Battle of Helska IV In 25 ABY , during the initial stages of the Yuuzhan Vong War , forces of the New Republic and the Praetorite Vong fought the Battle of Helska IV on the icy fourth orbital of the Helska system . Upon entering the galaxy from an extra - galactic source , the Praetorite Vong , who were the first units of the Yuuzhan Vong to be used in their invasion , proceeded to establish a base on Helska IV . However , the New Republic learned of the Praetorite Vong ' s existence after the invaders committed numerous atrocities , prompting a trio of principal New Republic personnel — former smuggler Han Solo , politician Leia Organa Solo , and Jedi Master Luke Skywalker — to assemble a task force whose greatest asset was the " Imperial II " - class Star Destroyer " Rejuvenator " . Although the New Republic strike force held the upper hand at first , it was soon beset by thousands of enemy coralskippers that executed maneuvers perfectly with each other due to the telepathic capabilities of the Praetorite Vong ' s yammosk war coordinator . As a result , the " Rejuvenator " was soon lost , and the New Republic ' s forces retreated . However , the New Republic forces soon returned to Helska IV to finish what they had started , using shieldship s that they had acquired to focus the yammosk ' s energy back at the planet and evaporate the ice , which would cool the planet . The plan succeeded , with the low temperatures causing a Mezzicanley Wave , which in turn caused Helska IV to shatter apart and destroy most of the Praetorite Vong forces there . The disastrous outcome for the Praetorite Vong forces at Helska IV ended their invasion of the galaxy , though more Yuuzhan Vong units would soon follow their lead and engage the New Republic . Prelude . The Yuuzhan Vong arrive . In the year 25 ABY — c . 60 : 5 — the Praetorite Vong , the leading forces for an extra - galactic Yuuzhan Vong invasion , arrived in the galaxy . Da ' Gara , a Yuuzhan Vong prefect , led the first part of the Praetorite Vong units in a worldship to Helska IV , an icy planet in the Outer Rim Territories . Da ' Gara established a base on the world , while his worldship resided in — and partially stuck out of — the icy crust of the planet , since the Yuuzhan Vong had found that the world would be an ideal staging area for their invasion . Meanwhile , Yuuzhan Vong agent Nom Anor kept the bulk of the forces of the New Republic , the galaxy ' s main government , near the Core Worlds , as he sowed disorder and conflict through manipulation . Soon after arriving at Helska IV , a group of scientists from the Extragalactic Society ' s research base on the world Belkadan traveled to Helska IV to investigate an extra - galactic object that they had seen entering the Helska system , which was , in fact , the Praetorite Vong ' s worldship . However , the group was captured , and only the young scientist Danni Quee survived to be taken prisoner . Meanwhile , a Yuuzhan Vong agent on Belkadan released a bioweapon on the world , terraforming it for the invaders ' purposes . Visitors soon arrived at the Praetorite Vong ' s doorstep once again , this time in the form of the Dozen and Two Avengers , a starfighter squadron led by the Jedi Knights Kyp Durron and Miko Reglia . The squadron had tracked the group of scientists to the Helska system after checking the data of a hyperspace buoy and , when they arrived in the system , were attacked by the yorik - et starfighters – also known as coralskippers – that the Praetorite Vong possessed . Although they at first held their own , the Dozen and Two Avengers were soon cut apart by the alien capabilities of the coralskippers , and all the starfighter pilots but Durron and Reglia were killed . Reglia himself was captured by the enemy . The Praetorite Vong then attacked the planet Sernpidal , causing its moon Dobido to crash into its surface and destroy the majority of the planet . From there , Da ' Gara ' s forces pursued refugees to the planet Dubrillion , where the New Republic repelled the Yuuzhan Vong with the help of Jedi Knights Jaina Solo , Jacen Solo , and Anakin Solo , along with their parents , former smuggler Han Solo and the politician Leia Organa Solo . In response to the attack , which was actually a probe by the enemy forces , Organa Solo and the other New Republic – affiliated personnel on Dubrillion , such as Solo and Jedi Master Luke Skywalker , started to arrange for a counterstrike against the Praetorite Vong forces on Helska IV . Destination : Helska IV . Speculating that the enemy must have a base underneath the ice crust of Helska IV , Skywalker planned to take an iceborer to the planet in the underbelly of the small carrier vessel " Merry Miner " , piloted by his wife , Mara Jade Skywalker , a Jedi Master who was fighting a Yuuzhan Vong – engineered disease . Skywalker intended to penetrate the ice cover in the iceborer and return from his mission before a fleet led by the " Imperial II " - class Star Destroyer " Rejuvenator " arrived in the Helska system ; the " Rejuvenator " , helmed by Corellian Commander Warshack Rojo , had arrived at Dubrillion shortly after the Praetorite Vong attack there . However , before Skywalker and his wife could execute their plan , Jacen and Jaina took the " Merry Miner " and its iceborer on the mission themselves , as they did not think the pair of Jedi Masters were the right ones for the task . Shortly after , the fleet itself departed for Helska IV , despite Organa Solo ' s attempts to make Rojo wait for additional reinforcements . With Jaina piloting the " Merry Miner " and Jacen situated in the iceborer , which was housed in a launch tube in the " Merry Miner " , they