Getting time on the James Webb Space Telescope (JWST) is the dream of many astronomers. The most powerful space telescope currently in our arsenal, the JWST has been in operation for almost four years at this point, after a long and tumultuous development time. Now, going into its fifth year of operation, the Space Telescope Science Institute (STScI), the organization that operates the science and mission operations centers for the JWST has received its highest number ever of submission for observational programs. Now a team of volunteer judges and the institute's scientists just have to pick which ones will actually get telescope time.
STScI received 2,900 individual proposals for observations for its fifth observing year. That’s up from a total of 2,377 last year, and is the highest on record, which has been increasing every year since the first cycle, which had only 1,173 proposals. As astronomers become more familiar with JWST’s capabilities, they seem to come up with even more ideas about how to use it.
It isn’t just astronomers that have submitted proposals in prior years either. According to a press release from STScI, the number of unique scientists that took the lead on submitted proposals this year grew by 17%, showcasing how new entrants are becoming involved in JWST’s ongoing exploration program.
Fraser discusses JWST's discoveries in its second year.Part of that might be due to some of the new features of this observational round. This year STScI introduced the Long-Term Monitoring Initiative, which allows for longer observational studies over multiple observing cycles - so a scientist could ask for some time in several of the next upcoming rounds of observations, including into JWST’s expected “extended life”. In fact, this observational cycle is due to mark the end of the “minimum” designed life of the JWST, though engineers currently expect that, due to an unexpectedly low fuel consumption getting to its L2 orbital point, the telescope could be in operation for 20 years or more.
Even with that extended life, it seems unlikely to be able to support all of the proposals flooding into it on a daily basis. Annually, the JWST has about 8,000 hours to allocate to scientific programs - the rest of the hours in a year are reserved for upkeep and maintenance tasks. Since each of the 2,900 proposals likely requires multiple hours of observational time, there’s no way to get to them all in a year. STScI expects that only about 8% of the proposals will be accepted.
Complicating matters further, several dozen proposals require input from other observatories, such as Hubble, ALMA, and even an early version of the Nancy Grace Roman telescope. Since the science is for these is only partially valuable if they don’t receive observational time on the other observatories as well, STScI’s proposal reviewers need to coordinate with the mission planners for those other telescopes as well - at least one of which (Hubble) is also operated by STScI.
*Pie chart of the submissions to JWST's 5th observing cycle by scientific category. Credit - STScI*
Many of those reviewers are part of an army of 550 volunteer reviewers known as the Telescope Allocation Committee. They review proposals on a “double blind” basis, meaning that they don’t know who the proposal is from, and the scientists that submitted the proposals also don’t know who was responsible for reviewing it. Hopefully that eliminates much of the bias, but experience with review processes shows that well-informed reviewers that are tied into their field will be able to recognize proposals from certain research groups given their penchants for studying specific topics.
Such double-blind reviews are still the best STScI can do, and it has been successfully managing JWST for years at this point. Selections for Cycle 5 of its observations will be announced in March, with the campaign set to begin in July. With hopefully 16 more years of operational life ahead of it, and an ever-increasing number of proposed uses for it, JWST’s future is looking bright.
Learn More:
STScI - Researchers Submit Record Number of Ambitious Proposals for Webb's Fifth Year of Science
UT - JWST Cycle 4 Spotlight, Part 1: Exoplanets and Habitability
UT - JWST Cycle 4 Spotlight, Part 5: Solar System Astronomy
UT - The Exoplanet TRAPPIST-1 e Takes Its Turn In The JWST's Spotlight
