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HST @ STScI Update

Rachel Osten (osten[at]stsci.edu)

Abstract

This Newsletter article summarizes recent Hubble happenings. Changes to how research grant funds are distributed will reduce the amount of obligated but unspent funds. Single-cycle grants will be limited to three years plus one possible no-cost extension. The number of no-cost extensions to grants will be limited. The Phase Ⅱ budget and proposal deadline will be strictly enforced in Cycle 26 and future cycles. Phase Ⅰ observing proposal requests for instruments subject to health and safety issues must describe observations in sufficient detail to demonstrate safety.  All visit-level and most exposure-level observing restrictions must now be specified in the Phase Ⅰ proposal. A special session at the 231st AAS meeting highlighted the scientific results enabled by Hubble's UV Initiative. Overall, the observatory and its instruments are healthy and operating nominally. Note that one of the solid-state recorders on Hubble experienced increased errors however, leading to a change in how it is being used. Gyroscope #2 displays large changes in its bias levels, leading to increased jitter while very recently Gyroscope #1 suffered an unrecoverable error.

A key component of the success of Hubble has been robust support of approved observing programs through grants to support data reduction, analysis and publication of scientific results. The rate at which grants are being spent in the last several years has been significantly lower than the rate at which funds are distributed to grantee institutions. This discrepancy accounts for a large amount of unspent funds on the Hubble grants program. Starting in October 2017, the Institute's Grants Administration office changed the funding allocation schedule for Hubble grants in order to reduce the pool of funds that are obligated, but unspent (also known as uncosted carryover). The total amount of committed funding has not changed.

The new process makes changes to the timing over which funds are dispersed. The percentage of the approved grant amount determines the amount of funding, as before. Future allotments will still be done in increments; however, it will be based upon invoicing and payments, rather than a pre-established schedule. Additional allotments of funding can always be made available upon request, and generally within one business day. The increments are based on the total amount of the award; see Table 1 for a summary. These changes will provide institutions with immediate access to funding through automatic funding releases. If no expenditures are reported within the first nine months of the award, a notice will be sent to the grantee. Should no expenditures be reported within the first twelve months, the available funding will be reduced by 50%. The grant award amount is not affected; only the funding available at the next increment. This applies to all new grant awards. Funding for existing awards will follow the schedule laid out in the most recent applicable grant award or amendment document.

Summary of Changes to Grant Availability
Approved Amount Available at Award Available at 90% Expended
Up to $30,000 100% Up to$50,000 50% 50%
Greater than \$50,000 20% 20% in equal increments

In addition, the number of no-cost extensions will be limited to one. The initial period of performance for an award is three years. A request with justification to extend the performance for up to 12 months will generally be approved. No subsequent extension requests will be accepted.

More detailed information regarding changes to the funding allocation process is available at the STScI Grants Administration website (http://www.stsci.edu/institute/grants).

These changes are necessary for the Hubble grants program to remain healthy and efficient.

Detailed visit- and exposure-level specifications have generally been specified at the time of the Phase Ⅱ proposal deadline.  A new change for Cycle 26 is the prerequisite that all special requirements placed at the visit level and most at the exposure level need to be stated explicitly in the Phase Ⅰ observing proposal with a brief justification.  Visit-level special restrictions include orientation requirements, guiding, timing requirements, conditional requirements, and special observation requirements. Exposure-level special requirements are those pertaining to target acquisition, target position, timing, special observations, implementation requirements, and special communications.

These additions are described in the Cycle 26 Call for Proposals.

The preparation of the Phase Ⅰ observing proposal request involves motivation of the science and description of the proposed observations.  Observers proposing to use instruments with health and safety concerns are required to include information in their description of observations that establishes the safety of the measurements. These must now be included in the Phase Ⅰ observing proposal. Programs that do not contain this information may be subject to cancellation.

AAS special session: Astrophysics enabled by Hubble's Ultraviolet Initiative

Observations with the Hubble Space Telescope open up a window on ultraviolet (UV) wavelengths which enables astrophysics that would not be possible otherwise. The Ultraviolet Astrophysics Legacy Initiative, in place since Cycle 21, recognizes the unique resource that Hubble has in its access to the UV portion of the electromagnetic spectrum and encourages proposals for this finite limited resource. The 231st meeting of the American Astronomical Society, which took place at National Harbor in January 2018, featured a special session entitled "Science Enabled by Hubble's Ultraviolet Initiative." The session highlighted some of the programs undertaken as part of the UV initiative covering the breadth of science done with UV observations. The invited talks set the landscape for future science at these wavelengths, and presented the key role UV observations will have in interpreting results from future missions like the James Webb Space Telescope. The speakers and their talk titles are listed below. A webcast of their presentations is available at this location (HST Special AAS 231).

Jelle Kaastra (SRON Netherlands Institute for Space Research); Deciphering AGN Outflows with Joint UV and Xray Observations

Daniela Calzetti (University of Massachusetts Amherst); Linking the Scales of Star Formation

Bill Sparks (STScI); Evidence of Plumes on Europa from FUV Observations with HST

Marc Rafelski (STScI); The Ultraviolet Hubble Ultra Deep Field

Jessica Werk (U. of Washington); Why Circumgalactic Matter Matters in Galaxy Evolution

Observatory status

Hubble's instruments continue to operate nominally, extending the scientific life of the observatory and enabling ground-breaking astrophysics.

Solid-State Recorder 3

In November 2017, Hubble's ground system began detecting increased errors when playing back science data received from the telescope. The errors originated on Solid-State Recorder 3 (SSR‑3), which was placed on the telescope in 1999. A tiger team formed to investigate possible causes reached a decision to use a different bus in one of the memory cards on SSR‑3 as a work-around.  There is no indication of any imminent failure of any parts.

Gyro 2

Gyroscope 2 (Gyro-2) on Hubble has been showing signs of aging with occasional large bias rate jumps and an increased level of jitter starting in the fall of 2017. The former has required periodic gyro scale corrections in order to ensure successful target acquisitions/re-acquisitions. These behaviors sometimes result in slightly extended acquisition times, delaying setting of the Take-Data flag and impacting a small number of science observations. Recent modifications to acquisition timing rules are expected to greatly reduce this problem without impact to target visibility times.

Jitter measurements with the Fine Guidance Sensors (FGSs) show a secular increase over the last year, with a marked uptick in the October 2017 timeframe. In addition to large bias rate drifts, Gyro-2 exhibits relatively high frequency noise (0.01 to 1 Hz), larger than any previous HST Gyro since Launch. This noise has resulted in increased boresight jitter by the FGSs and science instruments. Each science instrument team evaluated the jitter amplitude threshold above which science goals become compromised. The minimum range for science impact is 10-15 mas, depending on the instrument and the needs of the science programs. Currently no changes are being planned, but should the jitter increase beyond 15 mas, possible changes in the Gyro configuration may be implemented.

In the midst of careful scrutiny of Gyro-2’s behavior, Gyro-1 suffered an unrecoverable failure on the morning of Saturday, April 21. Its lifetime was consistent with those of other standard flex leads. This failure leaves a total of four working gyros on the observatory. Three of these are enhanced flex leads, which have an expected lifetime roughly five times longer than the standard ones. We do not want to retire Gyro-2 prematurely. The longer we use Gyro-2, the longer the observatory can use Three-Gyro Mode for science observations. The current plan is to remain in Three-Gyro Mode until a time when there are only two functional gyros, then drop to Reduced Gyro-Mode on a single gyro, with modest degradation in performance.