diff --git a/src/Utils/CurlConnection.cpp b/src/Utils/CurlConnection.cpp
index 50d819e..41769ff 100644
--- a/src/Utils/CurlConnection.cpp
+++ b/src/Utils/CurlConnection.cpp
@@ -16,7 +16,7 @@ namespace
 }
 }
 
-namespace Utils
+namespace utils
 {
 
 CurlConnection::CurlConnection()
diff --git a/src/Utils/CurlConnection.h b/src/Utils/CurlConnection.h
index 4527b38..e640321 100644
--- a/src/Utils/CurlConnection.h
+++ b/src/Utils/CurlConnection.h
@@ -5,7 +5,7 @@
 #include <curl/curl.h>
 #include <vector>
 
-namespace Utils
+namespace utils
 {
 
 class CurlConnection
diff --git a/src/Utils/math/Constants.h b/src/Utils/math/Constants.h
new file mode 100644
index 0000000..40b3250
--- /dev/null
+++ b/src/Utils/math/Constants.h
@@ -0,0 +1,16 @@
+#ifndef UTILS_MATH_CONSTANTS_H
+#define UTILS_MATH_CONSTANTS_H
+
+namespace utils::math
+{
+
+struct Constants
+{
+   static const double Rstar = 8.3144598;
+   static const double g0 = 9.80665;
+   static const double airMolarMass = 0.0289644;
+   static const double standardTemperature = 288.15;
+};
+
+} // namespace utils::math
+#endif // UTILS_MATH_CONSTANTS_H
\ No newline at end of file
diff --git a/src/sim/USStandardAtmosphere.cpp b/src/sim/USStandardAtmosphere.cpp
new file mode 100644
index 0000000..c87a52a
--- /dev/null
+++ b/src/sim/USStandardAtmosphere.cpp
@@ -0,0 +1,19 @@
+#include "USStandardAtmosphere.h"
+
+#include "Utils/math/Constants.h"
+
+namespace sim
+{
+
+USStandardAtmosphere::USStandardAtmosphere()
+{
+
+}
+
+USStandardAtmosphere::~USStandardAtmosphere()
+{
+
+}
+
+
+} // namespace sim
\ No newline at end of file
diff --git a/src/sim/USStandardAtmosphere.h b/src/sim/USStandardAtmosphere.h
new file mode 100644
index 0000000..172b42b
--- /dev/null
+++ b/src/sim/USStandardAtmosphere.h
@@ -0,0 +1,25 @@
+#ifndef SIM_USSTANDARDATMOSPHERE_H
+#define SIM_USSTANDARDATMOSPHERE_H
+
+#include "AtmosphericModel.h"
+
+namespace sim
+{
+
+class USStandardAtmosphere : public AtmosphericModel
+{
+public:
+   USStandardAtmosphere();
+   virtual ~USStandardAtmosphere();
+
+   double getDensity(double altitude) override;
+   double getPressure(double altitude) override;
+   double getTemperature(double altitude) override;
+
+private:
+
+
+};
+
+} // namespace sim
+#endif // SIM_USSTANDARDATMOSPHERE_H
\ No newline at end of file