7.5 means 7.5 tonnes of thrust. 7.5 tonnes of thrust = 75 kN of thrustVaroon Shekhar wrote: Thanks! What does the 7.5 in CE 7.5 signify? Guess this is where I'm confused/malinformed.
On the whole then, which of the 2 engines is the more powerful? Not to imply any kind of direct competition here.
Some interesting tidbits!dhiraj wrote: later all GSLVs will use the cryo engine that develops 90 kN ton of thrust, against 75 kN and they will carry 15 ton of propellant against 12.8 ton now possibly giving a longer burn time
Changes to b made are too complex and time consuming for just a single flight.dhiraj wrote:just a thought : having the current CE 7.5 in the mark 3 sub-orbital flight could have been something that could have been thought about and
tried if feasible something like a GSLV Mk 2.5
ISRO had given a project to IIT Kanpur to develop a rover to be launched with Chandrayaan-II, which the university's scientists completed in 2010, but the space agency was yet to pick it up and make part payment to the institute, according to its professor.
When contacted, an Indian Space Research Organisation official said in Bangalore that they will take some time to respond.
"In 2009, ISRO's Vikram Sarabhai Space Centre in Thiruvananthapuram had given a project to IIT Kanpur's mechanical engineering and electrical engineering departments to build a rover that would be launched along with Chandrayaan-II," Prof K S Venkatesh of IIT Kanpur's electrical engineering department said.
"ISRO had promised to give us Rs 7.5 lakh for the project, of which Rs 3.75 lakh was paid up front," he said.
The IIT-K professor said scientists at the institute had completed building the rover, weighing 100 kgs, in October 2010, after which it was "gathering dust" in a lab in the institute.
"Repeated phone calls and letters to ISRO failed to yield any result. Every time, ISRO scientists would assure us that they are coming soon to collect the rover, but till now no one has come," he said.
The professor said building the rover had cost much more than Rs 7.5 lakh, which the institute had paid, and that ISRO should at least pay the remaining amount due to IIT-K.
When asked about the possible reasons for ISRO not accepting the rover, Venkatesh said Chandrayaan-II was set to be launched in 2017, which could be why ISRO was not showing any haste in acquiring it.
The professor said his colleagues at the institute had realised that the project to build the rover, which would pick up samples from the Moon's surface and bring them back to Earth, would cost much more than Rs 7.5 lakh and had initially refused to take it up.
"However, the then IIT-K Director Sanjay Govind Dhande had insisted that the project would get the institute international fame and that IIT-K would pitch in with the money," he said.
According to him, IIT-K spent Rs 29 lakh on the project.
He said on completion of the project in October 2010, the team had contacted ISRO scientists by phone and letters, informing them that the rover was ready and they could come to inspect it. However, no one has come to claim the rover yet, he said.
I did not mean a GSLV MK 2.5 for just a single flight, rather a proper launch vehicle version for ISRO.KrishG wrote:dhiraj wrote:
just a thought : having the current CE 7.5 in the mark 3 sub-orbital flight could have been something that could have been thought about and
tried if feasible something like a GSLV Mk 2.5
Changes to b made are too complex and time consuming for just a single flight.
Currently, the scientists are developing crew capsule recovery parachutes for India's space programmes. “The design validation process with appropriate ground test are progressing at the Terminal Ballistics Research Laboratory in Chandigarh. It's a new area for us as the crew module has to be stable while landing. We have to ensure that the initial shock should not be very heavy, the speed reduction should be slow and limited to the human capability. The idea is to stabilise the crew module
http://tarmak007.blogspot.com/
Can you share an online link for the above.Varoon Shekhar wrote:Yet, the Frontline article( in my possession) entitled "Soaring Confidence",
AFAIK, there is no online link for the Frontline article written by T.S Subramanian, in the June 19th, 1992 issue of "Frontline". I bought this issue way back then, and I'm glad I saved it!dhiraj wrote:Can you share an online link for the above.Varoon Shekhar wrote:Yet, the Frontline article( in my possession) entitled "Soaring Confidence",
BTW i really miss the ASLV launch video, also the first few PSLV and GSLV launch video.
