Quote from: Galactic Penguin SST on 02/16/2018 10:27 amLooks like we have the first info of the composition of this new launcher:https://twitter.com/orfonline/status/964400636279205888Can someone who is well versed with Indian missiles and rockets comment if existing solid rocket motors may have been used here?The S85 looks like it is composed of various motor segments from the S139 which forms the first stage of PSLV and GSLV MK-2. The S-7 is the third stage of PSLV. S-4 seems to be a new motor. The optional fourth stage is the PS4 from PSLV. It looks like a very cost effective launch vehicle. I would put the cost at less then $5 million per launch.
Looks like we have the first info of the composition of this new launcher:https://twitter.com/orfonline/status/964400636279205888Can someone who is well versed with Indian missiles and rockets comment if existing solid rocket motors may have been used here?
Quote from: K210 on 02/16/2018 12:30 pmQuote from: Galactic Penguin SST on 02/16/2018 10:27 amLooks like we have the first info of the composition of this new launcher:https://twitter.com/orfonline/status/964400636279205888Can someone who is well versed with Indian missiles and rockets comment if existing solid rocket motors may have been used here?The S85 looks like it is composed of various motor segments from the S139 which forms the first stage of PSLV and GSLV MK-2. The S-7 is the third stage of PSLV. S-4 seems to be a new motor. The optional fourth stage is the PS4 from PSLV. It looks like a very cost effective launch vehicle. I would put the cost at less then $5 million per launch. No, the S85 has a different diameter than the the S139. The optional fourth stage is likely not the PS-4 from PSLV, which would be somewhat oversized.
Quote from: K210 on 02/16/2018 12:30 pmQuote from: Galactic Penguin SST on 02/16/2018 10:27 amLooks like we have the first info of the composition of this new launcher:https://twitter.com/orfonline/status/964400636279205888Can someone who is well versed with Indian missiles and rockets comment if existing solid rocket motors may have been used here?The S85 looks like it is composed of various motor segments from the S139 which forms the first stage of PSLV and GSLV MK-2. The S-7 is the third stage of PSLV. S-4 seems to be a new motor. The optional fourth stage is the PS4 from PSLV. It looks like a very cost effective launch vehicle. I would put the cost at less then $5 million per launch. That would be a world record even given the cost in India - but I have great doubts due to the big segmented first stage. This one is bigger than similar rockets in the US, Europe and Japan and their costs are in the $35 - 50 million range, and they use single body rocket motors. They will be pretty good if they can fly it at less than $20 million price (though ISRO won't be out of customers even at higher costs).
The PS4 has a diameter of 1.34m making it a perfect fit. Apart from PS4 isro has no other hypergolic upper stages.
with 500 kg payload to LEO and 116 t lift off mass, SSLV has a pretty poor payload ratio compared to other solid fuel rockets.
Quote from: Skyrocket on 02/17/2018 01:03 pmwith 500 kg payload to LEO and 116 t lift off mass, SSLV has a pretty poor payload ratio compared to other solid fuel rockets.That might be because for polar orbits, SSLV has to do a dog-leg to avoid Sri Lanka.
For comparison:Vega has a launch mass of 137 t and can orbit 1430 kg to LEO.Taurus/Minotaur-C has a launch mass of 73 t and can orbit 1320 kg to LEO.
May 4, 2018, 23:06 IST TNN[ Surendra Singh ]NEW DELHI: Indian Space Research Organisation (Isro) will rope in private companies or consortiums for its mini-PSLV project aimed at tapping the small satellite launch market. Isro chairman K Sivan told TOI that the first such rocket is likely to be tested by the middle of next year. The project – first reported by TOI – involves assembling a small rocket in three days, at a lower cost. It takes 30 to 40 days to put together a normal PSLV, which is 44m tall and 2.8m in diameter. Dr Sivan said, "Isro will initially build one or two mini rockets. Thereafter, private companies will be given the contract to build them. Antrix (Isro’s commercial arm) is working on the business model.” The consortium of companies that will be given the task to build the mini rocket may include industry majors like Larsen & Toubro (L&T) and Godrej Aerospace.
