The SpaceX Thread

[Barmaglot]

Technically, they tried with DC-X and VentureStar, but nothing much came of those.

 

[Megalodon]

Sputnik[/url]":299ibhgw]I'm not convinced there's no secret sauce. If there weren't, they'd be patenting, and releasing more footage.

Maybe in their manufacturing to get such good mass fractions and thrust to weight ratios, but I don't think anything the video would reveal. People can do the math for the boost-back trajectories independently.

UserJoe[/url]":299ibhgw]The secret sauce is their top level systems analysis that showed that cost savings of launcher recovery and reuse could make up for the cost penalty of reduced lift capacity and increased complexity in their target market.

So has everyone else's.

What's unique is the approach. A design was picked that was economical and low risk as an expendable booster, and it can fly as an expendable until the bugs are worked out.

IMO if something is unique here it's that a government backed flyback booster would have to be designed with enough margin that it would do so with high confidence from the outset. You couldn't have the plan be to debug as you went and end up completely changing your mind about how to do it as SpaceX has. Changing your mind would be a huge scandal and would require contract modifications.

 

[tinyMan]

Megalodon[/url]":10ejvahd]

Sputnik[/url]":10ejvahd]I'm not convinced there's no secret sauce. If there weren't, they'd be patenting, and releasing more footage.

Maybe in their manufacturing to get such good mass fractions and thrust to weight ratios, but I don't think anything the video would reveal. People can do the math for the boost-back trajectories independently.

Musk has said that SpaceX doesn't file many patents, because their competitors are primarily nation states and there is little chance of enforcing them. I guess it is better to keep them as trade secrets than to publish and (try to) enforce them.

The lack of patents doesn't mean that there is, or is not any secret sauce.

I, personally, think that the willingness to take risks, to iterate quickly and the ability to hire the best and brightest are big contributors to the success they have seen. That formula has worked in many industries.

 

[Megalodon]

PsionEdge[/url]":atakocb3]And screwing up satellite deliveries for his future customers as well.

Thing is, SpaceX didn't actually ask for an injunction on the engines in their lawsuit.

If SpaceX's contribution has been to draw attention to purchases that might well be illegal, perhaps there's a little blame to spread around to the people that got away with using a Russian engine all along on the assurance domestic manufacturing wouldn't be that hard.

I think the longer term issue is probably that the ULA may well not be a sustainable businesses on the bids they will win once they actually do have to bid; SpaceX could well disrupt launches they can't yet replace in that way. IMO if that's the real problem then we should be explicit about it.

 

[Barmaglot]

Didn't SpaceX claim their factory is set up to produce 30 rockets a year? Their launch manifest isn't nearly that big right now.

 

[MilleniX]

Anyone have any reference for whether SpaceX's current customers' launch contracts guarantee first launches on a given booster stack? Once they recover a full stage and requalify it, will they be offering flights on those 'certified pre-launched' boosters at a discount to whoever can be convinced to take them, or will they just accelerate their manifest to the extent that customers have the payloads ready to fly, and take on anyone else who signs up?

 

[Megalodon]

Musk has said all current launches are a new vehicle, and that a demo flight may be required to get any customers to agree otherwise.

 

[jbode]

Barmaglot[/url]":nhhcduiw]Didn't SpaceX claim their factory is set up to produce 30 rockets a year? Their launch manifest isn't nearly that big right now.

It's not so much how many rockets they can build, it's how many they can launch. They're going to have to step up their pace a bit.

 

[Anzig]

I can see the "once flown" boosters going for a premium if/when they get recovery working well. If the first stage is good for 4 or more launches, then the most valuable flights are in the middle, after it has been flight tested and before it nears end-of-life.

 

[Alamout]

I can see the "once flown" boosters going for a premium if/when they get recovery working well. If the first stage is good for 4 or more launches, then the most valuable flights are in the middle, after it has been flight tested and before it nears end-of-life.

Really depends on the failure profile. You could imagine it going either way--second flight is more reliable because you know there were no manufacturing problems, or first flight is more reliable because it's a fresh vehicle.

It'll take them a long time to get that kind of data...

 

[MilleniX]

It also depends on whether they really intend to refly entire, fully-integrated boosters, after just refueling and restacking, or whether they're initially going to pull parts off once-flown boosters and integrate them in fresh assemblies. If they only have bottlenecks in part of their manufacturing flow, and have more confidence in the durability of some parts than others, this might make more sense.

