NASA officials have acknowledged that the scheduled October launch of the James Webb Space Telescope (JWST) could be pushed back yet again, according to a report from the Government Accountability Office (GAO) released May 13. But this time, the issue isn’t with the telescope.
Instead, it's with the usually reliable, European-produced Ariane 5 rocket, which is slated to carry JWST aloft on October 31 from Kourou, French Guiana. “According to NASA project officials, the JWST launch date will likely be delayed beyond October 2021 due to anomalies discovered in the JWST launch vehicle,” says the report.
The issue lies with the Ariane 5's fairing, the nose cone that protects its payload as it accelerates up through the atmosphere. Once the vehicle reaches space, the fairing separates from the rocket in two pieces and falls away.
But in two recent launches, the rocket experienced “unexpected vehicle accelerations” during fairing separation, according to the GAO report. As a result, Ariane 5 launches have been postponed while the European Space Agency and Arianespace, the rocket's manufacturer, investigate the issue.
The bright side
The good news is that any potential delay may only be a matter of weeks, rather than months or years. The JWST launch will not go ahead until an Ariane 5 has flown and successfully demonstrated a fix to the issue, says the report. But there are two Ariane 5 launches — planned for June and August of 2021— ahead of JWST's scheduled October flight.
Although NASA has not officially announced any revision to JWST's current October 31 launch date, recent public comments reported by Space News indicate officials expect it will take roughly four months to prepare JWST after Ariane 5 is again approved for flight. So, if the June launch shows the fairing issue is resolved, JWST could be set to fly in November.