Feeds

back to article Elon Musk's 'Grasshopper' hover rocket scores another test success

SpaceX, the radical upstart startup rocket firm helmed by PayPal hecamillionaire and geek visionary Elon Musk, has announced a further successful trial of its hovering "Grasshopper" test vehicle. According to the company: On Thursday, March 7, 2013, SpaceX’s Grasshopper doubled its highest leap to date to rise 24 stories or …

COMMENTS

This topic is closed for new posts.

Page:

Silver badge

Funky

Can any rocket surgeons in the room explain what's generating the flame that appears parallel to the exhaust plume, but which doesn't look like it's providing any thrust?

1
0
Anonymous Coward

Re: Funky

I'm not a rocket surgeon but it looks like a turbopump - a fuel pump powered by a turbine engine.

2
0
Anonymous Coward

Re: Funky

yup, fuel pump turbine exhaust, which reignites and burns fully in the much hotter rocket plume.

1
0
Anonymous Coward

Re: Funky

Looks like an open-cycle engine, so, as the other AC says, it's the exhaust from the turbo pumps.

Compare http://en.wikipedia.org/wiki/Gas-generator_cycle_%28rocket%29 to http://en.wikipedia.org/wiki/Staged_combustion_cycle_%28rocket%29.

3
0
Silver badge
Pint

Re: Funky

Cheers

0
0
Flame

Re: Funky

The exhaust is actually the part that vectors. If you watch launch footage of the second stage in flight you can see it steer to perform attitude control. This way the main engine nozzle doesn't have to vector.

Here's a fantastic clip of the Space Shuttle main engine vectoring in a test fire: http://www.youtube.com/watch?v=BK0nG9aY6qU

Flame, because, you know.

0
0
Silver badge

Re: Funky

I watched it again and I can't see the small exhaust vectoring. I can see the extendable-strut thingies directing the main nozzle, so I think it's the main engine doing the vectoring.

Either way: impressive result!

0
0
Silver badge
Thumb Up

Congratulations !

Well done to everyone involved.

8
0
SW
Pint

Was this a 'manned' or a 'mannequined' trial...?

A beer to the guy standing just above the engines that went up and down without even losing his hat !

5
0
Anonymous Coward

Re: Was this a 'manned' or a 'mannequined' trial...?

The man with the hat is... The Dr.

;-)

1
0

Re: Was this a 'manned' or a 'mannequined' trial...?

Given the music accompanying this impressive vid, I took the passenger to be the Man in Black himself.

1
0
SW

Strange URL

What gives ?

Quote... http://forums.theregister.co.uk/forum/1/2013/03/12/miracle_anti_ageing_drug_australia/

Where's the anti ageing story?

11
0
Silver badge

Re: Strange URL

Pharma SEO fail?

1
0

Re: Strange URL

The anti-ageing properties will come somewhat later, when the current readers are deceased and Space X has achieved something fractionally closer to the speed of light for its spacecraft. The "Australia" bit is just a sly reference to America's way of thinking of Texas as a dumping ground for convicts and dimwits.

3
0
Thumb Up

Re: Strange URL

Glad I'm not the only one to have noticed that!

0
0
Go

Way to go, SpaceX!

Well, kudos to SpaceX. They put together a very smooth operation there.

Nice article too (weird about the URL but never mind...) but does anyone have any info on the number of 'hops' expected in 2013? And the expected milestone for each hop?

If I were one of the vice-presidents over at ULA, I'd be cashing in my stock options over the next few years...

2
0
Black Helicopters

Re: Way to go, SpaceX!

...or investigating ways to surreptitiously undermine/break SpaceX's progress.

2
0
Facepalm

Re: Way to go, SpaceX!

Oooh, sneaky - Me likey!

Seriously though, ULA is more likely to lobby Congress harder to get the Air Force/NRO/DOD launch contracts booked through ULA that they are to find ways to make their launchers cheaper. While SpaceX does have a foot in the door, ULA is in the dominant position over there. I'd say that that ULA's strategy was to keep milking their cash-cow for as long as possible before being relegated to the dustbin of history.

At which point the various execs transfer back to Boeing/Lockheed etc and start overseeing next-gen air-to-air/surface-to-air missiles or other new aerospace projects which, like the F-35, will be highly likely to come in waaaay over budget. But those execs will still get their huge salaries and bonuses so no worries there.

The actual workers will get their pink slips because management was't interested in building stuff that was competitive on the open market but hey, did anyone think it would turn out any other way?

1
0
Silver badge
Happy

I do like the way SpaceX seem to keep doing things that can't be done!

7
0
Boffin

So far...

Grasshopper is doing the same sort of stuff as the DC-X did a few years ago, http://www.youtube.com/watch?v=wv9n9Casp1o for instance is still a bit ahead.