A PSLV costs around Rs150 crore, while a mini-PSLV can be made with one-tenth the money. The rocket will weight one-third that of a normal PSLV which weights 300 tonnes. The mini version will have a payload capacity of less than 700 kg, compared to a normal PSLV’s capacity to carry more than 1,750kg to a sun-synchronous polar orbit of 600km altitude.
India's space agency aims to create a consortium of companies to build and market a small rocket to launch low-weight satellites at lesser cost and within shorter durations, as it seeks to tap into burgeoning global demand for such services.Led by Antrix Corp - the commercial arm of the Indian Space Research Organisation - the consortium will include engineering major Larsen & Toubro, Godrej Aerospace and Hindustan Aeronautics Ltd. The combine will help Isro build a small rocket capable of carrying 500 kilogram satellites into the lower earth orbit.
"Our aim is that one or two rockets will be launched by Isro, the industry should then make the rockets and launch satellites," said K Sivan, chairman of Isro in an interview with ET. He said Isro has approached these companies and that "they are all interested"."The price of a satellite launch on this small rocket is expected to be less than one-fifth of the current launch costs," Sivan added. The first development flight or launch of the rocket will be by 2019.
Typically, Isro takes around 45 days to assemble its workhorse the Polar Satellite Launch Vehicle (PSLV). The smaller rocket, to be powered by a solid booster, is expected to be ready for launch in three days.
S85 does seem a bit too big of a core to launch 500kgs to LEO. Simple delta-v calc would show a core 25ton block (S25) with S7 and S4 would be able to launch 500kgs to LEO considering delta-v losses of around 10% for drag and gravity which is the norm for a PSLV like vehicle. On top if you consider the dog-leg then they may need may be a S35 block. S85 seems an over-kill.
Not sure what they're basing any ranking on. What's IOC mean - "entry into service date"?
Quote from: PonRam on 08/03/2018 05:15 amS85 does seem a bit too big of a core to launch 500kgs to LEO. Simple delta-v calc would show a core 25ton block (S25) with S7 and S4 would be able to launch 500kgs to LEO considering delta-v losses of around 10% for drag and gravity which is the norm for a PSLV like vehicle. On top if you consider the dog-leg then they may need may be a S35 block. S85 seems an over-kill.I don't know the specifics but isro's solid motors do not use composite motor cases. This results in a worse thrust to weight ratio which results in the need for larger motors. Also the ISP for isro's solid motors are generally on the lower end which could also be a contributing factor towards the need for such a large first stage.
The SSLV ( small satellite launch vehicle ) is being developed at a furious pace at ISRO's Vikram Sarabhai Space Centre. The SSLV will be an on-demand rocket for small satellites weighing about 500-700 kg. It will be autonomous and highly intelligent, versatile and capable of adapting to different launch situations and requirements.
Its first test launch is planned for mid-2019. Once proven, the SSLV's production would be offered to industry through Antrix Corporation, according to ISRO Chairman K. Sivan.The SSLV is said to be Dr. Sivan's dream concept for a quick-response space vehicle, and the project was initiated when he was the Director of the VSSC until January this year.
Among the key missions to look for in 2019 will be the Chandrayaan-2, Aditya-L1 (India's solar mission) and two demonstration flights of the SSLV (small satellite launch vehicle).
Aside of this, the agency also plans to have two demonstration flights of the SSLV in May and October after which it can go into production phase. "These launch vehicles will cost one tenth of a PSLV and compared to about 45 days needed to prepare a launch vehicle for launch, this will need only 72 hours. Also, it needs only three to four people as opposed to 300. But it can only launch payloads with a mass of 500-700 kg and we hope that the industry can soon start making these," Sivan said.