These files consist of the vehicle in top and bottom sections and the four gear printed separately. This allows the bottom to be printed upside down. The gears fit inside the bottom to reduce the chance of breaking off.

UPDATE 2023 07 18:
I deleted the single file version because I am still editing the whole file. Hopefully, this is the end. If I get no issues, then I will add the single file later.
I changed the profile of the bottom of the Top Section - essentially changed the mid section of the vehicle to include a plug to connect the two sections together instead of having the plug part of the top section. This should make the printing better with less bridging on the intersections. I still suggest you print the bottom section upside down even if the slicer suggests otherwise. This should make a cleaner bottom, around the engine nozzles, at the expense of the bottom inside which no one will see when assembled.
So now, not counting the 4 gear, there will be three pieces; bottom, top and plug. I added a fillet on the probe and made it a little bit thicker. Hopefully it will make it less prone to break off.

UPDATE 2023 07 20:
Because the flat extrusions into top and bottom created by the boolean of the plug created some spaghetti issues along the "flat" shelf not being flat, I extruded the bottom section 2 mm deeper to delete the resulting gap between to the two sections when mated with plug. I also changed to clearance between plug and body sections to 1mm instead of 1.5mm. If you downloaded the previous version, you can still make that work if you scale the plug to be on 12 mm high, leaving the other dimensions as is. You can also just glue the two parts together without the plug.

DC-X started as an SDIO project to be a subscale operations test vehicle before going to NASA after flight 5 'mishap' to become DC-XA. DC-X/DC-XA flew 12 times and successfully landed 12 times. On the 12th flight one gear did not deploy and after engines shut down it fell over and was consumed in fire

I added a remix: https://www.thingiverse.com/thing:6207265 for those who have problems painting details (like me) with all the black parts separately.