If they drop it and break it like NASA did with the DC-X though it will be a lot easier and quicker to replace so it should soon surpass earlier efforts.

2
0
Silver badge

Re: So far...

and Armadillo have been 'hopping' for a while now.... another, not quite as rich, tech millionaire behind that as well

0
0

Re: So far...

Not sure you can directly compare this with the DC-X or Armadillo, which have indeed pulled off some pretty amazing flights, but in my non-expert opinion those look more akin to balancing a match-box on your finger rather than a vertical snooker cue as SpaceX have done.

0
0
Mushroom

Re: So far...

Don't forget that that fuel tank is nearly empty, so the centre of gravity is way down low --- the the whole point of the system is to land spent first-stage boosters, using the engines they already have, using the dregs of the fuel they've already used. The fact that the stage itself is six storeys high (twice as big as the office building I work in!) is deceptive.

1
0
Boffin

Re: So far...

The liquid oxygen tank is at the top though so the weight distribution is vaguely dumb-bell shape.

It's actually easier to steer a rocket using vectored thrust if the weight is high up, if you've got a Fred Astaire style dancing cane, or failing that a small hammer, handy try balancing it on a finger both ways up and see which is easier to control.

2
0
Bronze badge

Re: So far...

re Armadillos hopping.

Yes, they fatally target vehicle bumpers; Texas kamikazes.

0
0
Thumb Up

This reminds me of playing with the Ada rocket package, and being impressed with myself getting a perfect pad landing on the other side of the screen; possibly with a loop or two, although I can't remember if I cracked that. Admittedly it was only 2D, and open-loop to boot, but still fun.

0
0
Gold badge
Thumb Up

That's "T/W >1" untill they throttled it down.

And all of their hover tests needed that to take off in the first place.

But an excellent piece of work and gradual expansion of the flight envelope.

Breaking the Mach barrier some time this year?

0
0

Re: That's "T/W >1" untill they throttled it down.

No, that's T>W > 1 when touching down, as you can plainly see since the craft is slowing its descent at that time.

0
1
Anonymous Coward

Re: That's "T/W >1" untill they throttled it down.

Your post makes zero sense.

0
0
Pint

Musk is also planning to put a heat shield in front of the second stage, and have it re-enter the atmosphere and then land vertically like the first stage.

Then, only the capsule trunk would be lost .

0
0
Bronze badge

nice but is it efficient

It's a nice idea to be able to land your capsule. But I'm not sure it's a particularly efficient (i.e. low weight) solution. Maybe splashing in the ocean is not ideal, but the russians land theirs on land with parachutes. Maybe a small rocket just to cushion the last few feet and avoid a thump. Sure, you cannot get pinpoint accuracy, but recovering an undamaged capsule by helicopter or truck is a lot cheaper than carrying the extra fuel and rocket motors into space with you to enable you to land yourself.

It'd be pretty scary too coming in to land by rocket compared to parachutes. Presumably they have to kick in pretty late or you're going to waste a lot of fuel hovering down. Very little time to bail out if there is a misfire. Maybe the plan is for the astronauts to bail out and let the thing land itself... that would seem a lot safer.

But if they can get a reusable first stage (and even better, second stage too), that would really be key to making it cheaper, even if these parts cannot land themselves.

0
0
Silver badge
Facepalm

Re: nice but is it efficient

not really, the infrastructure to go collect & refurbish rockets is pretty hefty...

the ocean is a big place....

With a tail first soft landing, it is 100% intact, check the tyres, re-stack it etc... & reuse...

With parachute, its find it first, collect, test EVERY component to ensure nothing got damaged in the impact, then re-stack & reuse..

Don't underestimate the cost savings of NOT having 100 high paid guys standing round while you go on a rocket hunt...

But while this is all great, I still think Skylon & its successors are going to be the final key to opening space... but projects such as this will gain exposure and interest in investment, which will help others who don't have big multi-millionaires backing them

5
1
Go

Re: nice but is it efficient

The short answer is: yes, it is. Because parachutes are big and heavy, and the rocket engines are free --- you've already used them to launch with! The only overheads are the avionics, the landing gear, and some dregs of fuel left in the tank from the launch. As the tank is now almost completely empty, it's a lot lighter than it looks in the video.

Also, don't forget that this is just for landing the first stage. It's never reaching orbit. SpaceX are *also* working on rocket-landing the Dragon capsule, using scaled up versions of the existing manoeuvring thrusters, for exactly the same reasons, but that's a totally different system.

5
1
Bronze badge

Re: nice but is it efficient

If parachutes are 'big and heavy', why is nobody jumping out of aeroplanes with rocket packs?

Maybe it would be more costly. But consider a pilot ejecting from a $100m dollar fighter jet. His seat is already rocket powered, and yet he still comes down by parachute.

