Saturday, January 26, 2013
Thursday, January 24, 2013
Thursday, January 17, 2013
ISRO's Inflatable Space Structures development
ISRO's future plans of human space flight and planetary explorations will require large space structures like antennas and solar arrays to be deployed in space. These structure will have to be carried into space by launch vehicles that will require a large payload fairing and a large thrust. To minimize these requirements, ISRO is working on mastering the inflatable space structure technology. ISRO has already developed unfurlable structures, but due to their inherent problems like shape errors and large erecting force requirements, it is now developing technology for inflatable structures.
ISRO's Inflatable antenna in a container (credit: ISRO) |
ISRO's inflatable antenna prototype (credit: ISRO) |
Thursday, January 10, 2013
Chandrayaan-2 delayed to 2017
I came across this presentation [1] where I found that the Luna-Resource mission or Chandrayaan-2 mission has been delayed to 2017. I attach below two slides from the presentation with relevant information.
Luna-Resource or Chandrayaan 2 now planned in 2017 |
L-R or Luna-Resource mission moves from 2014 to 2017 |
[1] Moon Exploration Lunar polar sample return, ESA thematic information day, BELSPO, 3 July 2012.
Monday, January 7, 2013
ISRO Human Space Flight Program (HSP)
As a natural progression of its endeavors, ISRO has decided to start a Human Space flight program. It has been decided that the entire program will be split into following three different phases:
- First phase: design, development and performance demonstration of critical technologies leading to manned space missions.
- Second phase and third phase would establish the necessary infrastructure, do qualification tests including flight testing with test vehicles, PSLV, GSLV and GSLV Mk III and finally demonstrate the first Indian Human Spaceflight.
In the first phase, during the 12th plan period (2012-2018), ISRO has proposed to develop and demonstrate all the major technologies and infrastructure critical for Human Spaceflight Program (HSP) including pad abort test, Orbital Vehicle (OV), Crew Escape System (CES), Environmental Control and Life Support Systems (ECLSS) & Flight Suit, Human rating of Launch Vehicle (LVM3) and realizing essential facilities including third launch pad for the development and flight testing of these systems. Mission and configuration studies and technical developmental activities will also be initiated for the Human Lunar Missions.
The first major-milestone activity is “pad abort test” that is planned to demonstrate the performance of crew escape system (CES). This test will play a vital role in establishing the critical
abort maneuver of the CES which has to take the crew module (CM) to an altitude of about 2 km and range of about 2 km from the launch pad. The objectives of this pad abort test are:
- Verify the performance / functioning of various motors / systems of CES.
- Verify the capability of CES to take CM to the required altitude (~ 2 km) & range (~ 2 km).
- Demonstrate the deceleration & floatation capability of parachute and Crew Module.
- Validate the crew module recovery from sea.
Work on the Orbital vehicle is progressing well. ISRO has built an ergonomic model of crew module for study and is conducting plasma wind tunnel tests on scaled crew module models. ISRO has decided to convert the PSLV PS4 (4th stage) into a service module for the OV.
Ergonomic model of ISRO crew module. |
For meeting the requirements of HSP, human rating of GSLV MK III or LVM3 will also be initiated in the 12th plan period. The work will involve the following:
- Redesign of vehicle structures including propellant tanks and motor cases if necessary.
- Re-qualification tests including stage functional tests of S200, L110 and C25.
- Intelligent systems to monitor and identify the imminent failure of systems are to be developed.
- Redundancy schemes in all the avionics, control systems, pyro systems and mechanisms are to be re-looked and re-qualified.
- Additional facilities for structural test are to be developed for conducting these tests.
Artist concept of manned LVM3. |
Sunday, January 6, 2013
ISRO Mars Mission: Challenges
ISRO Mars Orbiter replica |
Following challenges will be faced by ISRO in its ambitious Mars mission planned to be launched in October 2013
- Radiation shielding: ISRO has learnt lessons from the untimely demise of its Chandrayaan-1 mission due to extreme radiation and thermal issues. In the Mars mission, the orbiter will have to face prolonged radiation in the Van Allen belt. This necessitates augmented radiation shielding for the orbiter.
- In-built autonomy: Due to the large distance of 55-400 million km between Earth and Mars, the is a one way communication delay of 20 minutes. This necessitates high order of autonomy in-built within Mars orbiter.
- Robust and reliable subsystems: Mars orbiter will take 300 days to reach the Mars where its subsystems will be switched on again. This demands robust and reliable subsystems design for the success of the mission. Particularly, propulsion system that will have to work again after 300 days of journey to Mars.
- Mars orbit capture: Mars orbit insertion is the most critical part of the mission that will decide its success.
A successful Mars mission will impart ISRO with expertise in propulsion, communication and control required for deep space exploration.
Friday, January 4, 2013
ISRO Mars Mission
ISRO mars mission |
Mars orbiter payloads: (information collected from paper abstracts available on the internet)
1. Mars Exospheric Neutral Composition
Analyser (MENCA)
MENCA
(Mars Exospheric Neutral Composition Analyser) is based on the
technique of quadrupole mass spectrometry and it operates in the mass range of
1-300 amu.
