SpaceX: First stage landed Satellites in orbit

[mfb]

A great launch, everything worked as expected, delivering 11 OrbComm satellites to Earth orbit (they all got deployed in the minutes after reaching orbit). But that was the routine part... although it was the first flight of an improved version of Falcon 9 1.1 ("Full thrust" version).
The first stage accelerated the second stage to about 1.5 km/s, then separated, turned around, flew back, and landed. It is the first time a rocket stage used for going to orbit has been recovered like that. Certainly a remarkable day in the history of spaceflight.



helicopter view

Full launch, landing and satellite deployment video

Two pictures from the stream (the numbers in the upper right corner are the second stage speed and height).

One satellite gets deployed, the box in the lower middle part of the image:

 

[Bystander]

Finally!

 

[enorbet]

THEY DID IT ! Finally proof of concept is accomplished with this recent successful landing.

http://money.cnn.com/2015/12/21/news/companies/spacex-launch-rocket-landing/index.html

Oh man I am just ecstatic! What a feat.

 

[mfb]

The helicopter view of the landing is better.

 

[mheslep]

Aye. First time in history, right, from a full orbital launch?

e

 

[rootone]

The first stage didn't get into orbit, it's purpose is to get the second stage moving at a sufficient velocity and great enough altitude prior to orbit insertion.
It's impressive engineering though.
Whether or not it pays off in the end depends on whether the soft landed booster stage is in fact re-usable fairly quickly, or whether the refurbishing costs are not very different to building a new one.

 

[mfb]

Using this stage again will certainly be interesting. I didn't see specific plans yet.

The first stage didn't get into orbit, but at least it reached space due to the target orbit of ~650 km - significantly above the ISS, for example.

 

[rootone]

I guess this particular one probably will not be re-used, well not as a whole, maybe parts of it.
More likely a lot of it will be taken apart and examined very carefully to see how components had performed, potential stress failures identified, and so on that could be improved.

 

[mheslep]

The first stage didn't get into orbit, it's purpose is to get the second stage moving at a sufficient velocity and great enough altitude prior to orbit insertion.
It's impressive engineering though.
Whether or not it pays off in the end depends on whether the soft landed booster stage is in fact re-usable fairly quickly, or whether the refurbishing costs are not very different to building a new one.

I know. I'm drawing a distinction between the Falcon mission which reached orbit and landed the 1st stg, and the recent Amazon funded mission which also landed but was only a suborbital mission.

 

[mheslep]

Using this stage again will certainly be interesting. I didn't see specific plans yet.

The first stage didn't get into orbit, but at least it reached space due to the target orbit of ~650 km - significantly above the ISS, for example.

Yes I think I recall from the video that the 1st stage separation occurs at about 10% of the final payload velocity.

 

[mfb]

Stage separation happened at 6000 km/h (and 77 km height), satellite deployment at 26000 km/h. That is 23%.
Full launch video
Vertical velocity seems to be more than 1km/s at that point. A very steep launch profile, but one that helps to get the first stage back to the launch pad.

 

[mheslep]

I've not seen any comment yet on why SpaceX abandoned the barge for landing, or how they gained permission for a landing attempt at the Cape. A demolition charge could not have completely avoided tons of misguided 1st stage raining on the Cape.

 

[rootone]

My guess is that a barge is essentially a boat and it can tilt and move unpredictably due to weather and sea conditions.
Landing on land eliminates the risk that something moves in a weird way that the onboard guidance systems can't cope with.

 

[mfb]

The landing platform is also much larger than the barge.
The previous missions all came very close to the drone ship, I guess the risk of the rocket going completely wrong was not that large. There is also the risk of the launch going wrong, with much more fuel.

 

[mheslep]

... There is also the risk of the launch going wrong, with much more fuel.

Sure, and launches fail occasionally on the pad with all that fuel, but none the less on the pad which is secured for that eventuality. Shortly after launch the vehicle is downrange over the Atlantic.

On more consideration, I imagine that since the 1st stage is also returning from over the ocean the high speed portion of the descent is safe enough, and if there's a deviation from profile in the last ~mile they still have time to destroy it. The Cape is well named; I had opportunity recently to travel down the FL coast close offshore, which is otherwise remarkably straight for hundreds of miles except for the Cape jutting out into the ocean. Its a kind of giant land barge for the FL coast.

 

[newjerseyrunner]

Here is a graphic that I found very interesting to demonstrate the ability of SpaceX

 

[Greg Bernhardt]

Stage separation happened at 6000 km/h (and 77 km height), satellite deployment at 26000 km/h. That is 23%.
Full launch video
Vertical velocity seems to be more than 1km/s at that point. A very steep launch profile, but one that helps to get the first stage back to the launch pad.

This video is fantastic. I love the timeline at the bottom.

 

[Lord Crc]

I've not seen any comment yet on why SpaceX abandoned the barge for landing, or how they gained permission for a landing attempt at the Cape. A demolition charge could not have completely avoided tons of misguided 1st stage raining on the Cape.

The ballistic return trajectory is such that it would land in water. Shortly before landing one engine fires and changes the trajectory so it intersects the landing pad.

 

[Dr. Courtney]

Great stuff. I have a good friend who works for SpaceX.

 

[mheslep]

Here is a graphic that I found very interesting to demonstrate the ability of SpaceX ...