From everything they've said, I think they're aiming for restack, refuel, and launch from the start, with no tear-down at all in the absence of worrisome diagnostics.

 

[Megalodon]

MilleniX[/url]":y4s3iolr]It also depends on whether they really intend to refly entire, fully-integrated boosters, after just refueling and restacking, or whether they're initially going to pull parts off once-flown boosters and integrate them in fresh assemblies. If they only have bottlenecks in part of their manufacturing flow, and have more confidence in the durability of some parts than others, this might make more sense.

From everything they've said, I think they're aiming for restack, refuel, and launch from the start, with no tear-down at all in the absence of worrisome diagnostics.

I think for the first one they're going to do a pretty thorough post mortem, with that gradually tailing off as they understand what needs work when the boosters come back.

 

[MilleniX]

For their hypothetical "return to launch pad and fly again that day", they're going to have to get that post-flight checkup down to basically zero for the units that are still in their original design lifetime.

 

[Megalodon]

MilleniX[/url]":1vs5j4wl]For their hypothetical "return to launch pad and fly again that day", they're going to have to get that post-flight checkup down to basically zero for the units that are still in their original design lifetime.

I would bet on a fairly extensive checkout, but a very automated one, including analysis of the data recorded on the previous flight (eg "pressure anomaly in helium tank B at 2:01" so one of the ground crew gets a maintenance item on their iPad).

 

[Tom the Melaniephile]

jbode[/url]":23rix30f]

Barmaglot[/url]":23rix30f]Didn't SpaceX claim their factory is set up to produce 30 rockets a year? Their launch manifest isn't nearly that big right now.

It's not so much how many rockets they can build, it's how many they can launch. They're going to have to step up their pace a bit.

Well, didn't they just lock in 39A at Canaveral, plus being in the final stages of clearance for the Texas launch site? They seem to be on track to crank up launches.

I really haven't looked it up - for the first stage landing, is there an "ideal" distance from the launch site where you would want the landing?

 

[Christopher James Huff]

Tom the Melaniephile[/url]":19qqgjes]Well, didn't they just lock in 39A at Canaveral, plus being in the final stages of clearance for the Texas launch site? They seem to be on track to crank up launches.

They got 39A, but there's still the issue of scheduling the range. The Texas site's apparently a couple years away from being used for launches, but should be a substantial help when it's up.

Tom the Melaniephile[/url]":19qqgjes]I really haven't looked it up - for the first stage landing, is there an "ideal" distance from the launch site where you would want the landing?

A couple hundred km downrange is ideal for landing the rocket with minimal payload impact. However, this puts the landing site in the ocean, and even if you had a patch of solid ground, it makes for an expensive return trip. It sounds like they want to land very near the launch site. Not on the launch pad, but on a nice flat landing pad near it.

Now, much of the reason for launching over the sea is not what happens in failures, but the fact that even every successful launch has meant a first stage falling out of the sky downrange. If they can demonstrate enough reliability in first stage control, perhaps with contingency measures for controlling the impact site if failures make landing impossible, they might be allowed to launch from an inland location. That would open up a lot of freedom in launch and landing sites.

 

[Megalodon]

Christopher James Huff[/url]":3tmglg7z]Now, much of the reason for launching over the sea is not what happens in failures, but the fact that even every successful launch has meant a first stage falling out of the sky downrange. If they can demonstrate enough reliability in first stage control, perhaps with contingency measures for controlling the impact site if failures make landing impossible, they might be allowed to launch from an inland location. That would open up a lot of freedom in launch and landing sites.

I don't think that's ever going to happen. If you look at the energy content of one of those rockets you get numbers that look like a small nuclear bomb, with bigger explosion potential than even a large aircraft because they carry liquid oxidizer. See: https://www.youtube.com/watch?v=Zl12dXYcUTo

Now for something like SpaceX's test vehicles that's tolerable because they can operate them over areas that are set aside for that purpose, but an orbital launch has to go sideways. If you're not coastal you're overflying populated areas.

 

[Lee L]

I am not a rocket scientist, but is it crazy to think maybe they could launch from Texas and land at the Cape, then launch from the Cape, at least getting 2 for 1 on each booster?

 

[Frennzy]

Now for something like SpaceX's test vehicles that's tolerable because they can operate them over areas that are set aside for that purpose, but an orbital launch has to go sideways. If you're not coastal you're overflying populated areas.

