Jump to content

Single-Stage Stuff [pic heavy]


Recommended Posts

Single-Stage Stuff

A while back I decided to make a Single-Stage-To-Orbit spaceship, since I had never made one before. At first I fiddled with some spaceplanes. This was the first time I'd ever visited the Spaceplane Hanger. I managed to kill more kerbals in 20 minutes than I've killed in years of game-time flying rockets, so I concluded that spaceplanes were not for me.

So I went back to the VAB, and tried slapping some jet engines on a rocket to see if I could make that work. The image below shows the family of test vehicles I made in the process of finding out how high jets engines can operate before they flame out and start the ship tumbling around (since the two engines never seem to flame out at the same time), and what kind of flight profile is needed to get into orbit. The jet engines didn't seem to do much in the way of gaining a lot of speed (which I gather is what they do with a spaceplane SSTO), but they serve to get you above the thickest part of the atmosphere and give you a little upward and sideways velocity. Unless I'm doing this wrong. But it wasn't too hard to get my first ship into orbit, and to bring it back down intact under parachutes for a landing on its legs. Then I tried a bit more fuel...but ran up against the limit that the two jet engines could lift. I briefly tried four jet engines, which accelerated upward smartly, but had the embarrassing result that the ship broke apart under its parachutes (pilot Dilger Kerman was fine...but the KSC administrators did not appreciate getting bombed by the lower section of his rocket). I tried a little "air-hogging" by giving each engine two ram-air intakes, but did not carry this to unreasonably extremes that I gather some people have tried. And after getting a design that could reach orbit well, I tried to see how big of a payload I could deliver to orbit with the ship...first with a small science package satellite, and then with some fuel tanks.

LQXoq8Z.jpg

So here is the SSTO Test Version 1g, with optional payload attached. Three FL-T800 fuel/oxidizer tanks, and one FL-T400 fuel/oxidizer tank (important: the side tanks feed into the central tank). Two basic jet engines, each with two ram air intakes (since this looked reasonable). The ram air intakes were attached with the magic of cubic struts. One LV-T45 rocket engine, a standard sized ASAS unit, a single-kerbal capsule (which can separate and return under its two parachutes if necessary), two more parachutes mounted on the central main tank, one docking port, four heavy-duty landing legs, and three ladders in case the kerbal actually wants to get out after landing. Action groups were set up to toggle the two jet engines on/off, and the central rocket engine on/off. And a Jeb 9000 control interface was added to handle the precision targeting of the landing location.

0AQ1Z4b.jpg

The first part of the flight is handled mainly by the jet engines. These need to be activated on the pad and allowed to spool up to speed before the launch clamps are released. These engines tend to run quite hot... the overheat warning is your constant companion during the boost. My first surprise came when I added more fuel tanks and the rocket got too heavy...then the jet engines struggled to the point where they exploded. Needless to say, this was also an unexpected surprise for Dilger, but he landed the ship handily on its rocket flame. The speed of the rocket needs to be kept above 80 m/s or so once the engines get hot...otherwise they will explode. It would be nice if I could give a little push with the rocket motor to help them along, but there is no separate throttle control for the jet engines and rocket engine, so it's a matter of briefly toggling the rocket engine on to speed up the ship and prevent the jet engines from overheating. Several intermittent bursts of the rocket engine can keep the jet engines sitting near the red line until the speed increases sufficiently that the rocket engine is no longer needed for this. I generally use an initial blast from the rocket engines just after I release the launch clamps to push the ship up to around 50 m/s... and then it can usually get to 80 m/s before the jet engines overheat and explode. With the two ram air intakes on each jet engine, the engines will operate to a little over 20,000 meters (this assumes the ship is moving more or less into the airstream, and not at too high of an angle of attack). You can watch the Air Intake resource to see when it drops down to 0.09, after which flameout will soon happen. I start the ship in a slight gravity turn starting at about 7,000 meters (about 10 degrees), and increase the tip over to 15 degrees at around 15,000 meters. The jet engines use fuel from the tanks, but not oxidizer...so you end up with an excess of oxidizer. But, the amount of fuel used by the jet engines is quite small. Still, it would be nice if I could choose to have less oxidizer or more fuel to begin with, since that excess oxidizer is just dead weight.

iGNK9VQ.jpg

At 20,000 meters, I use the action group keys to toggle on the rocket engine and toggle off the jet engines. I then start increasing the gravity turn to 45 degrees and beyond, keeping the apoapsis point safely ahead of the ship in the Map view. The jet engines are dead weight for the rest of the flight, but they apparently have helped enough to make this worth it.

