Predicting the Number of Hubble Proposals

By Julianne Dalcanton | November 17, 2009 7:06 pm

This is rather “inside baseball”, but back when Cycle 17 Hubble Space Telescope (HST) proposals were being written, I plotted up the number of proposals as a function of time until deadline. Right now, a signficant fraction of the astronomical community is involved in crafting “multicycle” proposals for the telescope. The idea is that there are probably useful projects that are sooooo time consuming that you couldn’t possibly do them through normal proposal channels.

Well, the race is on! Here’s the data on what I know of so far. We’re up to 8 proposals at 24 hours before the deadline. With the enormous sample of two, count ’em, two data points, we’re on the same curve as we were for Cycle 17 (plotted in black), but scaled down by a factor of 27. The blue line is extrapolating an exponential to the current rate of proposal submission. Both tracks argue for about 30 proposals going in. The scaling factor of 27 suggests that there will be an average of 27 people on each proposal, if Steinn’s argument that the number of proposals is set solely by the size of the community holds. The late-time development of this curve could be way off, however, because there is no way to put one of these together at the last minute. (On the other hand, the proposed experiments are so immensely complicated, that maybe the only way you get them done is waiting until the last minute).


I’ll update the plot if people give data in the comments! (Updated! I cut the blue exponential fit in the revised plot, as it was a lousy match.)

  • Olaf

    “Both tracks argue for about 30 proposals going in.”

    The exponential curve only argues for that if you assume that the cut-off time is at about t=0.2, same as for the other curve. It seems a bit of a stretch to call that an argument on the part of the exponential…

  • Brett Blacker

    I will be glad to show you the stats after the deadline. I publish this after every HST Deadline, both by days and hours and we usually run a contest here as well for our normal Cycle Deadlines.

  • Doug

    If the scaling law holds, wouldn’t it be more like 50-80 people per proposal? I would expect that for regular proposals the average number of proposers/proposal would be more than 1.

  • Kai Noeske

    Brett: Do you still sell HST shirts? I missed you last time I was at the Institute… does it make sense to harass you next time I come down? Thanks!

  • Julianne

    Thanks Brett!

    (For those of you not deep into all things HST, Brett is the dude who handles all the proposal intake. He is the man.)

  • Doug

    Little over 3 hours to go, and we were submission 1022 – I’m assuming this makes it the 22nd proposal? That puts it pretty close to the dashed line if so.

  • Brian

    at 4:45 PM EST, proposal number 24 (actually 1024, and 4:45 is actually when the confirmation email was sent from Brett) was submitted. FYI, new deadline is 8 PM EST

  • Tod R. Lauer

    27 @ 5:05P EST

  • Risa

    1023 @ 4:42 EST

  • Julianne

    1032 @ 6:57 EST.

    Seriously, I can’t believe there were that many groups able to pull this together.

  • Risa

    1038 @ 7:46 EST

  • Cusp

    We got ours in – 1016

  • Julianne

    Cusp — do you have a timestamp on Brett’s email? Could use a data point in there!

  • Ben

    @Doug – Average small HST proposals probably have several people on them, but are primarily written by one or two people. It is common for one person to be on several proposals, or even PI of more than one, because small proposals aren’t in direct conflict with each other.

    For these multi-cycle proposals, they will need to have a very broad science case, so that means a lot of people contributing at least a little bit. And the other issue is conflicts. All of the multi-cycle proposals are competing directly with each other since only about 2 to 4 can likely be scheduled. And some of them are in direct conflict, for example there will be several proposals for deep extragalactic imaging whose science cases overlap at least somewhat. There are some people who are in such high demand (like Risa) that they are on more than one proposal, and there are some who can do that without having a conflict of interest, but in general I bet that there is less overlap between proposal teams than there is during a normal proposal cycle.

  • NGC3314

    I hope the rest of you appreciate the fact that that GZ team decided, after lengthy discussion, not to submit a multicycle proposal. ( Brett – this is no way a hint about reviewing proposals, which some of us have done for 5 cycles already).

