Wednesday, 20 May 2015

A Cautionary Tale of Tactical Decision-Making at the Precipice of War

The Lexington Minuteman Statue (Author's Photo)

Jon's note: I was aiming to finish this piece honoring the citizen-soldiers of colonial Massachusetts in time for Patriots' Day; I'll settle for the proper month of the year.

19 April was the 240thanniversary of the outbreak of the American Revolutionary War. On that day in 1775, a British composite force of roughly 700 regulars and marines was dispatched from their Boston garrison to raid the Massachusetts colonial militia’s stockpiled arms and materiel in Concord. The resultant clashes that morning at Lexington Green and North Bridge were but minor skirmishes compared to the series of engagements that occurred during the raiding force’s afternoon withdrawal to Boston. The British raiders would have been annihilated had it not been for their timely reinforcement with a brigade of regulars on the return trip; the latter alone suffered an astounding 20% casualty rate during its several hours in the field. Whereas only 77 militiamen had met the British at sunrise, nearly 4,000 militiamen and elite minutemen from Boston’s environs had either clashed with or were maneuvering against the Crown’s troops by sunset.

Just 24 hours later, Boston was surrounded by nearly 20,000 militiamen.[1]Many of these men would go on to form the nucleus of the initial Continental Army raised by the Second Continental Congress and commanded by George Washington.

While militarily insignificant in comparison to the afternoon’s running battle, the Lexington salvo and its sequel at North Bridge could not have been more politically and morally decisive. In both cases, British professional soldiers fired first at Massachusetts citizen-soldiers even though the latter’s organized ranks had not aimed weapons at the former’s. The British thereby set the war-opening escalation precedents, with concomitant effects on public opinion in the colonies as well as in Britain (albeit aided by the American Whigs’ vastly superior strategic communications efforts).[2]The American Whigs’ passions for and commitment to their cause were galvanized accordingly; the same cannot be said of British popular (or Parliamentary) sentiments.

It’s a given that an armed conflict of some scale between the Massachusetts Whigs and the Crown’s troops was nearly unavoidable. The political objectives of the British government and the Whig-dominated Massachusetts Provincial Congress were fundamentally at odds, and the latter’s de facto political control over the Massachusetts countryside represented a direct threat to British sovereignty over the colony. Nor could the British tolerate the Whigs’ organization of the colony’s militia units into a well-armed, highly trained, and quickly-mobilizable army controlled by and accountable to the Provincial Congress.

But as we will see, it is not a given that the events of 19 April would unfold as they did. Had the opening volley occurred under different tactical circumstances that day, who’s to say that the Whigs would have captured the political and moral high ground at all? In fact, it is theoretically possible that a different set of British tactical decisions on Lexington Green could have avoided a clash there altogether. Or perhaps with greater British restraint upon entering the town’s center, the way the encounter unfolded might not have been as favorable to the Whig cause.

General Thomas Gage

It’s important to note that General Thomas Gage, governor of the Massachusetts colony and commander of the British forces based in the city, fully accepted the possibility of a violent encounter. Gage had received orders from London on 14 April to preemptively decapitate the growing rebellion. The general no doubt reasoned that the most effective means of accomplishing this task was to eliminate the militia’s depot in Concord, as the other major depot in Worcester was out of range for a quick strike. Since every British expedition outside the Boston the previous fall and winter had been met by militia units from the surrounding towns, Gage had every reason to expect the same would occur during the Concord operation. His thinking was almost certainly colored by the failed British attempt to seize cannon in Salem two months earlier; that ‘surprise’ raid had only narrowly escaped coming to blows with the local militia.

It is not shocking, then, that Gage’s first draft of orders for the Concord operation specified that “if any body [‘of men’ inserted above the line] dares [‘attack’ written, then crossed out] oppose you with arms, you will warn them to disperse [‘and’ written, then crossed out] or attack them.”[3]The actual written orders issued to the raid commander, Colonel Francis Smith, did not contain any explicit direction as to what should be done under such circumstances. I agree with historian John Galvin that Gage’s guidance to Smith regarding rules of engagement was likely verbal as to avoid creating a paper trail for an operation Gage had every reason to believe would result in bloodshed.

Colonel Francis Smith

Gage likely assumed that Smith’s force’s size and training would allow it to dominate the handfuls of militia units that he believed would be able to respond in the worst case. His plan was further predicated on operational surprise reducing the speed and mass of the militia’s reaction. Gage simply did not appreciate how the militia’s century-old networks for communicating warning across the colony, doctrine and posture supporting rapid mobilization, and practice in conducting decentralized operations in accordance with a higher-echelon commander’s intent completely undermined his raid plan.[4]

As we well know, superior Whig intelligence collection efforts enabled Paul Revere’s and William Dawes’s triggering of the militia’s warning network on the night of 18-19 April. Between that warning and the delays Smith suffered while ferrying his force across the Charles River to Cambridge, the Lexington militia company under Captain John Parker was fully ready on the town’s Green as Smith approached along the road to Concord that morning. Parker had not received rules of engagement from his regimental commander specific to this particular British expedition, and there’s no evidence that Parker’s orders to his men departed from the Massachusetts militia’s de facto practice of authorizing the use of force only in self-defense or to counter direct attacks against their towns. When his scouts reported the British were minutes away, Parker lined his company up on the Green perpendicular to the road from Boston roughly 100 yards from where the road forked at the triangular Green’s apex. This standoff distance was at the fringe of effective musket range against an opposing formation. He did not place his men in a battle-ready formation. All evidence points to Parker seeking to demonstrate his company’s resolve to the British and thereby deter aggression against the town.[5]

Major John Pitcairn

Smith’s leading elements of regulars under his deputy commander, Royal Marine Major John Pitcairn, approached Lexington Green with muskets loaded and primed. Several factors led to this weapons posture. For one thing, Smith’s force had not progressed very far from its landing area in Cambridge before it became apparent that militia throughout the region were mobilizing and that any chance at operational surprise had been lost. Smith’s scouts, including a party that had briefly captured Paul Revere earlier that morning, had also collected ‘rumor intelligence’ of up to 600 militiamen waiting for the British in Lexington. Just outside the town, Pitcairn’s own scouts reported a lone figure had attempted to fire at them but failed when his musket misfired.[6]Pitcairn and Smith consequently had every reason to believe that they might be entering a hostile situation. Their decision to move to a high weapons posture, then, was logical from a self-defense standpoint.