0
1
Bronze badge
Facepalm

Re: nice but is it efficient

Er....I suggested landing on land by parachute, not the sea.

And I specifically mentioned a small rocket just to cushion last few feet. There is no reason for such a landing to require any more of a refurb than a full rocket powered descent. It can be just as soft.

But you're right about the rocket hunt though. That's the killer. If only boffins could devise some way to locate things anywhere on the earth accurately within seconds, perhaps using satellites and atomic clocks?

0
0

Re: nice but is it efficient

"If parachutes are 'big and heavy', why is nobody jumping out of aeroplanes with rocket packs?"

Rocket packs are free if you're already in a rocket, because you...err, use the same ones you done launched with. Don't know too many folks who go skydiving from backpack rocket rigs...

0
1
Silver badge

Re: nice but is it efficient

The pilot lands by parachute after jettisoning the seat.

Now imagine the size/mass of a parachute necessary to recover the entire aircraft.

Not to mention that while the boosters don't go to orbit, they're moving pretty fast. They have to be slowed down.

Other options for returning boosters involve stub wings and runways - but that's extra weight too.

0
0
Anonymous Coward

@ Franklin

"done launched"

In what plane of reality does that combination of words have any meaning?

0
0
LPF

Re: nice but is it efficient

But dont you wish we had them :)

0
0
Silver badge
Thumb Up

Brilliant!

They may not the first to do this, but it is still a very impressive step forward for them!

I've wondered for years why not just build each stage a LITTLE bigger and make it able to land...

since fuel is cheap relative to the rocket construction costs!

Oh, and just think, for planets with little or no atmosphere, this would be a great way to land... I.E. the moon!

0
0
Silver badge

Fuel is cheap, but it's heavy. Then you need extra fuel to lift that extra bit of fuel, then you need more fuel to lift that fuel ......

The real trick here isn't the balancing, that's just having a computer faster than a zx81 and engines that can tilt faster than the pendulum frequency of the stack. The trick is managing the fuel down to the last drop especially tricky when one of the fuels is cryogenic.

0
0
Bronze badge

Rocket Landing is old hat

Some of the first efforts to use rocket braking were tried during WW2. It didn't quite work, partly because of the effects of the rocket blast on unprepared ground. The Soviet Union deployed a solution that involved a parachute, with the rocket pack between the payload and the parachute.

I've seen film of those WW2 tests. The rocket blast was excavating a crater, which was reflecting an asymmetric gas flow which flipped over the payload.

If SpaceX want to use the rocket landing approach, they have to be able to land on ordinary open ground, and they have to pretty accurately steer to a safe area. The Dragon capsule might be more stable, less likely to topple or flip, than a booster stage, but what size of target area will they need?

Water landings ain't easy, but the sea is big, and a lot more uniform. There are no trees and no sticking-up boulders.

1
3
Thumb Down

Re: Rocket Landing is old hat

There's also Hajile - achieving a 'soft landing' by firing solid-fuel cordite rockets just before impact. Didn't work at all well...

http://en.wikipedia.org/wiki/Hajile

0
0
Silver badge

Re: Rocket Landing is old hat @Dave bell

Surely the point is that they return to a specific point and land there - which is entirely possible - rather than landing on 'ordinary open ground'. So you can make a landing pad that can withstand the blast. You can also put it in an area with no trees or boulders. A bit like the pad they are practising on....

1
0
Silver badge
Holmes

Re: Rocket Landing is old hat

> Some of the first efforts to use rocket braking were tried during WW2

Hold on.

What EXACTLY were people trying to rocket-brake during WW2? And how??

Germans were just barely managing to get A4s airborne and on trajectory. Have you seen the analog on-board computers for that (google up Hoelzer's Mischgerät). It was a pretty tall order, and Hoelzer recalls prussian generals and university profs giving him the laughing treatment. Luckily for him he didn't get the cybernetics-is-a-jewish-and-bourgeois-science treatment too. Doing the even more tricky braking manoeuver sounds dicey.

0
0
Silver badge
Thumb Up

Great stuff!

"Grasshopper" does instantly remind me of the Kung Fu series with David Carradine, however.

That says a lot about my age, I suppose

5
0

Re: Great stuff!

Me, too...

"Glasshopper, you will not be kung fu master until you can catch a fly using chopsticks"

"But Master, I can do this"

"Not without killing the fly"

0
0
Silver badge
Boffin

Clever

Well, it's very clever, but it's hardly brain surgery.

2
0
Silver badge
Unhappy

Flying bedstead Mk2

Pity Neil's not around to give it a spin.

1
0
Bronze badge
Thumb Up

Woooooooooot!

Fantastic work. They are doing it right!

0
0

Page:

This topic is closed for new posts.