SpaceX SpaceX: First stage landed Satellites in orbit

[enorbet]

I'm glad the space age has finally caught up to where model rocketry was many decades ago.

In my distant youth, I designed and constructed a 4 stage model rocket, successfully launched, recovered, reloaded, relaunched and again recovered all 4 stages within 30 minutes.

I'd very much like to see man on the Moon again or on Mars. But I'm not optimistic that it'll be accomplished in the foreseeable future.

Not to take anything away from Model (paper and balsa wood) or even Amateur (Stainless Steel and/or Carbon Fiber) Rocketry achievements but I think your first statement is rather hyperbolic :) it isn't even just a problem with scaling ie: Square-Cube Law but rather that the comparison is actually more Apples-to-Oranges, given that almost no Model rockets and very few Amateur rockets carry any payload at all excepting the body of the rocket which, in the case of Model rockets, doesn't even need to exist since it is possible to glue balsa fins directly on "the engine" as well as an (optional) nose cone and it will fly just fine.

The body is commonly, aside from appearance, just an aerodynamic housing for the parachute. In those few with actual payloads, eggs and cameras are the most common payloads of Model and Amateur rockets and even in those most advanced cases the rocket to payload ratio is extremely high, making parachute-only landings possible and relatively safe and easy.

This doesn't even address the vast differences in Mass and complexity once we leave the realm of "burn once" solid fueled devices, nor even the need for precision in all systems, not to mention guidance which is entirely static on both model rockets and amateur. Even recovery parachute deployment is left to a timed slow burn built-in the engine at the factory in the case of Models and little more than a mercury switch activated by Brennschluss in Amateur rockets. Nothing is optimized nor controllable beyond lighting the fuse. Timing is left to "good enough to work" with usually zero flexibility. All of this makes for a vastly reduced combination of mass and complexity so that no serious comparisons are possible, certainly of no value nor concern.

I do agree that putting men on Mars is likely a very long way off in time, but I'm betting Men on the Moon will occur within 10-15 years at the most, but neither has anything to do with any non-existent lag behind modelers.

 

[Monsterboy]

I'd be doubly awesome if they could land the second stage on top of it, so that all they'd have to do between launches is re-fuel, and put another payload on top.

Lol ,that will be too risky what if the first stage lands fine and the second stage crashes on top of it ?? it will be better if they land just a few hundred metres from each other near the same launch pad from where they were launched, because Elon said (in TED Talks) that the goal was to reuse the rocket within a matter of hours.

 

[Xu Shuang]

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

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Only the first Stage rocket is recovered,which could cut the expense by half, at most.

 

[cjl]

Only the first Stage rocket is recovered,which could cut the expense by half, at most.

Why do you assume the first stage is only half the cost? It contains 9/10 of the engines, and something like 75-80% of the mass. I seem to remember hearing an estimate that the first stage was more than 75% of the overall cost of the launch vehicle.

 

[Blank_Stare]

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.

Thank you for that link - very nice to watch.

 

[mfb]

The first stage is by far the most expensive part. You cannot buy them individually for obvious reasons, so there is no official price tag, but 75% or more sound realistic.
A factor of 4 won't give us all a nice holiday trip in an orbital hotel, but it is a huge step in the right direction.

 

[mheslep]

The first stage is by far the most expensive part. You cannot buy them individually for obvious reasons, so there is no official price tag, but 75% or more sound realistic.
A factor of 4 won't give us all a nice holiday trip in an orbital hotel, but it is a huge step in the right direction.

I expect the resulting increased launch rate will also reduce cost beyond that afforded by reuse of the stage.

 

[mfb]

It should. SpaceX has a really crowded launch schedule, 30 launches next year. Some of them will get moved to 2017 for sure (and some of the 2017 launches to 2018), but even 15-20 launches would be a lot.

 

[Xu Shuang]

Why do you assume the first stage is only half the cost? It contains 9/10 of the engines, and something like 75-80% of the mass. I seem to remember hearing an estimate that the first stage was more than 75% of the overall cost of the launch vehicle.

Based on the experience of space shuttles, recovering the first stage doesn't mean the cost of the first stage is gone. The first stage would still need serious renovation before reuse. For space shuttles, the engine need to be replaced every three missions. For the rocket, the renovation cost would be less, but would still be far from an ideal reuse.

