The ISRO is readying one of the two back-up navigation satellites — IRNSS-1H — to replace it in space in the second half of this year. IRNSS-1A was launched in July 2013 and has an expected lifespan of 10 years.
PSLV C39 carrying IRNSS-1H scheduled for late July or early August
"IRNSS-1H on board PSLV-C39 will be launched by the end of this month. The exact date will be decided shortly," a senior ISRO official told PTI.
"The satellite is ready to move from our centre to Sriharikota on August 12 on a special vehicle for integration with the rocket at the space centre," said Annadurai on the margins of a technology event.The launch authorization board will decide on the date and time after all the checks were completed during the window for the launch schedule.
CHENNAI: India will launch a backup navigation satellite this month end as a replacement for the IRNSS-1A satellite whose three atomic clocks have failed. Reliable sources say the launch is tentatively fixed for August 31 on board PSLV-C39.
“Four satellites are enough to deliver robust navigation services. Even if IRNSS-1A is taken off the NavIC constellation, six are still operational. As per the original plan, we have two spares ready for contingency measures. So, one of them is being flown out this month,” a senior official said.
The next mission, PSLV-C39 will launch IRNSS-1H navigation satellite, on August 31, 2017. IRNSS-1H will augment the existing seven satellites of NavIC constellation.
Launch now planned for August 31source
PSLV-C39/IRNSS-1H Mission is scheduled to be launched on Aug 31, 2017 at 18:59 Hrs from SDSC SHAR, SriharikotaQuoteThe next mission, PSLV-C39 will launch IRNSS-1H navigation satellite, on August 31, 2017. IRNSS-1H will augment the existing seven satellites of NavIC constellation.
Nellore: In view of the problems that plagued the atomic clocks "highly accurate clocks that measure time in terms of vibrations in certain atoms" in one of the seven satellites of Indian Regional Navigation Satellite System, Indian Space Research Organisation's Satellite Application Centre is working towards ensuring that the other six satellites are not similarly affected.
The firm which supplied the clocks has updated the three atomic clocks in IRNSS-1H, which is scheduled to be launched on August 31 aboard a PSLV rocket. This satellite will replace IRNSS-1A whose atomic clocks have stopped working. According to sources, the firm had studied anomalies in the clocks along with the Isro team and found some problem with electronics. An improved version of the clock has been developed eliminating the hitch, which will be launched with the IRNSS-1H.
He said a team of scientists in Satellite Application Centre had conducted several ground tests before installing the modified clocks. Isro engineers will be moving the PSLV-C39 with the IRNSS-1H on board to the Second Launch Pad from the Vehicle Assembly Building on Sunday. The mission will be launched after a series of tests at 6.59 pm on August 31, 2017 from Satish Dhwan Space Centre, SHAR, Sriharikota.
Isro has readied two more satellites as per original plan and one among them, IRNSS-1H, is being launched now". Asked about the snags with the atomic clocks, he said that every country had issues with navigational satellite systems at one time or the other.He said only one among the three atomic clocks would be put to use at any point of time henceforth in all the NaVIC satellites. According to the senior scientist, firms supplying critical equipment keep track of their functioning and update the technology for future missions. He added that the companies also provide replacement whenever necessary. He expressed confidence in the satisfactory functioning of the improved version of rubidium atomic clocks.
Mission Readiness Review (MRR) committee and Launch Authorisation Board (LAB) have cleared the 29hr countdown of PSLV-C39/ IRNSS-1H Satellite mission for Wednesday, Aug 30, 2017 starting at 14:00 hr IST, and the launch of PSLV-C39/IRNSS-1H Satellite mission for Thursday, Aug 31, 2017 at 19:00 hr IST.
Mission brochure is up!Link
The 29 hrs countdown operations of PSLV-C39/IRNSS-1H mission have started on Wednesday, Aug 30, 2017 at 14:00hr IST
Propellant filling operations of fourth stage (PS4) of PSLV-C39 are under progress
Today’s launch to start era of private sector role in satellite buildingSurendra Singh and Chethan Kumar | TNN | Updated: Aug 31, 2017, 03:15 ISTNEW DELHI/BENGALURU: The launch of India's eighth navigation satellite, IRNSS- 1H, on Thursday will open a new chapter in the country's history of space exploration as, for the first time, the private sector has been actively involved in assembling and testing of a satellite. Earlier, the private sector's role was limited only to supplying components.The 1,425-kg satellite is all set to start its voyage from the second launch pad of the Satish Dhawan Space Centre at Sriharikota, riding the Indian Space Research Organisation's trusted launch vehicle PSLV-XL.A consortium led by Bengaluru-based Alpha Design Technologies successfully completed 25% of the development work of IRNSS-1H, under the guidance of Isro scientists.Isro chairman A S Kiran Kumar told TOI, "For the first time, a private company has been involved in the integration of a satellite. Progressively, we will involve more and more companies in satellite assembly activities." Kiran Kumar said, "Subsystems of the payload and launch vehicle are already being developed in collaboration with the industry."