Can anyone please share a link for the above. TIA
. I also have the "India Today" issue covering the first PSLV launch and failure/near miss. I might scan one or both articles and put them on the BR forum.Don't expect much from wiki, their editors are hell bent on degrading our missions. GSLV-F04 is still shown as "Partial Failure". I got into an argument with their so called editors and they said that they are experts in their field and their word is final despite the contrary results as evidenced by INSAT-4CR still being operational. I guess, even when 4CR crosses its designed life, they won't change the result. What would they have classified the result into, if ISRO does not say anything about the minor anomalies in the orbit achieved in their press reports? I guess other space agencies do not mention anything about errors in the orbits achieved in their press reports.Varoon Shekhar wrote:The wiki article on the ASLV mentions the 3rd launch( on May 20/1992) as a partial failure, because the satellite orbit achieved was lower than desired.
...........
This kind of particularity is missed by Wiki and by similar general descriptions of the flight. Also, despite the lower than expected orbit, the satellite, SROSS-3, did detect two gamma ray bursts in its short lifespan of 55 days. A bit of info absent in Wiki et al.
True, we are so disparaging of anything desi that we won't believe in a genuine desi achievement. To top it all, the technical details don't help, as many people shut off when provided with voluminous details, or don't read them on their preferred news outlets (BBC, CNN, for instance). People are only happy with Apollo 13ish Hollywood propaganda, anything else is not good enough. Even 2 weeks ago, I was arguing with a fellow desi who contended India should not waste money on space when there is so much poverty (sounded like a copy pasted line from BBC).partha wrote:^
That's a good point. ISRO and DRDO release more technical details about launches and tests compared to other agencies world wide (my observation, could be wrong) I wonder whether it is because it is hard to convince us Indians about an Indian achievement. It reminds me of a thread opened by Shivji to discuss that Indian mentality.
Clustering of engines is not simple, either. Control issues, and (depending on configuration), complex and heavy plumbing are common. This can also result in reliability issues. The Soviet Union moon rocket tried to make up for lack of large engines (which the saturn V had) by clustering. It failed and was covered up. [ http://en.wikipedia.org/wiki/N1_(rocket) ]. Also the rocket equation suggests that heavier and larger payloads result in substantial weight penalty for the rocket itself (mass fraction > 0.9 means for every kg payload,9 kg rocket needs to be present; heavier rocket structure at prior stages will have similar impact including greater operational cost). Hence it is reasonable to look for higher efficiency upper stage engines; and augment the first stage by boosters. It is rocket science after, alldhiraj wrote: why was clustering of Vikas engine not considered as a serious option
. The goal of GSLV was to extend the PSLV technology to a geosynchronous launch capability in the most straightforward way. hence any risk associated with clustering would presumably have been sought to be reduced. Of course, several missteps and unfortunate occurrences happened on the way to delay the execution; but doesn't necessarily invalidate the thinkingNo, Specific Impulse (Isp) is a measure of efficiency (fuel/mass efficiency) of an engine. Longer burn time means that the engine systems do need to be reliable to that extent.Hitesh wrote:Does having longer burn times mean it provide better more efficient thrust?.
www.pbs.org/newshour/bb/world/jan-june1 ... 01-18.html
Is India’s space program worth the money?
pbs.org | Jan 18th 2014
HARI SREENIVASAN: In early November, India launched a 320 ton rocket - on a mission to Mars.
If all goes according to plan, the Indian spacecraft will travel 485 million miles over more than 10 months, and go into the orbit around Mars in September. The U.S., former Soviet Union, and the European Space Agency are the only ones to have accomplished the feat.
DR. RADHAKRISHNAN: It is a challenging task, a complex task.
HARI SREENIVASAN: Dr. K. Radhakrishnan is the director of the Indian Space Research Organization. He was one of the engineers looking on when the Mangalyaan - or Mars craft in Hindi – launched. The probe will be studying the atmosphere of Mars and looking for traces of methane, which could be a sign of previous life.
DR. RADHAKRISHNAN: A lot of things are known about Mars, but there are several issues which are yet to be understood, understood precisely.