 

[cjl]

Based on the experience of space shuttles, recovering the first stage doesn't mean the cost of the first stage is gone. The first stage would still need serious renovation before reuse. For space shuttles, the engine need to be replaced every three missions. For the rocket, the renovation cost would be less, but would still be far from an ideal reuse.

The space shuttles and this share very little though - the engine design is completely different, the resuse model is completely different, the fuel is completely different... It remains to be seen how much can be saved through reuse, but comparing this to the shuttle seems somewhat irrelevant to me.

 

[mheslep]

Based on the experience of space shuttles, recovering the first stage doesn't mean the cost of the first stage is gone...

Not gone, but in the same cost model as commercial aircraft as opposed to one and done.

 

[HyperTechno]

A really great and successful attempt. This will benefit the future space explorations. Less space pollution and less wastage of materials and money!

 

[LURCH]

It's my understanding that the real savings here is not the reuse of the stage (by witch I mean that the stage was going going to be reused in any case). The big cost reduction is the fact that they don't have to go out to sea in a ship to retrieve it.

Don't know how much that cost, but I know it isn't cheap.

 

[mfb]

A really great and successful attempt. This will benefit the future space explorations. Less space pollution and less wastage of materials and money!

More junk in space, at least in the short run. First stages don't stay in space with any current rocket, so returning them does not help in that point. Cheaper launches mean more launches means more stuff in space.

It's my understanding that the real savings here is not the reuse of the stage (by witch I mean that the stage was going going to be reused in any case). The big cost reduction is the fact that they don't have to go out to sea in a ship to retrieve it.

No, the cost reduction is the actual re-use of the first stage (which is not demonstrated yet, but I hope we'll see it in the near future). Collecting waste (if done at all) would be cheap.

 

[LURCH]

Yes, I understand that reusable rockets are a big cost-savings, but this is far from being the first reusable rocket. Reusable rockets have been around a long time. What makes this rocket different is that it doesn't have to be fished out of the ocean. I'm just wondering if the cost of extra fuel to make the first stage come back and land is really going to end up being a significant savings, bearing in mind that the stage would be reusable whether it lands near the launch pad or in the ocean. And wether that savings will be immediate, or will it come in the form of bigger up-front costs that will be regained over time?

 

[mfb]

What makes this rocket different is that it doesn't have to be fished out of the ocean.

The Shuttle boosters needed months of "repair" - a bit cheaper than starting from scratch, but far away from what SpaceX wants to do: launch, land, and be ready launch again possibly within hours (currently weeks would be sufficient, fuller launch schedules can change that).

The size of the rocket is fixed for Falcon 9. If the payload mass allows it, they will continue to land on land, it has a higher success rate and saves some trouble with the drone ship. If the payload is too heavy, the drone ship is an option.

 

[HyperTechno]

launch, land, and be ready launch again possibly within hours (currently weeks would be sufficient, fuller launch schedules can change that).

Why don't they attempt some big Space shuttles that are capable of taking most of the things like supplies, satellites to space. NASA retired the space shuttles and I've heard that they did that because of the Colombia disaster... . But anyway, I think attempting a new shuttle project will help to lower the addition of Space Junk and also will save the cost...
Because although the rocket boosters come back, still some items are left in the space in the modern Rockets.
Whatever the problems with the former shuttles, I think the modern technology can come over them to make much safer and effective Space Shuttles.

 

[mfb]

The space shuttle was designed to lower costs, but various technical and management issues made it much more expensive than planned. The Columbia disaster contributed to the retirement, but it was never a cheap system.
The Falcon Heavy will have about twice the payload mass of the Space Shuttles.

Because although the rocket boosters come back, still some items are left in the space in the modern Rockets.

That is not different for SpaceX. Cheaper access to space can make special debris collection satellites more interesting.

 

[cjl]

Why don't they attempt some big Space shuttles that are capable of taking most of the things like supplies, satellites to space. NASA retired the space shuttles and I've heard that they did that because of the Colombia disaster... . But anyway, I think attempting a new shuttle project will help to lower the addition of Space Junk and also will save the cost...
Because although the rocket boosters come back, still some items are left in the space in the modern Rockets.
Whatever the problems with the former shuttles, I think the modern technology can come over them to make much safer and effective Space Shuttles.