One of the webcasts:http://www.isro.gov.in/pslv-c39-irnss-1h-mission/live-webcast-of-pslv-c39-irnss-1h-mission-launch
Hmm......have the fairing halves separated at all?
T+13 minutes. Variation in performance.
The question is, will it attain a stable orbit? And even if it does, if the fairing doesn't separate, IRNSS-1H will go nowhere.
Webcast abruptly cut?
PSLV appears to have failed in its 38th mission. Bringing in the industry to do satellite manufacturing and assembly don't appear to have paid off. Indian industry let down ISRO.
Remember the Orbital launch that suffered a fairing sep failure with OCO?
Does anyone know if they use pyros or pushers (like SpaceX) for the fairing separation?
Quote from: soltasto on 08/31/2017 02:07 pmDoes anyone know if they use pyros or pushers (like SpaceX) for the fairing separation?Pyro Systems
The third stage was meant to get to the east Pacific off Chile. The underspeed means that won't happen - beon the lookout for reentry reports in Borneo or New Guinea.
Quote from: jcm on 08/31/2017 02:54 pmThe third stage was meant to get to the east Pacific off Chile. The underspeed means that won't happen - beon the lookout for reentry reports in Borneo or New Guinea.Has the fourth-stage+satellite combo been given a tracking number yet? Will it be visible? It's a fairly reflective (given that it's all white, and big) thing, no?
The ISRO chairman announced on podium that due to heat shield seperation failure , mission unsuccessful on DD national tv.
Like Sea Launch.... if it fails, kill the webcast.
Quote from: AJA on 08/31/2017 03:01 pmQuote from: jcm on 08/31/2017 02:54 pmThe third stage was meant to get to the east Pacific off Chile. The underspeed means that won't happen - beon the lookout for reentry reports in Borneo or New Guinea.Has the fourth-stage+satellite combo been given a tracking number yet? Will it be visible? It's a fairly reflective (given that it's all white, and big) thing, no?Not yet, but it will be 42927 (2017-051A)Remember it will low on the horizon for observers in temperate latitudes - apogee is 6500 km over the equatorbut I'm too lazy right now to caclulate how far north that remains visible...
With a 167 km perigee, won't this fall from orbit fairly soon? - Ed Kyle
Quote from: edkyle99 on 08/31/2017 03:08 pmWith a 167 km perigee, won't this fall from orbit fairly soon? - Ed KyleEventually, the fourth stage & IRNSS 1H will decay from orbit. Don't know when exactly.
Quote from: ZachS09 on 08/31/2017 04:12 pmQuote from: edkyle99 on 08/31/2017 03:08 pmWith a 167 km perigee, won't this fall from orbit fairly soon? - Ed KyleEventually, the fourth stage & IRNSS 1H will decay from orbit. Don't know when exactly.I'd of thought fairly rapidly in that orbit and being quite a large item.Matter of days?
It's a bit embarrassing that the announcer kept repeating that performance was normal/nominal even though we could see that the altitude and velocity graphs were diverging from their expected plots. It seemed like he was reading off a script rather than examining the data. And especially given that they should have known by that point (minutes before) that the fairing failed to separate.
Quote from: maint1234 on 08/31/2017 02:02 pmThe ISRO chairman announced on podium that due to heat shield seperation failure , mission unsuccessful on DD national tv.That wasn't the ISRO Chairman. That was the RCO (Range Control Officer).Acting as per the instructions of the ISRO Chairman of course.
The failure is of the rocket and the satellite built by the private consortium remains untested, scientists said.
Object A has been cataloged:2017-051A/42928 in 166 x 6556 km x 19.16°
Shouldn't there be an abort mode that can be remotely activated when MCC knows that it's a LOM so as to stop what is effectively space debris being thrown into a high orbit like this?
