Second SLS Mobile Launcher preps for construction as hardware arrives at KSC

A second Mobile Launcher (ML-2) for NASA’s Space Launch System (SLS) is heading into its… The post Second SLS Mobile Launcher preps for construction as hardware arrives at KSC appeared first on NASASpaceFlight.com.

Second SLS Mobile Launcher preps for construction as hardware arrives at KSC

A second Mobile Launcher (ML-2) for NASA’s Space Launch System (SLS) is heading into its construction phase as Ground Support Equipment begins to arrive at the Kennedy Space Center (KSC). NASA called for a second ML to be constructed to cater for the slightly taller Block 1B SLS that is set to come online in the middle of the decade.

SLS already has a Mobile Launcher (ML-1), converted from its role with the defunct Ares-I rocket. Construction of that ML was initiated by a contracted award in 2008, with a total cost now estimated to be around $1 billion dollars USD.

Now residing in the Vehicle Assembly Building (VAB) ahead of hosting the Artemis-1 SLS rocket, the first flight hardware to be stacked on its deck will be the Solid Rocket Booster (SRB) segments that recently arrived at the Kennedy Space Center (KSC).

Artemis-1 booster segments ready for stacking – via Boeing

Its role with SLS is, however, was tied to one variant of the rocket, the Block 1 – which in turn is the interim version of NASA’s new Heavy Lift Launch Vehicle.

The plan has always been to swap the Block 1’s Interim Cryogenic Propulsion Stage (ICPS) with the more-capable Exploration Upper Stage (EUS), in turn moving to the SLS Block 1B variant. Initially, this was set to occur after two test flights – one uncrewed, one crewed – with the Block 1.

The ICPS is a renamed and modified 5 meter Delta Cryogenic Second Stage that is currently used on Delta IV Heavy rockets and was previously used on the Delta IV M+ 5 meter upper stage configurations of the Delta IV family.

The challenge faced by NASA’s Exploration Ground Systems (EGS) Program revolved around catering for the Block 1B rocket, which is slightly taller than the Block 1, and thus incompatible with ML-1.

Side-by-side comparison from 2016 of the Block 1 vehicle and ML umbilical tower configuration (left) and the Block 1B configuration. Prior to funding ML-2, the single Mobile Launcher was going to be partially taken apart and rebuilt to go from the left configuration to the right. Subsequent design iterations for the Block 1B tower have changed the EUS umbilicals and added a Vertical Stabilizer Damper above. Credit: NASA

An option to once again convert the current ML was ruled out due to the amount of time it would take and further impacts that would have on SLS’s already lethargic launch cadence. As such, the decision was made to build another Mobile Launcher dedicated to the Block 1B rocket.

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  • The second Mobile Launcher (ML-2) has a cost estimate of $450m. However, like ML-1, that cost is likely to rise over time based on the challenges involving ML-1, which ranged from being overweight to suffering from a slight lean. Both of these issues have since been resolved via engineering solutions.

    ML-1 will now be involved in more than just two launches due to NASA’s decision to launch several Block 1 missions to allow for delays surrounding the EUS. This in turn has removed some schedule pressure on the readiness of ML-2.

    However, with ML-1 in the VAB, the construction site north of the assembly building has been freed to allow for the build-up of the huge structure to begin in earnest. Signs the “construction phase” have begun have been marked by the arrival of hardware that will make up the complex arrays of umbilical lines and Ground Support Equipment.

    Hardware that has arrived at KSC for ML-2 include the Vehicle Support Posts (VSPs). Each of SLS’s two Solid Rocket Boosters require four VSPs, which act as the primary structural interfaces between the rocket and the ML. Each is 1.5 m (60 inches) tall with a base of 1.09 x 1.24 m (43 x 49 inches), made of cast steel with walls 10 cm (four inches) thick.

    VSPs for ML-2 arriving in the VAB – via NSF L2

    Precision Fabrication & Cleaning – as prime contractor for building this hardware element – sent 10 VSPs, which includes two spares, to the VAB instrumentation shop for outfitting with strain gages and cabling.