Because wings are large, heavy objects that have to be strengthened, heat-shielded, and carried along for the entire flight, even though they are only useful during the last 5 minutes. A shuttle looks really nice on the back of a napkin, but in practice, at least with current achievable payload mass fractions, you end up wasting a huge amount of fuel and effort carrying around something that's much heavier than needed.

 

[mheslep]

wings are large, heavy objects that have to be strengthened, heat-shielded, and carried along for the entire flight, even though they are only useful during the last 5 minutes.

True of the Shuttle wings but perhaps it need not be so. Some cruise missiles deploy wings in flight and most (all?) carrier air craft have fold-able wings. Stowed wings need not be heat shielded nor withstand high mach numbers nor drag the vehicle air frame on ascent, so weight comes down.

http://enu.kz/repository/2009/AIAA-2009-1291.pdf

While the Falcon Heavy and other vehicles will no doubt replace the shuttle's lift capacity, nothing yet comes close to the Shuttle's capacity for returning heavy payload to the surface: seven astronauts and all of their life support which can be reused, plus a few satellites in the trunk.

 

[mfb]

The unmanned Dragon can return 3 tons of payload, the planned Dragon 2 will have a similar capacity and can carry up to 7 astronauts up and down (not sure if they are included in the payload mass). Most things don't need to get back to Earth in a controlled way, mainly humans and a few experiment samples, and the Dragon is supposed to be re-usable as well.

Stowed wings need not be heat shielded nor withstand high mach numbers nor drag the vehicle air frame on ascent, so weight comes down.

An additional stowing system adds mass - you still need the wings with their structural integrity to survive re-entry, but now they also have to be retractable for the launch.

 

[mheslep]

...

An additional stowing system adds mass - you still need the wings with their structural integrity to survive re-entry, but now they also have to be retractable for the launch.

I'm thinking wings deploy at 20 to 30 thousand feet on descent. Before that a shuttle shape with no wings does rentry, with wings stowed in an area not exposed to hot gasses, like the top of the shuttle.

 

[mheslep]

The unmanned Dragon can return 3 tons of payload, the planned Dragon 2 will have a similar capacity and can carry up to 7 astronauts up and down (not sure if they are included in the payload mass). Most things don't need to get back to Earth in a controlled way, mainly humans and a few experiment samples, and the Dragon is supposed to be re-usable as well.
.

Shuttle payload return was 14 tons per wiki.

 

[HyperTechno]

nothing yet comes close to the Shuttle's capacity for returning heavy payload to the surface

Yep I agree with you. that was the greatest advantage of shuttles that you can not only send but also return payloads... and the dragon can't handle such an amount of load...
Space shuttles were problematic and were more expensive than traditional Rockets but yet advantageous in some ways...
What I think is it's better to develop a less expensive and effective shuttle project with the modern technology and I guess that's something the modern technology can do...
as with all the shuttle missions the profs and cons of shuttles are well known and what is needed is to come over the cons and develop the profs and I know it's not easy as saying but will worth giving it a try...

 

[HyperTechno]

Just an idea... What about making a shuttle(like thing) without wings and using parachutes in stages to slow it down...(in a way that it stays horizontally in landing)
Landing...mmmmmm... to ocean?. { a safe landing like the returning module of Rockets}

To make it lite

 

[mfb]

Just an idea... What about making a shuttle(like thing) without wings and using parachutes in stages to slow it down...(in a way that it stays horizontally in landing)
Landing...mmmmmm... to ocean?. { a safe landing like the returning module of Rockets}

To make it lite

That's the Dragon capsule approach. But with the additional feature of landing on land.

Shuttle payload return was 14 tons per wiki.

And what was used? Also per Wiki:

The orbiter also recovered satellites and other payloads (e.g., from the ISS) from orbit and returned them to Earth, though its use in this capacity was rare.

 

[cjl]

While the Falcon Heavy and other vehicles will no doubt replace the shuttle's lift capacity, nothing yet comes close to the Shuttle's capacity for returning heavy payload to the surface: seven astronauts and all of their life support which can be reused, plus a few satellites in the trunk.

