Inara Pey: Living in a Modemworld

The sixth integrated flight test (IFT-6) of the SpaceX Starship / Super Heavy behemoth took place on Tuesday, November 19th, 2024, and proved to be perhaps the most successful test yet of the system, even though the core aspect of the first part of the flight didn’t occur.

The vehicle lifted-off from the SpaceX Starbase facility at Boca Chica, Texas at 22:00 UTC. All 33 Raptor-2 engines on the Super Heavy booster ignited, and the massive vehicle lifted-off smoothly. All continued to run, and the initial phases of the flight passed without incident: the vehicle passed through Max-Q, reached Most Engines Cut-Off (MECO) at 2 minutes 35 seconds, leaving it with just three motors running.  Seven second later, hot staging occurred, Starship firing all 6 of its engines and then separating from the booster.

This was followed by the booster flipping itself onto a divergent trajectory to Starship and re-igniting the ring of 10 inner fixed motors to commence its “boost back”: gradually killing it ascent velocity and bringing it to a point where it could commence a controlled fall back to Earth, and then a powered final descent into being caught b the Mechazilla system on the launch tower, as seen during the October flight.

However, during the boost-back, the call was made to abort the attempt at capture, and to instead direct the booster to splashdown in the Gulf of Mexico. The booster then went through a nominal descent, dropping engines first (and causing them to glow red-hot during the compression of air inside their nozzles, despite the fact none were firing).

At just over 1 km altitude, the 13 inner motors did right, all of them firing for some 7 seconds and reducing the rocket’s descent from 1,278 km/h to just 205 km/h. At this point nine of the ten motors on the inner fixed ring shut down, with one appearing to run a second or so longer. When it shut down, there was a belch of flame of the base of the booster, which might indicate an issue.

Nevertheless, the three central motors continued to operate, gimballing to bring the booster to a vertical position and a brief hover right above the water before cutting off and allowing the rocket to drop end-first into the sea. Remaining upright for a moment, the booster then started to topple over. However, as the live stream cut away at that point, it was down to other camera to capture the subsequent explosion due to water ingress around the super-hot engines, etc., which destroyed the rocket.

The Starship vehicle, meanwhile, made it to orbit and continued on over the Atlantic and Africa to  the Indian Ocean, where it went through its de-orbit manoeuvres.

Whilst in the coast phase of the flight, the vehicle had been due to re-ignite one of its vacuum engines to demonstrate this could be done in space. This occurred at 37 minutes 46 seconds into the flight, the motor running for about 4 seconds. Although brief, the re-light was a milestone – Starship will need the capability while on orbit in the future.

The Starship’s return to Earth was anticipated as being potentially “whackadoodle”, and subject to possible vehicle loss. This was because SpaceX had removed elements of the thermal protection system designed to protect the vehicle from burning-up during atmospheric re-entry.

The purpose in removing tiles from the vehicle was to expose parts of the hull where, if Starship is also to be “caught” by the Mechazilla system on its return to Earth, it will need exposed elements on the side bearing the brunt of the heat generated by re-entry into the atmosphere, and SpaceX wanted data on how the metal of the vehicle held-up to being exposed to plasma heat, particularly given the previous two flights had seen plasma burn-through of at least one of the exposes hinges on the vehicle’s aerodynamic flaps.

As it turned out, the vehicle managed very well during re-entry; there was a significant amount of very visible over-heating on the leading edge of a flap, but even this was less than seen in IFT4 and IFT 5. It’s not clear as to how much damage the exposed areas of the vehicle suffered were TPS tiles had been removed, but given the vehicle survived, any damage caused was clearly not sufficient to compromise its overall integrity.

The drop through the atmosphere was visually impressive, the flight so accurate that as the vehicle flips itself upright at less than 1 km above the ocean, the landing zone camera buoy anchored ready to record the splashdown can clearly be seen. Immediately after entering the water, the Starship toppled, bursting into flame – but this time not immediately exploding.

Whilst a booster catch might not have been achieved, IFT6 can be classified a success. All criteria but the catch of the booster was achieved, and even though the later was lost as a result of a forced splashdown, the successful diversion of the booster to do so demonstrates an ability for SpaceX to divert a vehicle away from a landing tower in the event of an issues with the tower – providing said issues are spotted earl enough.

The flip side of this is that it exposes an inherent weakness in the system; the reason for the abort was that the actual launch of the vehicle had caused damage to the launch tower and its communications systems, calling into question its ability to make the catch. Tower / launch stand damage has been a recurring theme with Super Heavy launches, although the degree of damage caused has been dramatically reduced.

Even so, the fact that comms systems could be KO’d reveals how vulnerable the system is to a potential loss of vehicle (and the knock-on impact in terms of “rapid reusability”), particularly if there is no close-at-hand and available launch / catch tower available to take over the role. And while this abort was called when the vehicle was still 87 km altitude, with lots of time to bring it safely into a splashdown, can the same be said if an issue occurs when the vehicle is just 13 km above ground? Or ten? Or two? Or if the malfunction occurs in the final engine burn?

ISS Reports “Toxic Smell” and Atmosphere Scrubbed

Update: Several hours after this article was published, NASA issued a statement on the event described below.

Reports are surfacing of possible toxic contamination board a resupply vehicle at the International Space Station (ISS). Initial news on the situation was broken by the highly-reliable Russian Space Web, operated by respected space journalist and author, Anatoly Zak, but that the time of writing this piece, western outlets had not reported the story, which is still breaking.

On November 21st Russia launched the automated Progress MS-29 resupply vehicle to the International Space Station (ISS), carrying some 2.487 tonnes of supplies, including 1.155 tonnes of pressurised supplies, 869 Kg of propellants; 420 kg of water and 43 kg of nitrogen gas.

