Anyone know how SpaceX plans to soft land the falcon heavy boosters?

[The Pink Ranger]

Anyone know how SpaceX plans to soft land the falcon heavy's boosters? Assuming the falcon heavy does a typical gravity turn would the boosters actually reverse direction and land back at the launch facility? An article about the recent falcon 9 soft landing mentioned something about landing stages on floating pads but it didn't say if this was just for testing purposes or not.

Maybe SpaceX plans on using a ship with a flat top like an aircraft carrier for the boosters to land on? Or maybe even some kind of offshore platform akin to an oil rig?

[Airlock]

They plan to boost them back to the launch site.

http://www.nasaspaceflight.com/2014/04/rockets-return-home-spacex-pushing-boundaries/

"The ambitious plans for creating an advanced flyback booster-style vehicle were unveiled by SpaceX founder Elon Musk back in September of 2011, featuring first and second stages that would fly back to the launch site under their own power – something no other aerospace company has achieved."

There has been some speculation, however, that the center stage may be too far down range to boost back when it cuts out.

EDIT: Here's another article. Seems like they've considered an expendable center core.

http://aviationweek.com/blog/falcon-9-performance-mid-size-geo

“Where I basically see this netting out is Falcon 9 will do satellites up to roughly 3.5 tonnes, with full reusability of the boost stage, and Falcon Heavy will do satellites up to 7 tonnes with full reusability of the all three boost stages,†he said, referring to the three Falcon 9 booster cores that will comprise the Falcon Heavy's first stage. He also said Falcon Heavy could double its payload performance to GTO “if, for example, we went expendable on the center core.â€Â

Edited August 14, 2014 by Airlock

[Kerbart]

Very softly?

[Nibb31]

I don't think that SpaceX has stated anywhere that the Falcon Heavy will use reusable boosters.

Technically, I see no reason why they couldn't return the side boosters. The central core will have to be expendable though and the payload will be reduced.

Economically, the FH is supposed to maximise payload, which means that it's more about performance than reusability. If the payload doesn't maximise the FH's capacity, then it will probably make more sense to launch it on a smaller and therefore cheaper rocket.

The whole point is moot though, because nobody has any 50t payloads to launch.

[Jesrad]

Very softly?

See for yourself

[Moar Boosters]

During their last test of the Falcon 9, they didn't perform a normal gravity turn, they flew it at a much steeper angle than most launches so they booster wouldn't go further down-range.

I guess they wanted to make the re-direction burn as simple as possible for the test. I expect later on when they have more experience they'll be able to send the booster further down range and bring it back. It's going to be a balancing act between an inefficient launch angle, and the amount of fuel required to re-direct the booster back to a landing position.

[Red Iron Crown]

I don't think that SpaceX has stated anywhere that the Falcon Heavy will use reusable boosters.

Technically, I see no reason why they couldn't return the side boosters. The central core will have to be expendable though and the payload will be reduced.

Economically, the FH is supposed to maximise payload, which means that it's more about performance than reusability. If the payload doesn't maximise the FH's capacity, then it will probably make more sense to launch it on a smaller and therefore cheaper rocket.

The whole point is moot though, because nobody has any 50t payloads to launch.

The conceptual drawings of FH I've seen all have landing legs on each core similar to the F9R's, it pretty heavily implies reusability.

Why would the central core be unrecoverable? As I understand it, the cental core will burn out in a similar situation to the F9 booster, shouldn't be impossible to recover. The side boosters will be easier than F9R as they'll not be as far down range.

I'm not sure the economics will work out for SpaceX's reusability plans, but if they make it viable to reuse an F9 booster I don't see why FH would be less so for payloads that permit it.

[R0cketC0der]

The conceptual drawings of FH I've seen all have landing legs on each core similar to the F9R's, it pretty heavily implies reusability.

Why would the central core be unrecoverable? As I understand it, the cental core will burn out in a similar situation to the F9 booster, shouldn't be impossible to recover. The side boosters will be easier than F9R as they'll not be as far down range.

I'm not sure the economics will work out for SpaceX's reusability plans, but if they make it viable to reuse an F9 booster I don't see why FH would be less so for payloads that permit it.

The falcon heavy central core will have flow faster and further than a falcon 9 first stage. IIRC Elon Musk stated that the payload to GTO would be 21 one tones when flown completely expendable, 14 tones with the boosters recovered and the central core expended and 7 tons with all 3 cores recovered.

