Vega flight VV15
{{short description|Space launch}}
{{Use British English|date=June 2020}}
{{Use dmy dates|date=July 2019}}
{{Infobox rocket launch
| name = Vega flight VV15
| image = Vega flight VV15.jpg
| upright = 1.2
| alt = A Vega launch vehicle and the FalconEye1 satellite depicted in front of an outline of a profile of a falcon
| caption = Artwork featured on visitors' brochures
| rocket = Vega
| launch = 11 July 2019, 01:53:03 UTC
| operator = Arianespace
| pad = Centre Spatial Guyanais, ELV
| payload = FalconEye1
| outcome = Failure
| succession = Vega launches
| previous = VV14
| next = VV16
}}
Vega flight VV15 was the {{ordinal|15}} flight of the Vega launcher, and its first failure.
Payload
The flight, with a total payload mass of about {{cvt|1279|kg}}, was a single-payload mission that should have deployed the FalconEye1 satellite into orbit.
= FalconEye1 =
FalconEye1, a high resolution Earth observation satellite built by Airbus Defence and Space and Thales Alenia Space, for the United Arab Emirates Armed Forces (UAEAF), had a lift-off mass of approximately {{cvt|1197|kg}}, and was the only satellite on board the flight.
Mission description
= Launch date =
= Planned orbit =
File:Arianespace - VV15 - Mission Presentaton.webm
The mission was planned to last 57 minutes and 09 seconds from lift-off until separation, placing its payload into a quasi-circular Sun-synchronous target orbit with a mean altitude of about {{cvt|611|km}}.
= Launch log =
It was the {{Ordinal|311}} Arianespace mission (the sixth in 2019), and the {{Ordinal|15}} Vega launch (the {{Ordinal|2}} in 2019).
FalconEye1 was Airbus Defence and Space's {{Ordinal|131}} and Thales Alenia Space {{Ordinal|159}} spacecraft to be launched by Arianespace.
Failure
= Initial statements =
Only 9 minutes after liftoff, a first statement was read by Luce Fabreguettes, Arianespace's executive vice-president for missions, operations and purchasing, indicating that "[...] about 2 minutes after liftoff, around the Zefiro 23 (Z23) ignition, a major anomaly occurred, resulting in the loss of the mission. [...] From the first flight data analysis we will get in the coming hours more precise information, and we will communicate to everybody at the soonest. [...]".
Arianespace later repeated in a press release that "approximately two minutes after the Vega launcher’s liftoff, shortly after ignition of the second stage (Z23), a launcher anomaly occurred – leading to the premature end of the mission".
Avio also published the same press release and also a video by their CEO confirming the event: "Approximately two minutes after the Vega launcher’s liftoff, shortly after ignition of the second stage, a launcher anomaly occurred – leading to the premature end of the mission", and "At present, the cause of the anomaly is still unknown and is under investigation".
= Inquiry commission =
On the day of the incident, Arianespace and ESA announced that an inquiry commission would be appointed to investigate the causes of the failure and to produce recommendations allowing the Vega launcher to resume safe operations. It has been co-chaired by ESA's inspector general, Toni Tolker-Nielsen, and Arianespace's chief technical officer, Roland Lagier, and also included representatives from CNES and Avio.
On 4 September 2019, the inquiry commission submitted its findings, that were released the next day on 5 September 2019. In particular, a structural failure on the second stage's forward dome area resulting from higher temperatures was identified as the most probable cause of the failure:
:"The Commission identified as the most likely cause of the anomaly a thermo-structural failure in the forward dome area of the Z23 motor. Other possible causes such as inadvertent activation of the Z23 neutralization system have been found unlikely".
On 6 December 2019, Avio released its further findings, revealing that a thermal protection design flaw on the second stage's forward dome area was the root cause of this launch failure that allowed a hot gas leaking into the critical structural part of the forward dome area. Avio engineers were able to replicate the same failure mode with this launch failure. The issue was addressed though adding more thermal protection and taking other measures.{{Cite web|last=Berger|first=Eric|date=2020-06-17|title=An Italian-made rocket faces a big test on Thursday night |url=https://arstechnica.com/science/2020/06/an-italian-made-rocket-faces-a-big-test-on-thursday-night/|access-date=2020-06-18|website=Ars Technica}}
= Aftermath =
A set of corrective actions will be implemented by the rocket manufacturer to fix and reinforce the suspected part to prevent the repeat of the failure. Arianespace expected to resume Vega flight by late March 2020, almost nine months of hiatus. The maiden flight of upgraded Vega C would be in the second quarter of 2020.
But the return-to-flight was delayed several times. In June 2020, after being delayed from March 2020 due to COVID-19 pandemic, the launch was delayed again to mid-August 2020 due to unfavorable weather conditions and the need to recharge the satellites' batteries as the launch window in June had exhausted, making another launch campaign in the Guiana Space Centre, Ariane flight VA253, preceded this return-to-flight. Delayed again to 1 and then 2 September due to range conflict with delayed launch of VA253 resulting from a sensor problem on the Ariane 5 rocket. Delayed again by 24 hours due to Typhoon Maysak approaching the Jeju tracking station that was intended to acquire the rocket's telemetry. Finally, the return-to-flight was performed successfully on 3 September 2020 at the instantaneous launch window at 01:51:10 UTC, almost 14 months of hiatus.{{cite news |last1=Gray |first1=Tyler |title=Vega Returns to Flight with Rideshare Mission |url=https://www.nasaspaceflight.com/2020/09/arianespaces-vega-rtf-small-satellite-rideshare/ |access-date=3 September 2020 |work=NASASpaceFlight.com |agency=NASASpaceFlight.com |publisher=NASASpaceFlight.com |date=1 September 2020}} As a result, from the long delay, the maiden flight of upgraded Vega C would be the first half of 2021.
UAE Armed Forces announced the cancellation of subsequent FalconEye 2 satellite to be launched on a Vega rocket and ordered Arianespace to switch to a more expensive Soyuz rocket.
The failed launch of Falcon Eye 1 led to the highest recorded amount for a single insurance claim in history ($415 million) for a satellite launch failure.{{cite web|title=Satellite Insurance Rates Increasing After Failures of Vega, WorldView-4|url=http://www.parabolicarc.com/2019/08/01/satellite-insurance-rates-increasing-after-failures-of-vega-worldview-4/}}
References
{{Portal|Spaceflight}}
|publisher=Arianespace|access-date=11 July 2019}}
{{cite web|title=New updates about Vega Flight in 2020| website=YouTube | date=6 December 2019 |url=https://www.youtube.com/watch?v=iR6AuT0mcH4|language=en}}
External links
{{Commons category|Vega flight VV15}}
- [https://web.archive.org/web/20190629135831/http://www.arianespace.com/mission/vega-flight-vv15/ Vega Flight VV15] at Arianespace (Archived 29 June 2019)
{{Arianespace launches}}
Category:2019 in French Guiana