Alternately, I have had good results using a little more turn-over prior to 20,000 meters...but you can't turn over too much (since the jet thrust is holding the rocket up, unlike a spaceplane SSTO that has wings to provide lift). At the higher angles, I give occasional bursts from the rocket engines for a few seconds to keep the upward momentum going. At 18,000 meters, I turn on the rockets engines and keep them on after that. This more-angled trajectory allows the jet engines to operate longer, so it gives better efficiency.

I have tried the Turbojet engines instead of the regular jet engines, but I do not get as good of results with the Turbojets. First of all, they are heavier. Secondly, the ship spends most of its time on the jet engines at lower altitudes (again, unlike a spaceplane SSTO) where the regular jet engines are more efficient -- it flies through the high-altitude region of the jet engine operation rather quickly.

2IVXi3h.jpg

Here are two views of the SSTO ship in orbit at 105 km. The ship can reach a circular orbit of 500 km altitude and still have enough fuel to deorbit. But that would use up almost all of the fuel onboard, and your only landing option at that point would be to use the parachutes.

ruPyQWE.jpg

2StqR2z.jpg

From a low orbit, the ship has enough fuel that it can return and land on its legs using rocket power. I let MechJeb target the ship into KSC, and then either MechJeb or I can land it on its flame.

A8IGXBv.jpg

Dilger can easily handle the ladders, which is good since a fall from that distance might be deadly. This particular landing was from a 105 km orbit, and the ship still had 86 units of fuel left after landing. It typically takes about 35 units of fuel to deorbit the ship and target it for the KSC.

S2j5voR.jpg

If the ship goes out to a 500 km orbit, or if it carries a substantial payload into orbit, then landing on rocket power is not an option. In the picture below, the SSTO is lifting a small refueling pod into orbit. The refueling pod is made up of a FL-T200 tank, a FL-R25 RCS tank, a QBE probe core, two small solar panels and a battery pack to power the probe core, RCS thrusters for maneuvers, and docking ports on each end. The SSTO ship can put this refueling pod into a 125 km orbit and have enough fuel left over to return for a parachute landing.

wIVHwlW.jpg

When making a parachute landing, the two chutes that are mounted at the top end of the main fuel tank are deployed first. The timing of this deployment depends on whether the targeting for the landing location appears to be going a little long (deploy early) or short (deploy late). Do NOT deploy the two parachutes on the capsule yet. If you deploy all four chutes high up, the force of full-deployment at 500 meters can pull the ship apart. The pilot will survive on the two capsule chutes, and the lower part of the ship can probably also survive on its two chutes, but it looks embarrassing on the Kerbal Nightly News.

7WOSTmc.jpg

When the ship reaches 500 meters AGL, the chutes will fully open. Then the two chutes on the capsule can also be deployed to help slow the descent. And now would be a good time to lower the landing gear. If you have some fuel left, you can use the rocket engine to brake to a gentle landing. But be careful not to slow to a stop in the air, or your chutes will vanish... and then you better hope you have enough fuel to complete the landing on the engine flame. I've cleverly had to do this few times.

Mu25z64.jpg

And while precision in landing is a great thing, you CAN get a little too close to the launch pad. In the flight shown below, the ship came down near the edge of the launch pad structure...

7L1BenG.jpg

...and barely managed to not tip over. This was the closest Dilger came to getting blown up in this series of test flights.

nklUCuF.jpg

Later Update

Below is the slightly modified 1he version. It has a probe body attached so that the ship can take a kerbal to orbit and then return empty (or vice versa). The option of separating the capsule has been eliminated (I now trust this design...and the abort mode for a problem during launch is just to cut engines and deploy the chutes in sequence as needed, then land on the legs with a little rocket assist because the ship will be heavy with fuel). RCS quads have been positioned so they don't try to cause rotations while doing translations (which save on RCS fuel) for space station docking. I have been able to get this version into a 120 km circular orbit with just over 500 m/s of delta-V remaining. This was accomplished by flying the more-angled trajectory described earlier.

