reach the stars.

[HubertHeaver]

29. I didn't say we would reach the stars.

I did say the program creates demand for the highly educated. That demand causes a "ripple effect'\" throughout society.

[wingzeroday]

5. no streamer

No parachute or streamer deployment?

[agent46]

9. I remember

the science fiction of my childhood - library books from the fifties and early sixties. They all depicted the vertical take-off and landing rockets of the future.

One wonders about a connection with this developing technology.

[Trajan]

10. This concept has been tried before ....

The McDonnell Douglas DC-X ...

It's been tried before ....

I am no rocket scientist, but I do not like the concept, and here is why:

When launching rockets, weight is a major factor when considering escape velocity .... Fuel is one of the heavy hitters for weight in a launch system - You want just enough, but not too much, in order to have the most efficient launch process that will successfully insert a payload into orbit.

When we speak of the traditional staged rocket, we speak of a number of stages that each have just enough fuel to complete it's required burn. The empty stages fall away ....

Any rocket that would attempt to land vertically could NOT do so without fuel ..... so instead of exhausting all of it's fuel during it's ascent, fuel would have to remain in the system to reverse course and, slowly, land safely on the earth's surface. it would at least DOUBLE the amount of fuel required .... Perhaps triple or quadruple the fuel weight required, compared to typical launch systems.

What if the rocket exhausted it's fuel before it touched down ? ..... How much fuel would be enough to assure safety ?

In is NOT an efficient system, and efficiency is required for successful launch operations .... Grasshopper will never be safe enough for human spaceflight .... IMHO

[ChairmanAgnostic]

12. You are stuck in a rut, mentally.

For centuries, the ability to hit some one depended on the strength of your arm. Then sticks wre sharpened, metals refined, and the reach was extended. At the same time, tossing weapons became all the rage. Until propelling it with a bent bow and a string made the missile go farther and straighter. Then composite materials were used and the crossbow could even go through armor.

Powder, black powder - a magical substance of sulphur, niter, and other secret ingredients slowly replaced the cross bow as first spears of wood, then metal, then lead balls were shot at the enemy.

As more and more energy could be stored, first mechanically, then chemically, our reach increased. We are in the verge of a massive increases in the storage of even more energy, at lower cost and weight, meaning that the old chemical limitations you speak of will no longer apply.

The key is to look at the past as steps forward, not as a limitation of what we can accomplish.

[Trajan]

14. Yeah ... You're right

I am stuck in a rut, and I cant get out ...

Would somebody help me ? ....

Look .... I worked on all five Space Shuttles (Electrical/Electronics Technician), and one major concept has been drilled into my head - S A F E T Y for the astronauts, launch crews and the public at large .... NOBODY is trying to stop you from being imaginative and resourceful .... But in the end, someone's imaginative schemes wont ever see the light of day until they can be proven to be REPEATABLY safe ....

Safe for operators on the ground ... Safe for pilots in the vehicle, and SAFE for civilians in the flight path ....

In my personal opinion, at the present time, vertical landing is a dead end because it cannot achieve those goals ....

[muriel_volestrangler]

25. What are the "massive increases in the storage of even more energy"?

If they mean "the old chemical limitations you speak of will no longer apply" "at lower cost and weight", they sound far more important than reusable spacecraft.

[bananas]

13. No. it doesn't double the fuel weight, it only adds a small fraction.

Grasshopper is the first stage of a multi-stage rocket.
At launch, it has to have fuel to lift itself and the other stages to a certain height and velocity.
Then it seperates and lets the second stage take over.
At that point, the fuel tank is mostly empty.
So to land the first stage, it only needs enough fuel to land a mostly-empty fuel tank, and not the upper stages.
That takes a lot less fuel than is needed during launch.
So the extra fuel to land the empty first stage is a small fraction of the fuel it needs at launch.

[Trajan]

16. I dont see it that way

I am not convinced that only a small fraction of extra fuel would be required ....

Let's put it this way - UNTIL this vertical launch concept is proven safe, repeatably safe - it will never be used for missions ...

[bananas]

18. Absolutely - the Dragon capsule will have a heat shield, parachutes, and rockets.

The Dragon capsule will have a heat shield, parachutes, and rockets.
The rockets double for launch abort and propulsive landing.
The capsule can land using either parachutes or rockets.
Initially parachutes will be used.
Propulsive landing won't be used until there's full confidence in it.
Then the parachutes will serve as backup.

