RASCAL

Sensing and Navigation for Space Situational Awareness

Mission Overview

The Rascal mission can be broken down into four discrete stages, as discussed in the following paragraphs.

Phase 1: Launch Vehicle Ejection/Checkout

This phase will commence upon ejection of Rascal from its rocket. After forty-five minutes has passed, any deployables that rocket has on board (such as antennas, solar panels, etc.) will be deployed, and radio beacons down to the ground will commence. Once radio communication has been made with Rascal, a ground crew will perform a full checkout of each subsystem of the spacecraft, as to ensure that Rascal survived launch and ejection. This process will likely take 2 to 4 weeks, depending on how long it takes to initially make contact with the spacecraft. Once this full functional checkout has been completed, Phase 2 can commence.

Phase 2: Controlled Separation/Minimum Mission Success

This phase is initiated by the release of one of the two separate 3U spacecraft from their common baseplate. Upon release, said spacecraft will drift away from the secured spacecraft at a controlled rate (a few centimeters a second). During this process, each spacecraft will orient itself such that their image navigation tools are pointed in the other’s general direction. Each spacecraft will continue to point at the other until a separation gap of 100 meters has been attained. This process will likely take 3-4 orbits and will occur autonomously. Also during this process, zero-net thrust bursts will be issued by each spacecraft for observation by the other.

Phase 3: Rendezvous/Complete Mission Success

Once this 100 meter gap has been reached, a command will be sent to the released satellite to begin the process of returning within 10 meters of the secured spacecraft. The same processes that took place during separation will also occur during this phase. Once a less than 10 meter separation has been attained for at least one orbit, the process will be repeated with the secured spacecraft. As a note, in order to mitigate the risk of one satellite losing the other in orbit, GPS receivers and communications crosslinks will be included on each spacecraft, as to keep track of each satellite if too large a separation was attained or in the event of a failure of the propulsion or navigation systems of either spacecraft. This entire process will likely take 2-4 weeks.

Phase 4: Extended Operations

After the completion of Phase 3, the secured spacecraft will be released from the common baseplate. After achieving stability, it will begin to drift away from the other spacecraft and the baseplate itself. After achieving a distance of 10-50 meters, each spacecraft will attempt to rendezvous with each other, as well as the baseplate. If possible, each satellite will dock with the other, by means of Velcro, electromagnets, or some other means, as determined by analyses that will be conducted in the upcoming semesters. This phase of the mission is not the ultimate focus of this project, but merely an objective to be attempted after the successful completion of the mission parameters, as laid out in the previous 3 phases.