Blue Origin-Amazon's Bezos from doesn't agree there's a credit worthy distinction between the Falcon 1st stage and his suborbital flight. The twitter verse didn't take it well.

 

[Jonathan Scott]

I heard that the barge could still be used to support missions which need more fuel, by avoiding the need to fly back to the launch point.

 

[Greg Bernhardt]

Blue Origin-Amazon's Bezos from doesn't agree there's a credit worthy distinction between the Falcon 1st stage and his suborbital flight. The twitter verse didn't take it well.

I think this makes for a great competition that will only help advance the mission

 

[newjerseyrunner]

Blue Origin-Amazon's Bezos from doesn't agree there's a credit worthy distinction between the Falcon 1st stage and his suborbital flight. The twitter verse didn't take it well.

I disagree, Blue Origin's launch was a proof of concept, SpaceX's was a secondary feature of a fully functional payload delivery, both insanely impressive. I would liken it to the difference between Yuri Gragarian's full orbital flight vs Alan Shepard's suborbital.

I think this makes for a great competition that will only help advance the mission

Agreed, we are entering a very very interesting time in human history, I'm glad I'm alive to witness what will probably lead us to Mars in my lifetime. My impression that Elon Musk secretly hopes that his legacy to humanity will be Mars, and everything leading up to it will be forgotten.

 

[mrspeedybob]

How is this better then the parachute system used by the SRBs from the space shuttle?

There are the obvious benefits...
No cost associated with a recovery ship
No salt water

And the downside...
Additional fuel for the return trip and landing.

Does that about sum it up? What other benefits and downsides are there to this system vs the previous SRB recovery system?

 

[Monsterboy]

https://pbs.twimg.com/tweet_video/CWzGQVnVAAAdhdg.mp4

 

[mrspeedybob]

https://pbs.twimg.com/tweet_video/CWzGQVnVAAAdhdg.mp4

Umm...
That's a link to the pageant fiasco video. Was that an error, or are you trying to say this sort of recovery is just sexier?

 

[Monsterboy]

Umm...
That's a link to the pageant fiasco video. Was that an error, or are you trying to say this sort of recovery is just sexier?

That's the response Jeff got from Paul Gemperlein on twitter
http://money.cnn.com/2015/12/22/news/companies/jeff-bezos-elon-musk-twitter-feud/

 

[enorbet]

Umm...
That's a link to the pageant fiasco video. Was that an error, or are you trying to say this sort of recovery is just sexier?

Perhaps the inclusion of "sexier" came from the rumor that upon the successful landing, Elon Musk yelled "In your falcon face, Bezos!" ;)

 

[dschlink]

The barges are intended to be used for recovering the center booster of the Falcon Heavy, as it will be too far from land to backtrack without severely impacting the payload. They were used for the first trial landings, because SpaceX was having trouble getting permission to do onshore landings; if you read the notes leading up to Sunday's launch, you'll see that permission was up in the air as recently as prior Thursday.

 

[Lord Crc]

And the downside...
Additional fuel for the return trip and landing.

Fuel cost is almost negligible from what I understand. Someone mentioned the entire first stage fuel cost was just 0.7% of the total first stage cost. I can imagine a controlled landing at a pad being much more beneficial than a parachute wayer landing. Hot engine into salty ocean does not sound healthy.

 

[mfb]

How is this better then the parachute system used by the SRBs from the space shuttle?

The boosters were severely damaged by the impact and water and needed months of repair before they could be re-used. The vertical launch is much softer, and the hope is to re-use them within a day. Additional fuel is not an issue - fuel costs are negligible. It lowers the payload for a given rocket size, but if you have a Falcon Heavy or a small payload (and don't have to build a new rocket), this is not an issue.

 

[mheslep]

Fuel cost is almost negligible from what I understand. Someone mentioned the entire first stage fuel cost was just 0.7% of the total first stage cost. I can imagine a controlled landing at a pad being much more beneficial than a parachute wayer landing. Hot engine into salty ocean does not sound healthy.

It's not the fuel cost but the additional mass from additional fuel that is the issue. Payload mass is no more than single digit share of the total, so every additional kg of fuel (and tank and landing struts and ...) for boost back means a kg less of payload. The first step in this achievement was Spacex's breakthru reduction in vehicle mass (outer skin, turbo pump ,...), which then allowed fuel etc for a booster landing.

 

[mfb]

@mheslep: It is a bit better: payload has to go all the way to orbit, fuel for first stage return just has to get accelerated until the first stage engines cut off. That is a huge difference (~factor 5-10?).

 

[mrspeedybob]

How much difference would it make to have a landing pad on the balistic trajectory of the rocket at the time of separation, so that it doesn't have to reverse it's trajectory. Would this add significantly to the payload capacity?

I know this would require either a barge landing or a launch from somewhere other then Cape Canaveral. (Southern Texas maybe? With a landing pad in Florida)

 

[mfb]

I guess you'll have to ask SpaceX. They published some qualitative scheme a while ago, but without numbers. Something like:
Heaviest payload: Falcon Heavy, no reuse of anything, propellant cross-feed
A bit lighter: Falcon Heavy, landing of boosters
Even lighter: Falcon Heavy, landing of all three first stage elements, the middle one with some downrange distance
Even lighter: Falcon Heavy, landing of all three first stage elements close to the launch pad
Very light*: Falcon 9, landing of first stage

*still at ~13 tons to LEO, but very light compared to the 50 tons the first entry gives.