The Neutron-1 3U CubeSat was developed by the Hawaii Space Flight Laboratory (HSFL) at the University of Hawaii at Manoa (UHM) and the science payload, a small neutron detector, was developed by Arizona State University (ASU) as part of the LunaH-Map Mission. The science will focus on measurements of low energy secondary neutrons, one of the components of the LEO (Low Earth Orbit) neutron environment. This mission also has a radio amateur component by providing a VHF uplink/UHF downlink FM Voice Repeater for educational and amateur engagement. This mission is an also an opportunity to establish flight heritage and demonstrate the technological capabilities of the NASA EPSCoR funded Comprehensive Open-architecture Solution for Mission Operations Systems (COSMOS). COSMOS is an open-source set of tools that is being developed at HSFL as an integrated operations solution (including flight software, ground station operations, and mission operations center) for Small Satellite missions. It is intended to enable/facilitate SmallSat mission operations at universities with limited budgets and short schedules.

Goals of this mission:

  1. Science. Measure low energy neutron flux in a low Earth orbit (LEO) environment. Use Luna-H Map detector for on orbit validation.
  2. Amateur. Provide a V/U FM Voice Repeater for educational and amateur purposes. For more information, see the Amateur Operations Page!
  3. Technology. Demonstrate the Comprehensive Open-architecture Solution for Mission Operations Systems (COSMOS) as new mission ops technology.

Figure: Neutron-1 engineers at HSFL (left), payload team at ASU (right)

Science Mission

The NEUTRON-1 mission will measure low energy neutron flux in the low Earth orbit (LEO) environment in efforts to gather new science data. The data gathered by a 3U CubeSat platform can contribute to understanding the complex relationship between Earth and Sun through mapping neutron abundances LEO. In combination with data obtained by other spacecraft and ground-based measurement stations, we will evaluate the variability of galactic cosmic radiation as a function of solar variability.

The science team will study the unusual neutron abundances in relation to solar flares, solar particle events, and disturbances of the Earth's magnetic field. We will also evaluate our neutron data for potential application in space weather characterization and radiation safety. The proposed neutron flux detector design is based on established detection methods but will be miniaturized to fit within a CubeSat payload envelope.  In addition to the science, this first mission can provide flight heritage for further development of CubeSat based neutron detectors.

Amateur Mission

Neutron-1 was deployed from the International Space Station on November 5, 2020. Post deployment, the satellite is inhibited for 30 minutes as required for ISS safety. Once the 30 minutes have passed an internal timer will deploy the ISISpace UHF/VHF antennas and power up the radio which will then start a beacon every 60 seconds (only if the spacecraft is in nominal mode). The ISISpace TRXVU radio provides a beacon, uplink commands and a transponder capability in the radio amateur bands. Below are the radio specifications.

Transmitter Specs (UHF Downlink)

  • Set frequency: 435.300 MHz (as coordinated by IARU)
  • Tx peak power (EIRP): 27 dBm
  • Data rate: 1200 bit/s (default), up to 9600 bit/s
  • Modulation: BPSK-G3RUH
  • Data link protocol: AX.25
  • ITU emission class: 15K0G1DAN

Receiver Specs (VHF Uplink)

  • Set frequency: 145.840 MHz  (as coordinated by IARU)
  • Sensitivity: -104 dBm
  • Data rate: 9600 bit/s
  • Modulation: FSK
  • Data link protocol: AX.25
  • ITU emission class: 12K5F1DBN

SatNOGS Collaboration

SatNOGS is a global network of 200+ satellite ground stations. HSFL is currently adding its ground site node at UH Manoa. See links bellow:

Overall System Architecture

To support the science instrument the Neutron-1 bus system includes the HSFL On Board Computer (OBC) that serves to control the instrument data collection and to store and forward the data to the ground. The Electronic Power System (EPS) is a ClydeSpace 3rd generation EPS Range with a 40 Whr battery. The EPS provides switchable power to the various systems in the bus and it is charged with four body mounted solar panels. The CubeADCS provides the 3-axis system stabilization and pointing capability to perform the science experiments. Finally, the RF Communication system uses two different radios to transfer information. The primary T&C and science data is transferred via a Globalstar GSP 1720 duplex. The figure below shows the overall system diagram.


