Thud LOVE!!!

[Ohm is Futile]

On 10/25/2016 at 11:08 AM, EpicSpaceTroll139 said:

I've found them to be useful on 2.5m reusable rockets, allowing them to have good control authority in the lower atmosphere (where I need it to have a reasonable safety margin against flipping) on the way up without making them into lawn darts on the way back down (like fins do). 

I dunno, I never had issues with >1.25m engines not having enough authority in atmosphere. Also, I don't find that additional control authority helps prevent flipping much, usually your ascent profile is what is gonna make or break and no amount of control will save you.

I did learn to love the Thuds at lower tech levels, though. I find them especially good to replace Swivels when they just don't have the thrust to get you up there or to replace Reliants when you really need the gimbals. I've actually completely taken out the Swivels/Reliants off a lot of early designs and replaced them with 2x Thuds. Plus it looks kinda nice with the first nose cone flipped around at the bottom of the rocket.

 

On 10/25/2016 at 1:12 PM, String Witch said:

I use Thuds a lot on launch vehicles, clipped into the bottom so only the nozzles poke out, not just to aid control but as the main engines. It's very surface area efficient while looking the part.

They're putting out two thirds of the total thrust here.

 

Spoiler

Don't know why I've never though of that. I usually just go with boosters once I start launching 2.5m rockets (and stick with Reliants). Though, I don't tend to have TWR issues as much dV issues, which makes boosters a logical solution. I'd be curious to check how lugging extra engines and fuel within a single stage compares to side boosters (especially when you factor in fuel lines). Probably only useful for reusable ascent vehicles.

 

Quote

@KerikBalm [...] aerospike

Yeah, but the aerospike comes much later in the tech tree. That's not to say that makes it useless, but there are probably fewer opportunities to use aerospikes compared to Thuds in career mode.

Edited February 2, 2017 by Ohm is Futile

[MinimalMinmus]

The thud is rather good when:

1. For some reasons, I want to keep the bottom node intact (such as the "loco" of my Mun train, which was too heavy for conventionnal "make it land intact" as it had a fuel tank, so I used thuds to provide a lander stage, draining into the fuel tank, and I removed them once landed (they were settled on decouplers)

2. When I want to make a large rover a VTOL, a pair of thuds at it's barycenter get the job done very well, even for very large ones, before I switch to a more conventionnal rocket mode.

[Superfluous J]

We need a challenge where you have to take micronodes to Dres using only Thuds for propulsion. Simple scoring, just the number of micronodes on Dres when you're done is your score. Maybe minus the number of Thuds you had on the launchpad. Or divided by, so you can try for efficiency instead of raw numbers.

I may do this. I've already put too much thought into it.

Edited February 2, 2017 by 5thHorseman

[MinimalMinmus]

5 hours ago, 5thHorseman said:

We need a challenge where you have to take micronodes to Dres using only Thuds for propulsion. Simple scoring, just the number of micronodes on Dres when you're done is your score. Maybe minus the number of Thuds you had on the launchpad. Or divided by, so you can try for efficiency instead of raw numbers.

I may do this. I've already put too much thought into it.

Heh, I guess it would be the "Challenge that doesn't really exist"?

[Superfluous J]

8 hours ago, MinimalMinmus said:

Heh, I guess it would be the "Challenge that doesn't really exist"?

I was thinking more "The Unlovables Challenge"

[Zeiss Ikon]

On 10/25/2016 at 8:44 AM, IronCretin said:

I use thuds all the time. They make great extra engines when your first stage needs a bit more thrust, because their stats are in line with the lifter engines. One of my most used engine configurations in my last career was a skipper and four thuds, because I didn't have the mainsail yet, but my heavy payloads were too heavy for the skipper alone.

This.  My current base launcher, Selene 1, was too heavy to lift authoritatively with a single Mammoth, but adding four Thuds (and 480 kN) brought the liftoff thrust up enough to get off the pad smartly, without a huge amount of extra mass, totally unnecessary thrust levels from SRBs, or a lot of contortions to get other engines added onto the Mammoth cluster.  The four Thuds are just about like another half Vector added to the Mammoth -- which was just right for a vessel in the 150-170 T launch mass range.  They include their own fairing, too, so I don't need extra mass or effort to streamline a radial mounted engine.

Two Thuds equal one Reliant, for thrust.  They weigh more, of course, but they're a lot easier to add alongside an engine that needs just a little help.  And, as of 1.2.2, they have higher ASL Isp, and almost the same vac Isp.

[W. Kerman]

On 10/26/2016 at 3:02 PM, matik2002 said:

I use Thuds for boosters in rovers. The thing is...I never landed a rover before, so I am training before I launch a rover mission to Mun.

I had some on the bottom of my rover, but it's easier to land on the tail section of your rover and use SAS than to land with them on the sides of your rover.

[Guest]

15 hours ago, W. Kerman said:

I had some on the bottom of my rover, but it's easier to land on the tail section of your rover and use SAS than to land with them on the sides of your rover.

Use a probe core or docking port somewhere on your rover facing up, then 'control from here' and you can use retrograde hold for landing. It's good for anything that lands horizontally, and if you use a probe it offers KerbNet so the vehicle can pick its own landing sites and waypoints.