Astra’s comeback with mission for Spaceflight Incorporation Satellites
Rocket 3.3, the first Astra rocket to successfully launch to orbit, has successfully launched deployed Spaceflight Inc., satellites just over one month after ELaNa-41 failed during fairing and stage separation. The launch took place on Tuesday, March 15.
This mission for Spaceflight Inc., designated Astra-1, used the LV0009 vehicle lifted off from Launch Pad-3B at the Pacific Spaceport Complex in Kodiak, Alaska, which was where all of Astra’s test flights, including the successful orbital launch of LV0007, had occurred. Kodiak is the first of two active Astra launch sites, alongside Cape Canaveral which hosted the flight of LV0008 in February.
LV0009 launched along a southerly trajectory toward a Sun Synchronous orbit inclined 97.5 degrees to the equator at an altitude of 525 kilometers. Three minutes after liftoff, the first stage’s five kerosene and liquid oxygen-fueled Delphin engines, fed by electric pumps and with a thrust of 6500 lbs each, cut off, and the all-important fairing separation commenced.
Failure Analysis of ELaNa-41 Flight Hardware:
On the ELaNa-41 mission Astra’s LV0008 rocket experienced a bad signal in its flight hardware. The flight went as planned until this critical step. An error in a wiring diagram caused two wiring harness channels to be swapped in an incorrect order. Due to this error, the separation devices fired incorrectly causing an electrical disconnect. This disconnect prevented the last separation device from receiving its command to fire, so the fairing was not able to separate correctly. After the second stage ignited and finally separated from the first stage, a second issue, one with the flight control software on the upper stage, doomed the ELaNa-41 mission.
Missed signals started a chain of events that resulted in a “packet loss,” the loss of packets of data that prevented the flight control software from controlling the stage’s motions with its thrust vector control (TVC) system that controls the stage’s engine nozzle.
Astra Team was able to replicate both of these failures the resulting investigation. The fairing separation failure was replicated with hardware on the factory floor being built for upcoming flights, while the software failure was replicated with a hardware-in-the-loop simulator.
The flight hardware on the Astra-1 mission and subsequent flights has been fixed to prevent the fairing failure mode seen on ELaNa-41, while the software has been given three modifications to reduce the possibility of packet loss. Astra is confident that the issues LV0008 encountered will not recur.
Once LV0009’s fairing separation sequence was completed, the second stage separated and ignited its single pressure-fed Aether engine with 740 lbs of thrust. This engine, also using kerosene and liquid oxygen, is equipped with a large vacuum-optimized nozzle, and will fire from T+3:15 to T+8:40. Ten seconds after second engine cutoff, the payload deployment sequence was to start.
However, Astra was not able to immediately confirm the intended payloads had separated, noting the vehicle being far downrange as expected from tracking stations. Once the satellites returned within range of ground tracking stations, payload separation and mission success was confirmed.
Payloads for three different customers, all managed by Spaceflight Inc., will be carried on this flight. These include NearSpace Launch’s experimental S4 Crossover payload platform and the Portland State Aerospace Society’s OreSat0, the first satellite built by the state of Oregon. OreSat0 was originally scheduled to launch on the SpaceX Transporter-3 mission.
S4 Crossover is a prototype host platform that includes a Globalstar transmitter and an Iridium transceiver, along with environmental instruments to measure radiation and plasma densities that future payloads the platform might carry can be exposed to. The host platform will be powered by fixed solar panels mounted to the structure. So LV0009 was the second successful orbital attempt for Astra. Next up on the company’s manifest is three flights from Cape Canaveral in support of NASA’s TROPICS mission.