Have you *seen* east Texas?

 

[Barmaglot]

I thought that returning to launch site is a huge deal for a first stage, but apparently it's not as big as I thought it was. 2nd stage separation is around 60km altitude, ~50km downrange at mach 6, and first stage apogee is around 80km. Also, their advertised payload numbers for Falcon 9 v1.1 apparently already include the margin required for a return to launch site trajectory, and can be exceeded by burning the first stage to depletion.

 

[jbode]

Lee L[/url]":1w89l29s]I am not a rocket scientist, but is it crazy to think maybe they could launch from Texas and land at the Cape, then launch from the Cape, at least getting 2 for 1 on each booster?

No, for four reasons:

1. They can't reach the Cape from Port Isobel/Boca Chica without flying over cities like Tampa, Orlando, etc., which ain't gonna happen;

2. They're going to be launching mainly GEO/GTO missions from TX (that's one of the few inclinations available from that site without flying over populated areas), meaning they're going to be flying pretty much the opposite direction from the Cape;

3. The booster doesn't travel that far downrange (the CRS3 booster staged at around 90km or so; it's almost 1700 km to the Cape);

4. The conops is return to launch site (RTLS); that's their goal, by hook or by crook. Otherwise, the whole gas'n'go concept is a failure.

 

[jbode]

Christopher James Huff[/url]":2unbwu80]

Tom the Melaniephile[/url]":2unbwu80]Well, didn't they just lock in 39A at Canaveral, plus being in the final stages of clearance for the Texas launch site? They seem to be on track to crank up launches.

They got 39A, but there's still the issue of scheduling the range. The Texas site's apparently a couple years away from being used for launches, but should be a substantial help when it's up.

The problem with the Texas site is it has a limited range of inclinations available compared to the Cape. You're not going to see ISS missions launch from TX, for example. My understanding is that the TX site will be used mainly for GTO launches.

Now, much of the reason for launching over the sea is not what happens in failures, but the fact that even every successful launch has meant a first stage falling out of the sky downrange. If they can demonstrate enough reliability in first stage control, perhaps with contingency measures for controlling the impact site if failures make landing impossible, they might be allowed to launch from an inland location. That would open up a lot of freedom in launch and landing sites.

Yeah, it's going to take a lot of convincing for the FAA to allow staging over populated areas; I don't see this happening in less than a decade. That's assuming SpaceX can make this work, both technically and economically.

 

[Megalodon]

jbode[/url]":1lqxjgv5]The problem with the Texas site is it has a limited range of inclinations available compared to the Cape. You're not going to see ISS missions launch from TX, for example. My understanding is that the TX site will be used mainly for GTO launches.

Musk mentioned in some interview that they might actually be able to do ISS from Vandenburg with significant payload penalty. This seems to be because of the high inclination of the ISS orbit to allow Russian participation. They would swing way out over the Pacific, then curve eastwards and south.

Texas doesn't work as you say. It seems it mostly helps by taking some traffic out of Florida.

 

[Tom the Melaniephile]

jbode[/url]":t2j1h98m]

Lee L[/url]":t2j1h98m]I am not a rocket scientist, but is it crazy to think maybe they could launch from Texas and land at the Cape, then launch from the Cape, at least getting 2 for 1 on each booster?

No, for four reasons:

1. They can't reach the Cape from Port Isobel/Boca Chica without flying over cities like Tampa, Orlando, etc., which ain't gonna happen;

I was more thinking they might land in the Yucatan, if international politics doesn't get in the way. I guess they could just claim NAFTA...

 

[Gigaton]

That youtube video can be 'slightly' misleading. That was the entire fully fueled vehicle impacting right after liftoff.

For SpaceX:
Remaining fuel in the first stage is likely to be very low during return.
Compared to an aircraft, the weight for it's volume is very low.
It doesn't have to last 20+ years of service. (Several takeoff and landing cycles per day)
A powered vertical landing is likely to be less stressful* than landing on wheels. (Lighter mass landing struts)
It will not have any payload. (additional weight savings)

Given time, I can see the rules being relaxed (but not eliminated) for a return to landing sight for the first stage. Restrictions on launch will probably be the same. Landing reliability will be the issue. Not explosive potential. Crash a Boeing 737! That would be worse than a nearly empty booster.