Crazy thought about re-entry I had:-This is an unusual "spacecraft" in that it has ~half of its mass unsecured inside, with around 1/3rd of the stack envelope to move about. The aerodynamic moldline will tend to point it forward when drag is strong. This will also push 1H to the front, increasing this attitude's stability.- Being encapsulated, 1H will have its 800 kg of propellants freeze pretty soon. - No active control is possible whatsoever (S4 burned to depletion, sat dead soon)- Depending on the fairing's failure mode, it could well be completely structurally intact (pyros not fired). - Being designed for large heating and aerodynamic stresses, it will protect the stack for at least some part of the reentry if left as it is.- Crazy part: how strong is this fairing? As far as I know it's aluminum, but has it been changed to carbon fiber? This would give it some strength to withstand some of the most stressful reentry phases. Presumably not all of it though (seams are metal and would give in, splitting it, for example). This would make a full-on "warhead-like" scenario implausible, I think.- However, we've seen instances of other unprotected, frozen fully-fueled sats being recognized as potentially dangerous. This one will presumably be at least somewhat protected. Fairing failure will concievably happen along the separation seam first, and free the sat with little chance of big blows against the downstream structures.Should somebody be worried about hydrazine snowballs reaching the surface? :\
Could they throw a few SM-3's at it USA-193 style?
Quote from: --- on 08/31/2017 01:58 pmPSLV appears to have failed in its 38th mission. Bringing in the industry to do satellite manufacturing and assembly don't appear to have paid off. Indian industry let down ISRO.What does industry doing *satellite* manufacturing and assembly have to do with the LV's payload fairing failing to separate?
Quote from: input~2 on 08/31/2017 04:00 pmObject A has been cataloged:2017-051A/42928 in 166 x 6556 km x 19.16°Odd, I wonder what 42927 is being reserved for?
Has this ever happened before in Space Age history?...Payload fairing fails to separate, and a combined package of upper stage, satellite, and PLF enter orbit?A loose satellite encased inside its PLF, in orbital free-fall--is that unique too?
There were several examples, when the fairing was not separated and the whole combination did not reach an orbit.Cosmos 119 could not be separated from the last stage because the payload fairing was not separated.
Quote from: Alter Sachse on 09/01/2017 05:24 pmThere were several examples, when the fairing was not separated and the whole combination did not reach an orbit.Cosmos 119 could not be separated from the last stage because the payload fairing was not separated.True, and I'm sure several more. Mariner 3, OCO, and Glory. Just off the top of my head...My question is if an enshrouded satellite--payload fairing fails to separate--has ever made it to orbit?(Upper stage + PLF + satellite)
Quote from: zubenelgenubi on 09/01/2017 05:31 pmQuote from: Alter Sachse on 09/01/2017 05:24 pmThere were several examples, when the fairing was not separated and the whole combination did not reach an orbit.Cosmos 119 could not be separated from the last stage because the payload fairing was not separated.True, and I'm sure several more. Mariner 3, OCO, and Glory. Just off the top of my head...My question is if an enshrouded satellite--payload fairing fails to separate--has ever made it to orbit?(Upper stage + PLF + satellite)AFAIK, there was one Pegasus mission out of CCAFS with a NASA payload that suffered this exact same failure mode (PLF not separating, stack enters orbit and payload is stuck inside). I haven't been able to find out which mission this was.
A review meeting is slated for Saturday in Thiruvananthapuram, seat of the launch vehicle centre, according to people familiar with the developments.An informed official said the analysis should be completed before the next launches of the PSLV and the GSLV came up, starting October or November.
A debris tracking team linked to the Vikram Sarabhai Space Centre in Thiruvananthapuram has been monitoring the unreleased satellite which is moving in a low orbit even as it sits trapped inside the heat shield.V.Adimurthy, Adviser at ISRO, former VSSC Associate Director and former Chairman of the Inter-Agency Space Debris Coordination Committee (IADC), said, “The spacecraft is in a low orbit and there will be natural decay. Going by its falling pattern, we expect it to fall back to Earth may be between four and eight weeks.”Most of its parts of the 1425-kg will burn up as it re-enters the atmosphere. The huge quantity of propellants on it is also a worry. ISRO is part of the IADC and will also get inputs of the North American debris watch body, NORAD.
Teams have started ascertaining what went wrong, because the rest of the launch milestones went off as planned except for the heat shield issue – which never cropped up earlier, they said.
The PSLV-C39 rocket, which failed to launch the IRNSS 1H satellite on Thursday, was dragged down by at least one tonne of extra weight from the unseparated heat shield after the second stage, its velocity reduced by one kilometre per second. This greatly reduced the altitude it was to reach for a successful mission, say scientists privy to the project.
