LambdaSat (?-Sat Hellenic CubeSat) mission
LambdaSat (?-Sat) is a 1U CubeSat, developed and operated by the Lambda Team, an international group including Greek scientists and students from SJSU (San Jose State University ), San Jose, CA, USA. The mission received its name from the Greek letter lambda (?) and is the brainchild of Periklis E. Papadopoulos (of Greek origin), a professor of Mechanical & Aerospace Engineering at SJSU and the PI of the mission. NASA is funding the mission. 1) 2)
The objective of the ?-Sat technology demonstration mission is to test the satellite bus in the harsh space radiation environment and to study the effects of systems degradation. In addition, the satellite carries an AIS receiver (Automatic Identification System) and a scientific experiment hat looks at graphene behavior in space.
The research overview states:
• NanoRacks ?-Sat Hellenic Satellite (NanoRacks ?-Sat) is the first-ever Hellenic satellite designed and built by Greek scientists.
• NanoRacks ?-Sat demonstrates the first of-its kind space qualification of the nanotechnology material "Graphene" and its direct exposure to solar radiation and extreme space environments.
• NanoRacks ?-Sat aims to mitigate risk to Hellenic ships and their crews from piracies at sea by demonstrating a communications platform that monitors, with realtime positioning, Hellenic merchant ships for maritime security.
• Space qualification of innovative advanced three-fault tolerant spacecraft hardware is also a goal of NanoRacks ?-Sat.
• NanoRacks ?-Sat address the STEM (Science Technology Engineering and Math) educational objectives.
Figure 1: Photo of the LambdaSat 1U CubeSat (image credit: NASA, Periklis Papadopoulos)
LambdaSat uses 1U CubeSat structure of Pumpkin, Inc. of San Francisco.
The spacecraft uses a main computer and a main power board that conditions a power bus using solar power generation featuring body-mounted solar cells and deployable panels that create a total surface area of three CubeSat units.
A custom designed power system and main computer, built to meet three-fault tolerant space qualification requirements, operate all NanoRacks ?-Sat electronics.
Figure 2: LambdaSat in deployed configuration (image credit: NASA, Periklis Papadopoulos)
Communications are accomplished in a Short Burst Data mode using the Iridium satellite constellation which allows the satellite to downlink data quickly after acquisition. Standard communication sessions with ground stations will be made via a UHF transceiver operating in the amateur frequency bands.
UHF frequency: 437.462 MHz, downlink rate at 1.2 kbit/s AFSK, transmission power: 1 W.
Following successful deployment of the NanoRacks ?-Sat, communications are established by means of the Stensat, to downlink the Graphene experimental data. The Iridium communication platform is also enabled to transmit and collect the AIS (Automatic Identification System) data collected from the ground.
The LambdaSat orbital lifetime is estimated to be ~170 days after deployment; designed to deorbit (as required by orbital debris requirements) and disintegrate during reentry at the end-of-life of its mission.
Launch: The LambdaSat 1U CubeSat was launched as a secondary cargo payload on July 13, 2014 on the Cygnus CRS Orb-2 ISS resupply mission. The launch vehicle was Antares-120 of OSC and the launch site was MARS (Mid-Atlantic Regional Spaceport), Wallops Island, VA. The pressurized Cygnus spacecraft delivered 1,657 kg of cargo to ISS, including 300 kg of standard crew supplies, systems hardware and of science and research equipment. 3)
Orbit: Near-circular orbit , initial altitude of about 350-400 km, inclination 51.6o.
The secondary payloads on the Cygnus CRS Orb-2 mission were: 4)
• Planet Labs' Flock-1b: A flock of 28 nanosatellites (additional to 28 Flock-1 nanosatellites launched on January 9, 2014) from Planet Labs of San Francisco are aboard to take pictures of Earth. After deployment from the Japanese JEM module (using the NanoRacks LLC Smallsat Deployment Program). Once deployed, these two flocks will work in unison and capture imagery of the entire planet on a more frequent basis, forming the largest constellation of imaging satellites in Earth orbit.5) 6)
• TechEdSat-4 is a small CubeSat, built by NASA/ARC (Ames Research Center) in California that will investigate technology to return small samples to Earth from the space station. TechEdSat-4 will deploy using the NanoRacks services. Its primary objectives are to further develop a tension-based drag device, called exo-brake, and demonstrate frequent uplink/downlink control capabilities.