True, but I don't really consider payload return capability to be terribly important. Look at how often we actually brought something back compared to how often the shuttle was flown - it simply was never a capability that proved particularly useful.

 

[Monsterboy]

True, but I don't really consider payload return capability to be terribly important. Look at how often we actually brought something back compared to how often the shuttle was flown - it simply was never a capability that proved particularly useful.

It will turn out to be useful for long duration manned spaceflights right ? considering that one the main long term goals of SpaceX is to take people to Mars and back.

 

[mfb]

Why? You have to take the crew back - the Dragon V2 can do that. You probably want to return some samples with a manned mission to mars, but a few tons of payload should be more than sufficient for that. Getting the stuff from Mars surface to Earth orbit is the limiting factor, not getting it down to the surface.

 

[HyperTechno]

That's the Dragon capsule approach. But with the additional feature of landing on land.

Well I know that Dragon Capsule has the ability to land on land...
But is it big enough , to do everything the old shuttle could do?

 

[mfb]

It cannot do some thing the old shuttle could (getting heavy/large things back to Earth), but those things are not needed anyway.

 

[mrspeedybob]

I haven't seen any discussion about an obvious application of this technology for a Mars mission. That being, some sort of large rocket will be needed, on Mars, to get our people off of Mars and on their way home. The ability to land a large rocket in a condition which is almost immediately re-usable seems like a prerequisite accomplishment for the Mars mission.
How much of the technology developed to land the first stage of the Falcon form sub-orbital altitude and velocity on Earth, will be applicable to landing a complete, and fully fueled, and ready to use rocket on Mars from Martian orbit?

 

[cjl]

It will turn out to be useful for long duration manned spaceflights right ? considering that one the main long term goals of SpaceX is to take people to Mars and back.

In what way would that be needed for long duration spaceflight? I don't really see why you would need to bring back anything more than just the people and maybe a few samples or something, and a capsule works fine for that.

 

[mheslep]

And what was used? Also per Wiki:

True, but I don't really consider payload return capability to be terribly important. Look at how often we actually brought something back compared to how often the shuttle was flown - it simply was never a capability that proved particularly useful.

Agreed. I think though that to a degree the ISS made that possible, reduced the need for a large return vehicle, as a long term in orbit staging and storage point with full habitation capability. If in the future the ISS was abandoned, then the Shuttle's heavy return and in orbit dwell time might prove tricky to break up into multiple packages and multiple Dragon launches.

 

[cjl]

Agreed. I think though that to a degree the ISS made that possible, reduced the need for a large return vehicle, as a long term in orbit staging and storage point with full habitation capability. If in the future the ISS was abandoned, then the Shuttle's heavy return and in orbit dwell time might prove tricky to break up into multiple packages and multiple Dragon launches.

I'm still not seeing what you're trying to say here - what, specifically, would need to be brought back down?

 

[enorbet]

Re: Travel to Mars - A great deal to do with the viability of a return capsule has to do with velocity affecting the duration of the return trip. While it is possible that 2 months might vaguely be doable with the right people, 6 months is very likely to be intolerable. It was only 7 months ago that SpaceX was certified for Category 2 launches by NASA and while the new agreement with USAF(preview here http://www.spacex.com/news/2015/01/23/united-states-and-spacex-agree-settlement ) shows excellent progress, it may be a year or more before SpaceX has scaled up for increased size and function as well as the track record to be certified for Category 3. I'm willing to bet that SpaceX in general and even Elon Musk personally are keeping an eye on developments in many areas such as VASIMR to improve transit time and alter requirements to a more comfortable standing.

This is an important step and while huge in it's accomplishment in and of itself it is just one of many small steps that must be taken in order to make deep space travel both reasonably safe and relatively inexpensive. Patience, Padawan :)

 

[mheslep]

I'm still not seeing what you're trying to say here - what, specifically, would need to be brought back down?

The ISS and Shuttle provide a lot of habitation capability, for long to very long term. Capsules not so much. So, for example, in a future with not ISS, no Shuttle, what to do with a crew in a capsule that's disabled for some reason and can't re-enter. Or, how does one accomplish a two week service mission on some orbital instrument like Kepler, requiring multiple EVAs in large maneuver packs and requiring some kind of capture (as with the Shuttle arm)?