Figure: Neutron-1 Bus Overall System Architecture

Ground System

HSFL operates and maintains a UHF, VHF, and L/S-Band amateur ground station for satellite operations at the Kauai Community College (KCC).  This ground station is integrated with our in-house developed (and open source) COSMOS software to facilitate coordination of equipment and tracking of satellites. Using COSMOS, this system is capable of complete automation of satellite contacts.  HSFL has also started to setup a new ground station at the UH Mānoa Campus as a replacement to the MC3 ground station. The KCC ground station will be used as the primary operations station of the Neutron-1 mission. The figure below shows the full ground capabilities at the University of Hawaii.


This mission would not have been possible without the ongoing support and continuous funding of the NASA Hawaii EPSCoR Research Infrastructure Development Program and the Hawaii Space Grant Consortium. HSFL is incredibly thankful to the Air Force Research Lab for the provision of the solar cells.

We want to offer special kudos to the fiscal team at the Hawaii Institute of Geophysics and Planetology (Willam Doi, Karynne Morgan, Vi Nakahara, Sharisse Nakasone, Layne Nakano, Marcia Rei Nii, and Anela Nishimoto) in particular as well as the Research Corporation of the University of Hawaii fiscal team for their outstanding support with rushed replacement parts and complicated orders. They help us fly in space!

Various HSFL students and engineers have also given their support to this mission including, Glenn Galvizio, Christianne Izumigawa, Keane Hamamura, Aditya Kumar, Alex Noveloso, Cyrus Noveloso, Donna Noda (RPI), Spencer Young, Kenny Son, Willy Chang, Anthony Lopez, Laurence Diarra (USC), and Devan Tormey (USC). More than 100 students eventually got involved with this mission. The full Neutron-1 Team Roster can be found here.

The payload team was also critical to the success of this mission by delivering the neutron detector to HSFL. The payload team led by Arizona State University includes the following members: Craig Hardgrove (PI Luna-H Map), Teri Crain, Erik Johnson, Graham Stoddard, Igor Lazbin, Michael Fitzgerald, Nathaniel Struebel, Patrick Hailey, among others.

The Ground Station team on Kauai is led by Dr. Georgeanne Purvinis and Tom Ellis. Daniel Nafarrete is a trainee at Kauai Community College also assisting with this effort. For any unspecified acknowledgements, thank you to all who made a contribution to this mission!


You can connect with HSFL and the Neutron-1 mission via some of the following links. For any further questions on the Neutron-1 mission please contact at

Neutron-1 Mission Updates

UPDATE July, 2022: Neutron-1 Deorbited completing the mission lifecycle successfully.

UPDATE December 04, 2020 13:20 HST: Neutron-1 has been in orbit for almost 30 days and we are currently still in the commissioning phase of the mission. Neutron-1 was assigned NORAD ID: OBJECT RT(46923), and updated TLEs can now be found in the Space Track database. HSFL has received 15 beacons, and with each new data point, the Neutron-1 team has learned more about the status of the spacecraft. In order to increase the probability of getting a beacon, the team is requesting amateurs who are interested in transmitting to Neutron-1 send this audio file via FM standard FSK 9600 baud, G3RUH. This file will increase the beacon rate until the spacecraft restarts.  If you have any questions, please let us know by emailing!

The HSFL team is incredibly grateful for the amateur community who have been listening for beacons from Neutron-1! Every data point we get helps us to better understand the behavior of Neutron-1. Your support has been invaluable!!

UPDATE November 18, 2020 15:20 HST: HSFL has updated TLEs for Neutron-1!! We appreciate the amateur community who have been listening for Neutron-1’s beacon, you are awesome! Let us know if you are still listening for the beacon at or on Twitter @HSFLNeutron1

Neutron-1 (2020-11-18)
1 46923U 98067RT 20323.82600157 .00008297 00000-0 15183-3 0 9990
2 46923 51.6436 303.2084 0002916 39.7575 320.3627 15.50257655 2168

UPDATE November 10, 2020 18:20 HST: NanoRacks sent us some amazing photos/video from the ISS deployment! You can view them here. Big mahalos to NASA and NanoRacks for providing these amazing photos! We are waiting for updated TLEs, and as soon as we get them, we will post them here!

TLE Updated 2020-11-09

1 85421U          20311.64174749 +.00006677 +00000+0 +12458-3 0 00022
2 85421  51.6491   3.5815 0002381 351.1546   8.9401 15.50066020000286

UPDATE November 4, 2020 11:10 HST: HSFL received notice that the NRCSD was successfully installed onto the Kibo airlock slide table. Watch the deployment live via YouTube at 1040 UTC (0040 HST). Amateur operators can receive beacons sent from Neutron-1 starting 30 minutes post deployment. The HSFL Team will be updating the status of the UHF/VHF radio on our Amateur Operations Page and on Twitter (@HSFLNeutron1).