But inherent self-defense was not their only possible motivation. Gage’s first draft of his operation order suggests that he defined ‘opposition’ by an armed militia unit to mean such a unit’s presence within immediate tactical reach of Smith’s force, that this presence alone would satisfy demonstration of hostile intent (from our modern rules of engagement standpoint), and that Smith was therefore authorized to decide for himself whether or not to warn a militia unit prior to employing lethal force. Given that the entire strategic purpose of the operation was to decisively ‘break’ the rebellion, it is logical to assume Gage verbally empowered Smith (and Pitcairn by extension) to order a precedent-setting first volley for purposes other than the column’s inherent self-defense. It seems to have never occurred to them that the particular circumstances in play on the occasion of setting such a precedent might matter far more than the demonstration of power and resolve they might mean to convey.

Even so, a deliberate move to set a conflict-opening precedent would require that Smith and Pitcairn possess tight tactical control over their force’s firing discipline. Pitcairn claimed in his post-battle deposition that his final order to the British infantry companies on Lexington Green in the moments before the fateful first shot was the equivalent of what today we would call “Weapons Tight.”[7]But Pitcairn did not have tight control over those companies thanks to the actions of a single subordinate, Royal Marine Lieutenant Jesse Adair. London loaded the muzzle and primed the pan, so to speak. Gage aimed the weapon; Smith and Pitcairn were merely the executors. Adair is the man who placed his finger on the hair-trigger.
Adair was reportedly a ‘forward-leaning’ (but at 36 years of age, hardly young) junior officer.[8]He did not hold any command or staff responsibilities in Smith’s force; he was an ‘at-large’ officer in the expedition. Earlier in the morning he had served alongside a few of his peers as Pitcairn’s scouts; this was the group that reported the firing attempt by the ‘lone gunman’ outside Lexington. He and five other ‘at-large’ junior officers accompanied the expedition’s leading companies as they entered Lexington center and found Parker’s Lexington militia company positioned on the Green.

Situation on Lexington Green, roughly 0520 on 19 April 1775 (from Fischer, 192)

In their post-battle depositions, Adair’s compatriots claimed that several hundred militiamen were arrayed before them.[9]Their estimates were likely skewed by the fact that the Lexington Meetinghouse at the Green’s apex obscured full view of the field, not to mention the ‘intelligence’ regarding the Lexington militia’s strength they had collected earlier. Adair almost certainly interpreted Parker’s parade-ground formation as a threat to the British column, even as far back from the road as Parker had positioned his men.

If we assume Adair had authority to order the tactical employment of units not under his formal command (a disturbing proposition to say the least), then what were his options? He or one of his colleagues could have ordered the column to halt and then he or a colleague could have personally scouted the Green to assess the situation and perhaps even speak with Parker. He could ordered the column down the left fork in the road towards Concord and then detached several companies into flanking positions along the Green perpendicular to Parker’s formation so that the latter could not pivot and fire into the main column as it marched by. These two options exemplified restraint in a precipice-of-war situation. They would have allowed time and space for more measured decision-making.

Instead, Adair chose to dispatch several companies down the right fork in the road and into the Green to directly parallel the Lexington company at close range. The quick march he ordered past the Meetinghouse’s north side reportedly became a charge; the two companies of light infantry halted 70 yards from Parker’s men. At the same time, the horse-mounted Pitcairn rode around the Meetinghouse’s south side and onto the Green while the rest of the column turned left at the fork and then halted on the Concord road. By all accounts, combination of British regulars’ “huzzah” cries and the bellowed orders from Adair, the other ‘at-large’ junior officers on the Green, and Pitcairn made any British attempt to exercise tight tactical control impossible. At least some British officers, probably from Adair’s group on the battle line, yelled at Parker’s company to disperse. Measuring the situation, Parker ordered his men to do exactly that. Seeing the militiamen begin to withdraw, Pitcairn ordered the regulars on the battle line to “surround and disarm” them—an action that can only be explained by his not appreciating Parker’s attempt at deescalation. [10]The confusion and sense of imminent danger on both sides must have been profound. Little wonder, then, that shots rang out.

Looking east from the left side of the Lexington Militia Company's lines towards the Green's apex. British battle formation was roughly 70 yards forward from this position. (Author's Photo)

The British were convinced the first shot came from one or more militiamen withdrawing through the area behind Buckman Tavern across from the north side of the Green, or perhaps from a rogue sniper in or behind the tavern itself. The militiamen were convinced one or more British officers fired first with pistols.[11]I agree with historian David Hackett Fischer’s conclusion that both sides’ accounts are probably true, and that if there was a singular ‘first shot’ by someone on one side (whether accidental or deliberate) it occurred almost simultaneously with a singular first shot by someone on the other side.

