Hacker News Reader

Comment by soperj | Hacker News Reader

That sucks, I really was looking forward to the first stage recovery attempt. Does this mean in the future(if they ever manage to do it) that they'll scrap first stage recoveries in terrible weather?

View on HN

They want to return the first stage to land in the future (at least when possible, depends on the launch trajectory etc iirc). So high waves won't be an issue when they start returning the rocket to the launch site.

Also, I guess if reuse becomes routine and they need to land in the sea (because there aren't enough fuel to return to land) they could build a huge vessel capable of handling high waves.

If reuse becomes routine and the necessary authorities approve, they'll land on solid ground near the launch site. The floating rig was just for the initial tests.

In this specific case they don't actually have enough extra fuel to do a boostback burn, meaning the landing site has to be significantly down range of the launch site (400 mi IIRC).

Also worth noting: once cleared for landing on land, SpaceX can move their launches a few hundred miles West and omit the barge, landing the stages down-range at a coastal landing facility. Added bonus here is that returning cores via road is a heck of a lot cheaper than by sea, and you avoid that nasty salt-water-on-fancy-metal action.

Near the launch site? That seems a little ambitious, and expensive. Are they planning on doing a u-turn in high atmo? The energy required would be massive. Or are they planning on doing an orbit of some sort?

Doesn't the falcon heavy animation show the stages all landing at a different facility?

Given that most every launch will point in a different direction from the launch site (different inclinations), boats would seem the best option. They could then haul the stage back to base by sea.

Yes, it's called a boostback burn, and it's been a part of every landing attempt thus far. The first stage has burned so much fuel at the stage separation that it takes much less to return it home than it did to accelerate it. You are correct though that it limits the payload capacity of the platform.

I believe the Falcon Heavy animation shows the rockets returning to the launch site.

This launch was/is going to be the first one without a boost back. Because of DSCOVR's mass and destination (Earth-Sun L1 point), there isn't enough fuel to make a boost back burn. That's why the barge is ~650 km off the coast[0] instead of the 350 km it was for CRS-5[1].

[0] https://www.google.com/maps/d/u/0/viewer?mid=zp15b_P5ERVk.kQ...

[1] https://mapsengine.google.com/map/u/0/viewer?mid=zp15b_P5ERV...

Also, aren't they planning to launch from California and/or Texas in the future?

They've already launched from California, at Vandenberg AFB. They've begun constructing a drone ship for landing future rockets launched from Vandenberg, named Of Course I Still Love You (the one currently in use for KSC launches is called Just Read the Instructions).

And yes, they are currently constructing a new spaceport in Texas near Brownsville at the far southeastern corner of the state. Completion and first launches are anticipated in 2016. I'd guess they might use the current drone ship for landings from that one as well, but a lot can change in 2+ years so we'll have to see.

I believe that the Falcon Heavy animation showed the stages returning to the launch facility. SpaceX's primary goals with reusable stages are reduced cost and reduced time to refurbish, and landing at the launch site is a big part of that.

More info here:

http://www.reddit.com/r/spacex/comments/2kghua/falcon9r_boos...

It looks like they indeed perform a u-turn, with the proviso that some of the return is accomplished by pushing higher, increasing orbital period, and waiting for the earth to rotate underneath.

http://en.wikipedia.org/wiki/Sea_Launch

I'd presume if they can get the recovery rate and refurbishability rate high enough, they'd charge extra to companies that make them launch without recovery versus more flexible scheduling to guarantee recoveries.

Why would a company make them launch without recovery? SpaceX has always focused on the paid mission first and runs tests as a secondary task if there is sufficient resources available after successful payload delivery. Also, the cost is expected to drop by a factor of 10. Launches are ~60mil USD (can fluctuate based on specs). Even conservatively, the company would likely pay a 40 million dollar penalty if the whole rocket had to be jettisoned. Some missions with higher payloads will ideally be serviced when the Falcon Heavy comes on line.

In terms of weather, I reckon they could have a secondary site to land if weather prevented it in the primary zone. If you mean in the interim before approval of domestic landings on or near launch sites, spaceX probably has pre-existing contracts to do launches. Maybe they would discount them a bit for a better window, prior to Air Force/Regulatory approval.

At some point where recovery is more routine, SpaceX could offer pricing at something like: $60 million we launch your rocket without regards to whether or not we will be able to recover the first stage. $x million, x<<60: we launch your rocket only once the weather/conditions suggests we'll be able to do both. I can see some companies with very specific launch windows (say gravity assisted missions to outer planets) going for the former.

>Why would a company make them launch without recovery?

Because recovery reduces the capability of the rocket. If you look at SpaceX's web site you'll see they plan to have two versions of the Falcon 9 and Falcon 9 Heavy. One version will be recoverable, and one will not. A customer that needs ever last m/sec out of the launcher will not be able to use the latter.

The rockets will not last all that many cycles. It might just be a handful, or it may be a couple dozen, but after enough reuses they'll have worn out too much to continue. For that last flight you could fly it expendable without any sort of penalty. You might even give people a "this rocket is old and tired" discount for it. If customers who don't want to be subject to landing-related delays aren't too common, that could be enough to satisfy that need.

what's strange to me is why not continue to delay. how much money are they blowing by letting it land in the ocean? I suppose they are under some kind of contractual obligation?

I don't think "blowing money" really applies at this level, where it's a speculative test. The customer is paying the full price of the whole rocket, just like every other space launch that has ever been carried out up to now. They are perhaps missing an opportunity to get a full-power landing test in on a customer's dime, but it's better to not risk alienating customers with delays that have no relation to the mission that they're paying for.

Correct. They are contracted to launch a satellite. Anything more (such as doing landing experiments) are wholly secondary to that goal.

well that much is obvious. what I meant was, they have already delayed 3 days, why can't they keep delaying? does it say in the contract it has to be delivered by such and such date?

If they end up having to scrub today, the moon will be in the way for a while (this satellite is actually going out well past the orbit of the Moon) and the next launch window wouldn't be until the 20th.

Regardless of any contractual obligations, I think it's pretty obvious that future customers would be wary of SpaceX if they were to intentionally delay a paying customer's payload for a completely optional test, unrelated to the mission that was paid for.

Reply on news.ycombinator.com