CubeSat Handling of Multisystem Precision Time Transfer

Presenter Information

Nathan Barnwell, University of Florida
Watson Attai, University of Florida
Lucas Bassett-Audain, University of Florida
Maria Carrasquilla, University of Florida
John Chavez, University of Florida
Jon DeWald, University of Florida
Olivia Formoso, University of Florida
John Hanson, University of Florida
Belgacem Jaroux, University of Florida
Asia Nelson, University of Florida
Tyler Noel, University of Florida
Anh N. Nguyen, University of Florida
Seth Nydam, University of Florida
Ken Oyadomari, University of Florida
Jessie Pease, University of Florida
Cedric Priscal, University of Florida
Tyler Ritz, University of Florida
Steven Roberts, University of Florida
Paul Serra, University of Florida
Jan Stupl, University of Florida
Evan Waxman, University of Florida
Jasper Wolfe, University of Florida
John W. Conkin, University of Florida

Session

Poster Session IV

Comments

CHOMPTT (CubeSat Handling of Multisystem Precision Time Transfer) is a CubeSat mission that will synchronize an atomic clock on a CubeSat with one on the ground using laser pulses with an accuracy of ~100 ps. Current navigation systems, like GPS, utilize radio frequencies to synchronize ground clocks with clocks in space. One limitation of using radio frequency time-transfer is that it is susceptible to time-delay uncertainties in the ionosphere that can be difficult to model. The CHOMPTT mission reduces the uncertainty of ionospheric effects, which is inversely proportional to the frequency squared, by utilizing optical frequencies rather than radio frequencies. For future disaggregated navigation schemes, time can be broadcasted from a satellite, which has high accuracy synchronization capabilities with the ground, to other satellites in space. This would help to maintain a high accuracy common space time.

The concept of operations for the CHOMPTT mission is as follows: (a) When the satellite passes over the satellite laser ranging facility (SLR), the SLR facility emits a laser pulse toward the satellite; (b) that pulse is time-stamped with respect to the ground clock when it leaves the SLR facility; (c) An avalanche photodetector on the satellite detects the pulse's arrival time and time-stamps it with respect to a Chip Scale Atomic Clock on the satellite with an event timer; (d) At the same time a retroreflector on the satellite returns the pulse back to the SLR facility; (e) The reflected pulse is time-stamped with respect to the ground clock when it arrives back at the SLR facility.

The CHOMPTT mission has a planned launch in 2017 through NASA's CubeSat Launch Initiative and is a joint collaboration between the University of Florida who is responsible for the OPTI (Optical Precision Timing Instrument), the 1U payload and NASA Ames Research Center who is developing the EDSN-derived 2U CubeSat bus. The demonstrated synchronization performance of OPTI is ~100 ps in laboratory. The SLR facility is an experimental facility located at the Kennedy Space Center and managed by the University of Central Florida. This poster will cover the architecture and improvements to the payload to reduce the overall power consumption, in lab test results of the payload engineering design unit, and operational testing of the SLR facility.