The post-battle depositions on both sides, though, are consistent in asserting that Parker’s men on the Green did not fire first. And yet they were exactly who came under fire from the British companies on the battle line. The only legitimate targets, if any, were not on the Green. By indiscriminately engaging Parker’s men on the Green, the British undercut any claim to inherent self-defense. In doing so, and as pointed out earlier, they also undercut their political and moral position. The fact that Smith’s expedition failed to achieve any of its operational objectives in Concord and was nearly destroyed on the return trip, while very significant at the campaign-level, is strategically secondary.

Amos Doolittle's late 1775 engraving of the Lexington clash

The stupidity of Adair’s decision is magnified if we take the liberty of indulging in some counterfactuals. For instance, if there were in fact one or more Whig-aligned rogue gunmen not under Parker’s command in the vicinity of Buckman Tavern, then he (or they) would have found it harder to take the British under fire had Adair not deployed the two companies into the Green opposite Parker. Perhaps the rogue(s) could have maneuvered into a different position to engage the column on the Concord Road, but that would have only made it more clear that the fire had not come from Parker’s men. Granted, the subsequent chain of events would likely have been chaotic and might still have led to a direct exchange between Parker’s company and the British. Nevertheless, the facts on the ground would have been different—and the Whigs' assertions of the moral superiority of their cause might have been undercut.

It’s also entirely possible that the first shot would have occurred at North Bridge in Concord if it hadn’t in Lexington. Or perhaps the confrontation at North Bridge would not have resulted in an exchange of fire at all had all involved there not been aware of the hostilities a few hours earlier. All the same, it’s quite likely given Gage’s orders and the overall circumstances that some clash would have occurred either later that day or on a subsequent occasion. Such a clash would not necessarily have resulted from a strategically-impactful failure of British tactical decision-making.

It should be clear from this story that former U.S. Marine Corps Commandant Charles Krulak was quite correct with his concept of a “strategic corporal” two decades ago, except in the Lexington case it was a “strategic lieutenant” who ultimately directed the path of history. Any contemporary junior officer and his or her field grade commander could easily find themselves in a similar brink-of-war situation someday. Unlike the British government in April 1775, though, these modern officers’ political masters might actually want to avoid hostilities.

It follows that much should be learned from the many British operational and tactical mistakes that led to the clash on Lexington Green (of which I have only listed a few). In my opinion, the most important of these mistakes was Gage’s and his subordinates’ failure to appreciate that just because their government was willing to start a war to achieve its objectives didn’t mean the way the war started at the operational and tactical levels wasn’t of critical strategic importance. Neither Gage, nor Smith, nor Pitcairn made any discernable effort to think through exactly what ought to be sought or avoided in a first clash with the Whigs. Neither Smith nor Pitcairn made any discernable attempt to issue clear intentions to their subordinates regarding what to do in a confrontation, let alone to maintain tight tactical control over their force when actually in contact. As a result, they essentially tossed a lit matchbox in the form of Adair amidst several leaking barrels of gasoline. We should thank them for that, as while the results were disastrous to the Crown’s interests, they led directly to the birth of our democratic republic and its enshrinement of natural rights in law.

Russia offers to upgrade SAM Strela-10M3 for India

At the last meeting of the Russia-India Inter-governmental Commission, Russia offered to upgrade India’s existing short-range Strela-10M3 mobile air defence system (surface to air missile systems) to the level of the Strela-10M4 or Strela-10MN (night version), making it more combat-worthy.

Russia has offered to upgrade India’s existing short-range Strela-10M3 mobile air defence system to the level of the Strela-10M4 or Strela-10MN (night version), Vladimir Slobodchikov, managing director (MD) of the system being developed by the Nudelman Precision Engineering Design Bureau, told RIA Novosti in an interview on Tuesday.
“During a meeting of the Russia-India Inter-governmental Commission (IGC), we made a technical proposal to India for the modernization of the Strela-10M3 SAM (surface-to-air missile) systems. A formal offer was made under the aegis of Rosoboronexport,” said Slobodchikov, Doctor of Technical Sciences and member of the Tsiolkovsky Russian Academy of Cosmonautics.
The Strela-10 SAM has been under development in the KBtochmash since the beginning of the 1970s. This SAM system has been the flagship product of the company and, by the end of the 1980s, more than 700 of these systems were produced in the Soviet Union, making the Strela-10 SAM the most mass-produced such system in the country, Slobodchikov said. More than 400 such units were delivered to other countries.
“Modernization includes the upgrading of the combat vehicle, but we will not touch the rockets. The main drawback of the earlier versions was that the system could not work at night. It did not have thermal sighting capability. These new versions – the Strela-10M4 or Strela-10MN (night version), can work at night,  primarily thanks to the introduction of autonomous sector search and target acquisition capability,” said the MD of KBtochmash, which is part of the holding company NPO Precision Complexes OJSC, owned by the state corporation Rostec.
The Strela-10M3, he said, required that the operator see the target with his own eyes, or receive targeting information from somewhere, swing the launcher installation at the target, find and capture it, and then launch the missile.
“Now the Strela-10MN (night version) has been automated, a device detects a target in the sector, transmits a command to the operator, after which the operator captures the target and shoots,” said Slobodichkov.
The Strela-10M4 SAM is designed to protect military units, in various forms of battle and on the march, from air attack and reconnaissance devices, diving and flying at low and ultra-low altitudes.

