SSTO drop tanks?

[Wizard Kerbal]

     I wanted to make an SSTO but put drop tanks slung under the wing like the P—51 That would be dropped at 20 km, is that cheating?

[Cavscout74]

It isn't cheating but it's no longer properly an SSTO.    It can be a help to reach orbit if you're struggling with a spaceplane design - I've done that before when I was new at this.  I've also used drop tanks in orbit to boost my dV for interplanetary transfers.  I had a nice 5-passenger SSTO that was perfect for Laythe but didn't have the dV to go to Jool on its own.   I would take off from the runway with a pair or two of drop tanks (empty), refuel in orbit and the drop tanks would give it enough dV for the transfer, then get left behind after they served their purpose.  You do have the space debris issue with that approach though.

Edited February 10, 2021 by Cavscout74

[Spricigo]

No such thing as cheating exist outside of a challenge. It's up to you t o decide what happens in your game. 

As @Cavscout74 said, the craft will not be a  Single Stage to Orbit but that is it.

[jimmymcgoochie]

Not all spaceplanes need to be SSTO- there’s no shame in using drop tanks, wing-mounted boosters or any other detachable bits to get into space, the point is actually getting to space.

If you’re looking for a workhorse SSTO to use instead of an expendable rocket, take a look at this: https://kerbalx.com/Kronus_Aerospace/Kronus-LowTech-20-Ton-SSTO It’s easy to fly with or without a payload attached and only needs a level 2 R&D so is great for career/science modes, plus it has scope for upgrades that can boost its payload capacity; I put a single NERV on the back and managed 25 tons to LKO, then flew it back down to land on the runway.

[18Watt]

10 hours ago, The wizard of me said:

     I wanted to make an SSTO but put drop tanks slung under the wing like the P—51 That would be dropped at 20 km, is that cheating?

That’s a great question.   There have been challenges for making true SSTOs, where you don’t stage away any parts.  It’s absolutely possible, I use a few SSTOs in my career.

However, I may have been too focused on the SSTO concept.   I’m wondering now if I could make a better vehicle by dropping fuel tanks on the ascent.   The loss in recovered funds from the dropped tanks would be minimal, and I think I could improve the payload to orbit.  

That might even make for an interesting challenge, to see what designs people come up with- an ‘Almost SSTO’ where you can drop one or two tanks.
 

[Guest]

I personally do not consider drop tanks stages the same way as powered stages. I'm also fairly certain that laymen would describe a RL spaceplane with drop tanks a SSTO, if they were familiar with the term.

On these forums however – in the context of challenges, specifically – drop tanks do count as stages.

[Wizard Kerbal]

12 hours ago, jimmymcgoochie said:

If you’re looking for a workhorse SSTO to use instead of an expendable rocket, take a look at this: 

I have a workhorse 38 ton to LKO 100% recoverable rocket, the SSTO i’m asking about can carry small sats/tourists to LKO, I just want to extend it’s range to Minmus and Mun

[paul_c]

IMHO SSTO is overrated. There is an engineering balance in weight/complexity of staging, decouplers, extra engines etc vs the performance benefit it brings (ie once you're 99% of the way there, why are you hauling a 6t engine and 10t of empty fuel tank, instead of a 0.15t engine and 300kg of fuel (tanks)).

I believe for LKO, the performance (delta V) requirement is enough in that for pretty much all payload sizes from the smallest of probes up, staging makes sense. 2 stage might make sense for a really small rocket, for others 3 stages often makes sense.

[The Blazer]

Well, is definitely not cheating. That’s for sure. Some of my first spaceplanes dropped fuel tanks too, at least until I learned to make proper SSTOs.

5 hours ago, The wizard of me said:

I have a workhorse 38 ton to LKO 100% recoverable rocket, the SSTO i’m asking about can carry small sats/tourists to LKO, I just want to extend it’s range to Minmus and Mun

Right now I have one that weights only 18 tons and can go to Minmus and back, however it can only carry one Kerbal, so it might not be what your looking for.