reached the Helska system before the task force . Jaina brought the ship near Helska IV by putting the system ' s sun , Helska , behind them to shield them from enemy view . When the " Merry Miner " was close enough , Jaina launched the iceborer toward the planet . The iceborer was supposed to make it to the surface without using thrusters to avoid detection by the enemy , but Jacen heard a call through the Force telling him that an individual was in danger on the planetary surface , and he used the borer ' s thrusters to change his course toward the call ' s location . This alerted nearby coralskippers to his position , and , though Jacen punched through the ice in his ship with the help of a thermal charge , the Praetorite Vong starfighters tracked its trajectory back to the " Merry Miner " . Forced to retreat in a defenseless ship , Jaina tried to evade them by using the sun for cover but found herself trapped on the other side of the sun , with coralskippers surrounding her from all directions . The battle . Initial assault . The New Republic task force arrived in the system so close to the " Merry Miner " that it was able to immediately engage the coralskippers that were pursuing it , coming to Jaina ' s rescue . The task force was composed of the " Rejuvenator " , six new " Ranger " - class gunships , a collection of cruisers and starfighters , Skywalker and his wife flying the shuttle " Jade Sabre " , and Durron leading a starfighter unit . The upgraded freighter " Millennium Falcon " was also present in the task force , piloted by Organa Solo and her husband , with the craft being gunned by Anakin and entrepreneur Lando Calrissian , who was operating out of Dubrillion . The New Republic forces quickly mopped up the majority of the enemy forces and headed for Helska IV to attack the Praetorite Vong forces there . Meanwhile , Jacen had entered the chilly waters of the planet , wearing a captured Yuuzhan Vong cloaker to shield him from the cold ; upon seeing a group of Yuuzhan Vong warriors , who were going after Reglia to torture him in an attempt to break his mind , Jacen joined them because they were going toward the source of the call . Disguised as a member of the warrior caste thanks to the cloaker , Jacen entered a room in the ice crust with them , where he found the prisoners Reglia and Quee . Though Reglia was a Jedi , it was actually the Force - sensitive Quee who had put out the call for help , and Jacen then engaged the warriors in order to free the pair of prisoners . Knowing that the task force was closing in on Helska IV , Da ' Gara sent thousands of coralskippers of various sizes to engage the enemy forces , who were hounding the fighters that he had used to draw the New Republic forces closer to his world . Additionally , the planet was protected by the energy field of the yammosk war coordinator that was on Helska IV , the volcano armaments of the three worldships that the Praetorite Vong possessed , as well as many gravity - manipulating dovin basal s . The New Republic task force was suddenly set upon by the multitude of enemy fighters , who were all bound together telepathically by the abilities of the yammosk ; the telepathic link allowed the coralskippers to execute brilliant maneuvers and fly better . Two of the " Ranger " - class gunships were soon destroyed after a Praetorite Vong fighter used a dovin basal to draw all three of them into a collision . Elsewhere , the rest of the task force was hard - pressed , and the " Rejuvenator " itself became the main target of the coralskippers and the insect - like grutchin s . Rojo called for help from the rest of the fleet , but as they were all otherwise occupied with enemy fighters or unable to reach the Star Destroyer , the Corellian began to bombard Helska IV in retaliation for the continued assault on his ship . The " Rejuvenator " did not last long , however , and because of the coralskipper - inflicted damage , a volley of magma missile s from volcano cannons that lifted off from the surface of the planet annihilated the Star Destroyer , killing Rojo and the vast majority of on - board personnel . The Star Destroyer ' s destruction led the task force ' s leaders to signal a retreat from the system , though the " Jade Sabre " , the " Millennium Falcon " , and the " Merry Miner " attempted a last - ditch effort to extract Jacen from Helska IV before the retreat . During the battle , Jacen had fought off all the warriors with the help of Reglia and Quee , though the former sacrificed himself in order to kill some of the warriors . Afterward , Jacen had managed to get Quee and himself back to the iceborer . The trio of ships coming to rescue Jacen made it near to the surface of Helska IV , and after the iceborer extracted itself from the ice , allowing the " Merry Miner " to scoop it up in mid - air , all the ships escaped to hyperspace after their allies . A new plan . Soon after leaving the area around Helska IV , the three ships rendezvoused to formulate a plan for eliminating the Praetorite Vong threat . A consensus was reached that it would be possible to freeze the yammosk to death by using shieldship s to reflect the yammosk ' s energy back at the planet ; doing so would speed up evaporation on the surface , cooling the planet even further and hopefully achieving a temperature of absolute zero . Shieldships were brought from among Calrissian ' s collection of technology at Dubrillion and its sister world of Destrillion , and a small task force was assembled from the survivors of the original force . However , some survivors , including the remaining three " Ranger " - class gunships , opted to stay behind at Destrillion to wait for