• MicroMAS-1 (Microsized Microwave Atmospheric Satellite-1), a 3U CubeSat of MIT/LL (Massachusetts Institute of Technology/Lincoln Laboratory). The objective is to provide unprecedented observations of hurricanes and tropical storm dynamics.
• GEARRSAT (Globalstar Experiment And Risk Reduction Satellite), a CubeSat with a Globalstar communications terminal,built by NearSpace Launch. The objective is to study the Globalstar communications constellation.
• LambdaSat, a 1U CubeSat developed and operated by the Lambda Team, an international group including Greek scientists and students from San Jose, USA. The objective is to measure radiation effects on graphene material in LEO, and tracking vessels with an AIS receiver inside its footprint around the globe.
• Fifteen student experiments of the "Charlie Brown" mission are aboard and hosted by the SSEP (Student Spaceflight Experiment Program), an initiative of NCESSE (National Center for Earth and Space Science Education) and NanoRacks. They will investigate plant, lettuce, raddish and mold growth and seed germination in zero-G, penecilium growth, corrosion inhibitors, oxidation in space and microencapsulation experiments.
• Ten internal payloads from NanoRacks' customers are holding dozens of research experiments onboard.
• SPHERES (Smart Synchronized Position Hold, Engage, Reorient Experimental Satellites) experiment of NASA/ARC features a sensor and multiple cameras to enable 3-D mapping and robotic navigation inside the space station.
General NanoRacks CubeSat/nanosatellite deployment concept:
The NanoRacks CubeSats/nanosatellites are delivered to the ISS already integrated within a NRCSD (NanoRacks CubeSat Deployer). The NRCSDs can be stored inside the ISS until a deployment is requested. 7)
The secondary payloads (Flock-1b, TechEdSat-4, MicroMAS-1, GEARRSAT, and LambdaSat) will be deployed from the Space Station using a deployment mechanism supplied by NanoRacks LLC. The System uses the MPEP (Multi-Purpose Experiment Platform) of the JEM (Japanese Experiment Module) to which the NRCSDs (NanoRacks CubeSat Deployers) are attached. The dispenser holds up to sixteen 3U CubeSats and is attached to the MPEP that can be grappled by the JRMS (JEM Remote Manipulator System) and deploy the satellites in pairs upon command issued from inside the ISS or the JAXA Control Center in Tsukuba, Japan.
For a deployment, the platform is moved outside via the Kibo Module's Airlock and slide table that allows the JRMS arm to move the deployers to the correct orientation for the satellite release and also provides command and control to the deployers. Each NanoRacks CubeSat Deployer is capable of holding six CubeSat Units - allowing it to launch two 3U satellites or a number of 2U and 1U satellites.
Deploying CubeSats from ISS has a number of benefits. Launching the vehicles aboard the logistics carrier of ISS visiting vehicle's reduces the vibration and loads they have to encounter during launch. In addition, they can be packed in protective materials so that the probability of CubeSat damage during launch is reduced significantly. Also, once arriving at the Space Station, the satellites can be checked pre-deployment, making sure any damage is detected before committing them to flight.
• March 11, 2015: LambdaSat — the first Greek CubeSat — was released from the International Space Station on March 4, following its launch last summer, and its developers have invited radio amateurs around the world to listen for the LambdaSat signal and file reports. 8)
• After an ISS onboard waiting period of 8 months (Table 1), the LambdaSat nanosatellite was deployed on March 4, 2015.
• On July 16, 2014, Cygnus CRS Orb-2 arrived at the ISS and was captured by Commander Steve Swanson as he maneuvered Canadarm2 from a robotics workstation inside the station's seven windowed domed Cupola. In the following days, the station crew will unload the cargo from the docked spacecraft. The first Cubesat deployment via the NanoRacks deployer is now scheduled for the end of July. It should take about a week to deploy the first block of CubeSats. 10)
Figure 3: Artist's view of the deployed LambdaSat spacecraft (image credit: Lambda Team)
Sensor/experiment complement: (AIS, Graphene Experiment)
AIS (Automatic Identification System)
The AIS receiver is the main payload of the mission with the objective to track around the globe.
