|
NASA's ALBus CubeSat was launched from New Zealand on 16 December 2018. ALBus is a 3U CubeSat serving as a testbed for a high power electrical system, and the use of shape memory alloys (SMAs) in its solar panel hinges and release mechanism.  ALBus with its eight custom Pumpkin PMDSAS solar panels. Pumpkin designed and built the ALBus solar panels to NASA GRC's specifications within a very short time period. Additionally, ALBus utilizes a Pumpkin CubeSat Kit 3U structure. While the fixed 7S1P panels were relatively standard in their layout, the deployable 7S1P panels had special design features to accommodate ALBus' SMA hinges and the SMA-based release mechanism. Pumpkin worked with NASA GRC early career engineers to resolve all of these special requirements in an elegant fashion.
NASA has provided detailed technical information on ALBus and its development. On 5 May 2019 a Rocket Lab Electron rocket launched three small satellites from New Zealand’s North Island. Included in the manifest is AFRL's SPARC-1, a 6U CubeSat built on Pumpkin's SUPERNOVA bus, with two payloads. This is the second SUPERNOVA launch, after 2015's SUPERNOVA-Beta launch that ended with the failure of the Super Strypi launch vehicle on Nov 3, 2015.  Artist's conception of the SUPERNOVA-based SPARC-1 U CubeSat on orbit. Image courtesy of UNM/COSMIAC. While SUPERNOVA-Beta remains in a sub-aqueous orbit, SPARC-1 is now in a LEO Orbit and undergoing commissioning.
JPL has now demonstrated a laser communications pointing experiment between two JPL small satellites: ISARA (the receiver) and OCSD (the transmitter). ISARA is a 3U CubeSat that is powered by a novel, deployable Pumpkin solar array that stows around three sides of the 3U structure. The array's three monolithic panels are hinged together, and deploy to present 24 solar cells on top, and a Ka-band reflectarray (that is essentially an RF Fresnel lens), on the bottom. The flatness of these three panels is critical for the performance ISARA's Ka-band system.  Solar-cell side of ISARA's Pumpkin-built 24W reflectarray (RA) In 2018, Pumpkin was the exclusive provider of solar panels for NovaWurks' PODSAT, a short-duration GTO-class mission to validate several concepts of NovaWurks' cellular architecture. PODSAT's primary solar panels used are the exact same models as are currently flying in LEO on NovaWurks' eXCITe mission. Read more about PODSAT here.
On Monday, SpaceX delivered NovaWurks' eXCITe small satellite into LEO orbit. NovaWurks relayed to us on Tuesday that eXCITE's Pumpkin Deployable Clamshell Solar Arrays (DCSAs) using our PMDSAS technology had deployed, were delivering their expected power, and eXCITe was already operational. Small space has become truly responsive.  176W DCSA in deployed configuration Pumpkin's relationship with NovaWurks harkens back to the NGC/NovaWorks Mayflower 3U CubeSat mission, for which Pumpkin built a deployable 56W solar array in 2009. No comparable array existed at that time; ten weeks after an initial meeting, Pumpkin had delivered the all-new functional array to NovaWorks, and in 2010 the LEO mission executed successfully, carrying the NGC/NovaWorks core 2U and an additional 1U payload named Caerus from USC/ISI. To date, Mayflower is apparently the highest power-to-weight spacecraft ever built (56W in 4kg), and Pumpkin's 56W array was a critical enabling component. The 56W Mayflower array was the genesis for Pumpkin's current wide range of PMDSAS(TM) solar arrays. The Pumpkin DCSA on eXCITe uses the fifth generation of Pumpkin's PMDSAS solar panel technology, stows safely in its own clamshell, and when released, deploys to two independent strings of solar cells.
For this eXCITe mission, Pumpkin originally delivered two 112W DCSAs. By the time the various payloads of the eXCITe mission were finalized in 2018, Pumpkin had increased the power of each DCSA array to 176W within the same footprint, thereby demonstrating the overall versatility of the DCSA. Pumpkin also built the fixed solar panels on each HiSat cell in eXCITe. The DCSA and other space-proven Pumpkin PMDSAS solutions are available as COTS offerings.
We wish NovaWurks all the best in this holiday season, for their eXCITe mission. FLEET Space's Centauri 1 was deposited into its intended orbit by India's PSLV-C43 yesterday, and has already broadcast some initial health and status information. The Centauri CubeSats Pumpkin built for FLEET Space have best-in-class solar arrays, batteries and structural integrity, along with a 1GHz Linux C&DH platform. Centauri 1 & 2 are comprised of:
 Centauri 1, with panels deployed and UHF antenna still in stowed position.
When FLEET Space had a last-minute opportunity to launch 3U worth of CubeSats on a Rocket Lab Electron launch vehicle, with the caveat that the CubeSats had to be ready in two weeks (!), they came to Pumpkin. We not only typically have nanosatellite-class equipment in stock, but we also have a proven track record of working quickly on projects that require outside-of-the-box thinking.
