http://www.hinduonnet.com/thehindu/holnus/10111603.htm

India unveils space plane
PTI
New Delhi, July 11

INDIAN SCIENTISTS have designed a reusable space plane Avatar which
they say can launch satellites at extremely low cost and also take
tourists on a ride to space.

Work on Avatar, which had been under wraps because of its defence
potential, was unveiled on Tuesday in the United States by retired air
CMDE, Raghavan Gopalaswami, former chairman of the Bharat Dynamics
Limited and the key person behind this low profile project financed by
the Defence Research Development Organisation (DRDO).

Gopalaswami, a pioneer in liquid propulsion technology, was former
chief of Hyderabad-based Bharat Dynamics Limited. The project team
includes scientists from Defence Research Development Laboratory,
which designed Agni, Prithvi and other missiles, and CIM Technologies
a private company both based in Hyderabad.

The unique design of Avatar, which can be launched again and again 100
times and produces its own fuel in flight, has been patented in India,
Gopalaswami said before flying off to US to make the presentation on
the space plane at the global conference on propulsion at Salt Lake
City.

Applications for registration of the design have been filed in patent
offices in the United States, Germany, China and Russia, he said.

The current generation chemical rockets like India's Geostationary
Satellite Launch Vehicle (GSLV) are thrown away after a single use. A
handful of advanced nations have been in the race for more than a
decade to develop reusable launch vehicles to bring down the cost of
access to space.

Gopalaswami says their efforts so far failed because their design
called for large vehicle size (100 to 760 tonnes) and tens of billions
of dollars in development cost. Weighing 25 tonnes (60 per cent of
which is liquid hydrogen fuel), Avatar is the smallest space plane
claimed to be capable of entering into the 100-km orbit in a single
stage and launching satellites weighing up to one tonne.

Taking off horizontally like a conventional airliner, Avatar uses a
combination of "turbofan, ramjet and scramjet engines" to reach
crusing altitude of 10 kms and then a cryogenic rocket engine to take
it to space.

The mission over, it de-orbits, re-enters the atmosphere and lands on
own power like an airplane. A single Avatar can perform 100 such
missions in its life, which means 100 tonnes of payload in space. In
contrast, life of GSLV is finished after deploying 2 tonnes.

The unique feature of Avatar is that it does not carry any liquid
oxygen at take off. The entire 21 tonnes of liquid oxygen required for
the rocket flight is produced during the hour long cruise, at eight
times the speed of sound, by an on-board system that collects
atmospheric air, separates the oxygen, liquifies and stores it.

Avatar can use a cryogenic rocket engine identical to the one used in
GSLV, Gopalaswami said. Instead of satellite, one can put passengers
in the payload bay and turn Avatar into tourist plane. No special
training would be needed, as it would be like going in a Boeing 747,
it is claimed.

A space trip on board Avatar would cost a fraction of the $20 million
that an American businessman reportedly paid for a visit to the
international space station last May, according to its developers.

According to Gopalaswami, all concepts used in Avatar have been
mathematically proven and an engineering design has emerged. He admits
that India cannot build it alone. International cooperation both in
finances and technology is necessary for Avatar to become a reality.

"We have a design for a space plane. The US, Russia, Japan, Germany
and France have the critical technologies and the money. What we need
is a global approach to make low cost access to space possible,"
Gopalaswami said.

In the meantime the Avatar team is going ahead with a scaled down
version called "mini-Avatar" weighing just three tonnes at take off.
To be built by CIM technologies in about five years, mini-Avatar will
not go into space but will demonstrate all technologies used in Avatar
including oxygen collection.

"It will use technologies available within the country," Gopalaswami
said including the core engine "Kabini" developed for the light combat
aircraft.

"We have a whole team from 23 academic institutions working on this at
theoretical level," Gopalawami said. "We are building the knowledge
base... brilliant ideas are coming from our universities." Once the
technologies are validated by mini-Avatar in next five years, the
"real" Avatar could be commercially deployed in 10 to 12 years from
now, Gopalaswami hopes.

According to the India team, development of reusable space planes like
Avatar and its successor "hyper plane", which is still in the drawing
board, would make Space Solar Power (SSP) stations affordable
providing a global solution for the coming energy crisis.

A string of satellites in space will convert sunlight into microwaves
and beam to earth where it will be turned into electricity, says
Gopalaswami. Till now SSP stations were unthinkable because of high
cost of space launches but Avatar can change that, Indian scientists
hope.

Gopalaswami said the idea for Avatar originated from the work
published by the Rand Corporation of the United States in 1987. "They
threw the report into archives. It came to me as unclassified document
and formed the basis for our approach."

One hour at Mach 8!?? Sorry, I just flat don't believe it. Hypersonic
flight guzzles up fuel like crazy - and Avatar STARTS OUT with only 15
tons of hydrogen! 22 tons of O2 burn 2.75 tons of H2, so that leaves
12.25 tons of LOH for getting up to Mach 8 and then cruising for an
hour. Also, what kind of refrigirater is supposed to liquefy 22 tons
of O2 (which will start out rather hot) in 1 hour, and where does its
power come from?