diff --git a/src/config/param-validation.js b/src/config/param-validation.js
index 189283a..3a42607 100644
--- a/src/config/param-validation.js
+++ b/src/config/param-validation.js
@@ -1,6 +1,7 @@
 import Joi from 'joi';
 
 const flightName = Joi.string().regex(/^.*\-[1-9][0-9]{0,2}$/).required();
+const userId = Joi.string().regex(/^\d{21,}$/).required();
 
 export default {
   // POST /api/users
@@ -46,5 +47,12 @@ export default {
     params: {
       flightname: flightName
     }
+  },
+
+  userForFlight: {
+    params: {
+      flightname: flightName,
+      userid: userId
+    }
   }
 };
diff --git a/src/server/controllers/flight.js b/src/server/controllers/flight.js
index efdb7cc..580d836 100644
--- a/src/server/controllers/flight.js
+++ b/src/server/controllers/flight.js
@@ -1,12 +1,15 @@
+'use strict';
+
 import Flight from '../models/flight';
 import contentResponse from '../helpers/APIResponse';
 
 const FLIGHT_ERROR = 400;
 const FLIGHT_SUCCESS = 200;
+const DUPLICATE_USER_ERROR = 409;
 
 function getFlightInfo(req, res) {
   const flightName = req.params.flightname.toUpperCase();
-  const getFlight = Flight.getFlightFromFlightName(flightName);
+  const getFlight = getFlightFromFlightName(flightName);
   getFlight.then((flight) => {
     res.json(contentResponse(flight));
   }, (error) => {
@@ -20,9 +23,9 @@ function postFlightInfo(req, res) {
   const newFlight = new Flight(flightInfo);
   newFlight.save((err) => {
     if (err) {
-      res.sendStatus(FLIGHT_ERROR);
+      sendFailureStatus(res, err);
     } else {
-      res.sendStatus(FLIGHT_SUCCESS);
+      sendSuccessStatus(res);
     }
   });
 }
@@ -63,7 +66,64 @@ function isValidGeoJson(location) {
   return !!location.coordinates;
 }
 
+function putUserInFlight(req, res) {
+  const flightName = req.params.flightname.toUpperCase();
+  const userId = req.params.userid;
+  const getFlight = getFlightFromFlightName(flightName);
+  getFlight.then((foundFlight) => {
+    if (!foundFlight) {
+      return sendFailureStatus(res);
+    }
+    foundFlight = addMissingUserIdsProperty(foundFlight);
+    if (hasDuplicateUserId(foundFlight, userId)) {
+      return sendDuplicateFoundStatus(res, userId);
+    }
+    foundFlight = addUserIdToFlightInfo(foundFlight, userId);
+    foundFlight.save();
+    return sendSuccessStatus(res);
+  }, (err) => sendFailureStatus(res, err));
+}
+
+function getFlightFromFlightName(flightName) {
+  return Flight.getFlightFromFlightName(flightName);
+}
+
+function addUserIdToFlightInfo(flight, userId) {
+  flight.userIds.push(userId);
+  return flight;
+}
+
+function addMissingUserIdsProperty(flight) {
+  if (!flight) {
+    return flight;
+  }
+  const isFlightMissingUserIds = !flight.userIds;
+  if (isFlightMissingUserIds) {
+    flight.userIds = [];
+  }
+  return flight;
+}
+
+function hasDuplicateUserId(flight, userId) {
+  return flight.userIds.indexOf(userId) > -1;
+}
+
+function sendSuccessStatus(res) {
+  res.sendStatus(FLIGHT_SUCCESS);
+}
+
+function sendFailureStatus(res, err) {
+  console.log(err);
+  res.sendStatus(FLIGHT_ERROR);
+}
+
+function sendDuplicateFoundStatus(res, userId) {
+  res.send(DUPLICATE_USER_ERROR,
+    contentResponse({ duplicateUserId: userId }));
+}
+
 export default {
   getFlightInfo,
-  postFlightInfo
+  postFlightInfo,
+  putUserInFlight
 };
diff --git a/src/server/models/flight.js b/src/server/models/flight.js
index d57e270..55ba58a 100644
--- a/src/server/models/flight.js
+++ b/src/server/models/flight.js
@@ -9,7 +9,8 @@ const FlightSchema = new mongoose.Schema({
   launchLocation: mongoose.Schema.Types.GeoJSON,
   launchAltitude: Number,
   registeredTrackers: Array,
-  deviceIds: Array
+  deviceIds: Array,
+  userIds: Array
 }, {
   timestamps: true
 });
diff --git a/src/server/routes/flight.js b/src/server/routes/flight.js
index 486ac96..996d2c5 100644
--- a/src/server/routes/flight.js
+++ b/src/server/routes/flight.js
@@ -25,8 +25,16 @@ router.route('/:flightname/telemetry')
 router.route('/:flightname/telemetry')
   .post(validate(paramValidation.telemetry), telemetryCtrl.postTelemetry);
 
-/** GET flight telemetry */
+/** GET flight telemetry historical data */
 router.route('/:flightname/history')
   .get(validate(paramValidation.history), historyCtrl.getFlightHistory);
 
+// /** GET flight telemetry historical data */
+// router.route('/:flightname/users')
+//   .get(validate(paramValidation.usersForFlight), userCtrl.getFlightHistory);
+
+/** PUT userId in existing flight */
+router.route('/:flightname/user/:userid')
+  .put(validate(paramValidation.userForFlight), flightInfoCtrl.putUserInFlight);
+
 export default router;