The scientific objective of MENCA is to explore the Martian exospheric neutral
density and
composition at an altitude of ~500 km and above from the surface of Mars and to examine
its radial, diurnal, and seasonal variations. The low
inclination of the proposed orbit will provide an opportunity to encounter
Phobos, one of the two natural satellites of the Mars, on few occasions. This
will enable us to estimate the upper limits of the neutral density distribution
around it. The study of Martian exosphere is important for understanding the
escape rate of of Martian atmosphere and its impact on Mars’ climate change.
2. Lyman
Alpha Photometer (LAP)
Measurement of
atmospheric deuterium to hydrogen abundance ratio (D/H) is vital to examine the
escape process of water in the current atmosphere and also understand the loss process
of water in the evolutionary history of a planet. Lyman Alpha Photometer (LAP) is
a miniaturized ultraviolet photometer primarily designed for D/H measurement of
the upper atmosphere of Mars. LAP will measure the present day D/H ratio that
will be compared with the original D/H ratio estimated from observing pristine comets
and asteroids. The comparison will tell us how much hydrogen and therefore
water has been lost over the life time of the planet.
3. Methane Sensor
for Mars (MSM)
It is designed to
measure methane in the Martian atmosphere with ppb accuracy and map its
sources. It is based on Fabry Perot (FP) etalon filters that work on the
principle of multiple beam interferometry.
4. Thermal infrared
Imaging Spectrometer (TIS)
It is a grating
based spectrometer that uses un-cooled micro-bolometer array as detectors. TIS
will measure thermal emissions from mars surface.
5. Mars Color Camera (MCC)
It is designed to work in the visible range (0.4
micron- 0.7 micron) and is optimized to work from a highly elliptical orbit 500
x 80,000 km.
Thursday, January 3, 2013
ISRO Reusable Launch Vehicle Program: AVATAR & TSTO
One of the Space Visions of ISRO is to enable low cost access to space, which is not possible with the present expendable launch systems. The present launch cost of expendable systems, is roughly 10,000 US $/ kg for LEO orbit and around 20,000 US $/ kg for GSO orbit. ISRO is aiming to bring down this cost by half in the short term by the use of its new LVM3 (GSLV Mk3) and ULV expendable systems. But to make the harnessing of space resources more affordable, it is imperative that the cost
of access to space must be substantially brought down by an order of
magnitude.
Demand and Costs of Launch systems (credit: BN Suresh ISRO) |
Future needs demand reusability of launch systems (credit: BN Suresh ISRO) |
To achieve low cost access to space, ISRO has chalked down a plan to develop a new breed of reusable launch system called AVATAR to substantially cut down the launch costs (vehicle hardware contributes 70% of the total cost of the launch vehicle that is presently expended after one launch). AVATAR will be a Single Stage To Orbit (SSTO) launch system that will attempt to reuse maximum sub-systems and will use turbojet and dual mode ramjet-scramjet propulsion. The use of air-breathing ramjet-scramjet engines will preclude need for carrying all the propellants , particularly oxidizer, that will enable cutting the system cost.
Reusable Launch Vehicles (credit: BN Suresh ISRO) |
AVATAR SSTO launch system (credit ISRO) |
Avatar is an ambitious program and with the kind of engine and material technologies required, such SSTO launch system will take a long time to develope. Accordingly, ISRO has decided to first develop a Two Stage to Orbit (TSTO) reusable launch system for the immediate future by utilizing its current capabilities and target development of AVATAR in the long term.
TSTO for the immediate future (credit: ISRO) |
Targeted TSTO Features:
To realize the TSTO and associated new technologies, ISRO has been working on the development of a RLV technology demonstrator (RLV-TD) and is setting up necessary technology development infrastructure.
- 10 Ton to LEO and GTO payload capability.
- Vertical take off.
- Semi-cryogenic booster stage with avg. Isp of 330 seconds and cryogenic orbiter stage with avg. Isp of 400 seconds.
- Total lift off weight < 700 tons.
- Winged body booster that will boost the orbiter to Mach 10 at an altitude of 80-100 km then separate and return to launch site and land conventionally on an air-strip.
- Orbiter will deploy the payloads in the intended orbits and then deboost, re-enter and land on airbags or vertically on legs.
- Vehicle structure designed for 100 flights and engines for 50 flights.
- Turn around time should be 30 days.
- Payload fraction = 2%.
- Cost effectiveness < 1000 US $/ kg for LEO payload.
Wednesday, January 2, 2013
ISRO Unified Launch vehicle
ISRO's Unified Modular Launch Vehicle conceptualizes a generic launch vehicle configuration to be able to meet the varying requirement from mission to mission by varying the propulsion system with considerable cost advantage. Unified Launch vehicle will use a common semi-cryogenic stage and will have the features of a world class expendable launch vehicle, with maximum GTO payload capability of 6t and maximum LEO payload capability of 15t.
The development of Unified modular launch vehicle aims to reduce the number of propulsion modules for all the three types of launch vehicles (PSLV, GSLV MK2 & LVM3). This would mean that the core vehicle would be a standard configuration of cryogenic + semi-cryogenic stages and depending on the payload mass to be delivered in orbit, the solid strapon boosters with different propellant loadings could be added. Studies and developmental activities of ULV will be initiated in the 12th plan period.
Antriksh's concept of ISRO ULV |
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