9K35 Technical Data

Основные характеристики ЗРК типа "Стрела-10"
Principal Technical Specifications of the Strela 10 SAM System
Strela 10SV
Strela 10M
Strela 10M2
Strela 10M3
Зона поражения, км
Engagment Envelope [km]
- по дальности
- in range
- по высоте
- in altitude
- по параметру
до 3
до 3
до 3
до 3
Вероятность поражения истребителя одной ЗУР
Single Shot Pk for Fighter Type Target
Макс. скорость поражаемых целей (навстр./вдогон), м/с
Max veolicty of defeated target (approaching/receding) [m/s]
Скорость полета ЗУР, м/с
missile velocity [m/s]
Время реакции, с
Reaction time [s]
Масса ракеты, кг
Missile mass [kg]
Масса боевой части, кг
Warhead mass [kg]
Число ракет на боевой машине
Number of missiles on TELAR
Год принятия на вооружение
Table: Said Aminov Vestnik PVO

9K35M Battery Components

9K33M/M2/M3/A Battery Components
9A35M / 9A34M1+34 + 4 Round Amphibious TELARMT-LB
9T244/9T2451Missile Transporter / TransloaderUral 4320
PPRU-1M1Mobile Command Post / Acquisition RadarMT-LBu
PU-12M / 9S738-31Mobile Command PostBTR-60
P-40/1S12 Long Track 1Self Propelled  Acquisition RadarAT-T
9V839 / 9V9152Missile Repair/Test StationGAZ-66
Repair Station1P-15, P-18, P-19, P-40 Repair/Test StationZiL-131
9F624M1Mobile Training Simulator for TELAR CrewsUral-375
9K37M48Missile Warstock Deployed -

9K33M3  Optional Battery Components
P-15M Squat Eye1UHF-Band Low Level Acquisition RadarUral-375
P-15/19 Flat Face1UHF-Band Acquisition RadarUral-375
1L22 Parol 4 / 75E6 Parol 31IFF InterrogatorKrAZ-255
PRV-16 Thin Skin1Heightfinding RadarSP

KBT 9K35M3-K Kolchan / BTR-60/70/80 TELAR

Most production 9K35 / SA-13 Gopher systems were delivered on the Soviet MT-LB amphibious tracked chassis which forms the basis of the 9A35 and 9A34 TELARs. Yugoslavia integrated the 9K35 Strela 10SV system on an indigenous tracked chassis before the Balkans civil war and some of these systems were deployed during OAF.

More recently the late model 9K35M3 Strela 10M3 / SA-13 Gopher system has been integrated on a wheeled amphibious chassis under the designation 9K35M3-K Kolchan by KBT. The demonstrator for this design was fitted to a legacy BTR-60PBM 8 x 8 personnel carrier and displayed at the MAKS 2007 arms show in Moscow. The BTR-60PBM is a refurbished, relifed and re-engined baseline BTR-60, recognised by the enlarged aft engine bay.

Modifications to the BTR-60PBM series vehicle include replacement of the powered BPU-1 series automatic gun turret with the 9M35M3 TELAR turret previously designed for the MT-LB chassis, and the addition of side mounted magazines for four reload rounds. 

The choice of the GAZ BTR-60PB series vehicle is almost certainly a result of the vast existing user base of this family of vehicles, which was more widely exported than any other Soviet armoured personnel carrier. The successor 1970s BTR-70 and 1980s BTR-80 were exported  as widely as the BTR-60, the 1990s BTR-90 is operated only by Russia. The similarity in hull designs across this family of vehicles would permit adaptation of the demonstrator design to any of the BTR-60/70/80/90 series hulls. Conversion of existing in service BTR-60/70/80/90 series vehicles into the 9K35M3-K Kolchan is significantly cheaper than the manufacture of new MT-LB vehicles, which are also more expensive to operate than wheeled vehicles of similar size. Numerous life extension and engine upgrades are available for the BTR-60/70/80/90 family of vehicles. The BTR-60/70/80/90 are Russian equivalents to the US LAV-25 and Stryker family of 8 x 8 personnel carriers.

The 9K35M3-K Kolchan 9A35M3-K and 9A34M3-K TELARs are more capable than the fielded 1980s 9A35M3 and 9A34M3 TELARs, and this qualifies the system as a new variant rather than block upgrade. Battery composition emulates the earlier variants, with one of four TELARs equipped with an RF passive detection system. KBT have not identified a specific battery transporter/transloader vehicle to date, other than the existing Ural 6 x 6 9T244/245 transloader series an amphibous option are relifed BTR-60P/70/80 personnel carrier variants, or the current production GAZ-59037 8 x 8 flatbed transporter, based on the BTR-80/90 vehicles.

The new digital fire control system includes a new Focal Plane Array technology uncooled optical acquisition and tracking sensor with a 12º x 16º FOV, an Okhotnik digital image processing system claimed to improve detection range by 30% to 70%, and a Trona-1 moving map and navigation display system.

BTR-60PB and BTR-60PBM-A1 Comparison
Combat weight, kg1030010250/11250*
Overall dimensions:
– length
– width
– height (over turret)


Top speed over highway, at least, km/h8090
Top water speed, at least, km/h99
Fuel range, km500550
Water endurance, hrs1112
Obstacle capabilities:
– gradient, deg
– trench, m

up to 2

up to 2
Engine type2 × carburetor2 × turbocharged diesel
Engine power, hp2 × 902 × 110
BTR-70 and BTR-70M-A1 Comparison
Combat weight, kg1050011450/12450*
Overall dimensions, mm:
– length
– width
– height (over turret)


Top speed over highway, at least, km/h8095
Top water speed, at least, km/h99
Fuel range, km500550
Water endurance, hrs1011
Obstacle capabilities:
– gradient, deg.
– trench, m

up to 2

up to 2
Engine type2 × carburetor2 × turbocharged diesel
Engine power, hp2 × 1202 × 136

'US military aid better situates Pakistan to wage war against India'

The American military assistance to Pakistan, a latest list of which was recently put out by the independent Congressional Research Service (CRS), better situates its military to wage a war against India and not to fight terrorists, a noted US expert on South Asia has said.