After being placed in an initial parking orbit, the vehicle rendezvoused with the ISS on November 23rd, manoeuvring to dock with the zenith port of the Poisk module (mini research module – MSM 2), attached to the Zvezda main module of the Russian section of the station. Following docking, the vehicle was secured and the pressure between the module and Progress vehicle pressurised to allow the hatches between the two to be opened.

However, the hatch to the Progress has to be immediately closed due to a “toxic smell” and a potential contamination hazard in the form of free-floating droplets. Following the securing of the hatches, NASA’s flight controllers apparently ordered the activation of the Trace Contaminant Control Sub-assembly (TCCS) in the International section of the ISS, a system designed to remove traces of potential airborne contaminants, effectively scrubbing the atmosphere in the ISS, with the Russian crew activating a similar system within the Russian section for around 30 minutes, with the cosmonauts themselves donning protective equipment (as reported last week, the main hatch between the two sections of the station is now kept shut due to a continuous leak of air through the Russian Zvezda module).

The cause of the smell and the overall status of the MS-29 vehicle have yet to be determined; this is a developing story.

New Glenn Gets Ready

Blue Origin is approaching a readiness to launch their new heavy lift launch vehicle (HLLV), the New Glen rocket.

Earlier in November I reported on the new rocket’s first stage being rolled from the Blue Origin manufacturing facilities at Kennedy Space Centre to the launch preparation facilities at Space Launch Complex 36 (SLC-36), Cape Canaveral Space Force Station. These facilities already held the rocket’s upper stage, which had undergone a series of static fire tests of its motors whilst on a test stand at the pad earlier in the year.

Since the arrival of the 57.5 metre long first stage at the integration facility at SLC-36, Blue Origin engineers have been preparing the vehicle for launch. By November 14th, the first and second stages of the rocket has been integrated with each other, and worked moved to integrating the payload and its protective fairings to the rocket.

Originally, the inaugural flight for the massive rocket – capable of lifting up to 45 tonnes to low Earth orbit (LEO) – was to have been the NASA EscaPADE mission to Mars. However, due to complications, the flight will now be the first of two planned launches designed to certify the system for the United States Space Force’s National Security Space Launch (NSSL) programme. The payload for the flight will be a prototype of Blue Origin’s Blue Ring satellite platform, a vehicle capable of delivering satellites to orbit, moving them to different orbits and refuelling them.

On November 21st, the completed rocket – over 80 metres in length – rolled out of the integration facility and delivered to SLC-36, where it was raised to a vertical position, mounted on the 476-tonne launch table designed to support it and keep it clamped to the pad.

The actual launch date for the mission has yet to be confirmed, but it will see the company both launch the rocket and attempt to recover the reusable first stage, called So You Think There’s a Chance? Following separation from  the upper stage of the rocket, the first stage will attempted to make and controlled / power decent to and landing on the Blue Origin’s Landing Platform Vessel 1 (LPV-1) Jacklyn.

Artemis 2 Vehicle Progress

Even as NASA’s Space Launch System (SLS) continues to face a potentially uncertain future due to its per-launch cost, the second fully flight-ready vehicle continues to come together at NASA’s Kenned Space Centre in readiness for the Artemis II mission.

The mission, which is targeting a launch in late 2025, is due to carry a crew of four – Reid Wiseman (Commander); Victor Glover Pilot; Christina Koch, flight engineer and Jeremy Hansen (Canada), mission specialist – on an extended flight of up to 21 days, commencing with the crew aboard their Orion Multi-Purpose Crew Vehicle (MPCV), being placed in low Earth orbit, prior to transiting to a high Earth orbit with a period of 24 hours.

Once there, they will carry out a series of system checks on the Orion and its European Service Module (ESM), as well as performing rendezvous and proximity flight tests with the rocket’s Interim Cryogenic Propulsion Stage (ICPS), simulating the kind of rendezvous operations future crews will have to do in order to dock with the vehicles that will actually carry them down to the surface of the Moon and back. After this, the crew will make a trip out and around the Moon and back to Earth.

The Orion capsule for the mission is nearing completion, with core assembly completed and the internal fixtures, fittings and systems on-going. Earlier in November 2024, and sans its outer protection shell and heat shield, it was subjected to a series of pressure tests to simulate both the upper atmosphere and space to ensure it had no structural integrity issues.

Meanwhile, the SLS vehicle itself has commenced stacking. The core stage, with is massive propellant tanks and four RS-25 “shuttle” engines, arrived at the Vehicle Assembly Building (VAB), Kennedy Space Centre, in July 2024, and since this has been undergoing much work whilst still lying on its side.

More recently, work on stacking the two solid rocket boosters (SRBs) developed from those used with the space shuttle, that will help power it up through the atmosphere has also commenced.

The SRBs comprise 5 individual segments which need to be manufactured and then bolted together, prior to being filled with their wet cement-like solid propellant mix. The base segments of these boosters include the rocket motor and guidance controls, and on November 13th, these were rolled into the Vehicle Assembly Building on special transport / stacking gantries. Over the next several months, the two SRBs will be assembled vertically in one of the bays within the VAB, and then loaded with their propellant and capped off.

Once the SRBs are ready and their avionics, etc., checked out, the core stage of the SLS will be hoisted up into one of the VAB’s high bays, moving to a vertical orientation as it does so. It will then be lowered between the two SRBs so that they can all be joined together. After this the ICPS will be moved up into position and mated to the top of the core stage of the rocket, and then work can commence stacking the Orion and its ESM and their launch fairings.

Whether or not Artemis II makes its planned late 2025 launch (no earlier than September) is open to question; currently, NASA has yet to fully complete the work on ensuring the already manufactured heat shield for the mission’s Orion vehicle is fit for purpose, per my previous report on heat shield issues.