I'm looking for a juvenile SF novel that was in my junior high school library (1959 - 1962). A family is surveying a new solar system intending to file a claim on it. The father is injured, but his teenage son continues the survey. On one of the planets he finds a cache of alien "power cubes". As part of the claims process he has to place a beacon on each planet and in orbit about the system's son. The beacons broadcast a unique ID registered to his father. The son takes their spaceship in dangerously close to the sun to place the solar beacon. They leave the new system just as some claim jumpers arrive. The son uses the "power cubes" in their spaceship's drive to get back to earth. The claim jumpers challenge their claim in claims court, but the jumpers loose. The claims court had a message from an outpost saying that they had observed the beacon IDs in the new system changing one by one from the father's ID to the claim jumpers' ID EXCEPT for the beacon orbiting the new sun. The claim jumpers had been too afraid to go as close to the sun as the son had gone in order to place the beacon.
If anyone can identify this story I will be most appreciative.