UKUzeJ0.jpg

3-Kerbal Crew Carrier

My original version of the SSTO ship used a single-kerbal capsule and two jet engines, so the upscaled Crew Carrier was built using a 3-kerbal capsule and six jet engines. As before, each jet engine has two ram air intakes (since it fits and seems physically reasonable). The original used one LV-T45 vectoring rocket engine, so the Crew Carrier uses three LV-T45 engines. It has RCS for orbital rendezvous and docking. It has parachutes and landing legs and MechJeb targeting for landing back at KSC.

pPCJuOv.jpg

The test flights for the ship were conducted by Commander Nedmy Kerman, Pilot Merfred Kerman, and Flight Attendant Rodgan Kerman. Just kidding, Rodgan! Oh, how the guys had such fun picking on Co-pilot Rodgan. While the ship is still safely secured in the launch clamps, the throttle is pushed to maximum and the jet engines are activated by pressing a switch with a big "2" on it. After the jet turbines spool up to full speed, the launch clamps are released at the same time the rocket engines are fired by pressing the button with the big "1" on it. The rocket engines are only on for a short while as the ship clears the tower and speeds up to 50 m/s, when the "1" is pressed again to switch off the rockets. Then it's up to the fuel-sipping jet engines to very slowly accelerate the ship, and, more importantly, lift it above the lower, dense layers of Kerbin's atmosphere. At 10,000 meters, a 10-degree turn is initiated.

QfW54AJ.jpg

At 18,000 meters, the rocket engines are turned on and kept on by pressing the "1" button. At 20,000 meters the "2" button is pressed to shutdown the jet engines before they flame out. Then the gravity turn begins in earnest. Depending how how good the pilots are that day, the ship could have anything from 300 to 500 units of fuel left after circularizing a 120 km orbit. At least this was true of the pilots used to test-fly this ship.

1nd3I0R.jpg

Below we see the Crew Carrier 1 about to dock with the ancient Tanker Station 1 in a 200-km orbit. Depending on how much fuel the Crew Carrier made it to orbit with, it can reach an altitude of 400-500 km or so. Just be sure you keep enough fuel to deorbit (it takes about 130 units of fuel to deorbit from a 120 km orbit). The other ship that is docked to the Tanker Station is a "Fat Man" crew transfer vehicle that was launched long ago on an expendable launch vehicle. On board are Kelby Kerman, Dunsel Kerman, and Lembart Kerman, who got assigned to this mission when they kept coming up in the rotation instead of the crew I wanted. I suppose I should let them out of purgatory soon. There is no crew in the tanker's capsule, since they were extracted years ago when the second tank docked (and had a landing capsule for them).

d7NWzmU.jpg

After retro fire a clever MechJeb-assisted distance away from the KSC, the Crew Carrier drops backwards onto KSC property.

89vcKvz.jpg

If you have sufficient fuel and the skills of Jebadiah Kerman (or his software equivalent), you can land the Crew Carrier on its rocket engines. But that's more excitement than I typically care for...and we've carried along all these darn parachutes, so we might as well use them. The chutes anchored the the top of the lower main tank are deployed first so that structural component can take the main deployment stress when the chutes fully open at 500 meters. Then the other two sets of chutes at the top of the upper tank and on the capsule are deployed to slow the descent. (I have two chutes on the capsule because the abort procedure for this ship is to simply shutdown all engines and deploy chutes in a judicious manner...and I wanted to be sure there were at least a couple on the capsule in case things come apart.) Although the ship can land safely under the chutes, it's polite to return it bent as little as possible (otherwise the ground crew gets all snotty and is less likely to share their Beemans with you), so any fuel left in the tank should be used to cushion the touchdown.

m8oItRA.jpg

The ladder is a bit circuitous, but even if the kerbal is clumsy and manages to exit the capsule without holding on to the ladder (we're looking at YOU, Rodgan), their fall is cushioned by the apparently-soft ram air intakes, so they can survive.

ILttWDD.jpg

A second varient of the Crew Carrier was also tested. It incorporates a 4-kerbal hitchhiker container in case the need arises to move seven kerbals at once. This varient can make it to 120 km orbit and return (parachute landing only, of course...there will not be fuel for a rocket flame landing), and it should only be sent to retrieve kerbals from higher altitudes if there is also some fuel there that it can have for the return. Both versions of the Crew Carrier were also constructed in probe-controlled variants so that the ship can be launched empty to retrieve kerbals from orbit.

