Fix crash on motor load

model/Rocket.cpp

@@ -7,6 +7,10 @@ namespace model
 
 Rocket::Rocket()
 {
+    // A rocket needs at least one stage. Upon creation, we need to create at least one stage
+    currentStage.reset(new Stage("sustainer"));
+    stages.push_back(currentStage);
+
 
 }
 
@@ -39,7 +43,7 @@ double Rocket::getMass(double t)
    double totalMass = 0.0;
    for(const auto& stage : stages)
    {
-      totalMass += stage.second->getMass(t);
+      totalMass += stage->getMass(t);
    }
    return totalMass;
 }

model/Rocket.h

@@ -4,7 +4,7 @@
 /// \cond
 // C headers
 // C++ headers
-#include <map>
+#include <vector>
 #include <memory>
 #include <string>
 #include <utility> // std::move
@@ -57,7 +57,7 @@ public:
     * @param t current simulation time
     * @return mass in kg
     */
-   virtual double getMass(double t) override;
+   double getMass(double t) override;
 
    /**
     * @brief setMotorModel
@@ -84,8 +84,8 @@ public:
     */
    void setName(const std::string& n) { name = n; }
 
-   virtual double getDragCoefficient() override { return 1.0; }
+   double getDragCoefficient() override { return 1.0; }
-   virtual void setDragCoefficient(double d) override { }
+   void setDragCoefficient(double d) override { }
    void setMass(double m) { }
 
    std::shared_ptr<Stage> getCurrentStage() { return currentStage; }
@@ -94,7 +94,7 @@ private:
 
    std::string name; /// Rocket name
 
-   std::map<unsigned int, std::shared_ptr<Stage>> stages;
+   std::vector<std::shared_ptr<Stage>> stages;
    std::shared_ptr<Stage> currentStage;
    //model::MotorModel mm; /// Current Motor Model
 

model/Stage.cpp

@@ -11,7 +11,8 @@
 namespace model
 {
 
-Stage::Stage()
+Stage::Stage(const std::string& inName)
+    : name(inName)
 {}
 
 Stage::~Stage()

model/Stage.h

@@ -21,7 +21,7 @@ namespace model
 class Stage : public Propagatable
 {
 public:
-   Stage();
+    Stage(const std::string& inName);
    virtual ~Stage();
 
       /**