"This assistance better situates Pakistan to wage war against India while doing nothing to shape Pakistan's will or capabilities to target terrorists and insurgents," Christine Fair, author of several well-researched books on Pakistan and its military wrote in a recent article, days after the CRS in a report listed out the military hardware including fighter jets that the US has given to Pakistan.

"The assistance better situates Pakistan to wage war against India while doing nothing to shape Pakistan's will or capabilities to target terrorists and insurgents," Christine Fair said.

"The items that Washington has conveyed to Pakistan have little utility in fighting insurgents and terrorists; rather, they enable Pakistan to better fight India, a democratic American partner that has long endured Pakistani predations," Fair said.

A new American policy towards Pakistan, rooted in sober realism, is long overdue, she argued in her recent piece in National Interest.

Since 9/11, the United States has lavished Pakistan with nearly USD 8 billion in security assistance, USD 11 billion in economic assistance, and USD 13 billion in the lucrative programme known as Coalition Support Funds (CSF), she said referring to the CRS report.

Since then, Pakistan has availed of significant US weapons systems and armaments, including: a used Perry-class missile frigate; 18 new and 14 used nuclear-capable F-16s; an array of munitions (i.e 500 air-to-air missiles, 1,450 2,000-pound bombs); 1,600 kits that allow Pakistan to convert gravity bombs into laser-guided smarter bombs, 2,007 anti-armor missiles, 100 Harpoon anti-ship missiles, 500 Sidewinder air-to-air missiles, seven naval guns, 374 armored personnel carriers, and much more, she said.

A transfer of 15 reconnaissance unmanned aerial vehicles is also under way. "This list suggests that Pakistan's insurgents have developed air, naval and ground-force capabilities," Fair said.

According to the US author, Washington provides Pakistan access to these weapon systems even despite Pakistan's failures to comply with the numerous conditionalities which the US Congress has emplaced upon such assistance.

"Currently, the US provides this assistance under various waivers. In doing so, Washington erodes its own credibility, demeans its own laws, and rewards Pakistan for engaging in the very activities that the United States seeks to curtail.

Worse, given the fungibility of funds, the United States has subsidized Pakistan's investment in its jihadi and nuclear capabilities," Fair said.

Tuesday, 19 May 2015

Complete information on ASTROSAT – Spacecraft fully assembled and tests initiated


ASTROSAT is the first dedicated Indian astronomy mission aimed at studying distant celestial objects. The mission is capable of performing observations in Ultraviolet (UV), optical, low and high energy X-ray wavebands at the same time.

The project was conceived following the success of the Indian X-Ray Astronomy Experiment, carried on a remote sensing satellite launched in 1996.
The government cleared the Astrosat project In 2004 at a cost of Rs. 178 crore. The satellite was planned to be launched in about 4 years.

ASTROSAT would be India's first multiwavelength astronomy satellite. It will facilitate simultaneous observations of celestial bodies and cosmic sources in X-ray and UV spectral bands. The uniqueness of ASTROSAT lies in its wide spectral coverage extending over visible (3500-6000 Å), UV (1300-3000 Å), soft X and hard X ray regions (0.5-8 keV; 3-80 keV).

The following extract from a page on NASA's High Energy Astrophysics Science Research Archive Center (HEASRAC) website gives a perspective on the Astrophysics website.

"Most astronomical objects in the known Universe emit radiation spanning the complete electromagnetic spectrum stretching from long wavelength radio emission to extremely short wavelength gamma rays. Hence for a detailed understanding of the physical processes that give rise to frequency-dependent, time-variable phenomena, it is essential to carrry out nearly simultaneous multi-frequency observations. Important areas requiring broad band coverage include studies of astrophysical objects ranging from the nearby solar system objects to distant stars, to objects at cosmological distances; timing studies of variables ranging from pulsations of the hot white dwarfs to active galactic nuclei (AGN) with time scales ranging from milliseconds to few hours to days."

Research Institutions Involved with the Project
Other research institutions contributing to the collaborative effort of the project include:
  1. ISRO
  2. Indian Institute of Astrophysics, Bangalore
  3. Raman Research Institute, Bangalore
  4. Inter-University Center for Astronomy and Astrophysics, Pune
  5. Nuclear Research Laboratory, Bhabha Atomic Research Centre, Mumbai
  6. S.N. Bose National Center for Basic Sciences, Kolkata
  7. Canadian Space Agency.
Launch and Orbital Parameters
The 1,650 kg satellite with a science payload of 750 kg is scheduled to be launched in the second half of 2015 atop PSLV C-34.
It will be placed in a 650-km (400 miles) orbit with an 8° inclination for spectroscopic studies of X-ray binaries, supernova remnants, quasars, pulsars, galaxy clusters and active galactic nuclei at a number of different wavelengths simultaneously, from the ultraviolet band to energetic x-rays.

Project Progress
The satellite is planned to be launched during the second half of 2015 by PSLV C-34 to a 650 km near equatorial orbit around the Earth. It is significant to note that ASTROSAT is the first mission to be operated as a space observatory by ISRO.

ISRO in a press release on May 19, 2005 stated, "All the payloads and sub-systems are integrated to the satellite. Mechanical fit checks of the satellite with PSLV payload adaptor were performed successfully. Last week, the spacecraft was fully assembled and switched ON. Spacecraft parameters are normal, which indicates everything is functioning well. In the coming days, Spacecraft will undergo several environmental tests like Electromagnetic Interference (EMI) – Electromagnetic Compatibility (EMC), Thermal Vacuum, Vibration, Acoustic tests before shipment to Satish Dhawan Space Centre, Sriharikota.