[Red Iron Crown]

The falcon heavy central core will have flow faster and further than a falcon 9 first stage. IIRC Elon Musk stated that the payload to GTO would be 21 one tones when flown completely expendable, 14 tones with the boosters recovered and the central core expended and 7 tons with all 3 cores recovered.

It was my impression that the central core, when used in the fully recoverable mode, would expire at a similar altitude/speed as the F9 first stage; it would just deliver more mass to that point. I could be wrong though, and I'm sure the flight profiles are far from finalized.

[Nibb31]

Why would the central core be unrecoverable? As I understand it, the cental core will burn out in a similar situation to the F9 booster, shouldn't be impossible to recover.

It will be faster, higher, and further downrange than an F9R stage. That makes reentry trickier and the flyback burn even more expensive.

[The Pink Ranger]

They plan to boost them back to the launch site.

http://i.imgur.com/NEi7qKp.png

http://www.nasaspaceflight.com/2014/04/rockets-return-home-spacex-pushing-boundaries/

"The ambitious plans for creating an advanced flyback booster-style vehicle were unveiled by SpaceX founder Elon Musk back in September of 2011, featuring first and second stages that would fly back to the launch site under their own power – something no other aerospace company has achieved."

There has been some speculation, however, that the center stage may be too far down range to boost back when it cuts out.

EDIT: Here's another article. Seems like they've considered an expendable center core.

http://aviationweek.com/blog/falcon-9-performance-mid-size-geo

“Where I basically see this netting out is Falcon 9 will do satellites up to roughly 3.5 tonnes, with full reusability of the boost stage, and Falcon Heavy will do satellites up to 7 tonnes with full reusability of the all three boost stages,†he said, referring to the three Falcon 9 booster cores that will comprise the Falcon Heavy's first stage. He also said Falcon Heavy could double its payload performance to GTO “if, for example, we went expendable on the center core.â€Â

Oh man that's SICK. I started using this mod with FAR and I've been trying to figure out the best way to turn the side boosters around without the atmosphere tearing them apart.

Anyway 10 years from now the cape will be like the adult disney land. Can't wait to see a flaming column of awesome fall out the sky to a gentle touch down.

Edited August 14, 2014 by The Pink Ranger

[cantab]

The conceptual drawings of FH I've seen all have landing legs on each core similar to the F9R's, it pretty heavily implies reusability.

Why would the central core be unrecoverable? As I understand it, the cental core will burn out in a similar situation to the F9 booster, shouldn't be impossible to recover. The side boosters will be easier than F9R as they'll not be as far down range.

I'm not sure the economics will work out for SpaceX's reusability plans, but if they make it viable to reuse an F9 booster I don't see why FH would be less so for payloads that permit it.

I think that "payloads that permit it" factor is the key. FH is planned to get maximum payload when using fuel crossfeed. That will make the core go much further, while the boosters don't go as far, compared to not using crossfeed. A configuration using crossfeed, returning the boosters, and ditching the core would seem natural and might work well.

[magnemoe]

I think that "payloads that permit it" factor is the key. FH is planned to get maximum payload when using fuel crossfeed. That will make the core go much further, while the boosters don't go as far, compared to not using crossfeed. A configuration using crossfeed, returning the boosters, and ditching the core would seem natural and might work well.

Yes, the boosters would drop earlier than the falcon 9 first stage making them easier to recover, falcon heavy also have so huge capacity that loosing some is less critical than for Falcon 9.

In practice you get 4 launch platforms with increasing performance: Falcon 9 recovered > falcon 9 disposable > falcon heavy with booster recovery > falcon heavy disposable

[sojourner]

^Replace "Falcon 9 disposable" with "Falcon Heavy fully recoverable" and you've got it.

During their last test of the Falcon 9, they didn't perform a normal gravity turn, they flew it at a much steeper angle than most launches so they booster wouldn't go further down-range.

I guess they wanted to make the re-direction burn as simple as possible for the test. I expect later on when they have more experience they'll be able to send the booster further down range and bring it back. It's going to be a balancing act between an inefficient launch angle, and the amount of fuel required to re-direct the booster back to a landing position.

The trajectory used for that flight was a result of needs of the payload. Nothing to do with recovery attempt.

[Moar Boosters]

The trajectory used for that flight was a result of needs of the payload. Nothing to do with recovery attempt.

