sevenperforce

Looks like pyro bolt and a spring.

You mistake my point. Cutting the engines on a liquid booster immediately kills thrust on the firing stage, giving you just a little extra cushion as your LES carries you away. You can then unzip the booster for range safety once the capsule is well clear. An SRB engine cannot be immediately turned off without FTSing the whole stage, and you cannot FTS the whole stage until the LES pulls the capsule clear, which means it's possible to have SRB-to-capsule impact. Consider something like Ares I, where you have an SRB carrying a liquid upper stage carrying a capsule. If you had a CRS-7-style structural failure of the upper stage at Max-Q and you didn't have clean separation between the capsule's boost shroud and the upper stage, the still-firing SRB could push its way through the debris and impact the capsule from underneath. That's not possible with a liquid booster, because you can simply kill its engines.

Does anyone know what separation method is used for the slid strap-ons on the PSLV?

Uh, you would have a MUCH better time with LF rockets. Cutting the engines, waiting for clearance, and then unzipping the sides of an LRB is much safer than firing the FTS on a solid.

Aye, imitation something something.

Rockets are simply not a very effective way of getting people up high. Unless, of course, you're trying to get really, really high. And/or stay there.

Dammit!

Someone ought to make a really detailed subway map showing very clearly the dV cost of various destinations from LEO to cislunar space, specifically with lunar surface architecture in mind. At present, the default approach for sending anything to cislunar space is to fling it out of LEO with short-lived, high-energy chemical propellants, and then brake it into its destination with expendable stages and storable propellants. It's been that way ever since the first lunar missions. Do we change that? Lunar missions using F9 or FH would not. SLS would not. BFS, obviously, would. New Glenn and Blue Moon may change that; I don't know. Placement of architecture hardware is wholly dependent on having that subway map clearly identified and knowing how you're going to be getting stuff to the moon. Designing LOP-G to occupy an orbit designed for a vehicle that was not designed for lunar missions is such nonsense. EDIT: One complication of designing such a subway map is that there are numerous paths to a given destination which require more or less dV depending on how many burns you can perform. A three-impulse trajectory can take advantage of gravity wells that a two-impulse trajectory cannot: for example, a two-impulse trajectory will put you in NRHO for around 3.8 km/s past LEO, while a three-impulse trajectory can pull it off with 3.4 km/s. So either you design your map for all possible spacecraft capabilities, which means it rapidly becomes far too large to use, or you design it with your spacecraft's capabilities already in mind, which is putting the cart before the horse at the outset.

Ah, gotcha. Yeah, the reusable ascender is the only major difference from a Constellation architecture. A reusable lunar space truck is not a bad idea. I didn't see whether they were planning to refill (which needs some sort of IVP) or use drop tanks.

Interesting at which point?

Interesting details on TESS: https://www.nasa.gov/content/goddard/new-explorer-mission-chooses-the-just-right-orbit That will make for a tricky thing to model in my all-launches KSP save; I may have to break out some classical mechanics. I'm guessing I should go for a zero-eccentricity orbit with the apoapse at 12,000 km and the periapse deep enough that it completes two orbits for every single Mun orbit. Not quite sure where that will be. Launch to LKO with F9, then burn to TLI (but phased a few orbits off), then use the spacecraft's own engines to adjust for an intercept and slingshot that takes me out to the desired periapse, then a final burn to lower apoapse to 12K km. All while phasing such that the Mun's nearest approach is when the spacecraft is at periapse. EDIT: Wait a minute, more info. It will launch into a 28.5 degree orbit from the Cape initially, which will NOT reach to the moon, but a subsequent periapsis kick will raise it to the lunar flyby trajectory. The lunar flyby will increase inclination to 40 degrees, where it will stay. Curiouser and curiouser.

The Russian version of Project Pluto's Supersonic Low Altitude Missile. Though it looks smaller than its Uncle Sam counterpart so it may be a single-warhead delivery system. Also, I somehow really doubt the test launch shown on video used an actual live nuclear reactor.

Nonsense. Half a gee of acceleration at separation is not problematic with a sufficiently lofted trajectory.

SpaceX has never claimed it can place 63 tonnes of payload into LEO with all-core recovery; that's the expendable payload. Or do you mean a reused core and reused boosters? Because, yes, they'd need an upgraded PAF, but that's not a meaningful modification. 63 tonnes is Block 4, I think.

Wow. That's like Tesla saying "The price of a new Tesla is actually just $2,000 because imagine never having to pay for gas again!" Except that the JWST is actually going to DO something.

Clipper only masses 5-8 tonnes, so Falcon 9 can put it into LEO with RTLS or EEO with ASDS recovery. Clipper is intended to be able to handle a six-year coast to Jupiter, so extended Earth orbit loiter isn't really a problem. The transfer stage is the only time-sensitive element and it can launch whenever you want it to. Clipper has full independent maneuvering capabilities so rendezvous and docking to the transfer stage is a matter of software, not hardware...other than a simple IDA. With Falcon 9 ASDS putting it into EEO, you might even be able to get away with using another ASDS Falcon 9 for the transfer stage. You're looking at $124-150M...absolute max would be maybe $185M. And that's for an SLS-style direct-to-Jupiter launch. If you want to do a six-year coast via gravity assist stacking, just go FHR2 for a cool $95M and call it a day. Hmmmm........ www.rocketbuilder.com says that the cost of an Atlas V 551 is just $73M. That can't be right, can it?

FH is cheap for its LEO performance, so there's nothing to stop you from throwing Europa Clipper into LEO with a recoverable FH, then tossing up a separate transfer stage for the injection burn the following week. Much cheaper than configuring the SLS for Clipper.

It's very clever for BO. SpaceX has never offered to sell Merlins, so it wasn't something I thought seriously about, but there is no reason for BO not to sell its engines. They get an additional revenue stream to help them get up and going, their manufacturing benefits from economies of scale in a way that no single launch provider or engine manufacturer can, and they will always be able to outbid their competitor. Given that BO has proposed a lunar cargo lander based on BE-3, then it is obvious that they are already planning on something like ACES. Their switch of the BE-4U for a pair of BE-3Us may mean that the three-stage NG is simply scrapped because they no longer need it.

Atlas VI -- you mean, building Vulcan, but with AR kerolox engines?

I'll save the landing part of the mission as a separate mission and post it when it happens in December.

Damn, I should have figured this into my launch thread. Not that it's orbital, but....

In anticipation of tonight's launch:

DSN 1 / Superbird-8 and HYLAS-4 Second Arianespace launch, but first with the Ariane 5 family. This launch uses the ECA configuration.

Was just about to post in this thread and ask if anyone knows whether the fairing jettisons before or after MECO but now I know. Does anyone know if the Ariane 5 core stage uses separation motors?

Automatically scramming it, either via a deadman power system or some other failsafe, is pretty standard. But yes, if the casing ruptures, you do end up with a radiological spill.