The Hindu in July 2012 that the telescope took 11 years to develop. It has 320 mirrors of aluminium that had to be made with great precision and given a fine gold coating. These mirrors were arranged in the form of concentric shells, with struts to hold them in place. They had to be positioned with an accuracy of 20 microns, which was less than the width of a human hair.

Attitude Control System
TIFR is also developing the satellite’s attitude control system, consisting of two star trackers and gyros, to facilitate accurate pointing of the instruments towards a specific direction in the sky.
The challenges associated with developing the Attitude Control System have been overcome and delivery of the payload to the ISRO satellite center will begin from the middle of this year.
In particular, it will train its instruments at active galactic nuclei at the core of the Milky Way that is believed to have a super massive black hole.

ASTROSAT will carry five astronomy payloads for simultaneous multi-band observations:
  •  Twin 40-cm Ultraviolet Imaging Telescopes (UVIT) covering Far-UV to optical bands.
  •  Three units of Large Area Xenon Proportional Counters (LAXPC) covering medium energy X-rays from 3 to 80 keV with an effective area of 6000 at 10 keV.
  •  A Soft X-ray Telescope (SXT) with conical foil mirrors and X-ray CCD detector, covering the energy range 0.3-8 keV. The effective area will be about 120 at 1 keV.
  •  A Cadmium-Zinc-Telluride coded-mask imager (CZTI), covering hard X-rays from 10 to 150 keV, with about 10 deg field of view and 500 effective area.
  •  A Scanning Sky Monitor (SSM) consisting of three one-dimensional position-sensitive proportional counters with coded masks. The assembly will be placed on a rotating platform to scan the available sky once every six hours in order to locate transient X-ray sources.
ASTROSAT will be a proposal-driven general purpose observatory, with main scientific focus on:
  •  Simultaneous multi-wavelength monitoring of intensity variations in a broad range of cosmic sources.
  •  Monitoring the X-ray sky for new transients.
  •  Sky surveys in the hard X-ray and UV bands.
  •  Broadband spectroscopic studies of X-ray binaries, AGN, SNRs, clusters of galaxies and stellar coronae.
  •  Studies of periodic and non-periodic variability of X-ray sources.
 Open observing time on ASTROSAT will start one year after launch, for which proposals will be invited from the astronomy community. The primary data archive for ASTROSAT will  be located at the Indian Space Science Data Centre (ISSDC) near Bangalore, India.
The Ground Command and Control Centre for ASTROSAT will be located at ISTRAC, Bangalore, India. Commanding and data download will be possible during every visible pass over Bangalore. Ten out of 14 orbits per day will be visible to the ground station.

Astrosat is India's first dedicated astronomy satellite and is scheduled to launch on board the PSLV in 2015. Based on the success of the satellite-borne Indian X-ray Astronomy Experiment (IXAE), which was launched in 1996, the Indian Space Research Organization (ISRO) approved (in 2004) further development for a full-fledged astronomy satellite ASTROSAT 


An X-ray astronomy experiment for the study of spectral and temporal characteristics of cosmic X-ray sources was developed jointly by TIFR and ISRO Satellite Center (ISAC). The payload consists of three identical pointed proportional counters (PPC) and one X-ray Sky Monitor (XSM). Each of the detectors are controlled by independent microprocessor based processing electronics. A common electronics sub-system acts as an interface with the satellite bus. An oven controlled oscillator (accuracy one part in 109) provides high timing accuracy. The Indian satellite IRS-P3, carrying the X-ray astronomy instruments was launched on 1996, March 21 with Indian Polar Satellite Launch Vehicle PSLV-D3 from Shriharikota Range, India.

A large number of leading astronomy research institutions in India and abroad are jointly building various instruments for the satellite. Important areas requiring broad band coverage include studies of astrophysical objects ranging from the nearby solar systemobjects to distant stars, to objects at cosmological distances; timing studies of variables ranging from pulsations of the hot white dwarfs to active galactic nuclei with time scales ranging from milliseconds to few hours to days.

Astrosat is currently proposed as a multi-wavelength astronomy mission on an IRS-class satellite into a near-Earth, equatorial orbitby the PSLV. The 5 instruments on-board cover the visible (320-530 nm), near UV (180-300 nm), far UV (130-180 nm), soft X-ray(0.3-8 keV and 2-10 keV) and hard X-ray (3-80 keV and 10-150 keV) regions of the electromagnetic spectrum.


The Astrosat project is a collaborative effort of a growing list of research institutions. The current participants are:

  • Indian Space Research Organization
  • Tata Institute of Fundamental Research, Mumbai
  • Indian Institute of Astrophysics, Bangalore
  • Raman Research Institute, Bangalore
  • Inter-University Centre for Astronomy and Astrophysics, Pune
  • Bhabha Atomic Research Centre, Mumbai
  • S.N. Bose National Centre for Basic Sciences, Kolkata
  • Canadian Space Agency
  • University of Leicester (UoL), UK


ASTROSAT will be a proposal-driven general purpose observatory, with main scientific focus on:

  • Simultaneous multi-wavelength monitoring of intensity variations in a broad range of cosmic sources
  • Monitoring the X-ray sky for new transients
  • Sky surveys in the hard X-ray and UV bands
  • Broadband spectroscopic studies of X-ray binaries, AGN, SNRs, clusters of galaxies and stellar coronae
  • Studies of periodic and non-periodic variability of X-ray sources

Astrosat will carry out multi-wavelength observations covering spectral bands from radio, optical, IR, UV, X-ray and Gamma ray regions both for study of specific sources of interest and in survey mode. While radio, optical, IR observations would be coordinated through ground-based telescopes, the high energy regions, i.e., UV, X-rays and Gamma rays would be covered by the dedicated satellite borne instrumentation of Astrosat.