    They will then head to the Launch Equipment Test Facility (LETF) where engineers will calibrate the instrumentation on each VSP, before they are stored in preparation for delivery for integration into the ML-2 base structure.

    Metal is also being cut on the Exploration Upper Stage Umbilical (EUSU), which is a major modification that caters for the Block 1B rocket’s beefy upper stage.

    Modifying the ML-1 version of this umbilical for the EUS was ruled out via trade studies, which noted it would be more cost-effective to design and build a new umbilical from scratch.

    The new EUSU was an in-house design by NASA Engineering and is being fabricated by JP Donovan.  It too will undergo testing at the LETF before being delivered for integration onto the ML-2 tower.

    As with ML-1, all of the ML-2 arms and umbilical will journey through the LETF, located just south of the Operations and Checkout (O&C) Building at the famous spaceport. The area has a deep history, ranging back to the Shuttle era.

    Part of the LETF during ML-1 testing – via NSF L2

    It was the testing site for launch-critical ground support systems and equipment, such as the Orbiter Access Arm (OAA), External Tank Gaseous Oxygen Vent Arm, External Tank vent line, Tail Service Masts and umbilical systems, and Solid Rocket Booster Hold Down Posts.

    It has also been involved with Cryo testing for the defunct X-33 technology demonstrator for the VentureStar program and had a role in testing Delta IV ECS umbilicals and Centaur Upper Stage rolling beam tests.

    The facility allows for simulated launch vehicle events such as movement from wind, ignition and liftoff, effects of solar heating and cryogenic shrinkage.

    The fabrication, testing and installation of elements for ML-2 are all working towards a completion date for the huge structure in 2023, ready to support a schedule that allows for a potential – if unlikely – use of the Block 1B on the 2024 Artemis-3 mission.

    The post Second SLS Mobile Launcher preps for construction as hardware arrives at KSC appeared first on NASASpaceFlight.com.

    Source : NASA More   

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    Israel conducts surprise launch with Ofek 16 satellite

    The Israeli government and Israel Aerospace Industries conducted a previously-unannounced launch of a reconnaissance satellite… The post Israel conducts surprise launch with Ofek 16 satellite appeared first on NASASpaceFlight.com.

    Israel conducts surprise launch with Ofek 16 satellite

    The Israeli government and Israel Aerospace Industries conducted a previously-unannounced launch of a reconnaissance satellite Monday, using a Shavit-2 rocket to deploy the Ofek 16 satellite into low Earth orbit.

    Ofek 16 is a small electro-optical imaging satellite, which will capture high-resolution images of the Earth for Israel’s Ministry of Defence. The name Ofek, from the Hebrew word אופק‎, meaning Horizon, has been applied to all of Israel’s military satellites regardless of their mission, including two early demonstration missions and subsequent optical and radar reconnaissance spacecraft.

    With the launch of Ofek 1 in September 1988, Israel became the eighth country to develop its own orbital launch capability. It uses this capability exclusively for military payloads, relying on foreign rockets to carry its civilian and commercial satellites into orbit.

    The Ofek 16 mission is the eleventh known orbital launch to have been attempted by Israel, and the country’s ninth to have reached orbit. It is Israel’s first launch in almost four years – the country’s last launch coming in September 2016 with the Ofek 11 satellite aboard.

    Monday’s launch took place at 04:00 local time (01:00 UTC) from the Palmachim airbase on Israel’s coast, which has been the site of all of Israel’s orbital launches. Israel’s only coastline faces west onto the Mediterranean, so to avoid overflying the country’s neighbors – with whom Israel has historically had tense relations – rockets fly westward and target an unusual retrograde orbit.

    With inclinations of around 142 degrees, Ofek satellites orbit in the opposite direction to most other satellites and do not pass over the high latitude regions of the Earth as spacecraft in the polar or sun-synchronous orbits more typically used by reconnaissance missions.