reinforcements . By launching their attack so shortly after their recent defeat , the New Republic forces aimed to catch the enemy unaware , since the majority of the Praetorite Vong fighters were out looking for the survivors . The task force came in via hyperspace extremely close to the fourth orbital of Helska , and , as a result , one of the cruisers that had come with them and a quartet of starfighters were lost in collisions with each other or the planet itself . The half - dozen shieldships then took up position around the planet , decreasing their orbit with every rotation as the energy from the yammosk started to be reflected back upon the world . Coralskippers attacked the New Republic forces , and the New Republic starfighters worked to either provide cover for the shieldships or act as decoys . Skywalker also took an X - wing starfighter to act as a decoy , and Da ' Gara , who was confused by the small size of the attacking force , readily sent a contingent of fighters to engage it . As the yammosk was unafraid of the shieldships ' attempts to reflect its energy , Da ' Gara was similarly unconcerned with the shieldships , and he proceeded to call the scattered coralskipper hordes back to Helska IV to defend it and deal the finishing blow to the enemy . By that time , the shieldships ' s efforts had begun to evaporate the surface of the planet , generating a thick fog and cooling the planet . This same fog aided Skywalker by providing cover as he tried to draw the coralskippers away from the shieldships . While the " Jade Sabre " and the " Millennium Falcon " defended the shieldships , Jade Skywalker , serving as the former ship ' s gunner , suffered a relapse in her illness that left her unconscious . Because of its lack of a gunner , the " Jade Sabre " suffered numerous hits despite maneuvering attempts by its pilot , Jaina Solo , and the craft began to descend toward the planet below . Skywalker saved the falling ship , however , as he came underneath the " Jade Sabre " , flipped his X - wing on its back , and fired his repulsorlifts — thus giving the " Jade Sabre " the boost it needed to regain control and altitude . Thanks to the shieldships ' efforts , Helska IV ' s atmosphere was becoming increasingly colder , and , though the New Republic forces suffered losses of starfighters and a few shieldships , they soon caught a break . Due to the extreme cold that the evaporation was generating , the yammosk started to lose its control on the coralskippers , and their maneuvers began to cost the Yuuzhan Vong fighters as pilots crashed into one another . The yammosk had actually entered a deep freeze because the fourth state of matter , known as the Mezzicanley Wave , had been achieved ; the planet itself started to slow in its rotations as the fog evaporated completely from the atmosphere . The majority of the coralskippers present in the battle returned to Helska IV , confused by the events and aiming to protect the base . However , the leaders of the New Republic task force realized that the expansion created by the freezing water under Helska IV ' s ice crust would be disastrous , and they issued a retreat . The New Republic ships had not gone far before the planet exploded as a result of the ice expansion , destroying the majority of the Praetorite Vong forces and killing Da ' Gara . Skywalker , who was still in the atmosphere when the Mezzicanley Wave was created , barely managed to escape the destruction in his X - wing . Aftermath . Following the destruction of Helska IV , New Republic squadrons hunted down the remaining coralskippers that had survived the battle . Because of the Praetorite Vong ' s defeat , their reputation suffered greatly among the rest of the Yuuzhan Vong species , not to mention the loss of a large portion of their forces . The battle had a negative effect on Jade Skywalker , and her illness gained the upper hand , leaving her weaker . In response to the battle , which became known as the Battle of Helska IV , Organa Solo organized meetings with important officials to warn the galaxy at large of the threat that the Yuuzhan Vong posed , though the governing body of the New Republic chose to ignore it , believing that the Praetorite Vong were the last of the extra - galactic forces . Meanwhile , Nom Anor continued to sow disorder in the form of civil wars , and the main Yuuzhan Vong force soon arrived . They struck again at Dubrillion , this time capturing it , and proceeded to attack the planet Dantooine before engaging New Republic and Imperial Remnant forces at the planet Ithor . From there on , it was an all - out battle for control of the galaxy between the two sides . Behind the scenes . The Battle of Helska IV first appeared in the novel " " , written by R . A . Salvatore and published in 1999 as the first installment in " " series . The battle was later mentioned in other books in that series , as well as in " The New Jedi Order Sourcebook " , released in 2002 . " The Complete Star Wars Encyclopedia " , released in 2008 , first identified the battle by name in an entry on the planet Helska IV . The fighting at Helska IV was also mentioned in Daniel Wallace and Jason Fry ' s " The Essential Atlas " , released in 2009 . There are a few inconsistences in the sources that mention the Battle of Helska IV . In " Vector Prime " , the book contradicts itself about the number of cruisers that join the second part of the assault on the planet , as it says only one joined but later has two destroyed during the battle . " The Complete Star Wars Encyclopedia " " Merry Miner " entry incorrectly states that the ship was used to launch a warhead , which started the planet ' s freezing .