Английская Википедия:Ariane flight VA256

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Шаблон:Short description Шаблон:Use British English Шаблон:Use dmy dates Шаблон:Infobox rocket launch Ariane flight VA256 was an Ariane 5 rocket flight that launched the James Webb Space Telescope into space on 25 December 2021. It was 2021's final Ariane flight, its most valuable payload to date, and the Шаблон:Ordinal Ariane mission. The launch was described by NASA as "flawless" and "perfect".

Launch configuration

Rocket

Ariane 5 is a heavy lift two-stage rocket with two solid fuel boosters. It was used in its ECA variant, which offers the highest payload mass capacity. The total launch mass of the vehicle is of the order of Шаблон:Cvt.

Payload

The only payload on the flight was the James Webb Space Telescope (JWST), a NASA/ESA space-based observatory. The launch is one of the European Space Agency's contributions to the project. The telescope had a launch mass of about Шаблон:Cvt and a design lifetime of 5 to 10 years.

Preparation campaign

Arrival in Kourou

The payload arrived in Kourou, French Guiana, on Шаблон:Date where it was unloaded from the MN Colibri cargo ship and transported to the space centre.

Файл:The James Webb Space Telescope Unloaded from the MN Colibri (51584657771).jpg

Unloading from the MN Colibri

Integration incident

On Шаблон:Date an incident was reported by NASA and Arianespace that a clamp band securing the payload to the adapter was released during integration activities, causing vibrations to the telescope. After some tests were performed, a review board concluded on Шаблон:Date that no payload component was damaged, and fuelling operations could be started on the next day, with the launch planned for 22 December 2021 at that time.

Fuelling operations

Файл:JWST launch configuration.png

JWST in the Ariane rocket

Spacecraft fuelling operations began on Шаблон:Date, the fuelling system was disconnected on Шаблон:Date, and verifications were concluded on Шаблон:Date. The telescope's fuel system was filled with approximately Шаблон:Cvt of hydrazine and Шаблон:Cvt of dinitrogen tetroxide, needed to reach and maintain its orbit after separation from the launch vehicle.

Final assembly

Following the rocket, which had already arrived on Шаблон:Date, the telescope was moved to the final assembly building (Шаблон:Lang or BAF) on Шаблон:Date. The payload was encapsulated inside the fairing on top of the rocket on Шаблон:Date.

Interface communication issue

On Шаблон:Date, a joint press release by NASA and Arianespace revealed that "a communication issue between the observatory and the launch vehicle system" was being tackled, further delaying the launch to no earlier than Шаблон:Date.

Weather issue

Unfavorable weather forecasts for Шаблон:Date delayed the launch to Christmas Day, Шаблон:Date.

Файл:The James Webb Space Telescope in the Cleanroom at the Launch Site (51604442070).jpg

In the cleanroom

Launch

JWST and Ariane 5 Rollout

Ariane 5 and JWST at the ELA-3 launch pad

The rocket was launched from the ELA-3 launch pad of the Guiana Space Centre on 25 December 2021 at 12:20 UTC (09:20 local time, 7:20 am U.S. EST). The DDO (in French: Directeur des Opérations) of the launch was Jean-Luc Voyer, who concluded his shift by saying, "Go Webb!"

The launch was described by NASA as "flawless" and "perfect". A NASA systems engineer said “the efficiency or the accuracy with which Ariane put us on orbit and our accuracy and effectiveness in implementing our mid-course corrections” meant that there is “quite a bit of fuel margin ... roughly speaking, it’s around 20 years of propellant.”

Orbit

The James Webb Space Telescope was injected into a transfer trajectory that took it to the second Earth-Sun Lagrange point (LШаблон:Sub).

The separation of the launch vehicle second stage and the spacecraft occurred approximately 27 minutes after liftoff. The second stage downloaded video, the last known time the telescope will be seen, of the separation and initial deployment of the solar panels. After this separation, the telescope became autonomous and began its deployment sequence. About 29 days after liftoff, it executed a maneuver placing it into a halo orbit around the LШаблон:Sub point, where it can perform its science mission. Its next five months were spent on cooling NIRCam and the Mid-Infrared Instrument down further, calibrating its mirrors while focusing on HD 84406, a bright star in the constellation Ursa Major, and testing the instruments.

See also

• James Webb Space Telescope
• Timeline of the James Webb Space Telescope
• Launch and commissioning of the James Webb Space Telescope
• Ariane launches

External links

• James Webb Space Telescope detaches from Ariane 5 rocket
• Ariane flight VA256 at Arianespace