The mission would also study near simultaneous muti-wavelength data from different variable sources. In a binary system, for example, regions near the compact object emit predominantly in X-rays, the accretion disc emitting most of its light in the UV/optical waveband, whereas the mass of the donating star is brightest in the optical band.

The observatory will also carry out:

  1. Low to moderate resolution spectroscopy over wide energy band with the primary emphasis on studies of X-ray emitting objects
  2. Timing studies of periodic and aperiodic phenomenon in X-ray binaries
  3. Studies of pulsations in X-ray pulsars
  4. QPOs, flickering, flaring, and other variations in X-ray binaries
  5. Short and long term intensity variations in AGNs
  6. Time lag studies in low/hard X-rays and UV/optical radiation
  7. Detection and study of x-ray transients.

In particular, the mission will train its instruments at active galactic nuclei at the core of the Milky Way that is believed to have a super massive black hole.


The scientific payload has a total mass of 750 kg and contains six instruments.

  • The UltraViolet Imaging Telescope (UVIT) - The UltraViolet Imaging Telescope will perform imaging simultaneously in three channels: 130-180 nm, 180-300 nm, and 320-530 nm. The field of view is a circle of ~ 28 arcmin diameter and the angular resolution is 1.8" for the ultraviolet channels and 2.5" for the visible channel. In each of the three channels a spectral band can be selected through a set of filters mounted on a wheel; in addition, for the two ultraviolet channels a grating can be selected in the wheel to do slitless spectroscopy with a resolution of ~100.
  • Soft X-ray imaging Telescope (SXT)- The soft X-ray telescope on Astrosat will employ focussing optics and a deep depletion CCD camera at the focal plane to perform X-ray imaging in 0.3-8.0 keV band. The optics will consist of 41 concentric shells of gold-coated conical foil mirrors in an approximate Wolter-I configuration. The focal plane CCD camera will be very similar to that flown on SWIFT XRT. The CCD will be operated at a temperature of about −80 °C by thermoelectric cooling.
  • The LAXPC Instrument - For X-ray timing and low-resolution spectral studies over a broad energy band (3-80 keV) Astrosat will use a cluster of 3 co-aligned identical Large Area X-ray Proportional Counters (LAXPCs), each with a multi-wire-multi-layer configuration and a Field of View of 1° × 1°. These detectors are designed to achieve (I) wide energy band of 3-80 keV, (II) high detection efficiency over the entire energy band, (III) narrow field of view to minimize source confusion, (IV) moderate energy resolution, (V) small internal background and (VI) long lifetime in space.
  • Cadmium Zinc Telluride Imager (CZTI) - Astrosat will carry a hard X-ray imager in the form of CZTI. It will consist of a Pixellated Cadmium-Zinc-Telluride detector array of ~1000 cm2 geometric area. These detectors have very good detection efficiency, close to 100% up to 100 keV, and have a superior energy resolution (~2% at 60 keV) compared to scintillation and proportional counters. Their small pixel size also facilitates medium resolution imaging in hard x-rays. The CZTI will be fitted with a two dimensional coded mask, for imaging purposes. The sky brightness distribution will be obtained by applying a deconvolution procedure to the shadow pattern of the coded mask recorded by the detector. One of the major scientific achievements of CZTI would be the polarization measurements for bright galactic X-ray sources.
  • Scanning Sky Monitor (SSM) - The Scanning Sky Monitor will consist of three position sensitive proportional counters, each with a one-dimensional coded mask, very similar in design to the All Sky Monitor on NASA's RXTE satellite. The gas-filled proportional counter will have resistive wires as anodes. The ratio of the output charge on either ends of the wire will provide the position of the x-ray interaction, providing an imaging plane at the detector. The coded mask, consisting of a series of slits, will cast a shadow on the detector, from which the sky brightness distribution will be derived.
  • Charged Particle Monitor (CPM) - A charged particle monitor (CPM) will be included as a part of Astrosat payloads to control the operation of the LAXPC, SXT and SSM. Even though the orbital inclination of the satellite will be 8 deg or less, in about 2/3 of the orbits, the satellite will spend a considerable time (15 – 20 minutes) in the South Atlantic Anomaly (SAA) region which has high fluxes of low energy protons and electrons. The high voltage will be lowered or put off using data from CPM when the satellite enters the SAA region to prevent damage to the detectors as well as to minimize ageing effect in the Proportional Counters.

Ground support

The Ground Command and Control Centre for Astrosat will be located at ISAC, Bangalore, India. Commanding and data download will be possible during every visible pass over Bangalore. Ten out of 14 orbits per day will be visible to the ground station. The satellite is capable of gathering 420 gigabits of data every day that can be down loaded in 10 to 11 orbits visible at Tracking and Data receiving center of ISRO in Bangalore. A third 11-meter antenna at the Indian Deep Space Network (IDSN) was operational in July 2009 to track Astrosat.

The Submarine Killer Corvette's

           GRSE (Garden Reach Ship Engineering), Calcutta one of the leading shipyards of the country is all set to launch the last vessel being built under the P-28 program. The vessel will be cherished as Kavaratti.

The need for specialized ASW platforms

        Chinese have been inducting submarines to their fleet at an alarming rate. Adding attack submarines alone cannot address this, adding specialized vessels and aircraft can greatly subdue the threats posed by submarines along our coastline. Corvettes are one of the smallest warships, these vessels are fitted with missiles and torpedoes. The vessels can also accommodate anti-submarine helicopters thereby forming a credible force in anti-submarine warfare. Submarines operating in shallow waters close to the shores are matter of grave concern, with various countries building submarines that have the lowest acoustic levels, and it is crucial that India ramps up its anti-submarine warfare capabilities.