Within two weeks, we needed to come up with a working architecture, source the required components / assemblies, make any modifications required, integrate the FLEET payload and antennas (the pixelated portion above), and provide a software framework upon which FLEET could write their mission software. Given the very short notice and the desire to maximize the utility of the 3U of volume available on this ride, Pumpkin and FLEET settled on a dual-1.5U mission, with two hardware-identical 1.5U CubeSats. We decided to go with a battery-power-only architecture, as that reduced costs and complexity, and fits within the 1.5U available. Pumpkin immediately embarked on creating a new operating mode for our BM 2 battery; within a few days we had this up and running, and Proxima I/II were thus enabled. The two satellite were built with US and Australian teams working together and remotely, then environmentally tested with no issues, and finally delivered to Rocket Lab for LV integration. Proxima's Pumpkin components included:
The Pumpkin bus components occupy around half the volume and mass of each Proxima CubeSat; FLEET's payload(s) occupy the rest. The GPSRM along with its power-efficient orbit propagator enable Proxima's mission ops, and the low-power 16-bit PPM E3 PIC24 MCU running Salvo along with the BM 2 and its sleep mode guarantee an efficient use of the battery's available energy. Additionally, some of the code from Stanford University's QB50 project was donated to the Proxima mission, and lives on in Proxima I/II. More information on these CubeSats can be found here.
In July 2015, Pumpkin was approached by the Los Angeles County Museum of Art (LACMA) to work with Bahamian artist Tavares Strachan to create a 3U CubeSat-size work of art to be launched into space. Influenced by a visit to the Neues Museum in Berlin, the result of this very successful working relationship between Pumpkin and the artist is a distinctive, unique and beautiful objet d'art, that happens to also carry some hi-tech tags that will simplify its tracking while on orbit. On Friday, November 2, 2018, the FAA "made a favorable payload determination for the ENOCH payload," and ENOCH is now cleared for launch on the Falcon 9 flight from Vandenberg AFB on November 19. You can read more about ENOCH and the artist behind it here, here and here.  As part of the development of ENOCH, Pumpkin initially considered a scheme whereby ENOCH's canopic jar would be located inside two 1.5U CubeSat "shells" that would separate after launch. However, we ultimately felt that this was not a particularly elegant solution, and given the mass of the jar (it's made of cast brass), surviving shake and shock during the launch to properly separate thereafter would likely prove problematic and frankly, too much trouble. That's when AEK visited the Neues Museum in Berlin and saw Nefertiti's bust in its new home.
Our new approach was to present the canopic jar in a manner that focused the viewer's eyes on the jar, and not on the surrounding materials required for launch. With this new direction for ENOCH, we created a "sled" that is compatible with Planetary System Corporations Canisterized Satellite Dispenser (CSD). This resulted in a design that exposed the canopic jar as much as possible, and let the sled "fade into the background." Hence the deep black color to the sled. This layout meant that the canopic jar was heavily cantilevered at one end, which led to a few iterations when a lower-than-acceptable fundamental frequency was discovered during environmental tests. The base below the canopic jar also incorporates (hidden from view) the requisite hardware to vent the interior volume of the jar, as well as permanent magnets and hysteresis material to help ENOCH establish a stabilized attitude while on orbit. The sled has "feet" on the top and bottom, with an isogridded structure for strength and lightness, for symmetry and in order to satisfy the CSD requirements.  Lastly, since LACMA is not your typical satellite operator, we felt that adding a means to track ENOCH's orbit would be very useful, and so with LACMA's blessing we added three radar retroreflectors supplied by the US Navy to the structure (the white squares). With these radar tags, it will be relatively straightforward to track this "passive" nanosatellite.
We wish the ENOCH mission all the best. A fitting tribute to fallen astronaut Robert Henry Lawrence Jr. We just finished building two new, custom CubeSats in two weeks. Our customer needed a rapid response to a flight opportunity, and we responded with a mix of Pumpkin COTS components and customer-supplied payloads, all combined in a novel way. You'll be able to learn more about these puppies in more detail once they are on orbit. A big thank-you to all of the Pumpkin employees who went above and beyond their normal duties to complete this project! 2018-11-13 Update: These two CubeSats were launched and deployed over the weekend; you can see some footage of their deployment here. They're launched together from a 3U-size deployer, the one on the right side of the video.  As part of a crash effort to build two customer nanosatellites in two weeks, the reality of typical COTS lead times and a limited budget forced us to adopt a radically simplified approach to the satellite's power system. We decided to run each spacecraft solely from battery power, without any solar panels, etc. Pumpkin's BM 2 intelligent battery module is ideally suited to "battery only" missions, with an energy of up to 100Wh, SoC reporting, independent heaters, and various protections. At 14,000mAh, there's a lot of battery life in the BM 2. The BM 2's typical operating current is 20mA; when an EPS and solar panels are present, the cost of those 20mA is quite minimal. But for a battery-only mission, that's only about one month of operating, powered up, at quiescent currents.  In a spacecraft utilizing only battery power, a smart battery becomes the EPS, because of its ability to isolate loads from the battery's cells. Simple external regulators downconvert the battery voltage to more usable voltages like +5V or +3.3V. There is no need to switch power systems, since everything outside of the battery is unpowered while the battery sleeps.
To implement this functionality, we've added a new software feature to the BM 2 -- a sleep mode. When the BM 2 is sleeping, all power to the rest of the spacecraft is disabled, and the BM 2 maintains an internal "sleeping clock." With the BM 2 sleeping at around 1.5mA, a mission life of around 400 days is possible. Sleep can be commanded with single-minute resolution, with a maximum sleep time of 120 days (7200 hours) via a single command. When in a deep sleep, the BM 2 will wake up every two hours for one minute, giving the flight software the opportunity to cancel the sleep if desired. The new BM 2 firmware is currently being tested, and is available to all BM 2s built on Rev F1 or later hardware. |
RSS Feed
Copyright © 2015-2019