SSOT02(final type)

This is the first time I've ever shared a vehicle that can actually accomplish a space mission. I've had a lot of fun doing it before.
Since I often switch between my phone and computer, I often send some half-finished products, which I will highlight when sharing the finished products.
And now we're thinking about doing a Mars lander.

The SSOT shared this time is the final, improved version that achieves the three goals I originally envisioned
First, it could be launched in the atmosphere and put into orbit alone with one or two small satellites on board
If the satellite has a lot of mass, you have to fix it, and you have to get creative about how to fix it, and I don't know what to do here.
Second, the SSOT body can carry satellites that act as orbital tows after separating the first and second stage boosters, and the SSOT can transport cargo between any two planets in the star system when the electric boosters are turned on.
Third, the SSOT body can achieve a single aircraft to return to the atmosphere, and land in the space center.
The variable sweep wing is opened on return to Earth, changing its aerodynamic profile and using stage5 to separate the fuel tank mounted under the wing prior to landing.
The landing speed should be about 125. When the tires touch the ground, use the RCS to slow down immediately. The distance can be reduced to one fifth of the runway.