*The stress is transferred to the rockets. That may be less cost effective due to longer powered operation per flight.

 

[Megalodon]

Gigaton[/url]":23fhwgxj]That youtube video can be 'slightly' misleading. That was the entire fully fueled vehicle impacting right after liftoff.

I was responding to a suggestion of both landing and launching from inland; if you're launching inland you definitely have the fully fueled vehicle overflying stuff.

 

[PsionEdge]

Megalodon[/url]":1b6izu5c]

PsionEdge[/url]":1b6izu5c]And screwing up satellite deliveries for his future customers as well.

Thing is, SpaceX didn't actually ask for an injunction on the engines in their lawsuit.

If SpaceX's contribution has been to draw attention to purchases that might well be illegal, perhaps there's a little blame to spread around to the people that got away with using a Russian engine all along on the assurance domestic manufacturing wouldn't be that hard.

I think the longer term issue is probably that the ULA may well not be a sustainable businesses on the bids they will win once they actually do have to bid; SpaceX could well disrupt launches they can't yet replace in that way. IMO if that's the real problem then we should be explicit about it.

I'm not even talking about ULA launches. The customers are commercial satellite operators. His lawsuit may not have intended to, but regardless has very likely eliminated one of the most affordable launch options out there - converted Russian ICBM launches out of Kazakhstan. Perhaps it was by design after all in an evil genius sort of way.

http://www.spacenews.com/article/milita ... pace-firms

 

[Barmaglot]

19 Dnepr launches in 15 years are not exactly a huge chunk of the market.

 

[Megalodon]

PsionEdge[/url]":3jmgj3i1]I'm not even talking about ULA launches. The customers are commercial satellite operators. His lawsuit may not have intended to, but regardless has very likely eliminated one of the most affordable launch options out there - converted Russian ICBM launches out of Kazakhstan. Perhaps it was by design after all in an evil genius sort of way.

Those sanctions aren't the result of the SpaceX lawsuit. As the linked article clearly states, the holdup is the state department not issuing export licenses for satellites to be shipped to the launch sites. The lawsuit only resulted in an injunction against paying Russia for RD-180 engines, which have little activity in commercial launches.

Barmaglot[/url]":3jmgj3i1]19 Dnepr launches in 15 years are not exactly a huge chunk of the market.

The sanctions impact all Russian launches including Soyuz and Proton, which is significant.

 

[Barmaglot]

Point taken, but neither Soyuz nor Proton are converted ICBMs, or, if you count them as such, so are Delta IV and Atlas V.

 

[dio82]

Megalodon[/url]":1twdisuy]
Those sanctions aren't the result of the SpaceX lawsuit. As the linked article clearly states, the holdup is the state department not issuing export licenses for satellites to be shipped to the launch sites. The lawsuit only resulted in an injunction against paying Russia for RD-180 engines, which have little activity in commercial launches.

The sanctions impact all Russian launches including Soyuz and Proton, which is significant.

Ouch ... that is one hell of a double whammy of the law of unintended consequences. I doubt that Musk is such an Evil Genius that he anticipated the state department grounding all US manufactured satellite launches from Kazachstan.

Arianespace should leap for joy about the prospect of significant commercial satellite launches moving from Kazachstan to them. Edit: Arianespace is also doing Soyuz launches from Guyana ... does any body know what is actually happening to those?

 

[Christopher James Huff]

dio82[/url]":ja732iyo]

Megalodon[/url]":ja732iyo]
Those sanctions aren't the result of the SpaceX lawsuit. As the linked article clearly states, the holdup is the state department not issuing export licenses for satellites to be shipped to the launch sites. The lawsuit only resulted in an injunction against paying Russia for RD-180 engines, which have little activity in commercial launches.

The sanctions impact all Russian launches including Soyuz and Proton, which is significant.

Ouch ... that is one hell of a double whammy of the law of unintended consequences. I doubt that Musk is such an Evil Genius that he anticipated the state department grounding all US manufactured satellite launches from Kazachstan.

Again, SpaceX had nothing to do with the sanctions, those are entirely down to Russia's behavior with respect to Ukraine. Even the RD-180 injunction was not exclusively due to their complaint about being excluded from competition, it referenced the Executive Order 13,661 from back in March and a "Specifically Designated Nationals and Blocked Persons List" released the same day as the injunction by the Department of the Treasury that referenced Rogozin. If you took out all references to SpaceX, you'd still have sufficient reason for an injunction.