Former Isro Satellite Centre director SK Shivakumar said: "The launch vehicle was carrying at least one tonne more than its design permitted it, as the heat shield did not separate. This affected its velocity. For example, it should have attained a velocity of 9.5km per second at the end of it but attained only 8.5km per second."
Once a satellite is placed in orbit, the shield is expected to separate and fall off. In this case, the command for separation reached the heat shield's mechanisms but it did not trigger the mechanical process to release the satellite.
In effect, the heat shield began to weigh down the launch from the the 114th second. "I cannot accurately say by how much it missed the desired altitude. It was supposed to have an apogee (farthest point from Earth) of 20,650km but managed only 6,000-odd km," Shivakumar said.
Two objects now being tracked.42928 51A 163 x 6539 km x 19.15 deg42929 51B 175 x 6515 km x 19.15 degToo early to speculate usefully on what's going on with that.
1 tonne of extra weight doomed PSLV missionQuoteThe PSLV-C39 rocket, which failed to launch the IRNSS 1H satellite on Thursday, was dragged down by at least one tonne of extra weight from the unseparated heat shield after the second stage, its velocity reduced by one kilometre per second. This greatly reduced the altitude it was to reach for a successful mission, say scientists privy to the project.
The Failure Analysis Committee, headed by VSSC Director K.Sivan, is poring through the flight data of the mission in a bid to understand what went wrong. Dr.Sivan toldThe Hindu that a simulation exercise would be carried out to zero in on the exact reason. “We are on track and hope to reach a conclusion within a week,” he said.
Based on the initial inference, informed sources at ISRO said the command for separation had gone through but failed to trigger the mechanical process that pops open the heat shield. They said the investigations were likely to centre on the electrically-initiated pyro devices that initiate the sequence of separation.
What is intriguing for scientists is that the pyro device which probably malfunctioned, is based on an electro-mechanical process, one that is far less complex than thousands of other components in the rocket.
Isro chairman AS Kiran Kumar on Saturday firmly denied that the PSLV-C39 rocket carrying eighth navigation satellite IRNSS-1H failed on Thursday as it was carrying one-tonne extra load. A report in TOI on Saturday had stated that "the PSLVC39 rocket, which failed to launch the IRNSS-IH, was dragged down by at least onetonne extra weight". The report stated that this was more than the design permitted.
Speaking to TOI on Saturday prior to making a presentation at the Nehru Centre in Mumbai, the Isro chief said: "The report is incorrect and the rocket was not carrying any extra load." He said the heat shield added additional weight to the launch vehicle as it failed to get detached at the second stage and went along till the fourth stage separation point. "It was not because Isro put any additional weight prior to the launch," he said.
He added that a portion of the rocket with the satellite enclosed in the heat shield was currently orbiting 163km x 6,600 km and was being tracked by the multi-object tracking radar at Satish Dhawan Space Centre, Sriharikota. "It is expected to remain this way for another 25 days,'' he said. Kiran Kumar said a failure analysis committee was being formed to study the setback.
Dr K Sivan, director of Thiruvananthapuram-based Vikram Sarabhai Space Centre (VSSC), said, "Launch failure will not affect future missions as they will go as planned. But corrective measures will be taken in future for all types of vehicles as the heat shield separation mechanism is similar in all launchers."
The use of the term "heat shield" for the component that failed on this launch is incorrect and confusing. A heat shield protects spacecraft during reentry, a payload shroud protects them during launch. They are physically very different.
All propellant aboard PSLV fourth stage and IRNSS-1H has been vented. Accurate reentry location determination would be possible a week in advance.
QuoteAll propellant aboard PSLV fourth stage and IRNSS-1H has been vented. Accurate reentry location determination would be possible a week in advance.https://www.reddit.com/r/ISRO/comments/6y48ax/all_propellant_aboard_pslv_fourth_stage_and/
Decay dates from SatEvo:C: late October 2017B (PSLV DEB): around Christmas 2017A (IRNSS 1H/PSLV): early July 2018
“we have depleted all the propellant through the gap in the heat shield and the fourth stage.” Dr K Sivan Director VSSCAs per reddit above.
The Indian space agency is strongly suspecting the failure of pyro elements for the non-separation of the heat shield of its rocket Polar Satellite Launch Vehicle’s (PSLV) XL variant on Aug 31, said a senior official.
