SSTMLAB
by katateochi
uploaded 2018-07-17
135 downloads /
14
points
SPH
stock spaceplane
#SSTO #MunLander #Lab

SSTMLAB

Single Stage To Mun Landing And Back…With a LAB

and a tiny rover

Details

  • Type: SPH
  • Class: spaceplane
  • Part Count: 136
  • Pure Stock

This is a class of craft I’ve been trying (& failing) to build for ages; an SSTO capable of taking a dual crew (2 of each class) to land on Mun (with VTOL landing engines) and return to Kerbin without refueling…and because the acronym SSTMLAB has LAB in it, the craft had to have a lab too.

Another thing that somehow snuck into the design brief was a tiny rover, the SVSR - Small, Very Simple Rover.

SVSR

The SVSR is held upside down (as that’s the only way it’d fit) in the lower part of the science bay. To deploy it, open the science bay doors [AG:5] and then hit [AG:0]. There is an antenna which the rover will hit at one end as it drops, and that should make the rover flip onto it’s wheels as it lands. The SVSR has the four basic science instruments, four wheels and very little else!

Optional TAC Life support

The craft is built to work with the TAC Life Support mod. If you use Configurable Containers and TAC life support there are a set of tanks that will contain life support resources. If you don’t have Configurable Containers they’ll just contain more fuel.

Nestled around the front VTOL engine are two tanks containing food, water and oxygen and in the aft service bay is a container for waste resources.

Enough LS for 91 days with 8 crew, but if you’re running long research missions, just take a pilot & 2 scientists and they’ll have enough for 242 days.

Science

As well as a lab the SSTMLAB has the full set of stock science gear, crammed rather tightly into the service bay behind the lab.

To open the science bay hit [AG:5]. [AG:6] toggles solar panels but you only need those when running the lab (two RTGs provide enough power for everything else). [AG:7] runs all the experiments and crew reports, [AG:8] runs just the gravity scan and [AG:9] will collect all the results in a science container.

The SSTMLAB enables you to deploy a lab to anywhere in the Kerbin system and can enable some heavy science abuse (although Mun polar missions may only leave you with only just enough fuel to return to Kerbin orbit, & there may not be enough solar energy at the poles to power the lab). When you land in a biome you can run your experiments and put all the data into the lab for processing, and then run the experiments again and collect them in the science container. You can then get the full return value for the experiments as well as the science from processing them. Alternatively (if you really want to abuse science), when you return to KSC transfer the stored results to another craft and take them to another lab. This way you can double process the same results (as it’s done in different labs) AND if you recover & relaunch the SSTMLAB you can return to the same biome and do it all over again (as the onboard lab will be a fresh lab, so it’ll be happy process that biomes data again.

The Nose Cone

The nose cone does more than just look awesome, it contains a Communotron 16 antenna, an avionics hub (just because) and a probe core so the craft is controllable if the pilot passes out, or goes for a stroll on Mun. The nose cone also can be used as a self-destruct device, right click on the fairing base and click deploy and very little will be left intact.

EVA Limitation

There is an annoying issue about going EVA from this craft. Although the cockpit and passenger section hatches are visually clear, the game thinks they are obstructed (although it lets you out via the top lab hatch which is visually blocked!). You can go EVA from the passenger hatch if you open the VTOL bay doors [AG:3], but the nose cone design blocks the cockpit hatch.

Flight

Is this craft easy to fly? hmmm, yes and no. It handles nicely but it’s on a very slim margin so there’s little room for error or inefficient manoeuvres. I highly recommend using MechJeb’s SmartASS tool for precise control of pitch during ascent.

Ascent

Set pitch to 10 while on the runway and it will take off smoothly. Maintain a pitch of 10 degrees until you reach 1000m/s and then pitch up to 15.

As you start to loose speed fire up the LV-N engines [AG:2]. The Rapier engines will switch mode automatically at around 30km (and you may experience a sharp pitch up, but try to maintain 15 degrees pitch). After a short burn they’ll run out of oxidiser (there is more, but it’s locked and you need it for landing). Your Ap should be nearing 50km at this point. When the Ap is 50km reduce the pitch to 10 degrees and when the AP is 60km reduce the pitch to 5.

You will find that vertical speed will have dropped to almost 0, but should remain just above, this is ok as you’ll be on a very wide ascent and the Ap will continue to increase. Keep burning at a pitch of 5 until the Ap is ~125km. Coast to the Ap and then a very short prograde burn will put you in a circular orbit. At this point you should have a bit over 3200m/s dV (if playing pure stock. With TAC-LF and configurable containers, some fuel is replaced with life support resources and you’ll have about 100m/s less).

Very Important

After you reach orbit switch off the rapier engines [AG:1] and then right click on the large tank behind the science lab and unlock the oxidiser. You’ll need it for the VTOL landing engines and it’s much better to unlock it now, rather than in a frantic panic during the final stages of descent!

Mun Landing

This is quite tricky! Do most of the descent on the LV-N engines, but in the final stages of descent you have to switch into VTOL mode.

You need to aim to bring your surface speed down to around 100m/s on the LV-Ns by the time your altitude is around 3-5km.
At this point you can switch to the VTOL engines. Cut throttle and hit [AG:2] to switch of the LV-Ns. Hit [R] which will change your control point to a vertically orientated docking port and hit [AG:3] to open VTOL bay doors and switch the engines on. Pitch down to get your cross-hairs on the retrograde marker and then gently throttle up.

After that it’s landing as usual, but you don’t have a lot of oxidiser so there’s not a lot of room of adjusting landing site at this point. The VTOL setup is balanced for the typical fuel level it’ll have by now, but if you need to tweak the balance adjust the thrust of the front engine only. Adjustments of +/- 1-2 thrust will make a big difference.

Once you land hit [R] again (just to switch the RCS light off), hit [T] which will reset your control point to the cockpit and [AG:3] to switch off the VTOL engines. The abort action group will put the park brake on (without the air brakes being deployed) and switch off the wheel lights (the lights key [U] will toggle cabin lights as normal, but will always switch on wheel lights).

Ascent from Mun and return

You hopefully have a little bit of oxidiser spare after landing, but it’s only enough to raise you off the ground a little. Take off level (pitch 0) on the VTOL engines and also fire up the LV-Ns. As soon as the VTOL engines cut out pitch up hard to about 30-40 degrees and climb till the Ap is around 5-6km and then come down to 20 degrees and keep gradually reducing the pitch. Once in a stable Mun orbit you should have around 500-650m/s dV spare.

Do a transfer burn to Kerbin which puts your Kerbin Pe at 37km. As you approach Kerbin for aerobraking set the pitch to 40 degrees and hold that until the Ap drops to around 150km and then go prograde. You should then have just enough dV spare to raise the Pe back into a stable orbit and then deorbit to a KSC landing. Do the deorbit burn over the desert (just before the desert runway) and aim the trajectory directly at KSC. Then reenter at a pitch of 20 degrees until the craft starts to climb and then level out. This craft has very low drag and will lawn dart it’s way down, you may find you’re still going disconcertingly fast as you approach the runway!

Oh, and if you don’t like leaving rubbish all over Mun, remember to park the SVSR directly under the rear VTOL engines before you take off and it’ll get incinerated as you depart.

Try the Crew Transport Variant

A smaller, crew transport variant which has had all the science stuff ripped out to make room for 4 more Kerbals. This 10 kerbal variant has slightly more room for error.

swipe to switch images, tap to close
K
S
P