  • Julianne

    We do appreciate it! I’m guessing the numbers are so high because there are lots of previously rejected Treasury proposals that could easily be dusted off and expanded into MCTPs. It would be a tricky business, because if you’ve already submitted to the Treasury program, then you’ve kindof admitted that you _can_ do the project through a normal allocation. The MCTP call is pretty strict that they only want to see proposals that would never have been submittable in a typical Cycle. However, good science is good science, and the TAC may well be swayed. Plus, many Treasury programs are already compromises, so at a MCTP level, people can say what they _really_ wanted to do all along.

  • NGC3314

    It’s hard to believe that, in the first few cycles of review, 40 orbits was considered an outrageous total program size, and there were strenuous arguments about every orbit of some programs (well, the equivalent since allocations weren’t originally in orbits). In some ways, this is a sign that both the observatory and the community have been maturing. Or mellowing.

  • Steinn Sigurdsson

    Heh. My first successful Hubble proposal was for 99 orbits, because there was no way the TAC would agree to 100+ orbits for anything.
    The next successful proposal I was on broke the 100 orbit ceiling…

  • Brett Blacker

    We will be posting a few statistics on the Announcement page today. Just FYI, I guessed wrong myself, I was a little too high. As for HST shirts, we are in the process of taking orders hopefully in the next week or 2, so drop me an email and I will send you the link once it’s posted.

  • Julianne

    Brett — Steinn has long been wondering about the odds of acceptance vs proposal number. I can imagine all sorts of competing effects, and have no intuition for what might win out:

    Early submitters:

    Pro — (1) have their ducks in a row; (2) resubmitting a previously rejected proposal that has improved in response to comments; (3) TAC reads it when they’re fresh.

    Con — (1) may be less ambitious? (2) resubmitting a previously rejected proposal, that is unlikely to ever be compelling enough, no matter how frequently its revised; (3) TAC doesn’t yet have the full context for judging a proposal’s strength

    Late submitters: —

    Pro —

    (1) probably a larger fraction of ambitious proposals that take more time to put together; (2) TAC is increasingly grateful to find a proposal that they like, after wading through a large stack

    Con —

    (1) higher likelihood of being slapdash, last minute effort; (2) TAC is weary, and hates everything about everyone

    And on top of it all, one probably has to take out the secondary correlation of individual PI’s average success rate. There are some people or projects that are consistently well supported by the TAC, presumedly because they consistently present compelling proposals.

  • NGC3314

    I sense an assumption that reviewers read proposals in numerical order, which won’t always be so either in the solo preliminary reading or in the meeting discussions.

    My experience (going beyond HST) suggests an extra “pro” to late proposals, or at least proposals that one didn’t spend a great deal of time on – it’s easier to sound excited if you’ve had less time to think of all your own “con” factors!

  • Brian Siana

    It’s official.

    39 proposals ==> 26,801 orbits

    from the announcement page:

    “Thirty-nine proposals requesting a total of 26,801 orbits were submitted in response to the MCT Call. This represents an oversubscription of at least 12:1. The proposals are being distributed to the MCT TAC, who will meet in Baltimore in early January 2010. The results of their deliberations will be announced to the community by January 20th, and unsuccessful proposers will have the opportunity to recast their programs for HST Cycle 18 (Phase I deadline, February 26 2010).”

  • Brian Too

    Another abuse of statistics by people who should know better. Even acknowledging the pathetically tiny dataset and selection bias doesn’t make it right. I know this isn’t supposed to be terribly serious, but it speaks to a mindset that everything “must” fit that curve. I’ve seen the abuses too often to be cavalier about the matter.

  • Cusp

    Yeps – Sorry late (was traveling to Blighty)

    Date: Wed, 18 Nov 2009 18:45:23 -0500 [19/11/09 10:45:23 EST]

  • Ben

    I have now measured whether there is an effect of proposal order on acceptance rate, using Spitzer proposals (it’s not possible to do for HST from the public proposal numbers). The short answer is that there is generally not an effect, although one cycle was different for unknown reasons. See

    And yes, I was procrastinating.


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