For the first month and during the spacecraft commissioning phase, the beacon will transmit 1200bps BPSK every 60 seconds on the IARU coordinated  frequency of 435.300MHz . We welcome the worldwide Amateur community to collect the beacons and upload them here or forward them to The beacon format is now public and published here.

  • Spacecraft Name: Neutron-1
  • Call sign: WH6DNU
  • UHF Frequency (Downlink): 435.300MHz; BPSK; 1200bps
  • VHF Frequency (Uplink): 145.840MHz; FSK; 9600bps
  • Email beacon files to
  • Upload beacon files

Initial TLE (equivalent to ISS) * Updated 2020-11-06 @ 1300HST *

1 85421U 20311.64174749 +.00006677 +00000+0 +12458-3 0 0002 
2 85421 51.6491 3.5815 0002381 351.1546 8.9401 15.5006602000028

First contact with Hawaii is expected to happen at 8:20 HST, Nov 5. but the pass elevation is at 31.5 deg. so it may not be sufficient for data collection. The next opportunity for Hawaii will be at 23:18 HST, Nov 5. with a 50.3 deg. max elevation pass.

After the initial commissioning phase, Amateurs will be able to use the V/U FM repeater during available times and according to the available power budget. Stay tuned for more mission updates on our Twitter account @HSFLNeutron1 and this page. For questions, visit our Q&A sheet, email, or send a DM on Twitter!

UPDATE Oct. 23, 2020 14:15 HST: HSFL received notice from Nanoracks that the Neutron-1 deployment will happen on Nov 5 at 10:40 UTC (00:40 HST). You can watch the live stream here. Current Schedule:

  • Monday, November 2, 09:40 UTC (23:40 HST): NRCSD installation onto the Kibo airlock slide table
  • Thursday, November 5, 10:40 UTC (00:40 HST): Neutron-1 Deployment!

UPDATE Oct. 17, 2020 07:00 HST: HSFL participated at the “2020 AMSAT Space Symposium” with a presentation “Neutron-1 CubeSat: Amateur Mission”. The video is posted on the AMSAT Youtube Channel. Click the video bellow to see the Neutron-1 presentation (starting at 3h12).

UPDATE Oct. 16, 2020 07:18 HST: We received notice that the Neutron-1 deployment is scheduled for November 5! The installation of the NRCSD deployer into the Kibo airlock occurs Nov. 2. We are also on standby early for operations by Nov. 3 just in case deployments are pulled to the left.

UPDATE Oct. 13, 2020 13:00 HST: Dr. Peter Engler (Science PI) and our engineers Amber Imai-Hong and Miguel Nunes participated at the ThinkTech Hawaii show of ‘Likable Science’ with host Jay Fidell. See video bellow for the interview regarding the Neutron-1 mission.

UPDATE Oct. 5, 2020 09:00 HST: Neutron-1 arrived at the International Space Station early in the morning at 23:32 HST (5:32 a.m. EDT) as the Cygnus spacecraft was successfully captured by Commander Chris Cassidy of NASA using the ISS robotic Canadarm2 (see video bellow).  The ISS Astronauts will now move the Cygnus cargo into the ISS and we wait for confirmation on when the Neutron-1 orbital deployment will happen (currently expected mid-November).

Cygnus capture video:

UPDATE Oct. 2, 2020 16:30 HST: After a beautiful Antares rocket launch from Wallops, VA. the Cygnus spacecraft now carries Neutron-1 to the International Space Station. On Sunday Oct. 4, at 21:45 HST (October 5, 3:45 a.m. EDT) NASA TV will start the coverage of the Rendezvous and Capture for NG-14 Cygnus with the ISS. The spacecraft capture is scheduled at 23:20 HST (5:20 a.m. EDT). At 1:30 am HST (7:30 a.m. EDT) NASA will start the installation of the NG-14 Cygnus Craft to the International Space Station (times are subject to change).

UPDATE Oct. 2, 2020: Neutron-1 will be launching from Wallops Island, VA on the Cygnus NG-14 Commercial ISS Resupply Mission, now scheduled for Friday, October 2 at 3:16 p.m. HST / 9:16 EDT (you can check the NASA blog or NG-14 page for latest updates). The launch will be broadcasted live on NASA TV via this link. This launch is part of NASA’s ELaNa 31 mission carrying other CubeSats to space such as BobCat-1 from Ohio University and SPOC from the University of Georgia, Athens. Check the NASA TV video bellow to watch the launch: