Space themed smart Pointer exercise

#include <iostream>
#include <memory>
#include <string>

class CrewMember
{
    std::string name;

    unsigned int member_id_number;
// variable to count total crew objects
  inline static unsigned int crew_members_total = 0;

public:

  CrewMember();

  ~CrewMember();

  inline static unsigned int GetTotalCrewMembers(){ return CrewMember::crew_members_total; }

  const unsigned int GetMemberIdNumber(){ return member_id_number; }
};

//CrewMember.cpp

CrewMember:: CrewMember()
{
   std::cout << "A crew member has joined" << std::endl;
    member_id_number = crew_members_total;
    crew_members_total++;
}

CrewMember::~CrewMember()
{

}

class SpaceShip
{


       /*

        std::unique_ptr<CrewMember[3][3]> ship_crew_members = std::make_unique< new CrewMember[3][3]>;

        // generates error

        call to non-constexpr function 'void* operator new [](std::size_t)'
        std::unique_ptr<CrewMember[3][3]> ship_crew_members = std::make_unique< new CrewMember[3][3]>;
                                                                                                   ^
cannot resolve overloaded function 'make_unique' based on conversion to type 'std::unique_ptr<CrewMember [3][3]>'
        std::unique_ptr<CrewMember[3][3]> ship_crew_members = std::make_unique< new CrewMember[3][3]>;

       */

      // compiles fine
        std::unique_ptr<CrewMember[3][3]> ship_crew_members;

public:
  SpaceShip();
  ~SpaceShip();

};

// SpaceShip.cpp

SpaceShip:: SpaceShip()
{

}

SpaceShip::~SpaceShip()
{

}

class Galaxy
{
std::unique_ptr<SpaceShip> orions_comet;
public:

 Galaxy();
 ~Galaxy();

};

// Galaxy.cpp

Galaxy:: Galaxy()
{

}

Galaxy::~Galaxy()
{

}

int main() {

	Galaxy far_away_galaxy;

    std::cout << "The Total Crew mebers are " << CrewMember::GetTotalCrewMembers() << std::endl;
    std::cout <<"la codigo esta bien" << std::endl;

	return 0;
}