Musk is taking full advantage of the situation, but he didn't cause it.

 

[Megalodon]

dio82[/url]":ytbnhoav]Ouch ... that is one hell of a double whammy of the law of unintended consequences. I doubt that Musk is such an Evil Genius that he anticipated the state department grounding all US manufactured satellite launches from Kazachstan.

Again, that's not a result of the lawsuit.

Order things happened:

1. Sanctions. Denied export licenses.
2. SpaceX sues the Air Force.
3. Injunction against paying Russia for RD-180.

It's not an unintended consequence. It's not a consequence period.

The injunction will likely be lifted as the state department has responded to the court saying it should be. However this won't restore the Russian missions for these commercial launches because the blocked export licenses are not part of the injunction. The US will regain access to RD-180 engines, but these are used almost exclusively for government payloads, it won't mitigate the developing traffic jam on commercial payloads.

dio82[/url]":ytbnhoav]Arianespace should leap for joy about the prospect of significant commercial satellite launches moving from Kazachstan to them. Edit: Arianespace is also doing Soyuz launches from Guyana ... does any body know what is actually happening to those?

Because the commercial launches are blocked by withheld export license to Russia and the Soyuz launches out of Guyana are not in Russia those should be fine as far as export licenses are concerned. However there's a lot of tension around this anyway, and the US state department's export licenses for American built satellites is not the only thing that potentially blocks launches.

However the lead time on scheduling launches is enormous. I don't think anyone is able to respond this on sub-year timescales.

 

[Xavin]

Have you *seen* east Texas?

East Texas (north of Houston, east of Dallas) is actually densely populated for a rural area, and covered in trees, so it would make a terrible launch/landing spot. South Texas, where their proposed launch side is, is much flatter and emptier, in addition to having basically a straight shot over water to the Atlantic to the east.

I am not a rocket scientist, but is it crazy to think maybe they could launch from Texas and land at the Cape, then launch from the Cape, at least getting 2 for 1 on each booster?

The plan is to land back at the launch site. They only need something like 30% more fuel to do that, and it ends up being far cheaper than an entirely new rocket. The first stage doesn't actually get very much lateral velocity, it's mostly just going up.

The problem with the Texas site is it has a limited range of inclinations available compared to the Cape. You're not going to see ISS missions launch from TX, for example. My understanding is that the TX site will be used mainly for GTO launches.

The ISS has a dumbass politically motivated inclination that basically nothing else does, so not being able to hit it from Texas is not an issue. I imagine all NASA launches will happen from the Cape anyway, for other reasons.

 

[truth is life]

Xavin[/url]":1o1budw1]
The ISS has a dumbass politically motivated inclination that basically nothing else does, so not being able to hit it from Texas is not an issue. I imagine all NASA launches will happen from the Cape anyway, for other reasons.

It's not really "dumbass". Besides being necessary for Russian participation (which in turn was necessary for ISS happening at all), it allows the ISS to overfly a considerably larger portion of the Earth, and a much larger fraction of its land area, making it that much better for Earth observation. While given the existence of a number of other remote observation platforms this is not the most valuable possible thing that could be done with it, it is a small increment in its utility. (It's also worth pointing out that Skylab had a 50 degree inclination for entirely scientific reasons) The 28.5 degree inclination really only makes sense if you want an orbital port for use from Kennedy, which was never really on the table regardless of NASA's wishes (inasmuch as Congress never showed much interest in providing the proverbial bucks to build such a port during the Freedom era), or if you're building a station that doesn't have anything to do with Earth observation at all, which also wasn't the case during either the Freedom or ISS periods.

There's no one "best" inclination, it all depends on what you're doing and why you're doing it.

 

[PsionEdge]

Returned SpaceX capsule has water inside from unknown source:
http://www.spacenews.com/article/civil- ... covered-in

 

[Skoop]

Salt or fresh would be good to know for starters.

 

[BitPoet]

Skoop[/url]":exx0tnfw]Salt or fresh would be good to know for starters.

Volume would also be nice to know. We talking drops or gallons?

 

[Xavin]

Volume would also be nice to know. We talking drops or gallons?

Well, they said there was no damage to the cargo, so it couldn't have been too much.

 

[UserJoe]

Just watched the Dragon V2 unveil. Very impressive technology.