To the moon & back

From time immemorial, the moon been the reason of intense curiosity to mankind. And in the urge to study and learn more about this ever illusive object in the sky, innumerable lunar exploratory missions have been conducted over the past decades. As part and parcel of these missions various sophisticated equipments were used that were able to provide space astronauts with the necessary conditions to survive the journey to the moon and back.

Today, many of these apparels and techniques are being used in various other fields, contributing in terms of space suits for people with multiple sclerosis, to killing bacteria, viruses in community water supply systems.

So, here are some of the technical contributions of lunar missions.

# Cool suits, which kept Apollo astronauts comfortable during moon walks, are today worn by race car drivers, nuclear reactor technicians, shipyard workers, people with multiple sclerosis and kids with a congenital disorder known as hypohidrotic ectodermal displasia.

# Special kidney dialysis machines were developed as a result of a NASA developed chemical process that could remove toxic waste from used dialysis fluid.

# A cardiovascular conditioner developed for astronauts in space led to the development of a physical therapy and athletic development machine used by football teams, sports clinics and medical rehabilitation centers.

# Athletic shoe design and manufacture also benefited from Apollo. Space suit technology is incorporated into a shoe's external shell. A stress-free "blow molding" process adapted from NASA space suit design is also used in the shoe's manufacture.

# Insulation barriers made of aluminum foil laid over a core of propylene or mylar, which protected astronauts and their spacecraft's delicate instruments from radiation, is used to protect cars and trucks and dampen engine and exhaust noise.

# Vacuum metallizing techniques led to an extensive line of commercial products, from insulated outer garments to packaging for foods, from wall coverings to window shades, from life rafts to candy wrappings and from reflective blankets to photographic reflectors.

# Water purification technology used on the Apollo spacecraft is now employed in several spin-off applications to kill bacteria, viruses and algae in community water supply systems and cooling towers. Filters mounted on faucets can reduce lead in water supplies.

# A process for bonding dry lubricant to space metals led to the development of surface enhancement coatings, or synergistic coatings, which are used in applications from pizza making to laser manufacture. Each coating is designed to protect a specific metal group or group of metals to solve problems encountered under operating conditions, such as resistance to corrosion and wear.





The Indian Space Research Organisation (ISRO) built its Polar Satellite Launch Vehicle (PSLV) in the early 90s.

The 45 m tall PSLV with a lift-off mass of 295 tonne, had its maiden success on October 15, 1994 when it launched India's IRS-P2 remote sensing satellite into a Polar Sun Synchronous Orbit (SSO) of 820 km.

Between 1996 and 2005, it has launched six more Indian Remote Sensing satellites as well as HAMSAT, a micro satellite built by ISRO for amateur radio communications into polar SSOs, one Indian meteorological satellite into Geosynchronous Transfer Orbit (GTO).

During this period, PSLV has also launched four satellites from abroad (TUBSAT and DLR-Bird from Germany, Proba from Belgium and KITSAT from Republic of Korea) as piggyback payloads into polar SSOs.

Thus, PSLV has emerged as ISRO's workhorse launch vehicle and proved its reliability and versatility by scoring eight consecutive successes between 1994-2005 periods in launching multiple payloads to both SSO as well as GTO.




The Spacecraft for the lunar mission is cuboid in shape of approximately 1.50 m side. It weighs 1304 kg at launch and 590 kg at lunar orbit and accommodates eleven science payloads.

It is a 3-axis stabilized spacecraft using two star sensors, gyros and four reaction wheels.

The power generation would be through a canted single-sided solar array to provide required power during all phases of the mission. This deployable solar array consisting of a single panel generates 700W of peak power. Solar array along with yoke would be stowed on the south deck of the spacecraft in the launch phase. During eclipse spacecraft will be powered by Lithium ion (Li-Ion) batteries.

After deployment the solar panel plane is canted by 30 to the spacecraft pitch axis.

The spacecraft employs a X-band, 0.7m diameter parabolic antenna for payload data transmission. The antenna employs a dual gimbal mechanism to track the earth station when the spacecraft is in lunar orbit.

The spacecraft uses a bipropellant integrated propulsion system to reach lunar orbit as well as orbit and attitude maintenance while orbiting the moon.

The propulsion system carries required propellant for a mission life of 2 years, with adequate margin. The Telemetry, Tracking & Command (TTC) communication is in S-band frequency. The scientific payload data transmission is in X-band frequency.

The spacecraft has three Solid State Recorders (SSRs) on board to record data from various payloads.

• SSR-1 will store science payload data and has capability of storing 32Gb data.
  
  SSR-2 will store science payload data along with spacecraft attitude information (gyro and star sensor), satellite house keeping and other auxiliary data. The storing capacity of SSR-2 is 8Gb.
  
  M3 (Moon Mineralogy Mapper) payload has an independent SSR with 10Gb capacity.

Chandrayan-I is India's first unmanned mission to the Moon. Here are some of the interesting facts about it.

• It is likely to be launched from Sriharikota in the third week of October.
  
• Chandrayan-I will be launched by ISRO's Polar Satellite Launch Vehicle, also called PSLV.
  
• It will carry out 11 experiments in about two years.
  
• The mission aims to explore the dark side of the Moon. It will also look for the traces of water on the earth's only satellite. It will send high-resolution pictures, which will be received by ISRO's deep space network at Bylalu, near Bangalore.
  
• Chandrayaan-I will scan large lunar craters that receive no sunlight and are believed to contain frozen water.
  
• The mission will help Indian scientists locate He-3, which has the potential to produce a large amount of energy. The scientists hope to transport it to the Earth to run nuclear plants.
  
• Though deep space tracking network is expensive, India has built the required infrastructure for it.
  
• Chandrayaan-I mission is supported by the US and Russia.