The trajectory was specified by the customer, but it's no co-incidence that they chose this launch as one to test recovering the launcher.

[R0cketC0der]

The trajectory was specified by the customer, but it's no co-incidence that they chose this launch as one to test recovering the launcher.

They are using ANY current launch except for GTO launches for recovery testing.

[Javster]

Just had a really dumb idea: wings that fold out of the booster

[Moar Boosters]

They are using ANY current launch except for GTO launches for recovery testing.

This was the first time they attempted to re-direct it back to the launchpad. Previous tests came down in the ocean 100's of km downrange.

Javster... wings on the booster isn't a dumb idea. NASA proposed ideas for a reusable Saturn 5 first stage which had wings.

Edited August 14, 2014 by Moar Boosters

[magnemoe]

Just had a really dumb idea: wings that fold out of the booster

Would probably be as heavy as the spare fuel for boost back and far more expensive to develop, add that its harder to retire the rocket as an expendable stage after say 20 launches.

Has been plenty of ideas of winged boosters for flyback.

[sojourner]

The trajectory was specified by the customer, but it's no co-incidence that they chose this launch as one to test recovering the launcher.

They're using every launch with reserve capability to test recovery. The trajectory was just a bonus.

This was the first time they attempted to re-direct it back to the launchpad. Previous tests came down in the ocean 100's of km downrange.

Incorrect. They did not attempt redirect back to pad on that launch. Only soft landing. As already stated, it was closer in to shore due to the side benefit of the launch trajectory required by the customer. Edited August 14, 2014 by sojourner

[Moar Boosters]

They're using every launch with reserve capability to test recovery. The trajectory was just a bonus.

Incorrect. They did not attempt redirect back to pad on that launch. Only soft landing. As already stated, it was closer in to shore due to the side benefit of the launch trajectory required by the customer.

All reports I've seen say it was redirected back in the direction of the launchpad, unlike previous tests. I didn't mean to imply it was actually landed back there. They redirected it this time as a practice for their next attempt, which will be on land.

http://www.spaceflight101.com/orbcomm-g2-launch-1---falcon-9-launch-updates.html

[Borklund]

All reports I've seen say it was redirected back in the direction of the launchpad, unlike previous tests. I didn't mean to imply it was actually landed back there. They redirected it this time as a practice for their next attempt, which will be on land.

http://www.spaceflight101.com/orbcomm-g2-launch-1---falcon-9-launch-updates.html

That is wrong. Any stage that returns to land is going to return to a landing site separate from the launch site.

[sojourner]

^Your splitting hairs. Return to launch site in this case means "close by". Not literally on the launchpad.

All reports I've seen say it was redirected back in the direction of the launchpad, unlike previous tests. I didn't mean to imply it was actually landed back there. They redirected it this time as a practice for their next attempt, which will be on land.

http://www.spaceflight101.com/orbcomm-g2-launch-1---falcon-9-launch-updates.html

The reports you're reading are wrong. The stage was redirected back to Earth, not back in direction of the pad.

Edited August 14, 2014 by sojourner

[R0cketC0der]

All reports I've seen say it was redirected back in the direction of the launchpad, unlike previous tests. I didn't mean to imply it was actually landed back there. They redirected it this time as a practice for their next attempt, which will be on land.

http://www.spaceflight101.com/orbcomm-g2-launch-1---falcon-9-launch-updates.html

1. Earlier tests also did turnaround burns - this one just splashed down closer to the coast. However, SpaceX would also have been able to do that on earlier flights if they wanted.

2. The next attempt will also be on water. If everything works as expected, the next two attempts after that will try to land on a barge. Only if these will also work as expected they will move on to land.

[magnemoe]

That is wrong. Any stage that returns to land is going to return to a landing site separate from the launch site.

Pretty obvious, you want to land at an huge concrete area, preferable an test runway, however this will be inside the space center area.

I don't see why the customer will ask for a specific launch profile. They want an attitude and orbital plane but hardly care how they get where.

However as the dV requirements of the launch was so low they could try an boost-back. That happens with the first stage after separation is not the customer concern outside of the PR.

Then the first stage return become standard I expect payloads who enables first stage return to both be cheaper and get priority unless you pay premium as they are less expensive.

And yes this gives an safety margin for the customer, if something goes wrong like 1 of 9 engines fails they burn first stage dry and sacrifice it to save the payload.