The SpaceX CRS-6 mission to the International Space Station was planned for today, but delayed due to weather. Hopefully they’ll succeed in their attempt tomorrow. It didn’t sound like there were any technical holdups.
The primary mission is a relatively boring cargo mission–though they’re delivering an espresso machine, which I’m sure the astronauts will be happy about. The exciting part is the next attempt to land the first stage on an oceangoing barge.
For those that haven’t been following: launching rockets is expensive, and one of the primary factors here is the fact that the rockets get dumped into the ocean after being expended.
The first stage of a rocket is the biggest and (at least in this particular case) most expensive part, so it makes sense to focus on saving that. SpaceX’s plan is to have the stage (which is a full-fledged rocket in its own right) land on its tail on an oceangoing barge named Just Read the Instructions (after a ship in Iain M. Banks’ Culture series).
Their previous attempt ended in a fireball, but it was nevertheless a big success. Even hitting the barge at all was a tremendous achievement. And this is after a hair-raising hypersonic reentry, which SpaceX has made look easy at this point. They’ve fixed the problems with the previous attempt, so this one has a good chance of success.
Sticking the landing tomorrow is not the only remaining step towards a reusable rocket, but it’s a very significant one in that it “closes the loop.” They will finally have an intact stage that made it through the rigors of launch intact. Most likely, this particular stage will never see space again, but it will almost certainly act as a testbed for refurbishment efforts.
While the hoped-for landing is certainly the most exciting part, the cargo is not entirely boring. It also includes the Arkyd 3 satellite, a tech testbed for the Arkyd space telescope, part of a project aimed at a long-term goal of asteroid mining. Well, I think it’s kind of cool, anyway.
Good point! As you likely know, the Arkyd 3 on this mission is a duplicate of the one that was destroyed on the failed Antares-Cygnus launch last year. SpaceX has had an excellent primary mission record so hopefully there won’t be any issues in that regard.
What happens when you miss the landing spot and land in Suburbia? Bad publicity all around. Better to start out a long way from suburbia.
The barge is a safe target for now. The eventual goal is to target their landings in a vacant space at their launch facility. Which isn’t too far from suburbia.
Aside from accidents near anyone’s house rockets launch to the east and east of Florida is the ocean. SpaceX does have plans to have the rockets fly back and land on the ground but that adds further complications and fuel. So currently it’s “easier” to simply fly out and brake as you come down.
Too bad. Well, this is rocket science after all. Hopefully we get some more spectacular videos out of it as we did with the first. And I’m sure this will have some new and interesting failure mechanism.
Also, it’s not clear what the strategy will be for Falcon Heavy. Although the side cores will separate early and be able to fly back to land, the center core will be pretty far downrange and flying it back would be quite a payload hit. It might be that they depend on the barge for that even in the long term.
On the other hand, if they launch these out of their upcoming Texas facility, they might be able to land the center on a small island, or perhaps even in Florida.
It’s an interesting vehicle, though too far away to get too excited about it.
They’re targeting an idea which has come up in discussions here, and dismissed–separating only the engine module (and doing a mid-air capture of it).
It sounds really complicated to me. Rocket engines and their mounting structure form a tightly coupled part of the whole vehicle, and they’ll need some advanced mechanism to cleanly separate it from the tanks. Reintegration will be non-trivial. But they know what they’re doing, so I’ll reserve judgement until they’re further along. I just think SpaceX’s approach is cooler.
I can’t tell you how many of my KSP missions ended in tears after this exact failure mode. Coming down fine, looking good… just a little bit of lateral movement, but hopefully ok… touchdown! Oh crap, I’m tipping… ahhh! Boom.
Just throw a bunch of reaction wheel units on there and they should be good to go for next time :).
I missed the launch- why couldn’t they wait until I was home from work? Very inconsiderate of the SpaceX people. But as you say, Dr. Strangelove, hopefully there will be some spectacular video of the landing.
I wonder if ULA is aiming to develop a set of capabilities that might be a more reasonable alternative to the SLS when that program meets its seemingly inevitable end in 5-10 years.
Though I haven’t seen specific numbers, some articles state that the eventual Vulcan Heavy will have greater payload capacity than the Delta IV Heavy.
That would give the Vulcan Heavy about ~1/2 the payload of the Block 1 SLS
The Vulcan’s new upper stage, ACES, is designed to last a long time in orbit, with multiple restart.
Lockheed Martin (one half of ULA) is working on a refuelable space-tug concept for the next commercial resupply contract.
If this all works (big if there…) it seems like ULA might have the makings of a system that can use multiple launches to provide comparable capability of the SLS. Send the first launch without payload, leaving a mostly-full ACES in orbit. The crewed Orion goes up with the second launch to rendezvous with ACES, and now you have a crewed vehicle that can go beyond LEO. If that’s not enough, a third launch (before Orion) can send up a mission module and a tug for refueling and assembly.
Otherwise, I can’t see any compelling reason to give ACES the longevity and multiple restart capability for the few spy satellites which have been the only payloads for the Delta IV heavy to date (besides the Orion test).
Huh, not such a crazy speculation after all. A couple slides from the ULA Vulcan announcement presentation talk about the development of “distributed lift” and on-orbit assembly for all sorts of crazy things beyond just lobbing up a few big satellites.
The video cuts off before the Earth-shattering kaboom. But damn that thing is moving fast! That stage is over 200 feet tall and it swings over in about a second. It seems to successfully cancel its leftward velocity, but overshoots a bit when coming back to vertical.
Could just be that their control system needs a bit more fine tuning. Or maybe they need some additional control authority–they’re depending mostly on thrust vectoring (though you can see the cold gas thrusters kick in near the end). A few SuperDracos would be handy, though that’s a pretty big weight penalty.
Nice. How much easier would it be to land on a nice big flat pad with a few hundred meters’ error? It looks like it could have made it if it didn’t need to simultaneously move a couple dozen meters to the side while cancelling all horizontal velocity at an exact time and place. If it’s close enough, it just has to cancel the horizontal velocity. One less thing for the giant autonomous exploding vertical pendulum to worry about…
Yeah, I wondered about that. I also did a quick calculation on how much power the drone ship would need to maneuver in place below the rocket, but the numbers that came out were totally unreasonable.
There’s now this tweet:
*@ID_AA_Carmack Looks like the issue was stiction in the biprop throttle valve, resulting in control system phase lag. Should be easy to fix.
*
Interesting. Overshoot is certainly one possible outcome from phase lag. I wonder what their fix will be. Maybe just a tweak to the control system model of the valve? Or possibly a physical fix, like some kind of forced dither.