yPMXENc.jpg

Laythe SSTO

Most recently, I've been testing a version of the SSTO for my upcoming long-term mission to set up a base on Laythe. I originally planned to send one of the 3-kerbal Crew Carriers there to shuttle kerbals down and up from the surface as needed, but the 3-kerbal SSTO is a fairly heavy ship, and I wanted something lighter (just to make it easier to ship it to Laythe). I considered using my 1-kerbal version of the SSTO, and make multiple trips (it turns out that three trips with the 1-kerbal version uses a bit less fuel than one trip of the 3-kerbal version)... but more trips is more tedious flying for me, and more chance of accidents. So I considered stacking extra single-kerbal capsules on top of the original SSTO... at 0.8 tons each, that would be an additional 1.6 tons, which the vehicle should be able to just barely handle. But then I thought, why use a total of 2.4 tons of capsules (three of the single capsules), when I could use a 2.5-ton Hitchhiker Container and carry FOUR kerbals? So I tried it out:

UorCZEZ.jpg

The version above can BARELY make it into a 90-km Kerbin orbit ...and Laythe is a bit easier, so it should be able to make the trip down and up starting with a full load of fuel. But it looks too non-aerodynamic to suit my tastes (and adding tapering transitions makes it too heavy to reach orbit. So I built an intermediate version of the SSTO with four jet engines and two rocket engines and a Hitchhiker Container:

JcbfOXt.jpg

The intermediate version above can make it into Kerbin orbit just fine. There is a bit of a problem with flying these Hitchhiker versions compared to the capsule versions: the ship no longer has capsule torque to help you steer it. As a result, the Hitchhiker versions must be flown using RCS control. The ship above has four RCS tanks down underneath by the two rocket engines (to decrease the frontal area and decrease drag...once the program actually cares about such things. But I'm trying to be more aerodynamic here). But it's flyable with RCS.

When I have a successful SSTO, I always try LESS FUEL to see how it works. The version below can barely make it into a 90-km Kerbin orbit (although the return might be iffy because there is not a lot of fuel left to target your reentry). But computer simulations indicate it can handle the Laythe run down from orbit and back up to orbit with some fuel to spare. It weighs in at 30.72 tons fully fueled, and only 14.72 tones empty... which my Interplanetary Tug should be able to handle nicely for a delivery to Laythe.

Note that when using this as a Laythe shuttle, it leaves the Laythe orbital space station fully fueled, and then uses some fuel to deorbit and target the landing. With all eight chutes deployed, it comes down at just over 10 m/s with all that fuel on board, so some additional fuel must be used in a short braking burn just before touchdown. But at that point the ship still has enough fuel to return to an 80-km orbit around Laythe with fuel to spare.

0nw6ob8.jpg

Brotoro's KSP Web pages.

Link to comment
Share on other sites

I enjoyed reading , although I admit I skipped a little towards the end :)

but anyway, I too have enjoyed working with hybrid rockets, ascending on a combination of all of solid boosters, jets and rockets. However, I wonder how your designs will need to be radically altered if you were to install the deadly re-entry mod, or similar entry heat was to be implemented in the stock game.

Link to comment
Share on other sites

I like your post, but admit I did not read much of it.

You should try using the other jet engine, and using jet fuel tanks.

I tried using the TurboJet engine instead of the regular jet engine early on, but the result I got was almost the same (even a little worse) with the TurboJet. I think this may be because the jet engines on this rocket spend most of their time working at low altitudes while the slow-moving rocket is gaining altitude, and the regular jet engine is more efficient at those altitudes and speeds. The passes through the higher altitude range of the jet-powered flight relatively quickly (since it's moving faster by then...although not all that fast). So, unlike a spaceplane SSTO, this ship does not spend a lot of time in the high altitude, high-speed region where a TurboJet would excel.

I don't use jet fuel tanks because there is no jet fuel tank small enough to be of use for this rocket. This jet engines in these designs use very little fuel during the flight. For the single-kerbal version, the jet engines are only used for about 3 minutes 20 seconds. In that time they use up only 40 liters of fuel. As a result, I spend the rest of the flight carrying around the 32.7 liters of unused oxidizer. If I used jet fuel tanks on the rocket, I'd have a much larger amount of unused jet fuel to carry around because all the jet fuel tanks available have way more than 40 liters of fuel.

What I would like, of course, is to be able to just leave 33 liters of oxidizer out of the tanks prior to liftoff.

Link to comment
Share on other sites

I enjoyed reading , although I admit I skipped a little towards the end :)

but anyway, I too have enjoyed working with hybrid rockets, ascending on a combination of all of solid boosters, jets and rockets. However, I wonder how your designs will need to be radically altered if you were to install the deadly re-entry mod, or similar entry heat was to be implemented in the stock game.

