Why SpaceX is attempting to land rockets on a floating barge

Fox News ^ | Walt Bonner

[Jonty30]

It is the way to go, it may be in a primitive state at the moment, but it will pay of in the long run.

[cripplecreek]

I think they would be better off if the dropped the landing a pencil idea and go with the tried and true glide landing. Then they could concentrate on cutting turn around time and costs.

After all, for earth landing and launch, turnaround time and cost is their primary problem.

[867V309]

And if it crashes ....

What difference does it make?

[GeronL]

Much less than the shuttle, but they couldn’t do what the shuttle did.

[Kickass Conservative]

It should deploy a huge Propeller like a Gyrocopter.

Why just the other day I saw a Gyrocopter land in front of the Capitol Building. I think Musk can pull it off.

We’ve obviously got the Technology and there are Millions of Postal Workers than can Man the Rocket.

[Moonman62]

Much less than the shuttle, but they couldn’t do what the shuttle did.

...

They do what counts the most. For now it’s hauling supplies and garbage. Spacex also safely returns material. Within the next couple of years they’ll be transporting people.

[CivilWarBrewing]

Seems to me the booster rocket needs mini-thrusters on the TOP END to help correct the inertial tilt which occurs at landing, resulting in the toppling of the craft. Or, why isn't a parachute used to stabilize the rocket vertically upon its return?? Don't the Russians return their Cosmonauts this way in their capsule???

Also, what about a high platform with a large rectangular cut-out containing a heavy fire-retardant nylon NET where the craft could be aimed and caught (even sideways) within the net? Spacex should seriously consider this method of 'catching' the booster rocket on its return.

Hey SpaceX, you listening?!!!

[CivilWarBrewing]

Why no parachute??

[M Kehoe]

Good evening.

The key to this whole space exploration stuff is not propulsion by chemical reaction. It's "propulsion" by electromagnetism.

Ya'all do know that John Galt figured this all out long time ago?

5.56mm

[SpaceBar]

From the moment I saw the (failed) attempt to land the spent booster on the barge I thought ‘technical one-upmanship’. All sorts of nifty things are possible with computer controlled servo engines etc, but at the end of the day it’s probably more practical and cost efficient to splash it down with kevlar flotation bags, hook it, and haul it in. An engineer way back told me ‘appropriate tech beats high tech everytime’.

[Kirkwood]

“It will slow down 99%, deploy a huge hook or ring, and it will be caught, mid-air by the huge chopper or Osprey.”

LOL! I don’t think you realize how big that rocket is.

[Vince Ferrer]

Seems to me the booster rocket needs mini-thrusters on the TOP END to help correct the inertial tilt which occurs at landing, resulting in the toppling of the craft.

It has them. You can even see them thrusting in the latest landing video.

SpaceX Rocket's First Stage Crashes During Landing Attempt | Video

[Kirkwood]

“Seems to me the booster rocket needs mini-thrusters on the TOP END to help correct the inertial tilt which occurs at landing, resulting in the toppling of the craft.”

It has them.

[okie01]

but at the end of the day it’s probably more practical and cost efficient to splash it down with kevlar flotation bags, hook it, and haul it in.

'Ceptin' salt water and precision high-performance rocket engines are incompatible.

[Regulator]

Mmmm...like this? Dream Chaser

or this?

Energia Uragan

Fly back stages have been proposed, built and flown; it's still an overall trade that's hard to justify. Believe me, it's been done ad nauseum.

Stratolaunch is building a TSTO with flyable first stage (um, "airplanes"), and that seems to be the real way to go until somebody does a decent SSTO like Linear Airspike or the Skylon. Which may or may not work...but it seems like the ultimate best way to go with current engines.

Falcon 9 recoverable will eventually work, and for better or worse that's the path they took. Will it really be commercially viable? Bit more complicated...

[jag.drafting]

First thing I thought was why don’t they spin it when it lands sorts like how it spins or rotates after takeoff for stabilization? Then again I’m no rocket scientist.

[Moonman62]

It should deploy a huge Propeller like a Gyrocopter.

...

There was a rocket design like that about 15 or twenty years ago. I wonder what happened to the company.

[gaijin]

http://defensetech.org/2015/04/14/a-chinook-may-soon-capture-a-rocket-engine-from-the-sky/#more-24783

[no-s]

might be due to any perceived motion of the target?

This is a minor symptom that could contribute, but in the vid you can see a last minute trajectory correction to zero in on the barge and get vertical. This imparts a extra horizontal motion which the craft has trouble correcting. There's not much time for this - it has to be dead on due to a major constraint on the flight envelope - the engine is too powerful at minimum throttle. Even when throttled down to minimum it still produces more thrust than the weight of the craft. Therefore it needs to decelerate to zero velocity at the moment of landing but not before, aptly entitled "hoverslam". I suspect the barge is a bit too small, there's not quite enough time to null out the horizontal velocity before landing. Probably it would have no trouble landing on a field like the Ellipse, for example, which is within cross-range on ISS rendezvous launch I bet, heheh.

Maybe they should launch from a barge instead and arrange things so the landing field is properly down range. That new spaceport in Brownsville probably offers a sea of options for booster recovery as well.

[Vince Ferrer]

That is SLA’s approach to reusability, but remember, they are only grabbing the engine which separates out from the first stage, not the whole first stage like SpaceX. The SpaceX first stage is a lot heavier.