There Was a Major Unexpected Benefit to James Webb's Christmas Launch

 

Real-time footage showing the separation of JWST from the Ariane 5 launch vehicle. (ESA)

NASA found that the James Webb Space Telescope should have enough propellant to function in space for substantially longer than 10 years after a careful review of where it is today (December 29, 2021) and how it got there.

Webb's mission was expected to last at least 5-1/2 years, with mission engineers and scientists hoping for closer to ten.

The "significantly more than 10 years" announced this week is due to two factors: the precision of the Ariane 5 launch on December 25, which experts say exceeded the requirements needed to put Webb on the right track; and the precision of the Ariane 5 launch on December 25, which experts say exceeded the requirements needed to put Webb on the right track.

And today, because JWST's trajectory is so accurate, the first two mid-course correction man oeuvres used far less fuel than planned.

The first course correction occurred about 12.5 hours after launch, with a 65-minute burn. While 65 minutes may appear to be a long time, a 3 hour burn could have been required.

The initial fire set the observatory on an even more exact path and increased its speed by around 45 mph (20 meters/sec). On December 27, a second, shorter corrective manoeuvre increased the speed by around 6.3 mph (2.8 meters/sec).

The amount of fuel necessary to travel to L2 and maintain its orbit, as well as the possibility that Webb's components will decay over time in the harsh environment of space, limit JWST's lifetime.

Because of the precise trajectory the observatory is now on, it will require more propellant in the future for orbit maintenance and momentum control, resulting in a longer operational lifetime.

Which also means more science!

Illustration showing Lagrange point 2. (NASA)

In a blogpost detailing the course correction manoeuvres, Randy Kimble, JWSTIntegration, Test, and Commissioning Project Scientist at NASA Goddard, wrote, "The largest and most important mid-course correction (MCC), designated MCC-1a, has already been successfully executed as planned, beginning 12.5 hours after launch."

"We chose this time because the earlier the course correction is accomplished, the less propellant is needed."

What are the Lagrange points and why is JWST going there?

I made this digestible breakdown: hope it's useful for someone out here on Twitter! 1/6#Physics #SpaceExploration pic.twitter.com/MTpCxnH62T

— Marie-Liis with double “i” (@bymarieliis) December 27, 2021

The first pieces of the tennis-court-sized sunshields have been successfully deployed, according to Webb.

The forward and aft sunshield pallets were unfolded on December 28. The Deployable Tower Assembly, a six-hour procedure controlled remotely from the Operations Center, has also been extended. This tower separates the spacecraft from the telescope, allowing the sunshield to be deployed. Once everything is in place, this area will aid in keeping the telescope cool.

The release of the sunshield coverings, the expansion of the mid-booms, and ultimately the tensioning of the sunshield's five Kapton layers will be the next steps.

An animation of JWST deploying its sunshield covers. (NASA)

This will happen over the course of the next few days. The mission operations team included flexibility into the planned timeframe because the deployment of the sunshield is one of the most demanding spacecraft deployments NASA teams have ever undertaken, NASA notes, so the timing and even sequence of the next steps could vary in the coming days.

New facts are being uploaded to the "Where is Webb" website, where you can get all kinds of information about the observatory, according to NASA. The temperatures of the spaceship may now be monitored.

Due to being heated on one side and chilly on the other, Webb will have two separate temperatures. Webb's mirrors must remain extremely cold to study faint heat signals in the universe, therefore the sunshield will always face the Sun to filter off heat and light.

You’re hot and you’re cold… 🎵#NASAWebb is split into a “hot side” and “cold side” by its sunshield. The sunshield will always be facing the Sun to block out heat and light, as Webb's mirrors need to stay extremely cold to observe faint heat signals in the universe! pic.twitter.com/GciNPo04nr

— NASA Webb Telescope (@NASAWebb) December 29, 2021

Parts of Webb will reach temperatures of 85 degrees Celsius, or 185 degrees Fahrenheit, on the hot side. Webb will be around -233 degrees Celsius, or -388 degrees Fahrenheit, on the cold side.

Temperatures will fluctuate as Webb unfolds, then cool down to operating temperatures over the next several months, according to NASA.

This article was originally published by Universe Today. Read the original article.