 

[mheslep]

...keeping an eye on developments in many areas such as VASIMR

A manned Mars mission is probably doable with proven, current technology. On the other hand, VASIMR is nowhere close to feasible yet, so it means decades more waiting. Also, going to Mars on the slow road keeps open the possibility of an un-powered return loop in the case something goes wrong outbound. Going to Mars fast in the case of a loss of thrust power near Mars guarantees a tour of beyond Mars.

 

[HyperTechno]

It cannot do some thing the old shuttle could (getting heavy/large things back to Earth), but those things are not needed anyway.

hmmm. They'll build a better 1 when they need!

 

[HyperTechno]

I haven't seen any discussion about an obvious application of this technology for a Mars mission. That being, some sort of large rocket will be needed, on Mars, to get our people off of Mars and on their way home. The ability to land a large rocket in a condition which is almost immediately re-usable seems like a prerequisite accomplishment for the Mars mission.
How much of the technology developed to land the first stage of the Falcon form sub-orbital altitude and velocity on Earth, will be applicable to landing a complete, and fully fueled, and ready to use rocket on Mars from Martian orbit?

Well I have the same question. Can Some 1 answer this please?

 

[cjl]

The ISS and Shuttle provide a lot of habitation capability, for long to very long term. Capsules not so much. So, for example, in a future with not ISS, no Shuttle, what to do with a crew in a capsule that's disabled for some reason and can't re-enter. Or, how does one accomplish a two week service mission on some orbital instrument like Kepler, requiring multiple EVAs in large maneuver packs and requiring some kind of capture (as with the Shuttle arm)?

All the speculative designs I've seen involve having some habitation area that is not designed for reentry, and the capsule itself is just used for reentry (and it would detach shortly before the reentry occurs). As for service missions, most current satellites are not designed to be serviceable, and in most cases (including Hubble, at least by some estimates), it is cheaper to just launch an entire new satellite rather than trying to service an existing one. However, if you really needed to service one, again, send up the tools needed to service the satellite (and possibly also a long-term habitation area) with the capsule, and the overall payload requirements will still be less than for a shuttle-like vehicle.

 

[mfb]

The ISS and Shuttle provide a lot of habitation capability, for long to very long term. Capsules not so much. So, for example, in a future with not ISS, no Shuttle, what to do with a crew in a capsule that's disabled for some reason and can't re-enter. Or, how does one accomplish a two week service mission on some orbital instrument like Kepler, requiring multiple EVAs in large maneuver packs and requiring some kind of capture (as with the Shuttle arm)?

The ISS is a backup option for a very narrow range of orbits only. A space shuttle that cannot re-enter would have had the same problem.
3 tons of payload can support a crew for quite some time.
No idea about robotic arms.

I haven't seen any discussion about an obvious application of this technology for a Mars mission. That being, some sort of large rocket will be needed, on Mars, to get our people off of Mars and on their way home. The ability to land a large rocket in a condition which is almost immediately re-usable seems like a prerequisite accomplishment for the Mars mission.
How much of the technology developed to land the first stage of the Falcon form sub-orbital altitude and velocity on Earth, will be applicable to landing a complete, and fully fueled, and ready to use rocket on Mars from Martian orbit?

The launch payload would be a single capsule with humans and a few rock samples, if we use a Dragon v2 this is about 5 tons. Mars surface to orbit just needs ~3.5 km/s (plus <10% for gravity drag), that is significantly below the capacity of the second stage of Falcon 9. Using this second stage without modification but with less fuel, we get another 4 tons of structural mass, the specific impulse of 340 seconds would suggest a lauch mass to dry mass ratio of ~3, so we need an estimated 27 tons on Mars, maybe a bit more. This happens to match the dry mass of the first stage (26 tons). The current second stage doesn't have landing gears, but we did land something of that mass on Earth with 3 times the surface gravity.

Cross-check: The second stage has a maximal thrust of 800 kN, sufficient to accelerate 27 tons by 32 m/s, or roughly 10 times the Martian surface gravity.

All SpaceX-related numbers from this page.

 

[Monsterboy]

http://www.nbcnews.com/tech/innovat...acex-falcon-9-rocket-ready-fire-again-n488926

Elon says the first stage is 'ready to fire again' but...

