Scroll down to read this post.

 

I am now in the second week of my July fund-raising campaign for Behind the Black, celebrating its 14th anniversary. Thank you to everyone that donated so generously last week. I hope week two will do as well.

 

Your donations and subscriptions have allowed me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in the past two weeks has the mainstream media decided to recognize that basic fact.

 

Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Even today NASA and Congress refuses to recognize this reality.

 

In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.

 

Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.

 

Please consider supporting my work here at Behind the Black.

 

You can support me either by giving a one-time contribution or a regular subscription. There are five ways of doing so:

 

1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.

 

2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
 

3. A Paypal Donation:

4. A Paypal subscription:


5. Donate by check, payable to Robert Zimmerman and mailed to
 
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652

 

You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above. And if you buy the books through the ebookit links, I get a larger cut and I get it sooner.


Scientists release first image from Hubble in one-gyro mode

First Hubble image in one-gyro mode
Click for original image.

The Hubble science team today released the first image from the Hubble Space Telescope produced in its new one-gyro mode.

That image it so the right, cropped, reduced, and sharpened to post here, and shows NGC 1546, a nearby galaxy in the constellation Dorado about 52 million light years away. The inset shows at full resolution the small red galaxy near the top, to give some sense of the telescope’s capabilities in this one-gyro mode.

The details astonish me, and prove my pessimism about this new mode to have been wrong. I expected future images to be more fuzzy, with Hubble’s ability to take sharp images largely limited. The resolution here is excellent, and bodes well for future science observations.

Nonetheless, the telescope is still working under major limitations:

Although one-gyro mode is an excellent way to keep Hubble science operations going, it does have limitations, which include a small decrease in efficiency (roughly 12 percent) due to the added time required to slew and lock the telescope onto a science target.

As previously noted, prior to the use of the fine guidance sensors, fixed head star trackers position Hubble’s pointing closer to the target. If Earth or the moon block two of the fixed head star trackers’ fields of view, Hubble must move further along in its orbit until the star trackers can see the sky and its stars again. This process encroaches upon science observation time. Second, the additional time the fine guidance sensors take to further search for the guide stars adds to the total time the sensors use to complete the acquisition.

Third, in one-gyro mode Hubble has some restrictions on the science it can do. For example, Hubble cannot track moving objects that are closer to Earth than the orbit of Mars. Their motion is too fast to track without the full complement of gyros. Additionally, the reduced area of sky that Hubble can point to at any given time also reduces its flexibility to see transient events or targets of opportunity like an exploding star or an impact on Jupiter.

When combined, these factors may yield a decrease in productivity of roughly 20 to 25 percent from the typical observing program conducted in the past using all three gyros.

It really is time for the astronomical community to get its act together and begin work on developing and launching more large optical telescopes into space. Hubble has shown us the potential of in-space optical astronomy. That astronomers have not flocked in the last three decades to build more such telescopes is puzzling beyond belief.

Genesis cover

On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.

 

The print edition can be purchased at Amazon. Or you can buy it directly from the author and get an autographed copy.

 
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.


The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
 

"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News

7 comments

  • Clark

    I agree that the astronomical community needs to push harder to get more optical telescopes aloft (or at the very least, lobby more vocally to repair/refurbish Hubble). It seems, though, that with the advances made in adaptive optics, the momentum is very much behind the construction of large ground telescopes high up in places like the Andes mountains, perhaps for reasons of (less) cost and bureaucracy… neither of which applies to places like Hawaii, unfortunately.

    As goes the rest of the space industry, I have little doubt that it will be left to private endeavors to get the next generation of optical telescopes into space. Perhaps that is for the best?

  • Mike Borgelt

    Starship should be able to launch a nearly 9 meter single mirror telescope, larger if segmented. Then SELL access.

  • Chris

    Ok, I have seen this story on Hubble’s gyros going out for some time.
    This situation makes me ask several questions:

    Can’t a platform or “box” with three a priori aligned (X-Y-Z) gyros be simply attached to the Hubble spacecraft and then powered and have the alignment calibrate by a star calculation?

    Can’t these gyros be ring-laser-gyros that have no moving parts and lower power consumption? Is there some limitation with them that I’m unaware of? They have been around since before the Hubble launch I beleive.

  • wayne

    This is extremely informative….

    Scott Manley (June 14, 2024)
    Hubble’s Gyros
    https://youtu.be/Ra2IpumLMfs
    15:19

  • wayne

    Chris-
    definitely watch the Scott Manley video.

    in brief;
    -orientation sensing:
    Gyroscopes– the matter at hand.
    Sun-sensors- prevents telescope from accidentally pointing at the Sun
    Magnetometers- detects telescope orientation to Earth’s magnetic field.
    3 fixed head star-trackers for ‘gross’ orientation.
    Fine guidance star-trackers in instrument bay, viewing through the main mirror.

    attitude control hardware:
    Reaction wheels- conservation of angular momentum.
    Magnetorquers- removes excess angular momentum.

  • Chris:

    There were two limitations on ring-laser gyros. They were not sufficiently accurate, and had a mean-time-between-failure significantly shorter than the gas-bearing gyroscopes chosen.

  • Steven Carleton

    Maybe stunning images and break-through science from the PRC’s orbiting optical telescope will put NASA in the hot sight., Just read they refused a privately-funded mission to repair it – huh?
    https://www.space.com/china-space-telescope-xuntian

Readers: the rules for commenting!

 

No registration is required. I welcome all opinions, even those that strongly criticize my commentary.

 

However, name-calling and obscenities will not be tolerated. First time offenders who are new to the site will be warned. Second time offenders or first time offenders who have been here awhile will be suspended for a week. After that, I will ban you. Period.

 

Note also that first time commenters as well as any comment with more than one link will be placed in moderation for my approval. Be patient, I will get to it.

Leave a Reply

Your email address will not be published. Required fields are marked *