Rememer, Dragon is being designed as a Mars lander and ascent vehicle.
It is over-engineered for just going to LEO.
It will be able to carry people up and down from Mars surface to Mars orbit.
The heat shield is designed for high-speed reentry to Earth from Mars missions,
as well as reentry into Mars atmosphere.

[PavePusher]

21. Sigh...

UNTIL this vertical launch concept is proven safe, repeatably safe - it will never be used for missions ...

Well, yeah. That's how its done for.. well... everything, really.

What did you think they would do, toss a pile of parts in the air with a handful of people on board with no idea what would happen?

[muriel_volestrangler]

24. SpaceX's own estimate is that it cuts the payload to orbit by 40%

Last edited Sun Sep 23, 2012, 07:54 AM - Edit history (1)

but they think that's worth doing for the cost savings of quickly retrieving hardware:

However, the slower speed also means that the upper stage of the Falcon rocket must supply more of the velocity needed to get to orbit, and that significantly reduces how much payload the rocket can lift into orbit. "The payload penalty for full and fast reusability versus an expendable version is roughly 40 percent," Musk says. &quot But) propellant cost is less than 0.4 percent of the total flight cost. Even taking into account the payload reduction for reusability, the improvement is therefore theoretically over a hundred times."

http://www.popularmechanics.com/science/space/rockets/elon-musk-on-spacexs-reusable-rocket-plans-6653023

Looking at the video here, the first stage needs enough fuel to slow it from Mach 6 (in, it would seem, almost horizontal flight), give it some velocity back to the takeoff pad, and then cancel vertical velocity at touchdown. Maybe you can take advantage of the aerodynamics of a cylinder through near vacuum and denser atmosphere at supersonic speeds, and then subsonic speeds, to help in all that - I don't know. It seems a tricky thing to send something that far back without wings, but they are rocket scientists. The 2nd stage will use a heat shield to scrub off its speed, after a complete orbit.

[bananas]

26. Ok, that effectively doubles the fuel.

I stand corrected.

[bananas]

15. The upper stages will use heat shields to reduce velocity

so they won't need nearly as much fuel to decelerate as they needed to accelerate to orbit.

[PavePusher]

19. Ummm, no, it does not double (or triple or quadruple) the amount of fuel needed.

One need only look at the example of the moon landers to dispel this meme.

Don't forget that "efficiency" also includes the requirements involved in building/maintaining/recycling the craft itself. It may be far more efficient to reuse a large fraction of the vehicle than to trash the entire thing every time. Oh, wait, we have an example of that, don't we?



It is very likely that the weight penalty of the parts that enable re-entry/flight are equal to or more than the fuel penalty of VTOL capability. That's where the theoretical math and the actual engineering get rather fuzzy, and one has to do empirical experimentation to get firm answers.

By the way, using any declarative "It can't/won't be done" statement is a good way to look a little foolish in the history books. Just sayin'....

[Trajan]

22. I scoured my previous 3 posts for the words 'can't' and 'won't' ....

I did say this: "I am stuck in a rut, and I cant get out ..."

So, you have created an image of foolishness for me, based on words I didn't actually say? ...

At no time did I ever say it 'cant be done' .. or 'wont ever be done' ... So please put that fantasy to rest ...

I wont belabor the point ....


It MIGHT be possible to design a VTOL launch system that is efficient, repeatable and as safe as other launch systems ... It might be ....

That is future tense - As of this moment, there is no VTOL launch system in regular use, and those that had been in development were scrapped, for one reason or another ...

My point is: It remains to be proven that VTOL is a valid mode that is safe for regular use .... I personally think the obstacles to it's implementation are large and persistent .... Landing with 'just enough fuel' is a problematic approach, and, in the end, damning to the concept ....

That is my opinion .... I would love to be proven wrong, and Elon is just the guy to do it ....

I promise to not feel foolish if I am wrong ..... even if someone else wants that ....

[PavePusher]

23. "Grasshopper will never be safe enough for human spaceflight" n/t

"vertical landing is a dead end because it cannot achieve those goals ...."

[Dash87]

28. Unless if they develop a new fuel system that solves that issue.

I'm not a rocket scientist, and I have no idea, but never say never.

[4th law of robotics]

20. Cool

keep at it guys!

[Dash87]

27. Are they developing this in order to set the path for a space elevator?

Cool!

[Posteritatis]

30. That'd be a pretty different creature. I think a few other companies are working that direction. nt