INS Nirghat

          Under the P28 program, Indian navy has drawn up elaborate plans to induct about four corvettes, which will serve as dedicated ASW platforms. Stressing for a more flexed ASW capability, navy made away with the P28A program which has promised them with eight more corvettes. The corvettes being designed under the P28 program have been designated as the Kamorta corvettes which will displace around 3400 tonnes, these vessels can even be designated as miniature frigates owing to the size.

          The program was announced in 2003 and materialized in 2005, after GRSE was awarded the program for delivering four corvettes to the navy. The program was estimated at around $444 million and the program was designated as an indigenous program which mandated that the vessel had to be built in an Indian shipyard with most of the technologies going on board the vessel had to be roped in from Indian companies. GRSE drew up MoU’s with various Indian companies to equip the vessels with state-of-the art technologies. 

INS Pralaya

         The vessels are powered by four diesel engines which are supplied by Piestel, which together produce about 5096 HP of power and guarantee a maximum speed of up to 32 Kn. DCNS supplied raft mounted gearbox which helped to greatly subdue the vibrations of the engines. High quality steel was provided by SAIL, Wartsila provided low-vibration diesel alternators to power the electronics on-board the vessel. The vessel would also incorporate stealth features, an X-shaped hull was incorporated and the ship was developed with carbon fibre reinforced plastic which reduced the weight of the ship substantially. These features greatly reduced the acoustic signature and the noise levels of the vessel. 

Sensors and Processing systems

        The primary radar of the vessel is the DRDO developed Central Acquisition Radar or the CAR-3D, the Rohini was a dedicated radar for Naval platforms. Operating under S-band, the radar employs planar array antenna and provides simultaneous multi-beam coverage. The radar can track up to 150 targets simultaneously, and has a maximum operational range of 180 km. The vessel also houses the IAI developed, EL/M STGR (Search, Track and Gunnery Radar) fire control radar. The radar is all weather radar operating in X and Ka band, the radar is equipped with state of the art ECCM measures. The radar can acquire a missile at 15 km and an aircraft at around 30 km. BEL has significantly helped the ship’s designing and has integrated its Shikari, RAWL02, Sanket MKIII systems helping to increase the readiness of the ship.
Detection systems

INS Kora

       Vessels of Kamorta class are mainly developed for ASW hence the ship’s technologies are mainly developed for the same purpose, the vessel comes with state-of-the art Anti submarine weapons and Detection systems, these systems can acquire, track, neutralize or destroy any threats.

         The P-28’s, main detection system is the hull mounted SONAR system which was supplied by BEL. Modern warships are usually equipped with HUMSA. These systems are tasked with detecting and calculating, the enemy ship and submarine position. The SONAR also acts as the eye of the ship, by directing the ship along its intended path and averting any mishaps.

         The vessel will also feature Towed array sonar (TAS), a crucial system to detect any tow ships but yet many Indian vessels lack this crucial system. As the name suggests, these sonar systems are towed by the ship meaning they’ll be attached to the rear of the ship. The system can be integrated with other ships through secured channels, hence promising alertness across the waters. The TAS is extremely hard to be detected unlike the hull mounted SONAR systems, effectively enhancing the ships stealth capability. TAS is being developed by DRDO and NSTL, the DRDO produced TAS had failed to impress the navy and was procured from abroad.

Defensive suites

          The vessel is equipped with a defensive suite that can handle threats posed by any air, surface or submerged targets. To tackle any air-borne threats the ship is fitted with thirty two VLS cells which can launch Barak-1missiles. The Barak-1 can even neutralize sea skimming cruise missiles. The Israeli developed, Barak-1 is a battle proven point defense missile system which enjoys a range of about 12 kilometers.

         The ship is also equipped with two AK 630 CIWS (Close-in-weapon system) these systems are crucial to pick up target which the SAM systems may miss owing to the size of the inbound threats. These CIWS have an approximate operational range of up to three kilometers. The vessel is also fitted with Chaff and flare systems, the ECM (Electronic Counter Measure) system in the ship is believed to be one of the best in service and can effectively guard the location of the ship by feeding false inputs to the enemy systems.

         To tackle any inbound torpedoes fired by an enemy ship or submarine the vessel is fitted out with an indigenously developed torpedo decoy system, which launches torpedoes to counter any threats by engaging the incoming threat.

Offensive weapon system

      Being a mainstay vessel for conducting ASW operations, the vessel is equipped with six 533 mm torpedo tubes. The 533mm torpedo's are battle proven machinery which can penetrate even hardened hulls. To tackle the evasive moves of the submarine the vessel uses its depth charges which will force any underwater threat to surface. 

    The ship comes with two RBU 6000 multi-caliber rocket launcher which can launch 213 mm rocket, these rockets can intercept and destroy any incoming torpedo's and at times can also be used against submarines, the recently inducted 90R rockets can hit targets submerged in deep waters. 

    The primary offensive system of the vessel is the Oto Melera 76 mm main gun which can neutralize targets as far as twelve kilometers. The ship can also house an ASW helicopter, the Indian navy had chosen the American S 70 B but the plans to procure these helicopters has stalled owing to the scandals that has tagged the procurement process. The ship is NBC capable, meaning the ship can withstand any Nuclear, Chemical and Biological attacks.

    The first ship of the class, Kamorta was commissioned to the navy by Arun Jaitley , then MoD and currently operates under the Eastern Naval Command(ENC) and is home-ported at Visakhapatnam. The second vessel of the class, Kadmatt has entered its final test phase and is to be shortly commissioned to the navy. The third vessel under the program has reached final work phase and is to be soon launched for trials.