I have considered this. What I WANT is a rear heat shield part that can protect the rear end of a rocket. This thread here discusses the desired part in detail, but the image below gives you a quick idea of what I want:

MXQv8Nc.jpg

BUT, If all I could have was an inflatable heat shield like the ones that I've already seen, it could potentially be accommodated on my intermediate SSTO rocket design that has two rocket engines and four jet engines. If those engines (including the rocket engines) are mounted radially around the 2.25-meter tank, the bottom of the tank would be left free for mounting a "standard" inflatable heat shield.

But I would prefer that Squad make a toroidal heat shield design.

Link to comment
Share on other sites

This is great.

I say that but I haven't tested the designs in game yet. I just love the presentation and clear wording. Nice job sir.

I am presently in that part of my own space program where efficient payload delivery systems are needed for space station rendesvous and eventual planetary exploration. I love the experimentation.

I am coming to terms with the idea that bigger is not always better. My R&D team is getting a lot of overtime right now.

Link to comment
Share on other sites

Rocket nozzles actually make pretty good heat shields since they are already designed to handle high pressure high temperature gases. If you have a look at the Falcon 9 grasshopper concept:

No heat shield is required for the first stage at all.

Link to comment
Share on other sites

Brotoro, you are my hero. This is what i was looking for for my reuseable LKO light launcher\space taxi. And apparently you have a whole family of crafts tailored to many needs on space program - awesome! Could you post craft files please?

P.S. In case you don't mind using mods, KSPX has some radially mounted tanks storing only fuel or oxidiser. I suspect it might be possible to use them to tweak fuel loadout to eliminate this excess oxidiser leftover.

Edited by Scotius
addendum
Link to comment
Share on other sites

Brotoro, you are my hero. This is what i was looking for for my reuseable LKO light launcher\space taxi. And apparently you have a whole family of crafts tailored to many needs on space program - awesome! Could you post craft files please?

P.S. In case you don't mind using mods, KSPX has some radially mounted tanks storing only fuel or oxidiser. I suspect it might be possible to use them to tweak fuel loadout to eliminate this excess oxidiser leftover.

Here is the link to the craft file for the Single Kerbal version. But it is the version that has probe body control...since it's safer to try learning how to fly it without kerbals on board.

And here is the craft file for the 3-kerbal Crew Carrier. Again, this is the probe body controlled version.

I'm mostly a vanilla sort of guy, using few mod parts (except to try out cool features that wouldn't otherwise be possible, like using the Damed Robotics hinges for my folding rover). The little bit of extra oxidizer that ends up in these SSTOs is more of a nuisance than a real problem.

Link to comment
Share on other sites

Oh... I removed the MechJeb parts from those ship files so they would be stock... but I always use MechJeb to target those ships in for a landing at KSC, which would be a real pain otherwise.

I have not figured out a way to get MechJeb to fly those ships on boost. It keeps wanting to fire all the motors all the time.

Link to comment
Share on other sites

Whew. It works! At least 1-man version. After couple of snags with flaming jets i've managed to climb into stable orbit, with enough fuel to deorbit, if not land on flame. I need to work more on ascent profile to save more fuel. Now: what we need are SABRE engines, using liquid oxygen from the tanks to push jets beyond flameout threshold.

Link to comment
Share on other sites

i think in real life the rocket nozzles are not that good at protecting against heat unless they are active as most that get hot when active are kept cool by there fuel for eg L/O2 is pumped thru the nozzle before been used for burning to keep the nozzle from becoming to hot and changing shape etc. not to mention re-entry heat is far more times hotter than burning fuel

you def need a nice big heat shield to protect it or plenty of fuel to slow you down enough before hitting the atmosphere that u generate very little heat eg say 1km of dV for kerbin

Edited by Bessy
Link to comment
Share on other sites

  • 2 months later...

sorry to bring up a since disused thread, but this is exactly the one in which I want to post about this :)

I previously posted in this very thread about how these ships were at risk of being unusable once entry heating is a part of the stock game, and with a recent venture into the world of the `mission controller` mod the issue has again been raised in my game.

I am finding however, that with only moderate fuel needed, and with a proper descent profile, any and all ships can safely make it through the atmosphere of kerbin in the presence of the deadly reentry mod as it exists now. What that means for a stock game entry heating effect is not certain, but for the moment the reusable space program is back on!