Graphene is a 2D one-atom thick sheet of carbon with excellent electrical, chemical and mechanical properties. It has a unique band structure and is a zero bandgap material. As a material it is completely new - not only the thinnest ever but also the strongest (200 times stronger than steel). As a conductor of electricity it performs as well as copper. As a conductor of heat it outperforms good conducting metals such as silver and copper. It is almost completely transparent, yet so dense that not even the smallest gas atoms can pass through it. 12)
Andre Geim (a Dutch citizen born 1958 in Sochi, Russia) and Konstantin Novoselov (a British and Russian citizen, born 1974 in Nizhny Tagil, Russia) first isolated Graphene in 2004 and in 2010 they were awarded the Nobel price in Physics "for groundbraking experiments regarding the two-dimensional material graphene".
There is a huge interest of the scientific community since graphene can be used for transistors, sensors, resonators, solar cells, flexible electronics etc., exploiting one or more of the mentioned properties.
The 2D structure of graphene is represented by a single layer of carbon atoms that are arranged in a regular sp2-bonded hexagonal pattern. Exposing graphene to microgravity conditions will allow scientists to learn more about its properties and the way it reacts to ionizing radiation in such an environment.
Figure 4: Typical image of graphene atoms packed into a 2D honeycomb lattice (image credit: Lambda Team)
The project goal is to study the effects of radiation on graphene:
- Effect on Graphene bond-crystal structure
- Effect on electronic performance and mobility
- The effect on the substrate/dielectric interface
- Doping and scattering effects and performance degradation.
LambdaSat is carrying GFET (Graphene Field-Effect Transistor) wafers that will be used to examine the effect of radiation on the graphene bond-crystal structure, the effects on electronic performance and mobility, the effect on the substrate and dielectric interface and doping of scattering effects in the presence of radiation.
Figure 5: 3D Schematic of the fabricated graphene transistors (image credit: Lambda Team)
Figure 6: Photo of the exposed graphene experiment wafers on LambdaSat (image credit: NASA, Periklis Papadopoulos)
1) "NanoRacks-?-Sat Hellenic Satellite (NanoRacks-?-Sat )," NASA, July 15, 2014, URL: http://www.nasa.gov/mission_pages/station/research/experiments/1865.html#overview
3) "Orbital-2 Mission to the International Space Station," NASA Media Press Kit, July 2014, URL: http://www.nasa.gov/sites/default/files/files/Orb2_PRESS_KIT.pdf
4) Patrick Blau, "Cygnus Orb-2 Cargo Manifest," Spaceflight 101, URL: http://www.spaceflight101.com/cygnus-orb-2-cargo-manifest.html
5) "Orbital Sciences' Successfully Berthed Cygnus to ISS in Second Resupply Mission," NanoRacks Press Release, July 16, 2014, URL: http://nanoracks.com/orbital-sciences-successfully-berthed-cygnus-to-iss-in-second-resupply-mission/
7) "NanoRacks-Microsized Microwave Atmospheric Satellite (NanoRacks-MicroMAS)," NASA, July 15, 2014, URL: http://www.nasa.gov/mission_pages/station/research/experiments/1330.html#operations
8) "Radio Amateurs Invited to Listen for LambdaSat," March 11, 2015, URL: http://kh6jrm.net/2015/03/11/radio-amateurs-invited-to-listen-for-lambda-sat/
9) "NanoRacks Completes Historic Third Round of ISS CubeSat Deployments," Space Daily, March 11, 2015, URL: http://www.spacedaily.com/reports/NanoRacks_Completes_Historic_Third-Round_of_ISS_CubeSat_Deployments_999.html
10) "Orbital Sciences' Successfully Berthed Cygnus to ISS in Second Resupply Mission," NanoRacks, July 16, 1014, URL: http://nanoracks.com/wp-content/uploads/NanoRacks-Release-26-Cygnus-Successfully-Berthed-to-ISS.pdf
11) Ken Kremer, "Cygnus Commercial Resupply Ship 'Janice Voss' Berths to Space Station on 45th Apollo 11 Anniversary," Universe Today, July 16, 2014, URL: http://www.universetoday.com/113281/cygnus-commercial-resupply-ship-berths-to-space-station-on-45th-apollo-11-anniversary/
The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: "Observation of the Earth and Its Environment: Survey of Missions and Sensors" (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (firstname.lastname@example.org).