Thanks for your work on this!Why "the first digital satellite in the world"?
Quote from: Oersted on 02/02/2022 08:19 pmThanks for your work on this!Why "the first digital satellite in the world"?Indeed, it would be great to learn more about the background of that statement. Hope to hear from the experts. Based on what I read, it seems to go back to two points (1) the Philips Technical Review, VOLUME34,1974,No.1, article about the on-board computer system says"At the beginning of the project none of the existing aerospace computers met this combination of requirements"(2) The on-board computer was reprogrammable on-the-fly. Core storage, 4k, not tape. That capability was used to compensate for the wrong orbit insertion and to update observational targets.
Looking forward to it. The trailer is not available here in the USA though. It says "video does not exist".As background, when I did my first internship in the mid 80s at Philips Research (NatLab), the team I worked with worked out of a smaller Philips lab in Geldrop. As a space enthusiast, I was fascinated by the model of the ANS satellite. Seemed like a big chunk of ANS was done at the NatLab/PCG Geldrop though I have no details on the project as it was decade before my time. On these few pages, there is a photo on page 1 that looks like how I remember the model at the ceiling. PS: Wouldn't this be better in the "Historical spaceflight" Section?
Quote from: leovinus on 02/02/2022 01:26 pmLooking forward to it. The trailer is not available here in the USA though. It says "video does not exist".As background, when I did my first internship in the mid 80s at Philips Research (NatLab), the team I worked with worked out of a smaller Philips lab in Geldrop. As a space enthusiast, I was fascinated by the model of the ANS satellite. Seemed like a big chunk of ANS was done at the NatLab/PCG Geldrop though I have no details on the project as it was decade before my time. On these few pages, there is a photo on page 1 that looks like how I remember the model at the ceiling. PS: Wouldn't this be better in the "Historical spaceflight" Section?Emphasis mine.Yeah...the document in that link contains an image that we shot back in 2006. "WE" being the Nationaal Ruimtevaart Museum (NRM), situated in the Aviodrome aerospace museum in Lelystad, the Netherlands. We've had the ANS backup flight model mounted from the ceiling of the Aviodrome since 2004. In 2006 NRM shot a few images to enhance the Wikipedia page on ANS. NRM released the original image to the public domain and it has been popping up here-and-there on the internet ever since.That particular image and a few more below:
Indeed the ANS was the first satellite with a re-programmable digital coomputer on board that did the housekeeping as well as the data gathering of the scientific experiments and transmitting them to Earth. There wasn't a satellite in 1974 (when ANS was launched) that had the same capabilities. NASA still used tape for data storage. This is something the film also elaborates on a little more. Philips was really proud of this computer. NASA predicted that, given the requirements the Dutch needed for this computer it would weigh 22 kilograms and would use about 100 watt. But there only was 8 kilo and 8 watt available, so NASA said it couldn't be done. But Philips built it anyway and the end product weighed 7.9 kilo and used 8 watt. And it worked perfectly.The only glitches there were during ANS' lifetime were from ground-based equipment. And of course the faulty orbit caused by the Scout launcher.
Quote from: woods170 on 02/03/2022 03:03 pmQuote from: leovinus on 02/02/2022 01:26 pmLooking forward to it. The trailer is not available here in the USA though. It says "video does not exist".As background, when I did my first internship in the mid 80s at Philips Research (NatLab), the team I worked with worked out of a smaller Philips lab in Geldrop. As a space enthusiast, I was fascinated by the model of the ANS satellite. Seemed like a big chunk of ANS was done at the NatLab/PCG Geldrop though I have no details on the project as it was decade before my time. On these few pages, there is a photo on page 1 that looks like how I remember the model at the ceiling. PS: Wouldn't this be better in the "Historical spaceflight" Section?Emphasis mine.Yeah...the document in that link contains an image that we shot back in 2006. "WE" being the Nationaal Ruimtevaart Museum (NRM), situated in the Aviodrome aerospace museum in Lelystad, the Netherlands. We've had the ANS backup flight model mounted from the ceiling of the Aviodrome since 2004. In 2006 NRM shot a few images to enhance the Wikipedia page on ANS. NRM released the original image to the public domain and it has been popping up here-and-there on the internet ever since.That particular image and a few more below:Thanks for sharing. One clarification question please. I read somewhere about a "spare" for ANS. Is that the same as what you call "backup flight model" at NRM in Lelystad? And therefore, what was on exhibit at PCG Geldrop in the 80s was also the spare ANS (and not some other model) ? Thanks.
Quote from: leovinus on 02/02/2022 08:51 pmQuote from: Oersted on 02/02/2022 08:19 pmThanks for your work on this!Why "the first digital satellite in the world"?Indeed, it would be great to learn more about the background of that statement. Hope to hear from the experts. Based on what I read, it seems to go back to two points (1) the Philips Technical Review, VOLUME34,1974,No.1, article about the on-board computer system says"At the beginning of the project none of the existing aerospace computers met this combination of requirements"(2) The on-board computer was reprogrammable on-the-fly. Core storage, 4k, not tape. That capability was used to compensate for the wrong orbit insertion and to update observational targets. Emphasis mine.The ANS OBC was carefully programmed with an initial observation programs to be run after launch. However, the Scout launch vehicle screwed up targeting during first stage boost phase. Second, third and fourth stages of Scout were all 'dumb' and just carried out their original programmed flights. The primary result was ANS ending up in a wrong orbit. The secondary result was that the original observation programs in the OBC became useless. Instead of a nice circular sun-synchronous orbit, ANS ended up in a highly elliptical syn-synchronous orbit. Parts of the orbit came dangerously close to the Van Allen belt.However, due to having a re-programmable OBC the ANS mission was saved. The entire core logic behind the observation program was rewritten in just a few days, allowing the satellite to largely shut down upon dipping into the Van Allen belts, as well as the SAA. By executing the majority of the observation while in the ascending and descending parts of the orbit, it was possible to execute almost 90% of the previously planned observation program.Philips' brilliant OBC saved the mission that otherwise would have to be reflown using the spare ANS flight model.
[snip]Some background information about the film: The film is made in cooperation with the National Spaceflight Museum (NRM) in the Netherlands, where it will be shown at the exhibition floor, where a new display showcase has been created to display all the leftover artefacts of ANS (one of the test vehicles, instruments etc.).[snip]
Thanks for the extra and detailed enlightenment, Woods170! It's good to let people know what 'we' created back in the 1970s. (-:As an addition to what Woods wrote: The NRM now not only has the backup fight article, they also have the structural test article. Another one is located in the Uniberity Museum of Groningen, where they keep the thermal test article.@Leovinus: I cannot promise you anything, but it might be possible in the nearby future you will be able to see the film online on a pay-per-view channel of the film's producer, Stichting Beeldlijn. (They will ask just a very small charge.) IIRC, they are working on that right now. If that has been realised, I will surely mention it here. I'll also make sure there will be an English version available, because I think (hope..) there also will be some interest in the film across the border.