I am assuredly no pioneer when it comes to any kind of orbital maneuver, but my descent profile is as follows:

from any circular LKOrbit, say 75 or 80km, drop the periapsis to somewhere in the region of 38 or 39 km and begin descent. As you approach 40km your apoapsis will have been pulled right down behind you, and periapsis has probably dropped into negative values.

at this time, with the ship in its usual retrograde orientation, angle up somewhere in the region of 60 degrees, and at about 34 or 35km altitude, depending on your TWR I suppose, begin a burn. The intention (my intention) is to have the apoapsis move again ahead of the ship as you hit about 32km, and then I would raise it to anywhere just over 40km. The ship will then make its second hop, and drop back down, all the while bleeding off speed and now likely safe to pass through the lower atmosphere.

Trying to find altitudes to see the ship naturally `skip` in this way without burning is something that I am working on at the moment (on and off).

I`ll post some more detailed numbers, and a video of my maneuver shortly, but for reference I took up a variation on the SSTUBBY SSTO http://www.mindspring.com/~sportrocketry/ksp/SSTUBBY.html where the core tank was replaced by an 800, that is the tank double that size, and the ship made a safe reentry using fewer than 55l of fuel.

Link to comment
Share on other sites

sorry to bring up a since disused thread, but this is exactly the one in which I want to post about this :)

Hey, *I* don't mind at all when any of my old threads get bumped, especially when it's to hand out good news.

I am assuredly no pioneer when it comes to any kind of orbital maneuver, but my descent profile is as follows:

from any circular LKOrbit, say 75 or 80km, drop the periapsis to somewhere in the region of 38 or 39 km and begin descent. As you approach 40km your apoapsis will have been pulled right down behind you, and periapsis has probably dropped into negative values. at this time, with the ship in its usual retrograde orientation, angle up somewhere in the region of 60 degrees, and at about 34 or 35km altitude, depending on your TWR I suppose, begin a burn. The intention (my intention) is to have the apoapsis move again ahead of the ship as you hit about 32km, and then I would raise it to anywhere just over 40km. The ship will then make its second hop, and drop back down, all the while bleeding off speed and now likely safe to pass through the lower atmosphere.

This is very nice to know. I haven't installed the Deadly Reentry mod myself, since I'll avoid that nasty heating as long as possible, but I'm happy to hear that there may be hope for my SSTO rockets in future versions. Although I expect that having to fiddle with the entry profile will make it harder to land at a pinpoint target.

Some rep for you, good Rocketeer.

I`ll post some more detailed numbers, and a video of my maneuver shortly, but for reference I took up a variation on the SSTUBBY SSTO http://www.mindspring.com/~sportrocketry/ksp/SSTUBBY.html where the core tank was replaced by an 800, that is the tank double that size, and the ship made a safe reentry using fewer than 55l of fuel.

Needing to give the SSTUBBY more fuel for this is expected, since that ship was designed to be used at Laythe, and barely makes Kerbin orbit with its original fuel load. Did you have enough fuel after the skip entry to land on the engine flame, or did you use the chutes?

Edited by Brotoro
Link to comment
Share on other sites

I have been landing on chutes.. and quite a few chutes at that.

But it`s been tight to say the least. On one occasion after expending all fuel in the skip maneuver 4 radial chutes exploded to the heat.. I count it as a positive though, as I now know I can make do without those 4 chutes :)

I try to make splashdown rather landing most times. I`ve been using the engine array from the sstubby 2, but modifying it in other areas to try and improve upon its range for use at kerbin. The last landing attempt I decided to make the hop at a lower altitude, skipping up from about 29km to 36, and the heat exploded all my landing legs..

The ship came down on land, about 40m from the water.. and promptly fell over. but nothing exploded so all pieces were recoverable :)

Link to comment
Share on other sites

I have a suggestion: if you disable all of the liquid fuel at take off and rev up the engines, the rocket engines will not produce thrust but will instead dump oxidizer, meaning you don't have to haul 33 litres of oxidizer around anymore.

Edited by SDIR
Link to comment
Share on other sites

I`m not sure how many were in the original design, but I land my most recent construction with 2 drogues and 8 radial chutes (previously 12)

As I`ve added to it, and made it 4 times taller, I moved the rocket engines about halfway up the core to maintain control. Still I can`t help but feel everytime that I should be getting more speed out of the jets stage than I am.

Link to comment
Share on other sites

This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...