According to K. Sivan, Director, Vikram Sarabhai Space Centre (VSSC), all the systems during the rocket’s flight worked well while the only suspect place is the pyro elements.
One fortunate aspect of the failure is that ISRO has all the flight data as the rocket was not lost during its one way journey.
“Tests are going on to find out the reasons for the failure of heat shield separation. Each test takes around 72 hours,” Sivan told IANS.
"The PSLV rocket has been successful for the past several years. So the question of design failure does not arise. It could be an issue of a failed component or a process quality issue," M.Y.S. Prasad, a former Director of the Satish Dhawan Space Centre, told IANS.
This is the first time that a satellite launch mission has failed due to this reason, perplexing current and former officials of the Indian Space Research Organization (ISRO). "It is really perplexing that such a thing has happened. Normally, the PSLV rocket has several redundancies built into it," R.V. Perumal, a former ISRO scientist, told IANS.
Noting all the commands are pre-planned and built into the computers, he said that there cannot be any manual command. "The computers have to give the necessary commands. The commands have to be relayed by the electrical circuits. The pyro circuit has to get initiated which, in turn, has to cut the mechanical elements so that the two parts of the heat shield get separated," he said.
Prasad maintained that something could have gone wrong in this four-step sequence or in the sub-systems, as redundancies have only been built into some systems. "The computer programmes may have several redundancies to take care of an eventuality. So they can be tested on ground before and also during preparation for the flight. The electrical circuits and some pyro elements will also have redundancies.
"A rocket has several one-time operation systems. Such systems cannot be pre-tested and cannot have redundancies[/b]. Only sample tests can be made with items manufactured in that batch. And then a system is used in the rocket," he said, terming the one-time operation systems 'the riskiest items; in any rocket.Ruling out design failure, Prasad said the most probable cause of failure could be the quality of a rocket component or some error in the assembly of systems.
The Indian Space Research Organisation expects to resume launch of satellites in a couple of months once its failure analysis committee releases its report. The committee is conducting tests on why the PSLV-C39 mission of August 31 failed to release a back-up navigation satellite into space.ISRO Chairman A.S. Kiran Kumar on Friday said the committee would release its report "very soon". The launches would be resumed in November or December after necessary steps are taken. He was speaking on the sidelines of an event to mark 25 years of the formation of Antrix Corporation, which markets ISRO’s products and services.
Quote from: Steven Pietrobon on 11/02/2017 03:15 am"The committee looking into what led to failure of PSLV-C39 on August 31 has identified the primary reason. "There was a bellow in the system which did not allow pressure to build up and shredded the nose cone," said ISRO chairman AS Kiran Kumar on Monday."http://bangaloremirror.indiatimes.com/bangalore/others/Poor-pressure-build-up-failed-PSLV-C39/articleshow/61349021.cmsThe PSLV Users Guide says the following about fairing separation."The heat shield fairings are joined vertically through a contamination-free, linear piston cylinder separation and jettisoning mechanism (zip cord) running along the full length of the heat shield. A clamp band joint is employed for attaching the heat shield at its base to the vehicle.The heat shield fairings are separated by the actuation of the clamp band joint at the base and the zip cord. The gas pressure generated by the mild detonating cord of the zip cord expands a rubber bellow, pushing the piston and cylinder apart after shearing the rivets holding the two halves. The force acting on the half shells pushes them laterally away from each other thus achieving the required jettisoning velocity. The bellow assembly retains the residual gases and prevents contamination of the spacecraft."Perhaps the bellow did not expand properly? Maybe it is the part that "shredded" rather than the "nose cone"? - Ed Kyle
"The committee looking into what led to failure of PSLV-C39 on August 31 has identified the primary reason. "There was a bellow in the system which did not allow pressure to build up and shredded the nose cone," said ISRO chairman AS Kiran Kumar on Monday."http://bangaloremirror.indiatimes.com/bangalore/others/Poor-pressure-build-up-failed-PSLV-C39/articleshow/61349021.cms
Quote from: input~2 on 09/02/2017 07:31 pmDecay dates from SatEvo:C: late October 2017B (PSLV DEB): around Christmas 2017A (IRNSS 1H/PSLV): early July 2018Revised decay dates from SatEvo with latest TLEs (epoch > Sept 4, 22:48 UTC)C (PSLV DEB) early November 2017B (PSLV DEB) early November 2017A (IRNSS 1H/PSLV) mid-August 2018
IRNSS-1H + rocket stage is reentered March 2.