    The launch was relatively low-key, as is normal for Israel’s orbital launches, with no notice made public ahead of time. The first announcement came from the Ministry of Defence via Twitter, about an hour and a half after liftoff, confirming that Ofek 16 had been deployed successfully into orbit.

    In contrast to recent launches from nearby Iran, which were widely condemned, Israel’s launch has drawn little attention from the international community.

    Although understandably many details of the spacecraft and its planned operations have been kept secret, the Israeli government has been open and upfront about the military nature of Ofek 16’s mission – with the launch announcement confirming its role as a reconnaissance satellite and a follow-up tweet identifying it as an “electro-optical reconnaissance satellite with advanced capabilities”. Images and videos have since been released showing the spacecraft and its carrier rocket being prepared for launch.

    The Ofek satellites are manufactured by Israel Aerospace Industries (IAI), with the current-generation spacecraft based on the IMPS-2 platform. The satellites are three-axis stabilized, with two deployable solar arrays generating power. OPTSAT-3000 had a mass of 368 kilograms (811 pounds), so it is likely that Ofek 16 weighs in around this figure – although its mass may be constrained by the limitations of the Shavit-2 carrier rocket.

    Ofek 16 appears visually similar to the Ofek 11 satellite that was launched in 2016, and the two satellites are likely equipped with identical or closely-related systems.

    Although Ofek 11 was deployed successfully, the satellite experienced problems during the early stages of on-orbit testing and officials confirmed that work was underway to “stabilize” the satellite following unspecified malfunctions. The problems were reportedly resolved within a few weeks of launch, although it remains unclear to what extent – if any – the satellite’s operations or capabilities might have been compromised.

    Italy’s OPTSAT-3000 reconnaissance satellite, which was built by Israel and launched in August 2017, is believed to be of the same design as Ofek 11 and 16. While it is unclear whether OPTSAT-3000 has the same capabilities as its Ofek counterparts, more details about it are known than the Israeli satellites. OPTSAT has a maximum imaging resolution of about one meter (3.3 feet) and was designed to operate for at least seven years. Unlike the Ofek satellites, OPTSAT was launched by a Vega rocket from the Centre Spatial Guyanais, allowing it to be placed into a sun-synchronous orbit.

    As Israel is not known to have attempted any satellite launches between the Ofek 11 and 16 missions, it is not immediately clear whether the Ofek 12, 13, 14 and 15 designations have been skipped, or applied to other spacecraft – possibly satellites that have not yet been launched.

    The rocket pre-launch

    The Shavit-2 rocket that deployed Ofek 16 was a three-stage all-solid-fuelled rocket, consisting of two ATSM-13 motors burning sequentially, with an AUS-51 motor comprising the third stage. The Shavit family of rockets are derived from the Jericho II missile, which is itself an improved version of the original Jericho, which Israel developed in the 1970s in partnership with Dassault Aviation of France.

    The original version of Shavit, which was used for Israel’s first two satellite launches, used less powerful ATSM-9 motors as its first and second stages. This configuration was used in the successful deployment of two technology demonstration satellites – Ofek 1 and 2 – in September 1988 and April 1990. The Shavit-1 configuration, used for operational launches, replaced the first stage with an ATSM-13. It flew four times between 1995 and 2004. Two of these launches failed – resulting in the loss of the Ofek 4 satellite in January 1998 and of Ofek 6 in September 2004.

    From June 2007 onwards, the Shavit-2, with ATSM-13 motors for both its first and second stages, has been used – and Monday’s launch was the fifth flight of this configuration. Like the Ofek 16 payload, the rocket was built by IAI.

    Israel’s orbital launches are infrequent – with 1,392 days separating Monday’s launch from Israel’s last deployment of a satellite. Typically, about three years pass between missions – although this can vary – so it is unclear when the next Shavit launch will take place. When it does, as with Monday’s launch, it is unlikely that any advance notice will be given.

    The post Israel conducts surprise launch with Ofek 16 satellite appeared first on NASASpaceFlight.com.

    Source : NASA More   

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