SSTO with a S2-33 "Clydesdale" Solid Fuel Booster

[snaramor]

The new Clydesdale SRB from the 1.8: “Moar Boosters!!!” update has a dv of 3965m/s, which is theoretically enough to reach Kerbin orbit. The problem is that it's a single burn with no throttle control. 

The Challenge:

1. Create a craft powered by a single S2-33. You may adjust the Thrust Limiter and Fuel Qty in the VAB.
2. I don't know if it's possible to reach a stable Kerbin orbit. If it's not, then the highest periapsis wins.
3. If anyone can get to a stable Kerbin orbit, then the lowest eccentricity wins.
4. No Mods

Post a screenshot of your craft above 70km with the Maneuver Mode showing the Apoapsis and Periapsis.

Here's my best attempt so far:

Edited October 17, 2019 by snaramor
Specifying Kerbin orbit, because Kerbol orbit is easy.

[sturmhauke]

Is Breaking Ground allowed? If it is, you can use the controller to make thrust curves for SRBs.

[snaramor]

6 minutes ago, sturmhauke said:

Is Breaking Ground allowed? If it is, you can use the controller to make thrust curves for SRBs.

That's a great idea; I didn't know you could do that. Apparently you can also just map the SRB Thrust Limiter to the Main Throttle Action Group and control the thrust dynamically in flight, but that feels like cheating. I'm going to say that you can't do anything that will change the SRB's thrust once it's lit. Otherwise, I think it would be too easy. The challenge is reaching orbit with a single burn at a constant thrust.

[Pds314]

2 hours ago, snaramor said:

That's a great idea; I didn't know you could do that. Apparently you can also just map the SRB Thrust Limiter to the Main Throttle Action Group and control the thrust dynamically in flight, but that feels like cheating. I'm going to say that you can't do anything that will change the SRB's thrust once it's lit. Otherwise, I think it would be too easy. The challenge is reaching orbit with a single burn at a constant thrust.

I would almost consider that a bug. But IDK. Restarting or throttling an SRB is all kinds of bizarre. It actually makes me want to try reusing them by landing them like F9 boosters.

Edited October 18, 2019 by Pds314

[linuxgurugamer]

20 minutes ago, Pds314 said:

I would almost consider that a bug. But IDK. Restarting or throttling an SRB is all kinds of bizarre. It actually makes me want to try reusing them by landing them like F9 boosters.

There is a special class of SRB fuel which is electrically triggered.  Meaning that it will only burn in the presence of electricity.

Regarding throttling, not directly, but it is possible to tailor the SRB to have a specific thrust curve

 

[sturmhauke]

5 minutes ago, linuxgurugamer said:

Regarding throttling, not directly, but it is possible to tailor the SRB to have a specific thrust curve

This old thread has a discussion on the topic. On a real SRB, the thrust curve is achieved by altering the cross-sectional geometry and surface area of the propellant.

[Pds314]

Well, who wants to make a new "three parts to (absurd destination here)" video featuring a Clydesdale? Not sure how you'd break it off though without colliding it with something, since it's a bit hard to make it burn up in the atmosphere the a fuel tank. Although you may be able to just burn it off with the Twin Boar or the Thoroughbred.

EDIT: hmm.. burning through a Clydesdale bizarrely doesn't work.

Edited October 18, 2019 by Pds314

[Pds314]

However, we don't need to burn through a Clydesdale if we use Soviet pods from Making History. Clydesdale at constant 100% thrust put it on a suborbital trajectory, and then I circularized with 3k Delta-V remaining. This exact configuration probably isn't ideal for, say, going to Duna or whatever, due to the bottom being a weird ball shape, but I think you could definitely do something like that with a slightly different configuration of the same parts. Also you could almost surely improve the quality of the launch and orbit to at least match, but perhaps even exceed, StratzenBlitz's 3.2 km/s in LKO.

Edited October 18, 2019 by Pds314

[snaramor]

12 hours ago, Pds314 said:

However, we don't need to burn through a Clydesdale if we use Soviet pods from Making History. Clydesdale at constant 100% thrust put it on a suborbital trajectory, and then I circularized with 3k Delta-V remaining.

Except for this challenge, your only source of thrust is a single Clydesdale. You can't use any additional engines to do a second circularization burn. It's a single burn to orbit with no throttle control. The Clydesdale can get you on a suborbital trajectory very easily, and If you just burn straight up you can easily escape Kerbin's SIO to get to Kerbol orbit, but the challenge is to find a launch profile that can get you into a stable Kerbin orbin using only the single burn of a Clydesdale.