HARI SREENIVASAN: The mission to Mars is a source of immense national pride in India. But it might also signal a new Asian space race, and it’s already triggered a debate about the benefits of exploring another planet when so many Indians struggle for basic necessities.
Though it has been in existence for nearly 50 years, the very fact that India has a space program is unknown in much of the world. But since its inception, India has not only launched a mission to Mars, but has sent a probe to the moon, and has built and launched 70 satellites that do everything from measuring water resources to enabling mobile communications in rural India.
Radhakrishnan says that at its heart India’s space program is meant to improve life for India’s 1.2 billion people.
One critical mission: to predict where and when storms will hit land, so people in the storm’s path can be taken to safety.
In 1999 when a massive storm hit India’s east coast, more than 10,000 people died. But a few months ago when another powerful storm hit the same area only 21 people died. Nearly 1 million had been evacuated after early warning data from Indian satellites.
DR. RADHAKRISHNAN: Part of the use of these Earth observation satellites is to provide services to the fisherman, to the farmer, to the decision maker at the grass-root level.
HARI SREENIVASAN: So how does understanding the atmosphere of Mars, or whether there was methane help the farmer or the fisherman in India?
DR. RADHAKRISHNAN: It is not directly. Understanding of the atmosphere of Mars is not going to help him immediately, directly.
HARI SREENIVASAN: But he says technology from the Mars mission will help improve the satellites India has yet to launch, which will directly benefit ordinary Indian citizens.
But beyond the tangible scientific benefits, the feat of sending a rocket to Mars has been a huge point of pride for India.
As the Mars spacecraft left Earth’s orbit, Indians took to Twitter to express their excitement…A point echoed by Dr. Radhakrishnan, who says the mission has inspired the nation.
DR. RADHAKRISHNAN: People are keeping awake in the night to see how the Mars orbiter operations are progressing. So if you can transform so many young minds. And they say yes, we need to take up a career in science, it is a big transformation for the country, for the future.
HARI SREENIVASAN: And working for the agency is prestigious. Hundreds of thousands of engineers have applied for just hundreds of slots at the space agency.
The pride is also in part for how little India spends to explore space. The Mars mission costs 4.5 billion rupees or just over $70 million dollars. Compare that to the MAVEN mission - a similar NASA probe that is also currently en route to Mars - that cost nearly ten times as much.
The savings are achieved in part because engineering labor is cheaper, the program recycles and adapts components like launch vehicles, and builds far fewer models, relying heavily on computer testing.
But spending any money on space exploration here is controversial. India is still a developing country where nearly a third of the population - about 400 million people - live on less than a dollar twenty-five a day.
Brinda Adige runs an NGO called Global Concerns India focused on women and children here in a slum in Bangalore less than 10 miles from the headquarters of the Indian space agency. She says she was sad when she first heard about the Mars mission.
BRINDA ADIGE: At one end of the spectrum so much of money that is being spent to send a rocket out into outer space, when we know that here on Earth, in my country there are children, dying every day because they have no food to eat. So many of them, spending their days and nights without electricity. No roads, no education no protection for women and the girl child anywhere in this country.
HARI SREENIVASAN: Do you think that if they didn’t spend the money on the satellite then they would spend the money on women and girl’s issues?
BRINDA ADIGE: No, they would not. They would not. The priorities are certainly not looking at children, woman, human beings who are need of basic necessities, just to live.
HARI SREENIVASAN: So you’re not against the science, just the priorities…
BRINDA ADIGE: Yes.
HARI SREENIVASAN: Adige gathered a group of women from this slum who echoed some of the same concerns.
HARI SREENIVASAN: I asked the group that given the millions being spent on the mission to mars, what kind of impact additional money could have in this neighborhood.
They described a litany of issues, including bad roads, lack of access to medical care, the high costs of education, and complaints about sanitation issues like sewage runoff after the rains and a lack of safe drinking water.
One of these women, Manoja, who works as a cook in a nicer part of town took us to her mother-in-law's house and showed us the contaminated water that comes out of her pipes.
MANOJA: All of this water in the house smells terrible.