Though this particular history-making rocket appeared to be unscathed, Musk has said it's unlikely to be used for another mission and will probably be put on display instead.

"I think we'll probably keep this one on ground," Musk said after the landing. "Just because it's kind of unique, it's the first one that we've brought back. So I think we'll probably keep this one on the ground, but just confirm through tests that it could fly again."

 

[HyperTechno]

What about the cost of fuel used on landing the 1st stage back on ground? and also the cost of repairs?
aren't they expensive more or equal to the cost of building a new 1st stage?

 

[Monsterboy]

What about the cost of fuel used on landing the 1st stage back on ground? and also the cost of repairs?
aren't they expensive more or equal to the cost of building a new 1st stage?

No , that's the whole point of a reusable rocket ,the cost of fuel is very very less compared to the cost of the rocket ,this has been made clear earlier in this thread , the cost of repairs will also be very less compared to building a new rocket unless something goes wrong and the rocket crashes (in this case i don't think it can be repaired).

 

[mfb]

What about the cost of fuel used on landing the 1st stage back on ground? and also the cost of repairs?
aren't they expensive more or equal to the cost of building a new 1st stage?

See the previous posts, fuel is below 1% of the launch costs, and the additional fuel needed to get back is a small fraction of this 1%. The repair costs will need more long-term experience to get a reliable estimate, but the goal is to have it ready for flight within hours, so basically no repairs necessary.

It is really similar to an airplane - building a new one for each flight would be ridiculous even if you have to fly the existing airplane back empty.

 

[cjl]

See the previous posts, fuel is below 1% of the launch costs, and the additional fuel needed to get back is a small fraction of this 1%. The repair costs will need more long-term experience to get a reliable estimate, but the goal is to have it ready for flight within hours, so basically no repairs necessary.

It is really similar to an airplane - building a new one for each flight would be ridiculous even if you have to fly the existing airplane back empty.

Well... it's not quite that simple, unfortunately. The rocket does need to be bigger and heavier to lift the same payload, since it now needs to carry the extra fuel and equipment to allow the stage to return and land, and the launch profile used for this flight (and presumably all reusable flights) is rather different than what you would normally want (it was fairly lofted, with the first stage giving the rocket less overall delta V and downrange distance than you normally would). This trajectory required the second stage to be larger and more powerful than it would otherwise need to be to make up for the shortfall in downrange performance from the first stage. Since the second stage is not reused, any additional performance from the second stage is still rather expensive. However, despite these tradeoffs, SpaceX still believes they can save a lot of money through the boostback, and I would tend to believe them on that. I just want to point out that there are some other considerations on top of just adding the cost of the extra fuel for the boostback though.

 

[mfb]

The second stage has a fixed size, SpaceX cannot use a smaller one. Yes, returning to the launch pad reduces the maximal payload, but the payload was light enough to allow such a mission. Heavier payloads will have the first stage land on the drone ship, and even heavier ones get an expendable rocket (or move to Falcon Heavy in the future). That's something I wrote at least 5 times now in this thread. The Falcon 9 is cheaper than many smaller rockets - even without the re-use feature.

 

[cjl]

The second stage has a fixed size, SpaceX cannot use a smaller one. Yes, returning to the launch pad reduces the maximal payload, but the payload was light enough to allow such a mission. Heavier payloads will have the first stage land on the drone ship, and even heavier ones get an expendable rocket (or move to Falcon Heavy in the future). That's something I wrote at least 5 times now in this thread. The Falcon 9 is cheaper than many smaller rockets - even without the re-use feature.

The second stage has a fixed size, and that fixed size is larger than it would be if they had designed the rocket to be disposable while still carrying its' typical payload capacity. It's true that the design is fixed now, but the whole rocket design was based around the concept of reusability, so you can't just claim that everything would be the same size (and cost) if they had designed it as a disposable rocket from the start.

 

[mfb]

The baseline so far is a disposable rocket. The re-usable version is a modified first stage. A bit heavier and with a lower payload capacity. Well, "lower" - the Falcon Heavy will beat the heaviest operational system (Delta IV Heavy) by nearly a factor 2 (and cost ~1/4 per launch). Even with re-use of all three cores, it will have a higher payload capacity than all other rocket systems currently in use.