HARI SREENIVASAN: It smelled rancid
This is the municipal water the family pays for from the city. They have to spend extra on trucked in clean drinking water.
But Dr. Radhakrishnan defends the Indian space program budget - in total about $1 billion dollars this year.
HARI SREENIVASAN: So on a global level, India’s program is incredibly inexpensive. On a local level it is still very hard for people to comprehend on the streets of Bangalore, spending so much money going to different planet?
DR. RADHAKRISHNAN. The question is in absolute terms when you talk about the $1 billion dollars that we spend annually is it providing the benefits to the people? Space is touching the lives of every man and woman in this country.
HARI SREENIVASAN: Radhakrishnan points out that the entire Indian space program accounts for one third of one percent of the nation’s budget.
Those numbers may make it easier to justify what may be a larger goal, competing with another superpower.
Just last month china became the third country behind the U.S. and the former Soviet Union to land a rover on the moon and China has successfully completed manned spaceflights, a feat several years away for India.
But in going to Mars, India could best its neighbor. The competition is a fuel India is reluctant to admit.
In November 2011, a joint Chinese-Russian mars mission failed.
HARI SREENIVASAN: Is there political pressure to keep up with the next door neighbor, China?
DR. RADHAKRISHNAN: Each country has their own priorities, their own vision for the space program. India has its vision, China has its vision, we are pursuing our vision.
HARI SREENIVASAN: It doesn’t matter when China does what it does?
DR. RADHAKRISHNAN: It does its program, we do our program.
HARI SREENIVASAN: But it was right after China’s failure that the Prime Minister here said here’s our priority, we are going to Mars.
DR. RADHAKRISHNAN: See, November 2013 is an opportune time for a mission to Mars. And such opportune times occurs only once every 26 months.
HARI SREENIVASAN: While the Indian launch date did capitalize on when the distance between mars and the earth is shorter, to critics like Brinda Adige, this is simply a space race.
BRINDA ADIGE: ‘You’ve gone to Mars, now I also have to go to Mars.’ You’ve reached moon? I must also go and see whether there’s water on moon or not? Whether my people down here in this country have drinking water or not is secondary. The question arises… to what end?
HARI SREENIVASAN: To administrators like Dr. Radhakrishan, success with the Mars mission is another step in helping the world see the red planet and India in a new way.
That means, for a payload of 10 tons, you need a 90 ton rocket..which is fantastic! Some confusion there- are you talking of fuel fraction?mass fraction > 0.9 means for every kg payload,9 kg rocket needs to be present
Good point. If these men do get interviewed by western media should point out that US owes the largest debt in the world which will never get paid and still continues to send space missions to all over the universe with printed money and no one questions.Rony wrote:I dont understand why Indians and man like Radhakrishnan should indulge westerners by giving interviews to their channels and justify how we spend our money. I don't see this happening with the Russian or Chinese space agencies or even NASA chief give a interview to Indian journalist.
restartable engines are mainly used for upperstage as it gives the advantage of injecting satellites at particular orbitHitesh wrote:What s so important about restartable engine?
Space shuttle and proposed Ares rocket both used SRB so my understanding seems it is more of design approach.Hitesh wrote:Why is the solid fuel unusable for manned spacecraft?
Giving unwarranted explanations to others about one's decisions and behaviour is a sign of weakness. It automatically puts the listener in a position of authority. The better response would be to say: "Mind your own business since it is our money, not yours."Rony wrote:I dont understand why Indians and man like Radhakrishnan should indulge westerners by giving interviews to their channels and justify how we spend our money. I don't see this happening with the Russian or Chinese space agencies or even NASA chief give a interview to Indian journalist.
Rony wrote:I dont understand why Indians and man like Radhakrishnan should indulge westerners by giving interviews to their channels and justify how we spend our money. I don't see this happening with the Russian or Chinese space agencies or even NASA chief give a interview to Indian journalist.
This kind of discussion on another country's national program is fake.HARI SREENIVASAN: Radhakrishnan points out that the entire Indian space program accounts for one third of one percent of the nation’s budget.
Those numbers may make it easier to justify what may be a larger goal, competing with another superpower.
